i

THE EFFECT ON TACTILE DISCRIMINATION FOLLOWING HAND AND TOTAL BODY IMMERSION IN WARM AND COLD WATER;

WITH PARTICULAR REFERENCE TO DIVER PERFORMANCE.

Ph.D Thesis prepared by Glanfyll L. R. Lewis, A.R.I.B.A. (Surrey University).

° ^ O S L l_h

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SUMMARY:

A method has been described to measure the changes occurring in tactile discrimination following hand and total body immersion in various kinds of water at 5°C. 14°C. and 32°C.

Results show significant deterioration in tactile discrimination of the palmar and dorsal regions of the hand following immersion in water at 5°C when compared with a dry control condition. Similar deteriorations were noted following hand immersions in water at 14°C and 32°C.

Results achieved from subjects totally immersed in water at temperatures of 14°C and 32°C showed a significant deterioration in tactile discrimination of the palmar region of the hand as compared to a dry control condition.

It can be concluded that hand immersion in any kind of water at 5°C significantly affects tactile discrimination and that hand immersion and total body immersion in water at temperatures of 14°C and 32°C results in a significant deterioration in tactile sensitivity.

For the 32°C condition a 'wet' effect rather than a ’cold* effect is seen to be the major contributory factor in causing such a decrement, bearing in mind that the body temperature for the hand immersion is maintained in a controlled air environment of 18°C - 20°C and for the total immersion is kept at normal temperature by a wet-suit in water at 32°C.

The present study differs from previous work insofar as it deals with changes occurring in tactile sensitivity following immersion, rather than during immersion, and is therefore directly related to the condition of divers carrying out manual operations immediately following a dive.

CONTENTS

Page No.

Summary.

Acknowledgements.

1. Introduction......................... 1

2. Purpose of S t u d y . • 13

3. Environmental Framework.............. 15

4. M e t h o d s , • 17

4a. Statistical Methods................. • 28a

5. Subjects.......... .... ..... .....•• 29

6. Results and Discussion....••••••••••• 30

7. General Discussion. ..... 81

8. Conclusions, ...... 91

9. References......... ..... ....•••••••

10. Appendix........................... ....

Acknowledgements,

I am indebted to the following people for their help during the course of this study.

Professor Davis, Head of Biological Sciences,University of Surrey, for his overall supervision; Dr. Maule,Head of Mechanical Engineering, University College, London, for suggestions regarding experimentation; Professor Bowden of the Royal Free Hospital School of Medicine, for information on tactile sensitivity tests; Dr.Wilkinson and Dr. Poulton, of Cambridge Applied Psychology Unit for their help with cold and vigilance information; Dr. Aldridge Morris, Head of Psychology, Middlesex Polytechnic, and Michael Wh&eler, Department of Mathematics,North East London Polytechnic, for their statistical help;Michael Dames, Department of Electrical Engineers, North East London Polytechnic, for his counselling, and Dohn Bevan, Royal Navy Physiological Laboratory, for his valuable assistance on diving procedures in the cold.

I would like also to thank the many students and staff of the North East London Polytechnic who participated in this study particularly those who suffered considerable discomfort during the cold water tests in the interest of research.

Lastly, I am indebted to the North East London Polytechnic for allowing me laboratory space in order to design and build the environmental chamber and water tank used in the experiments.

1. INTRODUCTION:

Much work in recent years has been devoted to describing the problems associated with human activity underwater (Corriol, 1967; Bennett and Elliott, 1969; Elliott, 1969;Baddeley, 1968). The literature available, perhaps not surprisingly, concentrates on the physiological hazards of 'saturation'diving.When diving, the body and inspired gases are subjected to increases in pressure and the amounts of gases dissolved in the body tissues increase in time, in proportion to the pressure.

The term saturation is commonly used for dives of a duration so prolonged that the gases dissolved in the blood and tissues are in equilibrium with those inhaled. On returning to the surface, the excess gas dissolved in the tissues has to escape and unless pressure reduction is slow, bubbles of gas will form in the blood and extracellular fluids. Thus the diver has to ascend in stages, waiting at different depths until gaseous equilibrium is reached. Since the amounts of gas dissolved vary with the depth of dive and the time spent at that depth, decompression times also vary. For the saturated diver the time needed for decompression has reached its maximum for that depth. This being so, any increase in time of the dive will increase the ratio of useful time spent on the sea-bed to decompression time.

Since the development of saturation diving by Captain Bond of the U.S. Navy in the early 1960’s and subsequent testing procedures by Cousteau, Link, and others, it has become the most widely used technique allowing divers to live in underwater houses or ’habitats', in the sea, and thus to remain at sea-bed pressures for long periods.

These habitats are generally located in a position a little above the sea-floor allowing divers bottom access into an air environment which is kept at the same pressure as the surrounding water depth. The saturated diver is able therefore to live for weeks and occasionally months at a time, such as in the case of Tektite 1, in the 'habitat1 protected from wave action, and inclement weather conditions. He is able to leave the 'habitat' using sub-aqua equipment, and carry out work operations as and when required on the sea-floor.

The initial achievements, however, of being able to sustain man beneath the sea has tended to distort the picture of his true capabilities underwater. Bowen and Miller (1967) have pointed out that in operational terms the diver is a relative cripple.

Various estimates of an informal nature have revealed that the working diver is about 10^ to 20^ as effective as a man working at the same task on dry land (Mosby 1967). Other reports have substantiated this claim (Bowen, Andersen and Promisel, 1966; Pauli and Clapper, 1967; Bowen, 1967; Davis, 1970.) As well as showing that decrements in performance occur across a wide range of activities, Bowen points to decrements in symbol processing and clock tests, Pauli and Clapper indicate a increase in performance time for a two hand co-ordination test in water as compared with the same task being carried out on dry land. In addition, Pauli and Clapper found that group assembly tests carried out underwater took twice as long as the same tests completed on land even though subjects had had considerable practice beforehand.

Clearly, no one factor is responsible for a diver's impaired performance. The effects of increased pressure, buoyancy, lack of air, viscous resistance, cold, darkness, as well as a number of other hazards, all contribute towards widening the gap between intention and achievement.

Such hazards in some measure also exist within any habitat. Personnel have to fulfil a programme of work both inside and outside the habitat. Divers need to be skilled not only in diving but in some other scientific skill to aid the varied programme of work. There are requirements in such programmes for marine biologists and geologists; engineers, and psychologists, all of whom need to spend time both inside the habitat and in the water.

Constant adaptation therefore is a requirement for all personnel due to the fact that they are at one moment carrying our work tasks in the sea, and the next confined in a cramped, and often cold,air environment needing to check and operate critical equipment. Considerable attention therefore needs to be directed towards investigating the particular effects of certain critical environmental factors during the time spent in the habitat and immediately after a working dive.

For this study the effects of cold and wet were chosen as the major environmental factors, together with their effects on subjects1 tactile sensitivity, Divers returning to a habitat after being in the sea are both wet and cold. Bevan (1971) shows that at a water temperature of 4°C divers unprotected hands dropped to 15°C after being immersed for between 30 minutes and 60 minutes. Bowen (1967) has recorded skin temperatures for heart and foot as being 27°C and 17*5°C respectively. Skreslet and Aarefjord (1968) show the average skin temperature of the back of the hand of three divers after 30 minutes immersion in 3.5°C water as 19°C, a drop of about 12°C from normal hand skin temperature.

Crew members in fulfilling their function within the habitat are expected to operate levers, manipulate dials, turn knobs, press buttons, and generally perform a wide variety of tasks requiring manipulatory skill and tactile sensitivity (Bowen 1967).

Such tasks may well be required to be carried out either immediately after a prolonged diver or in the period u/hen the body is still recovering its normal temperature.

The habitat too is vulnerable in that the support services may fail under unusual conditions. There is often a real risk that power failure could cause a total blackout. Personnel experiencing such a mishap may well be forced to carry out critical operations and manoeuvres using their tactile sensitivity only.

From the divers point of view, all water is cold, thus causing a heat drain from the body. Average sea temperatures around the South coast of England vary from 8°C in February to 16.5°C in August(Keating> '1971).

Lewis (1941) has noted that at any temperature below 15°C - I8°C vasodilatation tends to develop in the skin causing a large increase in blood flow to the extremeties and subsequent heat loss to the water, although Keating (1972) gives 12°C as the highest temperature. If, for example, a finger or hand is held in a water temperature of 5°C the surface temperature of the skin rapidly falls until it is not far from the temperature of the water, due to the vessels of the skin contracting and limiting the flow of blood. The deep parts of the skin are similarly affected. During this period the finger is robbed of its natural heat and becomes painful. Spontaneous rewarming of the finger or hand then occurs normally after 6 or 7 minutes, Provins and Morton (i960) due to an increased amount of blood being released by the central nervous system.

Bevan (1971) has noted in an experiment using eleven male subjects wearing wet suits in a sea temperature of around11.5°C, that there was an average deep body temperature loss of

0.55QC and that on completion of the dive the deep body temperature continued to fall.

This finding is of considerable relevance to the present investigation as divers selected for a work programme using a habitat as a base are commonly expected to carry out two dives of an hour or so per day from the habitat, and is therefore an indication that effects produced by cold immersion continue after the immersion itself has been terminated.

fflackworth (1953) has pointed out that in very cold climates the very tasks for which gloves have to be removed are those requiring good manual dexterity and accurate finger movement. Russell (1957) has also noted that the best glove combinations available are not capable of either keeping the hands warm, or maintaining their functions efficiently. Protective clothing of this sort may interfere with the input of sensory information or with the responses required to perform a skil efficiently. The same is true of the work needed to be done by divers. Gloves worn by divers often fail to protect the hands from cold. Bevan (1972) reports a drop in temperature of some 18°C from 34^ to 16°C, for divers using gloves in 4°C water. Divers often need to take their gloves off during a work session underwater in order to facilitate finger movement for a particular task. The duration of exposure may vary considerably but in any case will serve to increase loss of heat from the hands.

The diver returning to an underwater habitat will have spent something of the order of 1 to 1-J hours in the sea. The water outside, taking a typical continental shelf temperature where most diving takes place, will be between 7°C and 12.5°C (Bowen 1967).

Recently, some uiork has been carried out using heated suits, either providing total or partial body heating (Bevan unpublished material; Beckman 1964; Burton and Collier, 1964; Kettle, 1972). Whether.these provide heating from thin copper wires embedded in the undergarments as in the Sealab 11 experiment (Pauli and Clapper, 1967) or through plastic tubing fed with warm water, the essential aim is the same, that is to extend the diver’s working period in the water. Thus whether he returns to the underwater habitat after 45 minutes using a non-heated suit, or after 2^ hours using a heated suit, he has still to contend with effects of wet and cold on his body and extremities. Kettle (1972) has noted that even though many types of heated suits were used in experiments carried out at the Admiralty Experimental Diving Unit, heat loss from the hands proved to be the major problem. The addition of electrical power to the wet suit gloves is considered unacceptable due to the fact that there is a conflict between electrical safety and the problem of electrical insulation in a water immersed situation. The design rules for electrical engineering based on a dry environment are severely stretched in a totally immersed state, and the problem is made more difficult when water pressure assists water penetration. Any leakage of electrical current from a power supply will produce a field of electrical potential which may be between a divers head and his feet or between his outstretched arms. If his body is exposed to the water, electrical currents will pass through it restricted only by his wet-skin resistance. If his skin is broken by cuts and abrasions which is often the case with divers, the currents will be greater.

Cold Water Immersion Experiments:

Previous experiments investigating the effects of cold on tactile sensitivity or manual and finger dexterity have largely used cold air for cooling the hands or body (UJeitz, 1941; Lockhart, 1966, 1968; Cavenagh, 1963; (Ylackworth, 1953; 1955, 1956; Bartlett

and Groujnouu, 1952; Clark, 1961; Wills, 1957; Russell, 1957; Keiss and Lockhart, 1970). Those experiments using water for cooling (Le Blanc, 1956, 1960; Provins and Morton, 1960; Adams and Smith,1962; Skreslett and Aarefjord, 1968; Baddeley, 1966; Bowen, 1967) have either concentrated on partial immersion using the hands, forearms or fingers, or have compared performance in the dry with performance underwater (Baddeley, 1966; Bowen, 1967).

Cold air studies point to a severe impairment in manual performance when the hand skin temperature falls below 13°C, when the body is kept warm (Springbett, 1951; Clark, 1961; Gaydos and Duslek, 1958), No impairment is experienced at 3°C above this level. The body surface can be cooled down to about 25.5°C before any further impairment appears. Lockhart (1966) lowered the body skin temperature to 20.5°C whilst keeping the hand skin temperature at 32.5°C and found a significant performance decrement in block stringing and block packing tasks. Cooling the body whilst maintaining the hands warm produced less impairment to manual performance tasks than when the hands alone were cooled to 12.5°C, thereby emphasising the role of hand skin temperature. UJhen lowering both the body skin temperature and the hand skin temperature simultaneously to 20.5°C and 12.5°C respectively, the greatest performance decrement was experienced.

Attempts at relating manual performance decrements to losses in tactile sensitivity have not been confirmed. However,Barlett and Gronow (1952) observed a distinct loss of dexterity in the thumb during their experiments. This loss seemed to contribute most directly to the overall performance decrement.

Provins and Morton (i960), using the Mackworth ‘U1 test to ascertain two edge threshold discrimination, found little change in performance at finger temperatures of 6°C or higher and marked impairment at temperatures of about 4°C or below. They suggest that either the nerve fibres or receptors, or both, are subject to cold block below about 6°C and therefore are no longer capable of excitation by a stimulus or transmission of the impulse having once been excited.

Mention must also be made of the way in which heat is lost from the hands when subjected to cold water immersion.Greenfield et al (1951) have noted that, due to vasconstriction, there is very little heat loss from circulating blood during the first five minutes of immersing one of the subject's hands in a water bath at 0°C to 5°C. After the fifth minute however, an increasingly large amount of heat is lost, reaching a peak at ten minutes and then slowly declining or remaining fairly steady. It was also noticeable that from this point on, changes in heat loss recorded from the other hand, which was used as a control and immersed.'in;:a calorimeter at 29°C - 32°C often reflected the changes on the cold side. Initial insertion of the hand into the cold water caused a transient decrease in the heat loss from the opposite hand. This was considered to be due to reflex vasoconstriction.

Greenfield et al (1951) have also shown that whilst slight differences existed in the heat losses from the fingers of the right and left hands immersed in a water bath at 0°C - 6°C, the general behaviour showed that both hands responded to cold immersion in much the same way.

It can be appreciated that the phenomena of reflex vasoconstriction and of vasodilatation are of particular importance to divers, bearing in mind that certain tasks carried out underwater, although requiring the glove to be taken off one hand only, may eventually result in a performance decrement using the protected hand due to heat loss from that hand to the thin film of water surrounding the skin or to the sea. Bearing in mind Greenfield's work, the assumption that the hand protected from the cold during a dive will be unaffected is incorrect.

In general, initial exposure to cold produces vasoconstriction at the periphery, thereby achieving a degree of peripheral thermal insulation and conserving body heat (Bowen, 1967). When the hand skin

temperature falls to about 10°C or below, a reflex vasodilatation may occur which results in an increase in peripheral blood flow and raises the hand skin temperature a few degrees. Vasoconstriction followed by vasodilatation may continue in an alternating sequence (hunting reaction) first described by Lewis (1930). Provins and Morton (i960) confirmed this general trend and noted that although vasodilatation occurred after about six to seven minutes immersion, detectable improvements in tactile discrimination did not occur until several minutes later.

Bowen (1967) suggests that individuals differ greatly in the extent to which they exhibit cold-induced vasodilatation, and suggests that individuals who delay or tend not to vasodilatate in cold appear as highly aroused individuals in other characteristics, teichner (1965) showed that the latency of response can be "lengthened by a person being subjected to a threat of an electric shock or by means of a "conflict uncertainty."

These findings and others (Le Blanc, 1961; Bowen and Miller, 1967) tend to indicate that persons of a "calm" disposition are able to tolerate cold water better than anxious persons and that the anxiety inherent in any diving activity may bring about a lowered tolerance to cold.

In considering further the effects of local or total body cooling on tactile sensitivity, it is necessary to look at another factor which is of particular relevance. This is the rate of recovery after exposure to cold. Bowen (1967) has noted that all divers returning from trials carried out in a water tank at a temperature of 8.5°C were shivering, some violently. They also experienced difficulty in talking and breathed rapidly and shallowly. Bowen reports that it took at least one hour for the divers to feel subjectively warm. Skreslet and Aarefjord (1968) in their investigations on divers acclimatization to cold water also reported shivering, and suggest that the initial elevation of deep body temperature commented on by Bevan (1971) is due to a shunting of blood

aiuay from the periphery into deeper tissues, thus effectively increasing the insulating value of the skin. Bevan also reported an initial elevation of the deep body temperatures of eleven divers in sea-water temperatures of 12°C at a depth of 3.1 metres and 11.5°C at a depth of 30.5 metres. This was immediately followed by a general fall in deep body temperature which continued even after subjects were removed from the cold water, Keating (1969) partly explains this apparently paradoxical situation, postulating that the skin temperature may remain low and thus maintain the thermal gradient responsible for the loss of deep body heat. Keating further suggests that as the cold-induced vasoconstriction of the skin subsides, the increase in the blood circulation would increase the conductivity of the superficial layers, thus for a short period accentuating the fall in deep body temperature. Russell (1957) investigated the effects of variations in ambient temperature on tracking skills and sensory sensitivity. He points out that since recovery implies a previous impairment, it could be predicted that the most pronounced evidence of recovery would be found at the lower temperatures, which previously had shown the greatest impairment in the performance studied. This hypothesis was supported by the results obtained. Russell also indicated that although tactile sensitivity was affected after relatively short exposures to the experimental temperatures, the evidence indicated that it also recovered rapidly. At the two coldest temperatures however,i.e. - 10°C and 0°C, the rate of recovery although rapid at first tended to decrease as duration of exposure to the temperature of the room increased. The mean recorded room temperature for all groups in this series of experiments was 23.33°C.

Significant improvement in recovery time can be achieved by cold-conditioning. Adams and Smith (1962) have shown that a change in cold induced vasodilatation develops during prolonged exposure of a finger to cold as a local phenomenon. During the period of experimentation, pain associated with this type of cold

exposure diminished and finally disappeared. Previous investigators (Glaser et al 1959) found no change in cold induced vasodilatation following experimental cold exposure of an extremity, although the periods of chronic cold exposure on these occasions were only one minute in duration as compared with the 20 minute immersion used by Adams and Smith. Recovery time has also been recorded by Le Blanc (1956). In tests involving eight subjects, he exposed firstly the arm with the hand excluded for 10 minutes; secondly the hand only for 10 minutes, and thirdly the finger for 5 minutes. Recovery time, i.e. the period of time that it takes before the skin temperature of the exposed part recovers to its normal temperature for these tests, was 10 - 24 minutes, 10.5 - 20 minutes and 4 - 1 0 minutes respectively#

Provins and Morton (i960) have suggested that water itself has little or no effect on the threshold for two-edge discrimination, and further suggest that there is no reason to believe that the water itself has any greater effect at lower temperatures. Their experimental procedure made use of an apparatus similar to the Mackworth "V" test, and consisted of a 300 mm transparent plastic ruler cut in half, with the two halves bolted together to form a \! - shape. The procedure involves the subject supinating his hand whilst the experimenter places the ruler on the outstretched finger. The position on the ruler at which the subject can just distinguish a gap (two edges) is determined by the method of serial exploration and the mean of six alternately ascending and descending runs are recorded as the control threshold value.

A diver, during the time he is underwater, although being protected by a wet suit is in constant contact with the water. The wet suit allows a thin film of water to enter between the skin surface and the inner lining of the suit. This layer of water is heated by the body and serves to delay the loss of heat to the sea

during a dive, UJhether the diver takes off his gloves or not underwater, his hands become and remain wet for the duration of the dive. The use of gloves however, does to some extent prevent the hands and fingers from becoming numb and useless for manipulative tasks (Bevan, 1972),

Of the studies mentioned dealing with the effects of cold exposure on tactile sensitivity and finger dexterity, and using water as the cooling agent, none, apart from Baddeley (1966), allow divers either to move during the experimental procedures, or provide moving water flowing past the diver, Bevan (1971) positioned subjects in a chair moored to the bottom by placing a weight belt in their laps, Skreslet and Aarefjord (1968) used motionless divers in both ponds and ice baths. Bowen (1967) carried out experimental procedures in a water tower and a flooded quarry and required divers to carry out tests whilst they remained in a fixed position on a platform.

Mackworth (1953) found that the effect of raising the wind speed from still air to only a few miles an hour was just as important as the effect of lowering the air temperature by 5GC. The same principle may apply to numbness experienced in water. A diver is very rarely in water that is still. Typical current movements are often between 2 to 4 knots and can be as much as 6 knots. In such a condition a diver with his gloves off, even in a relatively fixed posture, can experience a rapid onset of numbness and cold effects, thereby not only reducing his efficiency more quickly in water, but also after a return to a habitat.

2. PURPOSE OF STUDY:

It is clear from the literature available that experiments dealing with the effects on tactile sensitivity of localised and total body cooling have largely been carried out in cold air chambers. The results of such studies can not therefore be applied directly to the particular condition of divers, who although being totally immersed in cold water experience little cold effect during the eardy part of dives, due to the insulating nature of the wet suit and the warmed film of water surrounding the body. The diver therefore is in an environment which varies from warm/wet to cold/wet.

Experimenters using water as the cooling medium for hand/arm or finger tests have usually chosen water temperatures considerably below those normally experienced by most divers and have placed little importance on either the kind of water used or to the fact that cold water immersion tests add two variables to the experimental condition, that of cold and wet.

The total immersion experiments (Baddeley, 1966; Bowen, 1967) deal simply with the comparison of performance in a dry control state and in an immersed condition and pay no attention to performance immediately following a dive, Bowen (1967) makes reference toca loss in manual dexterity ( 2 3 %) and a slight loss in tactile sensitivity during a ’warm* water immersion at 20°C although results were stated as "provisional".

The overall purpose therefore of the present study was to measure performance using four environmental conditions:

(1) In an ambient room temperature of between 18°Cand 20°C.

(2) After immersion in warm water conditions at 32°C.(3) After immersion in cold water conditions at 14°C.(4) After immersion in cold water conditions at 5°C.

No experiments were carried out during the period of either partial or total immersion as the main intention of this study was to discover how a period of immersion affected the tactile discrimination of personnel following their return to a habitat. In addition it was concerned with investigating the extent to which tactile discrimination was affected during the recovery period.

In order to assess whether a ’wet* as opposed to a •cold* effect altered subjects' performance capability following immersion, water at a temperature of 32°C was used. In addition three kinds of water were used for the tests to establish whether osmotic pressure differences caused any variation in responses.

These were:-(a) Distilled water(b) Isotonic water 0.9 grammes electrolytes per 100 ml(c) Sea water 2/3 grammes electrolytes per 100 mlIn (a), because of osmotic pressure differences there

is a tendency for the distilled water to pass into the tissues.

In (b), the isotonic solution is in equilibrium with the tissues.

In (c), again because of osmotic pressure differences, there is a tendency for a 'leaching' or dehydration of the body tissues to take place.

A further purpose of this study was to construct an experimental design, which for both the preliminary and main experiments dealt with water movement, bearing in mind that previous experimenters have paid little attention to this factor.

3. ENVIRONMENTAL FRAMEWORKS

The particular need of this study in attempting to investigate the tactile sensitivity of divers after their return to a habitat, required that the experimental procedure be set within an environmental framework that would reasonably simulate those conditions existing in an underwater habitat.

A chamber was therefore constructed 3.6 metres long x 2.4 metres wide x 2.4 metres high. The chamber was positioned over a water tank 4,8 metres long x 2.4 metres wide x 1.2 metres deep, containing approximately 18,000 litres of water. The dry chamber was positioned over the complete width of the water tank below and at one end, see Fig.2 allowing 1,2 metres x 2,4 metres of open water surface providing access for divers into the tank from outside, A circular hole measuring 0,75 metres in diameter was positioned in the floor at one end of the habitat, thereby providing bottom entry for divers from the water into the habitat. Temperature control of the habitat was achieved by a water cooled air conditioning unit positioned at high level and set against the outside of the end wall. For total immersion experiments use was made of a water cooled refrigeration unit capable of reducing the air temperature inside the habitat to 6°C, although this degree of coldness was never required for the experiments described.

Relative humidity in underwater habitats generally is high due partly to the open access to the sea allowing divers free movement from inside to outside, and partly to water vapour given off by personnel and by wet clothes. Water vapour from personnel is made up from perspiration and expired air. It was

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ENI//RONMENTAL C

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therefore necessary to maintain a fairly high relative humidity during both the hand and total body immersions as a normal percentage between 40/S and 50 S was likely to cause the skin surface to dry too rapidly. A percentage of between 65^ and 75 o was therefore achieved by leaving the access trap door to the water tank open for some hours before an experimental period and closing the 'dry1 door from the normal laboratory environment. It was considered that this increase in humidity did not constitute an additional variable to the experimental procedure, bearing in mind that the period of time subjects were in the room was never longer than 30 minutes. UJater temperature in the tank was maintained at 14°C i 2°C during the total immersion tests and was therefore similar to the temperature experienced by divers in the sea. During the warmer weather it was occasionally necessary to partially drain the tank and run mains water to maintain the desired degree of coldness. As the experimental chamber was housed within a laboratory with roof lights facing north, there was little heat gain except in the mid-summer periods. In addition, the water tank section was lined externally with heavy duty aluminium foil to prevent the water gaining heat from radiation.

4. METHODS:

For clarification, the experimental programme has been divided into two sections. Firstly, the hand immersion experiments involving the subjects preferred hand being immersed in different kinds of water at different temperatures, and secondly, the total immersion experiments, using divers totally immersed in either cold or warm water. In both sections however, the testing procedure used to establish whether tactile sensitivity had been affected by immersion was the same and is described below.

Apparatus. Tactile Discrimination Test (Frey hairs)

The apparatus for t ie test consisted of seven graded nylon sutures, ten millimetres in length each housed at the end of a 340 millimetre long metal rod, the last 30,8 millimetres of which was angled at 90°, see Fig. 3. The hairs were graded so that pressure differences when striking the test site were evenly distributed through the range of hairs, see table 1, Fig.4.The apparatus was a modification of the Von Frey hair test and was similar to that used by Lele, Sinclair and Weddell (1954).The p resen ta tion tuas by the method o f paired com parison.

The testing procedure consisted firstly of selecting the area for stimulation on a chosen region of the hand and lightly touching the skin with the end of each nylon suture in a desired sequence. The metal rods were held at the end so that the fingers supported the rods as a cantilever. The required touch was produced by allowing the hair to fall lightly on the skin. Consistency was maintained by the writer being the experimenter on all occasions. In order to ensure that the area for stimulation was approximately the same for each subject, a glove template was used

G /ZAO EO A/yZOA/ S U TU K & S

APPARATUS USED FOR TACTUAL ST/MULAT/ON. AFTER VON-FREY.

F/G13

SPEO/FIGAT/ON OF NYLON SUTURES

SUTURE NO. D/AM /N M M 'S EFF. WT OF BUOW */ *225 -0 / grammes

2 •29 '0/4 gram mes

3 33 'O H gram m es

4 •3 7 020 gram m es

5 '4/ 0 2 2 gram m es

6 -44 • 0 2 5 gram m es

7 5 ' 0 2 8 gram mes

# F/GURES SHOWN REPRESENT TNE MEAN OP TEN READ/NGS US/NG A

1„ 'STANTON'S ' UN/MATtC 3 F/GURE BALANCE.

t a b l e : /

f /g : 4

incorporating cut-out squares 30 millimetres x 30 millimetres overall for the palmar and dorsal regions, see Appendix.

After having marked the skin around the profile of the cut-out, an additional grid uias added making up a total number of nine 10 millimetre x 10 millimetre squares. The glove was then removed. At this point the testing procedure was explained to the subject and a trial run carried out. Before experimentation began, record sheets were completed providing information concerning the environmental condition of the habitat and details of the subjects clothing, age, etc., after Biesheuval (1969), see Appendix.

Subjects were then presented with a series of papers on which were drawn hands marked also in squares and coded horizontally by the numbers 1 : 2 : 3 , and vertically A : B : C. lliith their preferred hand, subjects marked an appropriate answer of "y" or "n", representing "yes" or "no" in each square to the two questions asked. These were, (l) "Can you feel anything?” and (2) "Can you feel any difference between the first stimulus presented and the second?'.' Each of the 10 mm x 10 mm square was therefore stimulated 21 times.

During the testing period the subjects non-preferred hands were placed behind a screen at a comfortable height on a worktop exposing the area for stimulation, see Fig.5 • They were unable to see what stimulus, if any, had been applied and were asked on a number of occasions during the test whether their hands were comfortable. The experimenter sat in a seat alongside the subject and applied the nylon sutures to the squares marked on the subjects hand in the sequence A.l, A.2, A.3, B.l, B.2, etc; attempting at all times for the "paired comparisons" to locate the same point on the skin. Individual stimuli ranging from the lightest suture to the heaviest were first applied in order to achieve "thresholds" for each group. In most cases however, subjects were able to discriminate

F / 6.5 TACTILE DISCRIMINATION TEST

F/G.5

the touch of the lightest suture. Subjects were then asked to judge whether they could perceive a difference between two stimuli by the method of paired comparisons described by Brown (i960).

This involved presenting the sutures in the followingsequences;

1 with 2. 3. 4. 5. 6. 7.2 with 3. 4. 5. 6. 7.3 with 4. 5. 6. 7.4 with 5. 6. 7.5 with 6. 7.6 with 7.

UJhen it was necessary for control and experimental responses to be taken on the same day as in the case of the total immersion experiments, the presentation of sutures for the second occasion started with a comparison of 2 with 3. 4. 5, 6. 7. etc. and followed the same sequence as before ending with a comparison of 1 with 2. 3. 4. 5, 6. 7. This was to avoid learning effects.

Prior to any testing procedure a temperature reading was obtained of the particular part of the hand to be tested, using a "Zeatron" remote controlled electronic thermocouple, which was taped to the skin by a piece of 10 mm wide waterproof adhesive tape.

In the control state two readings were obtained, one immediately before testing began and the other immediately after completion. During the cold experimental tests, readings were taken before a test began and on four occasions during immersion, During certain test procedures, four additional readings were taken in order to ascertain the length of recovery time for the hand to achieve a hand skin temperature of 30°C which has been described by Provins and (Tlorton (i960) as normal.

The temperature inside the environmental chamber was maintained between 18°C and 20°C. Relative humidity was generally between 65$ and 75$.

As a check on the reliability of the testing procedure, one subject repeated the experiment on three separate occasions in the control condition. Fig 8a shows the scores achieved in each case for this subject.

The particular advantage of the testing procedure used is that the nylon sutures minimise changes in skin temperature due to contacts with warmer or cooler surfaces during testing.In addition, the testing procedure allows continuous information to be gained during the recovery period, and gives an indication of changes in tactile sensitivity during the testing procedure. Comparisons of performance can be made during this period due to the fact that the effective weights of the separate sutures are evenly arranged throughout the series, see table 1, Fig. 4.

Comparisons therefore can be made between sutures 1 : 2 ,2 ; 3, 3 : 4, 4 : 5, 5 : 6, and 6 : 7 over a period of time, see Figs: 11 ; 31 ; 50 ; 65 ; 80 ; 99 ; 123.

On only one occasion was the experimental procedure altered. This arose as a result of needing to test the end of the middle finger in Experiment 13. Instead of marking a 30 mm x 30 mm square on the palmar or dorsal region of the hand, a 10 mm x 10 mm square was marked on the finger through a glove template. An experimental procedure similar to that described earlier was adopted except that the single square was tested only once using the matched pair comparisons. The test site was therefore presented with a total of 21 paired sutures, which was the same number presented to each of the nine 10 mm x 10 mm squares used in all the other experiments.

Hand Immersion.

Experiment 1.

The immersion bath for this experiment was simpler than that used in the later experiments. It consisted of a (200mm x 200mm x 200mm) box made up from the 25mm chipboard. The top surface of the box included a circular hole of 115mm in diameter through which a waterproof plastic lining was gathered. A rubber gasket was employed as a seal around the edge of the hole, (see Fig.6). A hardboard top also with a 115 mm diameter hole was placed over the top surface so that the positions of the holes matched. One side was extended 150 mm to allow subjects to rest their arms comfortably on a foam pad secured to the arm rest during hand immersion. The whole apparatus was placed on a worktop at a comfortable height for subjects. The height of the worktop could be lowered or raised in increments of 25 mmfs by means of adjustable brackets to allow for individual differences in height when seated.

All experiments were carried out in the controlled temperature room previously described.

Eight members of the Department of Architecture attended individually for two separate sessions, firstly to establish a control (dry) reading in air maintained at a temperature between 18°C - 20°C, and then on a subsequent occasion for hand immersion tests. Only one test per subject was made on the same day. Control and experimental tests both involved obtaining threshold readings for tactile discrimination as well as performance readings using a matched pair comparison described earlier, although on this occasion no threshold readings were obtained as all subjects were able to feel the lightest stimuli presented to their palms. Total immersion time, was 20 minutes for each subject with an additional testing period of between 18 and 20 minutes, commencing immediately after withdrawal of the hand from the water bath. An immersion period of 20 minutes had been used by Adams and Smith (1962).

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The sea-water used had an electrolytic salinity of 3 grammes per 100 cubic centimetres. Temperature readings of the subject*s palm were taken by attaching a thermocouple to the test area with a small piece of adhesive tape. Hand skin temperature readings were taken before the immersion and control experiments began and on four separate occasions during the immersion. Further readings were taken after withdrawal from the box. Additional hand skin temperature readings were taken at intervals during the test session and at the end of the testing procedure in order to ascertain the rate at which the temperature of the tested area recovered its normal temperature. For the control condition only one further reading was taken at the end of the test session.

As the immersion box was not thermostatically controlled, temperature readings were also taken of the water at 5 minute intervals. There was a tendency for the water bath to gain in temperature up to 2°C due mainly to the heat loss from the hand.There was also some difficulty experienced in the organisational aspects of this experiment in that no ice was available to cool the water. The whole box therefore had to be placed in a refrigerator overnight and taken out the following day. Almost without exception the water bath when recovered from the refrigerator was at too low a temperature to proceed with the testing immediately, and there was a delay ofan hour or so before the water reached the correct temperature.

Owing to the relatively small size of the box, it was not possible for this experiment to include a propellor blade in order to achieve water movement. This however was achieved for experiment 2 and all subsequent experiments.

Experiment : 2.

For this experiment a larger insulated immersion bath was used measuring 450 mm's x 225 mm's x 225 mm's. The top surface of the bath was covered with 12 mm plywood with an opening of 250 mm's x 100 mm's and rounded at both ends. The immersion bath was lined as in experiment 1 with a plastic liner gathered through the hole and secured down to the top surface, see Fig. 7. The bath was divided in two halves by a light mesh metal screen to the full depth of the bath mounted on a metal angle screwed to the top cover plate. Also mounted on the angle was a small battery driven electric motor driving a propeller blade submerged on one side of the metal screen. Water flowed through the mesh division allowing the subjects' hand to experience water movement during the full period of immersion. The mesh screen served to protect the subject's hand from the propeller blades and to smooth out water flow.

Subjects placed their non-preferred hands in the water bath up to the wrist, the experimental apparatus being located inside the controlled temperature room at a comfortable height on the adjustable work top previously described. The procedure used in the previous experiment was adopted, with the exception that on this occasion the dorsal region of the hand was investigated.It was considered necessary to establish a comparison between the palmar and dorsal region bearing in mind that previous work had paid little attention to this factor.

Six members of the Department of Architecture attended individually for separate sessions (five male and one female) to establish (dry) control readings in an air environment of between 18°C - 20°C, and (cold-wet) readings. The salinity of the sea-water on this and all subsequent occasions was 3 grammes per 10D cc's as before.

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Total immersion time was 20 minutes for each subject with an additional testing period of between 18 minutes and 20 minutes, commencing immediately after withdrawal of the hand from the water bath. Hand skin temperature readings were taken in the same manner as in experiment 1,

Some difficulty was again experienced in cooling the water to the required temperature owing to the fact that the bath needed to be placed in the refrigerator overnight, and therefore generally reached a temperature lower than that desired. Experience however of the duration of time needed for cooling prior to an immersion prevented long delays in this experiment.

Subsequent Experiments:

The apparatus used for the third and all subsequent hand immersion experiments consisted of a thermostatically controlled stainless steel water bath fitted with a heating and cooling coil, see Fig. 8. Accuracy of water temperature was - 1°C, Uiater movement was provided by a propeller in one cornerof the tank. The immersion period was 20 minutes as before, subjects being asked to place their non-preferred hand in the water up to the wrist whilst their arms rested on a foam pad onthe edge of the tank.

As in experiments 1 and 2, hand skin temperature readings were taken at the beginning and end of both the control and immersion tests, using the remote control 1zeatron* thermocouple. During immersion this was attached by a small piece of waterproof adhesive tape to the test site. Readings for the cold immersions were taken at five minute intervals during the immersion.

Subjects were questioned during all cold immersion tests about their subjective feelings. These were recorded andare briefly described in the results.

Total Immersion Experiments (Cold).

During the total immersion experiments carried out in the tank below the controlled environment chamber, care was taken to ensure the divers safety. All equipment was checked before a dive in the manner recommended by the British Sub-Aqua club. Divers wore standard 5 mm lined neoprene two-piece wet-suits, covering the body from the neck down to the ankles, as well as a face mask, neoprene helmet, boots, rubber flippers and weight belt. Breathing equipment was a single compressed air cylinder strapped to the back with either a single hose or twin-hose demand valve. No gloves were worn on either hand.

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At the start of the experimental procedure, the diver entered the water via the hole in the floor of the chamber and sat on the bottom of the tank in full view of the supervisor. He/she tuas allowed to spend a few minutes adjusting to the conditions. A rope was fastened around the divers waist, the other end of whichwas held by the supervisor in case of emergency. After the periodof adjustment, divers were encouraged to move freely around thetank, A signal between the diver and supervisor was agreed beforea dive and was a modification of the signals approved by the British Sub-Aqua club. This was, one pull on the rope for "I am O.K.”; two pulls "I am moving away"; three pulls, "I am coming back;’1 four pulls, "Emergency11. The recognised signal for divers on a line differs only in that two pulls means "I am going down", and three pulls, "I am coming up." The other two signals mean the same,

A second experimenter observed the diver through 6 no.150 mm. diameter perspex portholes positioned in the sides of the tank, and relayed information periodically to the supervisor concerning the divers general welfare and position in the tank, fflovement of thedivers, however, was sufficient to stir up the bottom layer of sand andgravel, thus causing the visibility to be reduced to less than 300 mmfs, and therefore caused some difficulty in observation. The total dive lasted 20 minutes. As far as reduced visibility was concerned it was a hazard which most subjects had experienced before when diving in the sea, either as a result of marine organisms andparticulate matter reducing visibility, or from their own workefforts on the sea-floor. As a safeguard, however, divers undergoing cold water immersions in the tank were told to expect reduced visibility before they submerged.

During all total immersion dives, hand skin temperatures were recorded by taping a thermocouple from a remote reading "Zeatron" meter to the part of the hand to be investigated in a manner similar to that described previously. Readings were taken before the diver entered the water to establish his normal hand skin temperature, at two minute intervals during the immersion, on four occasions during the tactile discrimination test to ascertain the temperature recovery rate, and again at the end of the test session.

On emerging from the water tank after an experimentalsession, divers were helped off with their helmets, mask, weightbelts and breathing apparatus, retaining their jacket and trousers to avoid being chilled. They then seated themselves at their experimental table. Excess water was lightly removed from their body surface, hands and arms, and the testing procedure previously described was begun. The testing grid on the part of the hand to be investigated was on all occasions marked prior to immersion by the use of indelible ink, owing to the practical difficulty ofmarking on wet skin. Subjects were again asked after the immersionto comment on their feelings during the dive with particular reference to cold effects.

Total Immersion Experiments. (Warm).

Due to the practical difficulty of providing 18,000 litres of warm water in the tank, it was decided to carry out the warm total immersion experiments in the polytechnic swimming pool, which was positioned only a short distance away from the environmental chamber. Co-operation was gained from the polytechnic authorities to increase the temperature of water from the normal 27°C - 28°C, to 32°C, this being the temperature of the skin surface, (Provins and Morton (i960). The testing procedure for establishing tactile

sensitivity to a one point stimulus was carried out in the environmental chamber, the subjects having to walk down one flight of stairs and along thirty feet of corridor to the chamber after the dive. It was donsidered that although this was not ideal because of the need for subjects to carry out a small amount of exercise after the immersion, i.e. walking, it was a better procedure than carrying out the tactile test in the swimming pool where distractions caused by people using the pool, together with the uncontrolled temperature and cross-draughts, would almost certainly have affected the results to a much greater extent. Checks of equipment were carried out in the same manner as for the cold dives, and divers wore the same equipment as previously.

Prior to the dive, which lasted 20 minutes, subjects were told to move freely in the deep end of the pool, and to come out when a rubber brick was thrown into the water. Safety precautions were obviosuly not as stringent as for the cold dives in the tank, although it was considered necessary to have a standby diver on the side in case of emergency. No rope was attached to divers in this experiment. Hand skin temperatures were taken prior to immersion and at the end of the experimental session, the testing grid being again marked prior to immersion. On entering the controlled chamber, subjects went through the same experimental procedure as described previously for cold immersion.

4a STATISTICAL METHODS USED.

Statistical analysis involved tiuo well established techniques. Student's *t* was used, with a correction for related means, where the same subjects provided data under different experimental conditions. UJhere different subjects performed in each experimental condition, and where the main concern was to test whether independent groups had been drawn from the same population, the Mann-UJhitney 'U' test was used. 'This is one of the most powerful of the non-parametric tests, and it is a most useful alternative to the parametric 't* test... ' (Siegel 1956).

NOTE:-

Siegel (1956) has remarked that 'Power is .. related to the nature of (the hypothesis). If (the hypothesis) has direction, a one-tailed test is used, A one-tailed test is more powerful than a two-tailed test. This should be clear from the definition of power'. In the present research programme the research hypotheses always had such a directional character.

28a.

5. SUBJECTS:

Hand Immersion Experiments:

For the hand immersion experiments subjects were generally taken from the student population of the Department of Architecture, as well as from the administrative staff of the Polytechnic# Ages ranged from 19 years to 48 years, and included a total of 14 women.

Some subjects during cold hand immersion found the lower temperature too much for them and had to stop the experiment before completion of the twenty minute period# Four students were unable to complete the cold immersion due to feelings of nausea and one vomited after approximately 12 minutes of immersion in water at 5°C# One further subject complained of nausea towards the end of the twenty minute period, but was able to complete the required time for cold immersion together with the testing procedure.Although such reactions to localised cold effects are of obvious interest, investigation of the cause of such symptoms was beyond the scope and intention of this study*

Total Immersion Experiments:

The total immersion experiments, requiring subjects to be immersed either in the water tank below the environmental chamber or in the swimming pool, demanded that divers had previously undergone the necessary training procedures required for sub-aqua work# (Ylost subjects had either demonstrated their capability in the swimming pool, or were members of local sub-aqua clubs and had considerable experience of sea-diving. All subjects had passed the necessary S.C.U.B.A. (Self Contained Underwater Breathing Apparatus) tests.

Experience in diving ranged from eight weeks to five years

6. RESULTS AND DISCUSSION (Hand Immersion).

Experiment 1. Control with 5°C Sea-HJater (palm).

Introduction:

This experiment was designed to provide a baseline for the later group of experiments and dealt simply with assessing whether sea water cooled to 5°C significantly affected tactile discrimination of the palmar region.

Sea water was chosen for two reasons:-(a) Previous work related to tactile discrimination

has not been concerned with assessing whether 'types1 of water had any significant effect on tactile discrimination, although it was known that 5°C water produced a lowered sensitivity.

(b) Because of the relationship to the working condition of divers.

Subjects:The eight subjects, (aged between 19 and 25) consisted

of male and female undergraduate students from the department of architecture and male and female members of the administrative staff, see Fig.9.

Results:Fig. 12 shows the mean ;hand skin temperature of all

subjects during the immersion and testing periods. All subjects showed a rapid drop in hand skin temperature during the first five minutes of immersion ranging from 15°C to 23°C, S.D. control = 18;S.D. experimental = 21.7, (and is in agreement with Adams and Smith, 1962; Glaser and UJhitlow, 1957; Provins and (Ylorton, I960).

A rewarming effect was noticeable after approximately 5 minutes, which was generally maintained or increased until the end of

the 20 minute immersion. Whilst most subjects showed a normal hand skin temperature at the end of the 15 - 20 minute testing period, two subjects failed to reach a temperature of 28°C indicating that the recovery period for these subjects was in excess of the period required for assessing tactile discrimination by the method used.

Fig. 10 shows the summary graph of subjects performance during the testing period. It is clear from this graph that there is, as one would expect, an initial increase in sensitivity when the lightest suture is compared with sutures of the larger diameters, e.g. no's. 5 : 6 : 7 . At this stage the difference between sutures is at the maximum for the test.

Performance, however, declines when the next series begins, (i.e. suture 2 with 3 : 4 : 5 : 6 : 7) and fails to recover above 42^ for all the remaining paired comparisons.

Both the individual and summary graph show that subjects experience a decrement in tactile sensitivity particularly during the mid period of the testing procedure, even though at this point there are considerable differences in the paired comparisons presented, e.g. 2 with 5, 2 with 6, 2 with 7, 3 with 5, 3 with 6,3 with 7, etc. This is particularly noticeable in the scores of subjects 1, 3 and 6, see Figs. 13, 15, 18.

Performance scores were obtained for both the immersion and control condition by adding up the correct scores obtained from the matched pair comparisons. These are given in Fig. 9. The results showed a significant decrement in tactile sensitivity.P < 0.05.

31.

All subjects experienced some pain and discomfort during the cold immersion test, complaining of numbness and pain, particularly at the wrist where the hand entered the water as well as at the extremity of the fingers. Numbness followed the initial feeling of pain, which in two subjects spread to the upper part of the arm.

Typical comments from subjects with regard to the cold water immersion were as follows:

1) "There is a burning sensation and prickling."2) "The hand seems to stop near the water line."3) "The hand feels colder at the interface of the

air and water."4) "There is a burning sensation at the end of the

thumb and first finger.

The four female subjects achieved noticeably lower scores than the male subjects in both the control and immersion condition. Statistical analysis using the 't1 test however, revealed no significant difference between male and female groups of subjects.

Discussion:

Greenfield, Shepherd and UJhelan (1951) have shown that it takes approximately eight minutes for the distal 2.8 cm. of index finger to reach equilibrium with a water bath at 5°C, and suggest that the hand equilibrates much more slowly than the finger tip.

Provins and Morton (1960) suggest that with a greater length of finger exposed to the cold water, the time taken to achieve equilibrium would be a little longer. During this experiment however on no occasion did the immersed hand reach equilibrium with the water.

An average temperature rise of 4°C occurred between the first reading taken after 5 minutes of immersion, and the third reading, taken after 15 minutes of immersion, and is in agreement with Morton and Provins findings of a rise in temperature after 6 or 7 minutes due to vasodilatation,

Greenfield et al (1951) show that during the initial stages of immersion in water at a temperature between 0 - 6°C, heat loss from the circulating blood was small or negligible for about 5 minutes, and then rapidly increased. It reached a maximum by the 7th - 10th minute and then either declined slowly or remained fairly steady. There is little indication that the sequence of hand skin temperature changes achieved in this experiment using a saline solution differs markedly from those of Adams and Smith (1962) Provins and Morton (i960) Greenfield et al (1951) or Le Blanc (1961) except that the hand skin temperatures of all subjects during immersion did not reach equilibrium with the water and was generally 8°C - 9°C more than the temperature of the water. This is not in agreement with any of the four previous studies.

It is clear that hand skin temperature is likely to rise gradually after withdrawal of the hand from cold - immersion, although varying times for recovery have been noted by other experimenters, Le Blanc (1961) showed that recovery of the index finger of Gaspe fishermen after 10 minutes immersion in water at 2,5°C took 9 minutes to achieve a temperature of 31°C, A control group with little experience of cold water immersion only achieved a temperature of 24,5°C after the same period of time. The subjects used in the experiment described also achieved a mean hand skin temperature of 24,5°C after 10 minutes, although this increased to 28,5°C after 20 minutes.

Subjects used by Provins and Morton after immersion in 0°C water generally failed to achieve a hand skin temperature of 24°C after 7,5 minutes.

In the experiment described, hand skin temperature recovery in the main was unaided by the testing procedure owing to the minimal cross sectional area of the sutures, and was not fully complete after 20 minutes, see Fig, 12. The subjects used in this experiment were not used to cold water immersion and therefore can be described as unacclimatized subjects.

It would seem from these and other experiments described that acclimatized subjects tend to recover more quickly following cold water immersion than do unacclimatized subjects. Adams and Smith make mention of psychological effects on temperature responses in their work with Caucasian subjects, and are supported by an earlier study of Meehan (1956). Twice in Adam and Smith's investigations psychological states were shown to modify test responses. On both occasions stress was induced by verbal suggestion producing a fall in temperature of 10°C in a period of 4 minutes. The curve produced is similar to an initial cooling curve for non-conditioned subjects.

Although the implications of psychological states of mind on performance was considered to be outside the scope of this study, the relevance of acclimatization of subjects to cold exposure is seen to be a factor that is likely not only to affect cold induced vasodilatation (Adams and Smith, 1962) but also to affect the period of recovery.

The impairment in tactile sensitivity shown, in Fig.10 during the period of testing is reflected to some extent in the control state also, and can be seen to be partly due to the arrangement of matched pair comparisons. Variations however in scores are widest at this mid-point of the testing procedure and point to a relationship with ,the rewarming of the skin. At this mid-point in the testing procedure the average hand skin temperature for the eight subjects was 24.5°C.

Although much literature concerns itself uiith hand immersion and the effect of vasoconstriction and vasodilatation on tactile sensitivity, little work has been carried out in relation to the recovery period, and to the way in which normal hand skin temperature is regained after cold exposure,

Hensel and Zotterman (1950) by using what was then a new intracutaneous thermo electric method, showed that an after sensation of cold may persist, although rewarming of the skin has occurred at all points. This phenomenon was studied by applying thermo-electrically controlled thermal stimuli to the tongue of a cat. This corresponded to the application and removal of a cold object. Action Potentials of the cold fibres were recorded. It was shown that below an environmental temperature of 21°C, the recorded cold impulses did not disappear for a long time after the beginning of rewarming, producing a discharge of cold impulses of considerable duration.

It is not clear how such a phenomenon would affect tactile sensitivity of the hand during the recovery period, although it is to be assumed from Hensel and Zotterman1s work that cold impulses are being produced for some time during the testing procedure in the present series of experiments. As stated earlier the room temperature was maintained at a temperature of 18°C to 20°C, Bearing in mind that Hensel and Zotterman showed no disappearance of cold impulses until the establishment of a constant room temperature of 22°C, it is reasonable to assume that changes in tactile sensitivity could have been affected by persistent cold impulses.

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32

1

/ Z /-3 /-4 E5 J-G f -7 23 2-4 25 2-6 2-7 3-43-S3-6 3 74-546 4-7 5-G 5-7 6-7

ORDER OF RA/R PRESENTATION

GPAPH SHOWING COMPARISON OFTACT/LE SENS/T1V/TY .DUF/NG TEST/NO PEF/DD.

EXP. No: Jf/g : /5

SCORE

SCORE

EXPERIMENTAL.987

6

54

3

2.

1

!Z /-3 1-4 f-S !■<£ 1-7 2*3 2-5 6 2-7 3*4 3-S 3-6 3-7 45" 4-6 -4-7 5-G 57 6-7

ORDER OF HA/R PRESENTATION SUBJECT N °A

EXP. No: 1

CONTROL9

a7

PALM65

4

3

2.1

/-2 /-3 / 4 1-5 J-G t-7 2-3 2-4 2-5 2. 6 27343-53-<S 3-74546 47 5-6 5-7 G-7

ORDER OF NA/R PRESENTATION

GRAPH SHOWING COMPARISON OF: TACTILE SENSITIVITY DURING TESTING PERIOD.

EXP. No: ifig : /6

SCORE

SCORE

EXPERIMENTAL3

8

7 PALM6

5

4

3

2.1

I'Z A3 14 f -S / <S 17 2-3 2.4 252-6 27 34 3-5 3-6 3-7 4-5 4-6 4*7 5-G 57 67

ORDER OF HAfR PRESENTATION SUBJECT No: 5

EXP. no: /.

CONTROL9

a765

4

3

2

1

/•2 f-3 /-4 f-5 /•<S f -7 23 2-4 2-5 2-6 27 3-43-53-<S 3 74,54-6 4? 5-G 5-7 6-7

ORDER OF HAfR PRESENTATION

GRAPH SHOWING COMPARISON OFTACTILE SENSITIVITY .DURING TESTING PERIOD\

EXP. N o : /f ig : 17

EXPERIMENTAL

PALM

AZ A3 A4 AS AG 17 2 7, 2-4- 2-S 2-6 27 3-4 3-53 6 3 745 46 7 5-6 5 7 6 7

ORDER OF HAIR PRESENTATION SUBJECT N°. S

EXP. n o : I

AZ A3 A4 AS A<3 A7 2-3 24 25 2-6 2-7 3-4353-6 3 7 4 5 4 6 47 5-G 57 6 7

ORDER OF PAIR PRESENTATION

GRAPH SHOWING COMPARISON OFTACTILE SENSITIVITY DURING TESTING PERIOD.

exp . n o : i

F IG : 16

SCORE

SCORE

EXPERIMENTAL9

87

PA i6

54

3

2

1

IZ /-3 14 /'S 16 /■ 7 2 3 24 2-5 2-6 2.7 3-4 3-5 3 G 3 74*5 4-6 4*7 5-6 5 7 6 7

ORDER OF HA/R PRESENTATION SUBJECT N ° 7

EXP/Vo I f

CONTROL9

87

6PA

54

3

2

1

AZ /’3 / 4 f-5 J-G f -7 2-3 2-4 2-5 2,6 2-7 3-43-53-6 3-7454-6 47 5-6 5-7 6-7

ORDER OF HA/R PRESENTATION

GRAPH SHOWING COMPARISON OFTAOT/LE SENSITIVITY DURING TESTING PERIOD.

EXP. No: / f i g : I S

SCORE

SCORE

EXPERIMENTAL9

87

6

s

4

3

2

1

IZ 1-3 14 /S / <S /• 7 2-3 2-5 S 2-7 3-4- 35 3-G 374-54-6 4 7 5-5 5 7 6 7

ORDER OF HNR PRESENTATION SUBJECT M 6

EXP. n o : /

9

a7

654

3

2

1

/•Z / 3 /-42 /-^ J-G f-7 2-3 2-4 2-5 2-6 2-7 3-43-53-G 3-74-54-6 4-7 5-6 5-7 6-7

ORDER OF RNR PRESENTATION

GRAPH SHOWING COMPARISON OF! TACTILE SENSITIVITY DURING TESTING PERIOD.

exp. no : /p is : 20

Statistical Method:

Experiment

Summary:

HoHa

2Tdt

t

t

From tables

Compares Performance in a Controlled air environment with Performance after hand immersion in 5°C sea-water (palm).

This experiment made use of the ’tf test.

JET = Sigma, (fcfie sumN = No. of subjects

nd = o (null hypofhesis). d = difference.nd = o

= 158 Z 6 2

= d - nd

Z 6 2 - (Z4)2

N (N-l)

= 19.375 - 0/ 2#208

y se

= 3.087 (df = 7).

P < 0.05

= 5,328one sided test.

Hand Immersion.

Experiment ? 2. Control with 5°C Sea-UJater (dorsal).

Introduction:-

Because of the known variation in tactile sensitivity of the palmar and dorsal regions of the hand Stevens (i960) it was considered necessary to establish to what extent the dorsal region was affected by immersing the hand in 5°C sea-water# It was also intended to establish threshold readings for the cold immersion test.

Sub.jects:-

Six subjects aged between 22 and 30 were used from the Department of Architecture. They consisted of five male and one female. See fig. 21.

Results:-

The initial effect of immersing the subjects hands in a saline water bath at 5°C - 2°C, produced a rapid decline in hand skin temperature to an average reading of 9°C during the first 5 minutes.A lower reading of 8.5°C occurred during a further 5 minutes levelling out to a plateau at around 10°C, see Fig. 12. At the end of the 18 - 20 minute testing period, the hand skin temperature had risen to a mean of 24.8°C, 4°C below that of the previous experiment.

The testing procedure was applied to the dorsal region of the hand in the manner previously described in METHOD. Scores obtained from applying the graded nylon sutures in paired comparisons proved not to be significant when compared with control scores achieved in the controlled air environment. Threshold readings were attempted in the

manner previously described, although most subjects failed on occasion to detect the lightest stimulus presented, the mean threshold for the 6 subjects occurred below suture no. 1, see Fig. 22. Due to the fact that no subject gained 100% detection during the presentation of the lightest stimulus a statistical test was run to establish whether this was significant at the .05 or .01 level. Results proved negative.

It can be seen from a comparison of Experiments 1 and 2, Fig. 12, that there was a 4.5°C difference between the lowest immersion temperature of the palmar region as compared with that obtained from the dorsal region of the hand although the temperature of the saline water was the same on both occasions. Hand skin temperature of the dorsal region taken before and after controlled testing showed temperatures ranging between 28°C and 30°C and were slightly below those recorded for the palm.

It was hypothesised that due to the smaller number of ^ouch1 receptors in the dorsal region of the hand as compared to the palmar region, it would be less likely that subjects would be able to discriminate differences between the stimuli presented.Mean scores therefore achieved by the six subjects, both during the control test and the experimental session, were expected to be lower than those achieved in Experiment 1, see Fig. 9. UJhilst the mean control score for the dorsal region was below that of the palmar control score, the score achieved for the experimental condition for the dorsal region of the hand showed an increased mean score to that gained from the palmar region.

Subjects tactile sensitivity during the control and experimental sessions is shown in Fig.10. As in Experiment 1 only small differences are noticeable during the early part of the testing procedure. However, at around the mid point of the procedure, i.e. after approximately 10 minutes, wider variations between experimental and control tests; again appear.

During this experiment these wider variations occurred after the presentation of suture 2 with suture 6, and continue until the presentations of sutures 5 with 6. This differs only slightly with the variations plotted for Experiment 1, in that noticeably wider variations occurred after the presentation of suture 2 with 4 and continued until the presentation of suture 4 with 6, In both cases there is a tendency for the scores to merge during the last two or three minutes.

Discussion:The fall in hand skin temperature during cold immersion

differed from experiment 1 by a mean of - 4.5°C, and indicates considerable differences between the mean hand skin temperature of the palmar and dorsal regions during cold immersion. Greenfield et al (1951) has suggested that this is due to the fact that the temperature of the blood in the radial artery although significantly less than 37°C when the hand is immersed is still around 10QC higher than the temperature of the blood over the dorsal veins.

The graphs for experiments 6, 7 and 8, which will be discussed later, also confirm this finding, and show hand skin temperatures for the dorsal region to be only 5.5°C above the water temperature.

As in Experiment 1, hand skin temperature did not reach equilibrium with the water and subjects generally did not recover their normal hand skin temperature after the 20 minutes of testing. The difference between the hand skin temperature of the dorsal and palmar regions after testing was completed was 4°C, see Fig. 12.

There was again evidence, albeit slight, in this experiment, of a rewarming phase occurring approximately 10 minutes after immersion: this is in agreement with the findings of Provins andMorton (i960) and Adams and Smith (1962), although both these experimenters tested subject’s index fingers and not the dorsal region of the hand. The duration of immersion however, was the same in both cases.

Performance during the mid part of the testing procedure, although not indicating a lowered tactile sensitivity than that of the control see Fig.10, does indicate considerable ’variation' in subject's tactile sensitivity during this period as compared to the control group.

Because of the small number of subjects used for this experiment it was decided to repeat this experiment as part of a later series.

: sc o pes : e x p e r im e n t : 2

TEST/NG GOND/T/ONS

ENV. GOND/T/ONS GOLD/WETJMMER8I0N

WETmmers/on

CONTROLA/R

TEMPERATURE1

s °c\ °c.f

32° C. /8°G TO 20°C

/MMERS/ONI

HAND | BODY\

RAND I BODY...f -....“.......

TVPE OP WATERi.....

S.W. 1 1I

....1 .—! . .

.... . — ■ - r ------- --------- ----------

TEST S/TE1

dorsa\1fl DORSAL

SETT J SEX AGE SCORE : NO OE CORRECT RESPONSES/ M 22 /OO \ 1 972 M

M2323

U4 | ““ r n:rni.." ( 953 7KT j i

1... 744 M 22 94 \ 1

i /065 F 30 & \ 1

t65

6 M 24 77 j t

I 637 1__ I - - . ...\ .. .. .8 1

11... 1

..... ■ — - - - - - - - - - - - - -

S 1.. }i1 - -. . . . . . . . . . . . . . .

JO 1f

I«TOTAL SCORES 5/6 500

MEAN SCORES 86 ■ - - ~ -.- - ---■. . . . . 83-3

STANDARD DELATION /8-S Z6 -7

RESULT I WOT S/GN/F/CANT :.... -... - . . . . . . -

EXPER/MENT A/o / F/6 :2/

K E Y : O — 0/S T/LLE D WATER/ - ISOTONIC SOLUT/ON

S.W- SEA-W ATER P i — M AINSS.P. - SWIMMING POOL WATER

PER

CENT

DE

TECT

IONS

100

30

30

7060

50

40

30

20

10

4 5 72 3 B

STIMULI (SUTURES)

GFAPH SHOWING % OF DETECTIONS TOINDIVIDUAL STIMULI. FOLLOWING £XP. N°.2.S°C. HAND IMMEHSION.

FIS: 2Z

SCORE

SCORE

EXPERIMENTAL9876

5

4

3

2

1

IZ E3 14 f'S EG E7 23 24 2-526 27 3-4 3-536 3 74-5 4-6 4-7 5-6 5 7 6-7

ORDER OF RMR PRESENTATION SUBJECT Ml

EXP. No : E

CONTROL9

a7

65

3

2

1

/Z E3 E4 1-5 EG 1-7 2 3 24 2 5 26 27 3*435 3-6 3-7454-6 47 5-6 57 67

ORDER OF HNR PRESENTATION

GRAPH SHOWING COMPARISON OF. TACTILE SENSITIVITY DURING TESTING PERIOD.

exp. no: a fig : 23

EXPERIMENTAL

12 1-3 14 IS I-G t-7 23 2-4 2-5 2-6 27 3-4 3-5 3-6 374-5 4-6 47 5-G 5-7 6-7

ORDER OF HAIR PRESENTATION SUBUEDT A/o;2

EXP, N o: 2

CONTROL

1-2. 7-3 1-4 15 I tS 1-7 2-3 2-4 2-5 26 2-7 3-43-S3-G 3-74-S 4-G 47 5-G 5-7 G-7

ORDER OF HA/R PRESENTATION

GRAPH SHOWING COMPARISON OFTACTILE SENSITIVITY DURING TESTING PERIOD.

EXP. N o : 2f i g : 24

EXPERIMENTAL

IZ 13 h4 / S i-6 17 2 3 24 2 5 2 6 27 34 3536 3 74-5 4-6 4-7 5-6 57 6 7

ORDER OF HA/R PRESENTATION SUBJECT NP Z

EXP No: 2

CONTROL

A2 /-3 ;-4 /'5 /■& f‘7 2-3 24 25 26 27 343536 3 74.546 47 56 57 67

ORDER OF NNR PRESENTATION

GRAPH SHOWING COMPARISON OFTACTILE SENSITIVITY .DURING TESTING PERIOD.

EXP. No: 2 FIG : 25

EXPERIMENTAL

12 1-3 1-4 /-S /-S /•7 2-3 2-4 2-5 2-6 2-7 3-4 3’S 3-6 3-7 45 4-6 47 5-6 5-7 G-7

ORDER OF HNR PRESENTATION SUBJECT NO 4.

EXP. n o : 2

CONTROL

' /-Z !-3 f-4 1-51-e 1-7 2-3 2-4 2-5 Z-G 2-7 343-S3-e3-74-S4-e,47 5-6 576-7

ORDER OF HNR PRESENTATION

GRAPH SHOW/NG COMPARISON OF: TACT/LE SENSITIVITY DURING TESTING PERIOD.

EXP. no : zf i b : 26

EXPERIMENTAL

12 /3 14 /S / <S hi 2 3 24ZS26 21 3-4 353-6 3 745 4-6 4*7 3-6 57 6-7

ORDER OF HA/R PRESENTATION SUBJECT N°. 5

exp no : a

CONTROL

/-Z /-3 ;-4 /-5 J-G f-7 2-3 2-4 Z-5 2-6 2-7 3-43-53-6 3-7454-6 47 5-6 67

ORDER OF HAIR PRESENTATION

GRAPH SHOWING COMPARISON OFTACTILE SENSITIVITY DURING TESTING PERIOD.

EXP. no : 2FIG : 2 7

SCORE

SCORE

experimentale8

654

3

21

/Z /-3 t-4 IS MS 1-7 2-3 .Z-4 2 52 6 2 -7 3*4 3-SJ-6 3-745 4-6 4-7 5"-S S’ ? 6-7

: ORDER OF HAIR PRESENTATION SUBJECT NP 6

EXP. no; 2

CONTROL9

a7

654

32J

AZ 1-3 1-4- t'5 1-6 1-7 2-3 2-4. 2-5 2-6 2-7 3-43-53-6 3-74-54 6 4-7 5-6 5-76-7

ORDER OF HA/R PRESENTATION

GRAPH SHOWING COMPARISON OFTACTILE SENSITIVITY .DURING TESTING PERIOD.

EXP. no : 2F/G : 28

Statistical Method.

Experiment: 2. Compares performance in a controlledair environment with performance after hand immersion in 5°C sea-water. (dorsal).

Using the *t* test,

£ d = - 16

<Td2 = 792

lYlake the hypothesis Ho : [\!d = 0

Ha : Nd =>0

t = d - nd

t = - 2.6624. 7

t = - 0. 53

two sided test = 2.571.

Hence at 5% significance we accept the hypothesis Ho.

Conclusion:- There is no evidence to dispute that the two responses have the same mean. Therefore result not significant.

Hand Immersion.

Experiments. 3. 4. 5. Control uiith distilled, isotonic and sea-waterat 32°C.

Introduction:-

Having established that sea-water at a temperature of 5°C caused a significant decrement in tactile discrimination as compared to subjects tested in a controlled air environment, it was decided to test whether different types of water affected such discrimination and in addition whether it was the ’coldness* or 'wetness* that contributed to the drop in sensitivity.

It was decided therefore to conduct a series of experiments covering the following:-

(a) A control group of 10 subjects in a control air environment maintained at a temperature between 18°C to 20°C (C).

(b) An experimental group of 10 subjects immersing their non preferred hand in sea-water at 32°C.( s . u i . ) 1

(c) An experimental group of 10 subjects immersing their non preferred hand in isotonic solution at 32°C. (I)1

(d) An experimental group of 10 subjects immersing their non preferred hand in distilled water at 32°C. (D)1

In order to assess the effects of ’coldness* using these three types of water, a further series of experiments was carried out using the same control group. These are described in experiments 6, 7 and 8.

The dorsal region was chosen for this first series as this area is known to have fewer touch receptors and tends to be less sensitive than the palmar region^Stevens (i960). It was considered therefore, that if there proved to be a significant difference between the control condition and the experimental conditions described using the dorsal region, there was likely to be a significant difference between control and the experimental condition using the palmar region, whereas the opposite would not necessarily be true.

The measure of tactile sensitivity during the testing procedure was achieved as before by the presentation of graded nylon sutures in a matched pair comparison sequence, described earlier in METHOD, the results of which are shown in Fig. 29.

Subjects:

For this series of experiments subjects were taken from the student population of the Department of Architecture and Land Surveying, as well as from the administrative staff of the Polytechnic. Ages ranged from 19 to 47 years, see tables, Figs. 29; 42; 48.Different subjects were used for each of the four groups making up a total of 40 subjects.

Results.

Experiment No. 3.

Control with 32°C Distilled Water (dorsal).

Fig. 30 shows the summary graph for 10 subjects variation in performance during both the control and experimental conditions.

There is an initial improvement in the number of correct responses during the early stages reaching a peak above that of the control group after the presentation of sutures1 with 5 and 1 with 6, From this point there is a noticealbe decrement in tactile sensitivity as compared with the controls until the end of the testing procedure. Statistical analysis using the Mann UJitney U test showed the differences between (C) and (D) to be significant, P< 0,05,

There was no significant difference between scores achieved using the three types of water.

Results,

Experiment No, 4.

Control with 32°C Isotonic, (dorsal).

Fig. 30 shows the summary graph for 10 subjects variation in tactile sensitivity during both the control and experimental conditions, together with the standard deviations, and is similar to that of experiment 5, Predictable peaks in performance in the control condition are seen again when light sutures are compared with the heavier sutures, e.g, 1 with 7,2 with 6 or 7, etc. Scores during the mid and end period of the testing procedure show noticeable decrements, but are less marked than those occurring in experiment 5. There is also a greater variation of scores in the experimental condition than in experiment 5,

Statistical analysis using the Mann UJitney U test showed the differences between (C) and (l) to be significant P<0.05.

-44.

Experiment No, 5.

Control with 32°C Sea-water (dorsal).

Fig. 49 shows the summary graph of 10 subjects during the twenty minute testing period. A noticeable decrement in tactile sensitivity for the experimental condition can be seen with the exception of suture 1 with 7.

The arrangement of paired comparisons results in a noticeably higher number of correct responses, reaching a peak when the lightest suture is compared with the heaviest, both in the control and the experimental condition, but produces peaks only in the control condition for the other widely spaced sutures,The experimental scores show decrements ranging from 8% - 38%

from that of control. Statistical analysis using the Mann UJitney U test showed the differences between (C) and (S.W.) to be significant P<0.01.

Discussion:- Experiments 3 : 4 and 5.

The results gained from this series of experiments demonstrate that tactile discrimination is significantly impaired following the immersion of subject's hands in three types of water, i.e. sea-water, isotonic solution, distilled water at 32°C. This is in disagreement with Provins, (unpublished observations). Provins and Morton (1960) used water as the cooling medium for an investigation to ascertain deterioration in the two edge discrimination, using the Mackworth 1V/' test apparatus described earlier, and used 30°C water as the control condition. They hypothesised that immersing the finger in water at about normal hand skin temperature would have little effect on the threshold for two-edge discrimination and that there was no reason to believe that the water itself had any greater effect at lower temperature.

Bowen (1967) using divers immersed in a water tower showed that a warm water condition of 18°C produced a loss in manual dexterity of 23$ as compared to a dry land performance, and that"a slight loss in tactile sensitivity was found'1 at this temperature. The experimental procedure was the same as that used by Morton and Provins, i.e. the Mackworth 'V* test. Bowen summarises these preliminary findings by suggesting that, "On a provisional basis, therefore, there was distinguished a "water" effect, that is the difference between dry land and warm water performance; and a "cold" effect; that is, the added difference contributed by the cold water condition."

Bowen's work is not directly comparable to the present study due to the fact that his experiments were carried out whilst his subjects were totally immersed in water. The indication however, of a 'water effect* is borne out by the results gained from the present study in experiments 3, 4 and 5.

It is noticeable from the performance scores of experiments 3 : 4 and 5 that at the end of the testing procedure, differences between control and experimental were 12$ ; 18$ and 21$ respectively, giving a mean difference of 17$. Comparable percentage differences between control and the 5°C immersions occurring at the end of the testing procedure were 30$ ; 24$ and 24$, giving a mean difference of 26$. This series is described next.

SCORES : EXPERIM ENT. : 3

TESTING CONDITIONS

ENV. CONDITIONSGOLD/WET IMMERSION

WETIMMERSION

CONTROLA/R

TEMPERATURE\

°c\ °c.?

32° C. /a°C TO 20°0,

/MMERS/OA/1

HAND \bODYi

HAND ! BODYI

.... ...............- ......

TYPE OF WATER

i1

..... . 1 ......1

sZ7 I : : : : : ------------ --- -------------- — —

TEST SITE11

iDORSAL DORSAL

8BJT SEX AGE SCORE : NO OF CORRECT RESPONSES A6E

I M 4-7 i .

1 /33 1 ne M 252 M 22 I

1 133 i 137 M 203 M 23 I

i /22 \ 134 M 244 M 20 1

i ... ! 116 M 785 M 23 1

...............i ________ 97 ! 122 M 796 F 20 1

i 5 -7 | 95 M 227 M 19 i

i 5 0 j 120 F 248 M 20 1i 8E i 71 F 248 M 34 I

..... : 1 ....■ - (04 \ 152 M 7910 M 42 1J 33 J 105 M 26

353 I 168 ...

MEAN SCORES 35-3 116’8

STANDARD DEVIATION 30-25 21-7

RESULT 1 SIGNIFICANT AT P = •05

EXPERIMENT NO / 3 FIG : 29.......... — ............ -.... --

k e y : d — o/st/lleo water/ ~ JSOTOMC SOLUTION

. SM- SEA-WATER M - MAWS S.P. - SWIMMING POOL WATER

control

experimental

CONTROL VERSUS 32°C ISOTON/C

• DOiim 71 S£> ? / • ; ro. — ......

i l ~£X C7# SD = IS ~

<A 1

f

\ \ ; K \ \ ' ) r '* NK\V\ >

✓f

\ \ \ i \ ' \ fnt

\\ sf

\ > >\\ //\< tf O i ?P SAi f

l-Z /-3 h4 J-5 i-G /• 7 2-3 2-4 2-S 2-6 27 3.4 3.3 3.e 3.7 4.5 4.5 7 S.G 5q G.y

ORDER OF HAIR PRESENTATION 10 SUBJECTS

EXPt No: 4CONTROL VERSUS 32°C DISTILLED

100

soCOhTJiCL SJJ

80

70

60

50

ArO

/Z /-3 /-4 A5 17 2-3 2-4 2-5 2 6 2-7 3-43-S3-6 3 7 4 5 4 6 4? 5 6 5-7 6 7

ORDER OF HAIR PRESENTATION 10 SUBJECTS

GRAPH SHOWING COMPARISON OFTACTILE SENSITIVITY . DURING TESTING PERIOD.

exp. no: 3F IG : 3 0

% SC

ORE

% SC

OR

E

m controlo — _ o exper/rm nfo/

CONTROL VERSUS 3 2 aC. /SOTON/C/oo

8 0

•

b Z /-3 f-4 /’5 f-6 /-7 2 3 2-4 2-52-6 2-7 5-4 2-5 3-6 3-7 4.-5 4-6 -7 5-6 5-7 6-7

. ORDER OF HAIR PRESENTATION /O. SUBJECTS

e x p : 4-

CONTROL VERSUS 3 2 0£D/ST/LLED/OO

90

8 0

4 0

20

/-2 /-3 /-4 /-5 1-6 /-7 2-32-42-52-62-73-4 3-53-6 3-7 4-54-6 4-75-6 576-7

ORDER OF HAfR PRESENTATION /O. SUBUECTS

s E X P : 3 T

GRAPHS SHOWING COMPARISON LN TACTILE SENS/T/V/TY FOR HAIRS / 2 12 3 /3 -4 / 4 -5 / & 6 ! 6-7. E /6 :31

SCORE

SCORE

CONTROL9

81

6

54

3

2

1

12 i<3 1-4 15 1-6 /-7 2-3 2-4 2-S 2-6 2-1 3-4 3-S3-G 3-745 4-6 4-7 5-6 5-7 6-7

ORDER OF HAJR PRESENTATION SUBJECT No;j

exp no: 3:4 :5.

CONTROL9

a7

65

4

3

2

1

/-2 1-3 14 1-51-6 1-7 2-3 2-4 2 5 2-6 2-7 3-43-S3-G 3-74-54-6 4-7 5-6 £-7 G-7

ORDER OF HAIR PRESENTATION . SUBJECT NO:R

GRAPH SHOWING COMPARISON OFTACTILE SENSITIVITY MOPING TESTING PERIOD.

e x p . n o : 3 : 4 - : 5.f ig : 3 2

SCORE

SCORE

CONTROL98765

43

2.

1

IZ /-3 /-4 /5 /•£ /-7 2-3 .2-4 2 SZ-6 27 3-4 3-S3-G 3 74-5 4-6 4*7 5-6 5-7 G-7

: ORDER OF HAJR PRESENTATION SUBJECT NO;s

EXP. N °: 3 :4 : 5.

CONTROL9

a

7

654

3

2J

A2 /*3 /-4 t-5 J-G 17 23 24 25 26 Z-7 34353<S 3 7454-6 47 56 576 7

ORDER OF HAIR PRESENTATION SUBJECT M 4

GRAPH SHOWING COMPARISON OFTACTILE SENSITIVITY DURING TESTING PER/DD.

EXP. N o : 3 : 4 : 5 . f / g : 33

CONTROL

!Z t-3 t-4 /S l-e /■ 7 2-3 2-4 2S 2-6 27 3-43-S3G 3-745 4-6 4-7 S &5-7 G-7

ORDER OF HAIR PRESENTATION SUBJECT MS

exp. no: 3:4-: 5.

CONTROL

/■Z 1-3 /'4 !-5 ! G !-7 23 2-4 2-5 2G 27 3-43S3-G 3-74 S 4-6 4-7 S-6S-7 G-7

ORDER OF HAIR PRESENTATION SUBJECT me

GRAPH SHOWING COMPARISON OF: TACTILE SENSITIVITY .DURING TESTING PERIOD.

e x p . n o : 3 : 4 : 5 .f i b : 3 4

WOftif

SDORE

CONTROL

s8*76

54

3

21

/v? /-3 1-4 i'S 16 17 2 -~Z 2 4 2S 2-6 27 3-4 3-53-6 3 745 4-6 &7 5-6 57 6 7

ORDER OF HAIR PRESENTATION SUBJECT NO. 7

e x p .n o : 3 : 4 : 5 .

9

a7

6i5

3

2

1

/•2 A3 /4 1-5 AG f-7 23 24 25 26 27 343-S3-G 3 74,54-6 47 56 57 6-7

ORDER OF NA/R PRESENTATION SUBUEOT N 0£

GRAPH SHOWfNG COMPARISON OF. TACTILE SENSITIVITY DURING TESTING PERIOD.

e x p .n o : 3 : 4 : 5. E / e : 35

CONTROL

1Z 73 74 75 IS 77 2-3 2-4 2 S 2-6 27 3-4 3-S3-6 3-74tS 4-6 4-7 5-6 57 G-7

ORDER OF HAJR PRESENTATION SUBJECT M 9

EXP.N°: 3 : 4i 5.

CONTROL

' 72 73 74 IS 1-6 77 2-3 2-4 2S 2-6 2-7 3-43 S3-6 3-7434-6 47 S-6 S-7 6-7

ORDER OF HAtR PRESENTATION SUBJECT MOO

GRAPH SHOWING GOMPAR/SON OF; TACTILE SENS/T1V/TY .DUP/NG TEST/NG PEP/DD.

exp. n o : 3 : 4-: s.FIG : 36

SCORE

SCORE

3Z°C . DISTILLED WATER9

87

654

3

21

/vZ 7-3 /*4 / 5 16 /• 7 2-3 .2-4 2’5 .8-6 -2-7 3*4 3-S3-6 3-745 4-6 4-7 5-6 5 7 6 7

ORDER OF HAIR PRESENTATION SUBUEGT m i

exp m: 3

3 Z 0C. DISTILLED WATER9

a7

654

3

2.

1

/-2 A3 A4- 15 A6 A7 23 2-4 25 26 27 34 353-5 3 74,54-6 47 5-6 5-7 6-7

ORDER OF HNR PRESENTATION SUBUEGT No. 2

GRAPH 5HOW/NG COMPARISON OF. TACTILE SENSITIVITY DUPING TEST/NG PEP/DD.

EXP. N o: 3f i g : 37

SCORE

SCORE

32°C. a/STILLED WATER9876

5

4

3

2

1

I'Z 7*3 14 / S /■& 1-7 2-3 2-4 2-526 21 3 4 3 53-6 3-7 4-5 4-6 47 5-fi 57 6-7

ORDER OF HA/R PRESENTATION SUBJECT N U J

EXP.No 13

32°C. jO/ST/LLEO WATER9

a7

65

3

2

1

/■2 /-3 /-4 t-5 AS f-7 23 24 2-5 Z-G 27 3-43-S3-<S 3-7454-6 47 56 5-7 6-7

ORDER OF HAIR PRESENTATION SUBJECT M 4-

GRAPH SHOWING COMPARISON OF: TACTILE SENSITIVITY DURING TEST/NG PERIOD.

EXP. N o: 3f ig : 3 3

SCORE

SCORE

3Z°C. DISTILLED 'WATER987

6

54

3

2

1

I Z A3 A4 / S AG 17 23 24- 2 S 2 6 2 7 34 35 3 6 3-7 4-5 4*6 4-7 5-6 3-7 <3-7

ORDER OF HAIR PRESENTATION SUBUEGT A/O.fr

EXP N °: 3

J2°C.D/$TILLED WATER9

a7

65

4

3

2

1

/■2 A3 A4 C5 AG f-7 23 2-4 25 20 27 343530 3 74,540 47 56 57 67

ORDER OF PAIR PRESENTATION . SUBUEGT NO. 6

GPAPH SHOW/NG COMPARISON OF; TACT/LE SENS/TMTY EUF/NG TEST/NG PEFf/DD.

EXP. N o: 3FIG : S9

SCORE

SCORE

3Z°C. DISTILLED WATER987

654

3

2

1

/•2 t-3 14 /S 16 /• 7 2-3 2-4 2-5- 2-6 2-7 3-4 3-5 3-6 3-7 45 46 47 5-6 5-7 6 7

ORDER OF HAJR PRESENTATION SUBJECT- NO. 7

EXP No:3

3Z°C O/ST/LLED WATER9

s

7

654

3

2

1

AZ /*3 / 4 15 J-<5 1-7 23 24 25 Z..& 2-7 3-4353-6 3'74 5 4 6 47 56 67 6 7

ORDER OF HAIR PRESENTATION SUBJECT NO 6

GRAPH SHOWING COMPARISON OF: TACTILE SENSITIVITY DURING TEST/NG PERIOD.

EXP. N o: 3f ig : 40

SCORE

SCORE

3Z°CD/ST/ILED WATER9876

5

4

3

2

I

hZ 13 1*4 1*5 1*6 1*7 23 2-4 2*5 2*6 21 3 4 3-S3-G 3*745 4-6 47 5*6 5 7 6*7

ORDER OF FAIR PRESENTATION SUBUEGT m 9

EXP. No 13

3Z°C D/ST/LLED WATER9

a7

65

.3

2

1

/*2 /3 /-4 f-5 /*6 f-7 23 24 2*5 2<S 2*7 3*4353*2 3*74*54*6 47 5*6 5*7 6*7

ORDER OF PAIR PRESENTATION SUBUEGT NO./O

GRAPH SHOWING COMPARISON OFTACTILE SENSITIVITY .DURING TESTING PERIOD.

EXP. no : 3p is : 4*1

Statistical Method.

Experiment : 3, Compares performance in a controlledair environment with performance afterhand immersion in distilled water at o32 C. (dorsal).

Using the Mann tUitney U Test.

U = D D C D D C D D D C C C C D C D D C C C

Where C = Control ConditionD = Distilled Water Condition.N = N° o f subjects.

N.l = N.2 = 10.

U = 2 + 4 + ( 7x4) + 8 + ( 3 x 10).

U = 72

From Table K: U is significant at P < 0.05.

S U /v / iv i r t n x ur~ o u o u o . u / o u n is - u i -o h i v u

SCORES : EXPERIMENT : 4

TEST/NG COND/T/ONS

eny. cm a /rm sGOLD/NET /MMERS/ON

MET/MMERS/ON

CONTROL IAIR

TEMPERATUREi

°o\ °G.i

32° a 18°CTO 20°C

/MMERS/ON.' ''""-""iHAND | BODY

1PANE \ BODY 1

............

type o f m m /i

\1

.1.....1

l

/ !-. -..'-------- -.

TEST S/TE1

!

1OOfiSAk! DORSAL

S3JT SEX AGE SCOPE No OF CORRECT RESPONSES AGE

/ N7 20 i1 99 1 //8 M 2E

2 M /9 i1 /OS \ Z37 M 20

3 M 23 ii /24~\ /34 M 24

45

MM

23 1! //6 M 78

/d I..... i ..... /o r | 722 M 79

S F 33 Ir 89 1 SS M 22

78 .

F 24 1r /3 I j /20 F 24

M 20 1.i.... 84- i 7/ F 24

3 M 24 1..... t 67 1 /E2 M 73

/O M 26 1t 1/4 ! /OS M 26

TOTAL SCOPES /o z / f/68 j

MEAN SCOPES /02 / 7/6-8 J

STANDARD DEY/AT/ON 18 2/-7

RESULT I S/GN/F/CANT AT P= • 05*

EXPER/MEA/T ALO / 4 F/6 : 42

KEY : 0 — 0/ST/LLED WATERI - /soromc SOLUT/ON

. S.W-SEA-WATERM — MAINS S.P. - SWIMMING POOL WATER

SCORE

SCORE

3 2 °C. ASOTON/C SOIUT/OA/9

87

65

4

3

21

!Z /<5 t-4 / S /-<S /• 7 2-3 4 2-5 2-6 2 7 3-4 3S3-6 3-74-5 4-6 4>7 £-6 57 6 7

1ORDER OF HAIR PRESENTATION SUBJECT m /

EXP. N°'.4

3Z°C . ASOTON/D SOLUTAON9

8

7

6

S

4

3

2

1

AZ /-3 /4 b5 J-G /-7 2-3 2-4 2-5 26 2-7 3-43-53-6 3-7454& 47 5-6 5-7 6-7

ORDER OF HAIR PRESENTATION . SUBUEGT No. 2

GRAPH SHOWING COMPARISON OF: TACTILE SENSITIVITY .DURING TEST/NG PERIOD.

EXP. n o : 4fib : 4 3

SCORE

SCORE

J2°c. /soroN/o solution987654

3

21

/•2 1-3 1-4 1-5 1-6 1- 7 2*3 2-4 2-3 2-6 2-7 3-4 3-5 3-6 3-7 45’ 4-6 4-7 3-6 S-7 67

ORDER OF HA/R PRESENTATION SUBJECT m 3

EXP, No 14

S 2 °c , /SOTON/C SOLUTION9

a7

65

4

3

2.1

1-2 /'3 1-4 1-51-6 1-7 2-3 2-4 Z'5 2-6 2-73-43-53-6 3-7454-6 4? 5-6 5-7 G-7

ORDER OF RNR PRESENTATION SUBJECT NO A

GRAPH SHOWING COMPARISON OFTACTILE SENSITIVITY DURING TEST/NG PERIDOT

EXP. N o: 4n o : 4 4

SCORE

SCORE

32°C. ISOTONIC SOLUTION987

6

s

A

3

2.1

I Z /3 14- / S / <s / 7 2 ~s 2 4 2-5 Z-6 27 3-4 35 35 374-5 4-6 4-7 5-6 5-7 6 7

ORDER OF HAM PRESENTATION SUBUEGT M 5

EXP. No: 4

3 2 ° C. ISOTONIG SOLUTION9

8

7

65

A

3

1

/■z /-3 ;-4 t-5 J-6 f'7 23 24 25 2S 27 34353-6 3-7 4S 4& 47 5-G S-7 6-7

ORDER OF HAIR PRESENTATION SUBUEGT me

GRAPH SHOW/NG COMPARISON OF; TACTILE SENSITIVITY DURING TESTING PERIOD.

EXP. m : 4f ig : 4 5

SCORE

SCORE

3Z°C . MTON/C SOLUTION9

87

6

54

3

2.

1

IZ 13 J-4 f-5 J-6 17 2-3 2 4- 2-5 2 6 27 3-4 35 3-6 3-74-5 4-6 4-7 5-6 5-7 6-7

ORDER OF HA/R PRESENTATION SUBUEGT NO 7

EXP. No: 4

3 2 ° C. /SOTON/C SOLUTION9

a7

654

3

2

1

J-Z J-3 /-4 t’5 J-6 J-7 2-3 2-4 2-5 2-6 2-7 3-43-53-6 3-74-54-6 47 5-6 5-76-7

ORDER OF HA/R PRESENTATION SUBUEGT NO. 8

GPAPH 'SHOW/NG ' COMPARISON OF. TACT/LE SENS/TIV/TY .DUfi/NG TEST/NG PEP/DD.

EXP. No: 4f ig : 46

SCORE

SCORE

3 2 °C. /SOTON/C' SOLUT/ONs8

7

65

4

3

2.

1

1-2 13 1-4 IS 1-6 /• 7 2-3 2-52-6 27 3-4 3-53-6 3-74*5 4-6 47 5-6 5-7 6-7

ORDER OF HAfR PRESENTATION SUBJECT M S

EXP M l 4

3 2 °C. /SOTON/D SOLUTION9

a7

654

3

2

A2 1-3 /-4 15 J-6 1-7 2-3 2-4 25 26 2-7 3-43-53-6 3-7454-6 4-7 5-6 5-76-7

ORDER OF PAIR PRESENTATION SUBJECT M ./O

GEAPH SHOWING COMPARISON OFTACTILE SENSITIVITY DUPING TESTING PEPIDD.

EXP. N o: 4f /6 : 4 T

Experiment : 4. Compares performance in controlled airenvironment with performance after hand immersion in Isotonic solution at 32°C. (dorsal).

Using the fflann UJitney U Test.

U = I C I I C I I I C I I C C C C I I C C C

Where C = Control ConditionI = Isotonic Water Condition.

N.l = N.2 = 10.

U = 1 + 3 + 6 + (8 x 4) + (10 x 3)

U = 72.

From Table K U is significant P < 0.05.

. <J U /V / / V 1 / C/r~ <JULJVC--LS J JLS£— /f-VL-KJ r~IJ V

SCORES . EXPERIMENT : £

TEST/NG GOND/T/ONS

ENV, GONO/T/ONSCOLD J WET /MMERSION

WETAMMER8/0N

CONTROLAIR

TEMPERATURE1

°c\ °c.' 1

32° C. /3°C TO20°c

ZMMERS/ONI

HAND | BODYi

PANE t BODY \— - . . . . . . . . . . . . . . . '

TYPE OP WATER

\11

- 1 ......... s m \ : : z- -----—— :------ ‘---------

TEST S/TE111

iOORSA& DORSAL

SECT SEX AGE SCOPE : NO OF CORRECT RESPONSES AGE

/" i r ~ _

P 2 0 \1 m 1 Z/8 M 2S

M 24 1I 38 1 Z37 M 20

3 M 23 11 « j A34 M 2S

4 M 26 1I • * * ! . 7/6 M /8

S M 33 11 ..f?e !.......... /22 M /9

2 2a P 38 11 /OZ | SS M

7 M 26 {......1- .......... 76~\ A20 P 24

8 M 2 2 ... 1 ......... ... ■ 1 88 ! 7/ F 24

3 M 2 S 1 72 | /52 . M 79iO M /3 .. 1 ■1 63 I /OS M 26

TOTAL SCOPES SOS 7/68

MEAN SCOPESSO-S 7 /6 ’6

STANDARD DELATION /4-3 2h7 ..:

RESULT I S/GN/F/CANT AT P= BETWEEN - 00/ & - 0 /

EXPER/MENT A/o / E F/G : 48

KEY I O — O/ST/LLEO WATER / - ISOTONIC SOLUTION S.W— SEA- WATER M - MMNSS.P. - SWIMMING POOL WATER

SCORE

% SCORE

%

contro/

e x p e r im e n ts !/

CONTROL VERSUS 5°C D/ST/LLED

• TCI W 7 ROL & 7 = 2 /- \ 7-— —

<P. S i 2 3 - 5..

>/

<s*f\

i —<■ / ✓

<\ \ \ \1 J

/

<— -A sr

V * \ f K p

</ V '

\ > \

\t/

(r /

/\\I

A*f K/

<MNi— ^

D ?/?SAL

I Z 13 1 4 I S 1<S 17 2 3 24 2 -S 2-6 2 7 3-4 3-S 3-6 3 - 7 4- S 4 6 4'7 S - 6 S > 7 6-7

ORDER OF m /R PRESENTATION /O SUBdEGTS

EXP n o : 6

CONTROL VERSUS 32°C SEA-WATER100

9 0WN) 2 h

B O

7 0

6 0

S O

4-030

DOR.3A

/■Z f-3 /■& 1-5 J-e !-7 2-3 24- 2-5 Z-e 2-7 3-43-S3-& 3-74,54-G 47 5-6 S-7 G-7

ORDER OF HNR PRESENTATION /O SUBJECTS’

GRAPH SHOWING COMPARISON OFTACTILE SENSITIVITY DURING TEST/NG PERIOD.

EXP. m : 5 r / e : 43

% SC

ORE

i 7

% S

CO

RE

-O

CONTROL VERSUS S°C DISTILLED/o o -

. 80DORSAL

601

20

/-Z J-3 1-4 h5 hS f'7 2-3 2-4 2-52-6 2-7 3-4 3-5 3-6 3-7 4-5 454-7 5-6 5-7 6-7

ORDER OF HAIR PRESENTATION /O . SUBJECTS

p x p : 6

CONTROL VERSUS 3 2 °C. SEA- WATERtoo

90

60

30

20

. 7 2 1-3 1-4 1-5 !■& /-7 2-32-4 2-52-62-7 3-4 353-6 3-7 454-6 4 7 5 6 5-76-7

ORDER OF HAIR PRESENTATION /O .S U B U EC TS

jEXP . 5.

GRAPHS SHOWING COMPARISON IN TACTILE SENSITIVITY FOR HAIRS 1-2125154:4515-616-7. PI61 50

32°C . SEA WATER

i-Z 73 1-4 I S IS < 7 2-3 24 2 S 2-6 27 3-4 3S3-6 3-74-5 4-6 4-7 £■& 5-7 6-7

ORDER OF HAJR PRESENTATION SUBJECT NO. /

EXP. No: 5

3 2 °C. SEA WATER

AZ /-3 /•<£ t-S I B !-7 2-3 2-4- 2-5 20 2-7 3-43-S3S 3-74 S 4 S 47 5-6 S-7G-7

ORDER OF HAIR PRESENTATION SUBJECT NO.2

GRAPH SHOW/NG COMPARISON OF: TACTILE SENSITIVITY DUF/NG TEST/NG PEP/DD.

EXP. N o: 5 .f / g : E l

SCORE

SCORE

32°C . SEA- WATER987

654

3

21

I Z /-3 14 /-S / <S / T 2S 24 25 2-6 '2-7 34 3-53-6 3 74*5 4-6 47 5-6 5-7 6-7

I ORDER OF HA/R PRESENTATION SUBJECT m 3

EXP. A/P’E

3 2 ° C. S E A -W A TE R9

a7

6

5

4

3

Z

1

/ 2 /-3 ;-4 1-5 J-G /*7 2-3 2-4 25 2G 2-7 3-43-53-G 3-74,54& 47 5-6 5-7 G-7

ORDER OF HA/R PRESENTATION SUBJECT A/P4

GRAPH SHOWING COMPARISON OF; TACTILE SENS/TIV/TY DURING TEST/NG PERIOD.EXP. No: sf /b : E2

SCORE

SCORE

3 2 ° C. SEA-WATER987654

3

2t

/vZ 1-3 14 J-S /<S t-7 2-3 24 2 SB-6 27 3-4 3-53-6 3-74-54-6 &7 5-6 5-76-7

ORDER OF HA/R PRESENTATION SUBJECT W .5

EXP. No: 5

3 2 °C. SEA-WATER9

a7

65

3

2I

/•2 f-3 /-4 1-5 J-G /-7 2-3 2-4 2-5 2-6 2-7 3-43-53-6 3-74.-54-6 47 5-6 5-76-7

ORDER OF FAIR PRESENTATION SUBJECT m e

GEAPH SHOW/NG COMPARISON OF: TACT/LE SENSmy/TY.DUR/NG TEST/NG PEE//DD.

EXP. no : gF /G : 5 3

3 2 °C. SEA - WATER

1Z /-3 1-4 IS 13 1-7 23 2-4 B-S 2-6 Z7 3-4 3-53-6 3-74-5 4-6 4-7 S-G 5-7 6-7

ORDER OF HA/R PRESENTATION SUBJECT m 7

EXP. no : 5

3 2 aC. SEA-WATER

!-Z 1-3 7-4 IS I B 1-7 23 2-4 3-5 ZG 2-7 3-43-S3G 3-74-S4-G 47 5-G S-7 G-7

ORDER OF HNR PRESENTATION SUBJECT NO.3

GRAPH SHOW/NG GOMPAR/SON OPTACTILE SENSITIVITY DURING TESTING PERIOD.

EXP. N o: 5f /6 : 54

3 2 °C. SEA- WATER

hZ A3 h4 IS AC AT 2-3 2-4 2S2-6 27 3-4- 3S3-6 3-74*5 4-6 4-7 5-6 57 6-7

ORDER OF HA/R PRESENTATION SUBJECT MS

EXP. N°: 5-

3 2 ° C. SEA-WATER

AZ A3 f-4 A3 AS A7 23 2-4 25 2-6 27 3-4.3S3-6 3-7454-6 47 S-6 S-7 67

ORDER OF HNR PRESENTATION . SUBJECT M /0

GRAPH SHOW/NG COMPARISON OFTACTILE SENSITIVITY DUPING TESTING PEPIDD.

EXP. no : 5F/G : 5 5

Experiment : 5. Compares performance in controlled air environment tuith performance after hand immersion in sea-water at 32°C. (dorsal)

Using the Tflann Witney U Test.

U = C C C C C C C S C S S S S S C S S S C S

UJhere C = Control ConditionS = Sea U/ater Condition.

N.l = N.2 = 10.

U = 7 + (8 x 5) + ( 9 x 3 ) + 10.

U = 84.

From Table k, U is significant where P< 0.01.

A further statistical analysis was carried out to establish whether there was a significant difference between the Control Condition C, and the three different water conditions P. to = 10. I\l2 = 30.

Results proved to be significant P < 0.009

49.

Hand Immersion.

Experiments 6. 7. 8. Control with distilled, isotonic and sea-waterat 5°C.

Introduction:

This series of experiments was aimed at assessing the effects of coldness on tactile sensitivity using the three types of water described, and in addition was intended to verify or refute the results of experiments 3. 4 and 5 with regard to changes in tactile sensitivity as a result of using different types of water.The inclusion of Experiment 8 (Control with 5°C sea-water), was intended to provide the additional experimental data required as a result of using too few subjects in Experiment 2.

Subjects:-

This series of experiments used 35 no. male and 5 no. female subjects taken from the student population of the Department of Architecture and Land Surveying, as well as from the administrative staff of the Polytechnic. Ages ranged from 19 to 45 years, see tables, Fig : 56. As in experiments 3. 4. and 5, different subjects were used for each of the four groups described below, making up a total of 40 subjects.

Experimental Series.

(a) A control group of 10 subjects in a controlled air environment maintained at between 18°C and 20°C. This was the same group used for the previous series (C)^ and consisted of 8 no. male and 2 no. female subjects.

(b) An experimental group of 10 subjects immersing their non-preferred hand in sea-iuater at 5°C (S.lli)2

(c) An experimental group of 10 subjects immersing their non-preferred hand in isotonic solution at'5°C (1)2

(d) An experimental group of 10 subjects immersing their non-preferred hand in distilled mater at 5°C (D)2

Results;

Experiment No. 6,

Control with 5°C Distilled Uiater (dorsal)

Fig. 57 shouis the mean hand skin temperature for the dorsal region for subjects during the cold immersion and recovery period, and is generally in agreement both with previous work by Adams and Smith (1962) Glaser and UJhitlow (1957) and Provins and Morton (i960), together with the cold immersion experiments carried out in this study. On this occasion, however, there was little evidence of a rewarming effect which had occurred in both Experiment 1 and 2, the hand skin temperature generally was recorded as between 4.5°C and 5,5°C above the water bath temperature.

Subjects generally failed to reach a normal hand skin temperature at the end of the 20 minute testing procedure, and in most cases were 5°C or 6°C below this 30°C - 32°C level. Rewarming during the testing procedure occurred fairly consistently, the hand skin temperature gaining approximately 4°C every five minutes except in the first five minutes.

51

Fig. 49 shoius the variation in tactile sensitivity during the testing procedure. It can be seen that apart from the Characteristic' peak occurring around the presentation of hair 1 with 6 and 1 udth 7, there is a consistent decrement throughout the testing procedure ranging from 10% to 33^.

Statistical analysis using the Mann UJitney U test showed the differences between (C) and (0 ) 2 to be significant,PC0.01.

Results:

Experiment No. 7.

Control with 5°C Isotonic Solution (dorsal)

The fall in hand skin temperature during cold immersion and subsequent rise during the testing procedure are again typical of the results gained previously. These are shown in Fig. 72. A rewarming phase after approximately 10 minutes is noticeable producing a temperature rise of 2.5°C at the end of the 20 minute immersion. Noticeable decrements in tactile sensitivity can be seen in Fig. 64, especially towards the end of the testing procedure. It is also noticeable that decrements occur in many cases particularly during the middle of the testing procedure even though at this point there are considerable differences in the paired comparisons; see individual subjects graph. The summary graph Fig. 64 shows noticeable decrements in the comparison of suture 2 with 5; 3 with 6; and 4 with 7.

Statistical analysis using the Mann UJitney U test showed the differences between (C)^ and (1 ) 2 to be significant P < 0.01.

52

Results:

Experiment No, 8,

Control with 5°C Sea-Water (dorsal)

Fig. 72 shows the fall in hand skin temperature during cold immersion and subsequent rise during the testing procedure.A rewarming phase is again noticeable.

If compared with Fig. 12 for Experiment No. 2, it can be seen that on this occasion the hand skin temperature is a few degrees higher at all stages of recording during cold immersion. These results correspond more closely with the results of Experiments 6 and 7, see Figs. 56 and 63.

A comparison between variations in tactile sensitivity during the testing procedure for Experiments No. 2 and No. 8, reveal little similarity. There are, however, strong similarities again between the performance of subjects during this experiment and Experiments No. 6 and 7, see Figs. 49 and 64. Peaks in performance are reached when comparisons are made between sutures 1 with 6 and 1 with 7, in all cases thereafter performance fails to achieve a level above 54^ arid is generally between 15^ to 20/b below that of the control group performance until the end. Differences in standard deviations too, for these three experiments were only 2.5 apart although different subjects were used for each experimental group.

Statistical analysis using the fflann UJitney U test showed the difference between (£) and (S.UJ)2 to be significant. P < 0.01.

Further statistical analysis to assess differences between the scores achieved using the three kinds of water used, i.e. (D)2;(l)2 and (S.Ui) proved to be not significant.

Discussion: Experiments 6 : 7 : 8 .It is clear from the results of this series of experiments

that the performance of the 30 subjects making up the three experimental groups (D)2, (l)2, (S.Ui)2 are similar in many respects. The mean scores for each experiment were 83.2; 84.8, and 86.7, see Figs: 56; 63; 71,

53

Clearly, the use of three types of mater for the experiments had no effect on tactile discrimination for a period of 20 minutes following the immersion periods. Similar decrements, however, are seen in tactile sensitivity as compared to the control condition for all three experimental conditions. These decrements are still in evidence at the end of the testing procedure, see Figs. 49; 64, although the hand skin temperature by that time had risen by 17°C for (D)2; 12°C for (l)2; and 15°C for (S.UJ)2.

Decrements occurring at the end of all three experimental sessions, were 30% below the control group, 24^ below the control group, and 23^ below the control group, indicating that there is likely to be a further period of recovery necessary before the hand achieves normal sensitivity. Recovery after all three experimental conditions was similar to that of experiment 2. These are shown in Figs. 57 and 72.

Le Blanc's acclimatized fisherman took only 9 minutes to achieve a finger temperature of 31°C after immersion in a water bath maintained at a temperature of 2.5°C. On this occasion finger temperatures were recorded around 4°C for the greater part of the immersion representing an increase of 27°C in 9 minutes during the recovery period.

The present series of results add weight to the view that unacclimatized subjects take longer to recover their hand skin temperatures resulting in a noticeable decrement in tactile discrimination up to and probably extending beyond a period of 20 minutes.

During the three experimental conditions, (D)2; (l)2 and (S.Ui)2 none of the 30 subjects achieved temperature equilibrium with the water as Figs. 57 and 72 show. The mean temperature above that of the water was 5°C for (D)2; 7°C for (l^J anc 5.5°C for (S.UJ)2 and confirms

54

the findings of Experiment 1 in relation to temperature drop during, immersion. As stated, these recordings are not in agreement with either Adams and Smith (1962) rflorton and Provins (i960) Le Blanc (1961) or Greenfield et al (1951), On only one occasion in the case of subject 9 in experimental condition (D)2 did the hand skin temperature of the dorsal region approach that of the water. In this isolated case the subject achieved a temperature of 1°C above the water bath on two recorded occasions. It is likely that the difference between the temperature drop recorded in this present series of experiments and that recorded in previous work is due to the fact that in all other cases only the fingers were immersed.

Greenfield and Shepherd (1950) measured the heat lossofrom the terminal 2.8cm of the index finger in water between 0 - 6 C

at the height of vasodilatation and found it to vary from 1,100 to 3,400 cal/lOOml/minute or 6 kg.cal/hr. They found that the heat loss from the hand was not proportional to that of the finger tip and that the whole hand loses only 48 kg.cal/hour. Two main reasons for this are given. Firstly, the circulation through the fingers is capable of passing a great deal more blood per unit volume per minute than that through the whole hand (UJilkins, Doupe and Newman 1939).Secondly, more heat may be lost per unit volume of blood passing through the finger than through the whole hand.

Greenfield et al (1951) suggest that the temperature in the radial artery during their experiments could have been well below 37°C and that the temperature of the skin over the dorsal veins, which is close to the test site in the present series of experiments was likely to be considerably above 0°C.

At the height of vasodilatation therefore, some variation in the skin temperature between the finger tip and the dorsal region of the

hand seems to occur due to the relatively high heat loss from the finger tip as compared with that of the hand. This would tend to explain the differences in hand skin temperatures recorded in the present series of experiments as compared to previous recorded finger temperatures.

An increase in heat flow from the hand or fingers into cold water, however, does not necessarily indicate a lower skin temperature, Le Blanc, Hildes and Heroux (1960) showed that the heat flow from acclimatized Gaspe fishermen was significantly higher than that from the control group, but that their finger temperature during the 10 minutes of immersion was an average of 1,5°C greater than the control group, Le Blanc has postulated that the greater loss was due to a lesser insulation brought about by a greater blood flow rather than a change in the thickness of the skin and subcutaneous tissue.

During all cold immersion experiments, including the three described in this series, note was taken of subjects experiences during cold immersion, Most subjects complained of feeling acute pain during the first five minutes of immersion.Typical comments during this period were as follows:-

(a) "There is a burning sensation like a bad burn",(b) "lYly knuckles feel most painful".(c) "There is a feeling of pain at a specific point",(d) "There is a stinging sensation between the thumb

and first finger".

In most cases the initial feelings of pain decreased after the first 5 minutes, but in some subjects feelings of pain persisted throughout the full duration of the experiment.

SUMMMY U t b U a J L U / i ) U t / S / L O /V V U

SCONES . EXPERIMENT / 6

TEST/NG GOMD/T/ONS

ENV. 00//D/T/0NS GOLD/WET /MMERS/ON

NET/MMERS/ON

CONTROLA/R

TEMPERATURE 5 °C. °C 32° C. /8 °C TO20°C.

/MMERS/ON HAND BODY"■ 5

HAND \ BODYi

TYPE OP WATER D ...

l.... 1 ....

! ......— .--------1----

TEST S/TE DORSAL1I1 dorsal

S37T SEX AGE SCORE : MO OF CORRECT RESPONSES AGE

/ M 4-5 /0 781 //8 M 2 S

£ M 2 4 /3 9i1 /3 7 M 2 0

3 M 2 3 76r -— -I /3 4 M 2 4

4 M 2 3 6 8 1. _ | //6 M /3

S M 2 3 8 6 i________ 1............

/22 M /96 M 2 / 8E

. . , j 1 SE M 2 2 .

7 M /S 80 \ /20 p 2 48 P 2 / 4 3 I__ » 7 / F 2 4S M 2 0 7S

i1 7SZ Ml 79

fO P 36 68 I1 /OS M 2 6

TOTAL SCORES 8 3 2 f/6 8

M E AM SCORES 8 3 2 ... -...... /Z 6 ‘8

STANDARD DEVIATION 2 3 E : 21-7

RESULT I S/GN/P/CANT AT R= BETWEEN • 0 0 / X -0 /

EXPER/MENT A/o / 6 P/G : S 6

k e y : o — o/st/lled water/ - /SOTOM/C SOLUT/ON S.W- SEA-WATER M- - MAINS S.P. - STEMMING POOL (MATER

5°G D/ST/LLED WATER35

V G R ^ R /O OC C O LA A A G R IE R /O /D /A / tY A T R R30

25

2 0

fe B

O /O5 / 5 4 025 30 35M/NUTES

HAND SK/N TEMPERATURE DUR/NG'/MMERS/ON AND RECOVER/ /O. SUBJECTS EXP:N<> : 6

. COOL/NG R£.R(OD AAV WATLR

W A R M /A G R 2RAO .O/ a a a a A

2 5

20

§4 /0

/O 35305 25O / 5 20M/NUTES

RAND SK/N TEMPERATURE DURING/MMERS/ON AND RECOVERY EXP'.m

F/G : 57

SCORE

SCORE

5°C. DISTILLED WATER

t'Z 13 14 / S t <S / 7 23 24 2 S 2-6 2 7 34 3 S3 6 3-7 45 4-6 4>7 5-6 5 7 6 7

ORDER OF HAIR PRESENTATION SUBJECT MI

EXP. No: 6

9

a7

65

4

3

2

1

/2 /'3 / 4 /'5 J-6 f-7 2 3 24 2-5 26 27 34.3-53-6 3 74,546 47 5-6 £ 7 6 7

ORDER OF RA/R PRESENTATION . SUBJECT N°.2

GRAPH SHOW/NG COMPARISON OFTACT/LE SENS/TIV/TY .DUR/NG TEST/NG PER/DO.

EXP. no : 6F IG : 58

5°C D/STJLLED m T E R

i Z 1-3 1-4 75 T<S 17 2* 2 4 2-5 2 G 27 3-4 3 53 6 3745 4-6 47 £■& 5-7 6-7

ORDER OF HAfR PRESENTATION SUBJECT m.3

e

exp. no: e

/•■Z A3 /-4 IS IS 1-7 212-4 2S 2-S 2-7 24.3 53s 3-7 4 5 4-G 47 5-6 5-7 e-7

ORDER OF HAIR PRESENTATION SUBJECT N°.4

GRAPH SHOW/NG COMPARISON OFTACTILE SENSITIV/TY DUR/NG TEST/NG PER/DD.

5°C DISTILLED WATER

t-Z !-3 t-4 / S AS t-7 2-1 24 2S 2 B 27 3-4 3 S 3-e 3-7 4S 4-6 4-7 5-6 5-7 6-7

ORDER OF HA/R PRESENTATION SUBJECT N°. 5

EXP. N o: e

/■Z /-3 Z-4- t-s t-e !-7 23 24 2-5Z-e 2-7 3-43S3& 3-74542 47 S-6 S-76-7

ORDER OF HAIR PRESENTATION SUBJECTm 6

GRAPH SHOW/NG COMPARISON OFTACTILE SENSITIVITY DURING TESTING PERIOD.

e x p . n o : 6F /6 : 6 0

5°D DISTILLED WATER

l-Z /■3 h4 I S /■e h7 2-3 2-4 2S S B 21 3-4 3-S3-6 3-74-54-6 4-1 S B 516 7

ORDER OF HA/R PRESENTATION SUBJECT N0.7

EXP. N o: 6

/■2 h3 /<2 hS he h7 2-3 2-4 2-5 2-B 21 343S3-B 3-74S4-G 47 5-6 S I 6-7

ORDER OF HNR PRESENTATION SUBJECT NO. 8

GRAPH SHOW/NG COMPARISON OFTADT/LE SENSITIVITY .DUR/NG TEST/NG PER/DD.

EXP. N o : eF / 6 : 6 /

SCORE

SCORE

5°G DISTILLED WATER

9

8

7

65

4

3

2.

1

hZ A3 /*4 /5 /6 /-7 2-3 2-4 2-3 *6 2-7 3-4 353-6 3-74*5 4*6 4*7 5*6 5 7 6 7

; ORDER OF HAIR PRESENTATION SUBJECT NQ;9

EXP. no: 6

9

a7

65

4

3

2.

1

/ Z A3 /-4 1-5 J-6 /-7 2-3 2-4 2-5 Z-6 2-7 3-43-S3-6 3-74-54-6 47 5-6 5-7 6-7

ORDER OF HAIR PRESENTATION SUBJECT NO JO

GRAPH SHOW/NG COMPARISON OF.TACTILE SENSITIVITY DUR/NG TESTING PERIOD.

EXP. N o: 6F IG : 62

Statistical Method,

Experiment ; 6, Compares performance in a Controlledair environment with performance afterhand immersion in 5°C distilled water (dorsal).

Using the IKlann UJitney U. Test.

U = D D D C D D D D D C C D C C C C C C D C

Where C = Control Condition

D = Distilled Water Condition.

H1 = N2 10

U = 3 + (8 x 2) + ( 9 x 6 ) + 10.

U = 83

From Table K, U is significant at P<0.01

SCONES . EXPEE/MENT / 7

TESTING CONDITIONS

ENV. CONDITIONSGOLD/WET IMMERSION

WETIMMERSION

CONTROLAIR

TEMPERATUREi

E °c\ °C.%

32° C. 78°C TO 20°C

IMMERSIONi

HAND j BODY iPANE I BODYi ■ ■■■•;--- -------- ■ ............

TAPE OF WATER

i11 I f. . 1 - . ■1 - - ;— - - - :- - -

TEST SITEI

OOPSAL J 11I DORSAL

SBJT SEX AGE SCOPE : NO OF CORRECT RESPONSES AGE

I M 2.2. IIS j i 778 M 25

Z Ml 26 83 J 1 737 M 20

3 M 35 37 | i1 134 M 244 M 23 130 [ . . 1 . . -i 776 M 78

5 M 38 70 j Ii 722 M 79

67

M 28 76 J 1 95 M 22M 28 73 | ” ]... { . 720 F 24

8 M 24 67 i I• . 7/ F 243 M 22 52 j 1 752 M 7910 Ml 25 1

i 705 MI 26

TOTAL SCOPES 348 7763

MEAN SCOPES 34-8 776 3

STANDARD DEIN AT ION22-35 27-7

RESULT : SIGNIFICANT AT P~ BETWEEN -007* - Of

EXPERIMENT Aio .* 7 FIG : 63

KEY: 0 — 0ISTILLED WATER/ - ISOTONIC SOLUTION S.W~ SEA- WATER M - MAINSS.P. ~ SWIMMING POOL WATER

m_______ . m control

0_________;___0 experimental

CONTROL VERSUS 5°C SEA-MT£Ft

COKTRCL HD80

<>— < r '6050

& 40

I 30>*5 2 0

}> — <K

DORSAL

lZ 13 14 I S I S 1-7 25 24 2-5 Z-G 21 3 4 3-5 3-G 374-5 4-6 47 5-6 5-7 6 7

ORDER OF HAIR PRESENTATION 10 SUBJECTS

EXP. NO'. 8

CONTROL VERSUS 5°C ISOTONIC100

90[SO

eo

70

6050

k| 40

1-2 / 3 /-4 1-5 1-6 i-7 2-3 2-4 2-5 Z G 2-7 3-4353-6 3-74,54 & 47 5-G 5-7 6-7

ORDER OF HAIR PRESENTATION 10 SUBJECTS

GRAPH SHCW/NB COMPARISON OFTACTILE SENSITIVITY DURING TEST/NG PER/DD.

EXP. Aio: 7fig : 64

control

■exper/mentaf

CONTROL VERSUS E°C SEA-WATER!0 0

6 0

/-2 /-3 /-4 15 ('S i ‘7 2-3 2-4 2-52-6 2-7 3-4 3-5 3-6 3-7 4 5 46 47 5-6 57 6-7

ORDER OF HAIR PRESENTATION /O SU3UEC7S

E X P . 'S

CONTROL VERSUS 5 ° C ISOTONIC

60

3 0

20

/-2 J-3 1-4 f'5 1-6 /-7 2-32-42-52-62-73-4 3-53-6 3-7 454-6 475-6 576-7

ORDER OF RA/R PRESENTATION tO.SUBZJECTS

<exp:7

BRA PHS SHOWING COMPARISON IN TACTILE SENS/T/VITY FOR HAIRS 1212 Z :J 4 : 4-5 : 5-6: 6'7. F/G165

SCORE

SCORE

5°C ISOTONIC9

8

7

65432.1

I Z 1-3 1-4 15 1-6 1- 7 2-3 2’52-6 2-7 3-4 3-53-6 3-745 4-6 47 5-6 5-7 6-7

ORDER OF HAIR PRESENTATION SUBJECT mi

EXP, No: 7

9

a7

65

WESAL43

1

/-2 1-3 /4 1-5 1-G !-7 2-3 2-4 2-5 2.-6 27 3-43-S 3-0 3-74. S4-6 4? 5-6 5-7 6-7

ORDER OF HAIR PRESENTATION SUBJECT N°.Z

GRAPH SHOWING COMPARISON OF: TACTILE SENSITIVITY DURING TESTING PERIOD.

EXP. no : 7FIG : 66

SCORE

SCORE

5°C /SOTONICe8

7

6

5

43

DC*2

1

.AZ /-3 /•* / 5 /•£ / 7 2-3 2-4 2526 2 7 3 4. 3 53 6 3 745 4& 47 5-8 57 67

ORDER OF HAIR PRESENTATION SUBJECT N°. J

EXP. N°l 7

9

a7

65

4

3

2

1

AZ /-3 /•<£ /-5- /-S /-7 ^-3 24 2-5 2-6 2-7 3 4 3 5 3 6 3 7 4 5 4 0 4-7 56 57 67

ORDER OF HAIR PRESENTATION . SUBJECT N°.4

GRAPH SHOWING COMPARISON OF; TACTILE SENSITIVITY DURING TESTING PERIOD.

EXP. N o: 7f ig : 67

SCORE

SCORE

5°C. ISOTONIC

987

6543

21

/•2 A3 h4 I S / <S ( 7 2-3 24- 25 2-G 27 34 3-5 3 6 3 74-5 4-6 4^ 5-G 5-7 6-7

ORDER OF HA/R PRESENTATION SUBJECT NO 5

EXP. No: 7

9

a7

6

5

4

3

2

1

/-2 /-3 /-4 t-5 EG t-7 2-3 24 2-5 2-G 2-7 3-43-53-6 3-74.-54-6 47 5-6 5-7 6-7

ORDER OF HAIR PRESENTATION SUBJECT M 6

GRAPH SHOWING COMPARISON OFTACTILE SENSITIVITY DURING TESTING PERIOD.

EXP. N o: 7f ib : 68

5°C. ISOTON/C9

87654

3

2

1

12 13 i-4 /-S J-G /7 2-3 2-4 2 S 2 G 21 3 4 3-53-6 3 745 4*6 4-7 5-G 5 7 <3*7

ORDER OF HAIR PRESENTATION

EXP, No: 7

1

9

a7

65

4

3

2

1

/•Z /'3 /•<£ 7-5/ <S 17 23 2-4 2 5 2-<S 2-7 3-43-S3-G 3-745 4<5 4-7 5-6 5-7 G-7

ORDER OF RA/R PRESENTATION SUBJECT m 8

GRAPH SHOWING COMPARISON OFTACTILE SENSITIVITY .DURING TESTING PERIOD.

EXP. N o: 7FIG : 69

SCORE

SCORE

6° C. ISOTONIC9

87

6

54

3

2

1

hZ A3 14- f'S A8 /- 7 2-3 2-S2-G 27 3-4 3 53 6 3 7 4 5 46 4*7 5-G 5-7 6-7

SUBJECT NO. 9'ORDER .OFHAfR PRESENTATION

9

8

7

65

3

2

1

/-2 A3 A4 A3 AS A7 ^-3 ,24 2-5 26 2-7 3-4 3-53-G 3-74-54& 47 5-G 5-7 G-7

ORDER OF PAIR PRESENTATION . SUBJECT N° 10.

GRAPH SHOWING COMPARISON OF: TACTILE SENSITIVITY DUPING TESTING PERIOD.

EXP. no : 7FIG : 70

Experiment : 7, Compares performance in a Controlledair environment with performance after hand immersion in Isotonic water at 5°C, (dorsal).

Using the Mann UJitney U, test,

U = I I I I C I I I C I C I C C C C I C C C.

UJhere C ? Control condition I = Isotonic water

Njl = n2 = 10

U = 4 + 7 + 8 + (9 x 4) + (10 x 3)

U = 85

From Tables K, U is significant at P<0.01.

SCORES . EXPERIMENT : 8

- •

TESTING CONDITIONS

env. conditionsgold/ w e tIMMERSION

N ETIMMERSION

CONTROLAIR

TEMPERATURE1

5 °c \ °C. 1 ... 3 2 ° C. /e°G TO 20°C

IMMERSIONj, ,

HAND | BODY1

PAW 1 BODYt

TYPE OP WATER1

S.W .V1r

.. 1 ..I ..—....— — .-

TEST SITE1

OORSAiIi DORSAL

S3JT SEX ABE SCORE : NO OF CORRECT RESPONSES ABE

I M 2 0 68 j i i / e 2 5£ M 20 ISO ] 1111.. i ¥rri1"t 137 20

M /9 BL !... \i 134 2 44 M 2 3 ! ii 1/6 185 M 79 8 7 J i. : i 122 /96 M 2 / 3 / ! 1 3 5 2 27 M 2 4 7 7 j 1... I . 120 2 48 E 30 86 ! 1 7 / 2 43 M 2 3 7E \ 1 152 19/O M 2 / 8 9 J 1 105 2 5

TOTAL SCOPES 8 6 7 I/6 &

A4EAN SCOPES 8 6 - 7 776-3 Z

STANDARD DEVIATION 2 ! .- •-.......-...... 2 h 7

RESULT I SIGNIFICANT A T BETW EEN - 0 0 / J, -01.

EX PER IM EN T NO / 8 PIG : 7t

KEY : D — 0/ST/LLED WATER/ - /SOTON/C SOLUTION S.W- SEA-WATER M — MAINSS.P. - SWIMMING POOL WATER

TEMPERATURE

°C TEMPERATURE

5°C SEA-WATER

VG R jE R /O Oc c o u a / g r ^ r / o o /A / IV A T R R/? £ '- W A R M !

/A/ AIR30

25

20

o

DORSAL

WATE/l TEMP

O iO5 20 25 • 30 35

RAND SK/N TEMPERATURE DUR/NGIMMERSION AND RECOVERT /O. SUBJECTS EXP:N°:8

5°C /SOTON/C

COOL/NG /=>ER/OJD /A/ yVATRR

ERE -- WARM/A T3 £>£ER/0. C> /A/ A/A’

30

25

20

IO

O /5 355 / O 3020M/NUTES '

HAND SKIN TEMPERATURE DURING/MMERS/ON AND RECOVERY 10. SUBJECTS EXP'.m 7

FIG: 72

5°C. SEA-WATER

12 /3 h4 V S hG 1-7 2-3 24 25 2 & 21 3-4 3-53-6 3 745 4-& 4-7 5 6 57 6-7

ORDER OF HAIR PRESENTATION SUBJECT N °.I

EXP. No: 8

5°C. SEA-WATER

/•2 A3 ;-4- /-5 J-G /*7 23 24 2-5 26 27 343-536 3-74-54-6 47 5-6 5-76-7

ORDER OF NNR PRESENTATION SUBJECT M 2

GRAPH SHOW/NG COMPARISON OFTACTILE SENSITIVITY DURING TESTING PERIOD.

EXP. N o: 8FIG : 73

5°C. SEA-WATER

O C R & U

I'Z 1-3 1-4 IS IS 7-7 S ’S 2-4 252-6 27 3-4- 3-S 3-S 3-7 4,5 46 4-7 5-6 5-7 6-7

SUBUECT N°.3ORDER OF HAIR PRESENTATION

EXP. No: 8

E aC. SEA-WATER

' /-Z 1-3 !-4 I S IS !-7 2-3 2-4 2-S 2-6 2-7 3-43-S3S3-74-S 42 4-7 5-6 S-7 G-7

ORDER OF HAIR PRESENTATION SUBJECT NA4

GRAPH SHOWING COMPARISON OFTADT/LE SENSITIVITY .DUPING TESTING PEP/DD.

EXP. No: 8F/G : 74

E°C .SEA -m TER

12 t-3 1-4 I S t-6 t-7 2-3 2-4 2-S 2-G 2-7 3-4 3-S3-6 3-74-5 4-G 4-7 S-G S-7 6-7

ORDER OF HAIR PRESENTATION SUBUECT N°. S.

EXP. No: 8

5°C. SEA-WATER

/■2 t-3 f-4 IS !-G 1-7 2-3 2-4 2-S 2-6 2-7 3-43-S3-G 3-74-S4-G 47 S-G S-7 G-7

ORDER OF HNR PRESENTATION SUBJECT NO. 6

GRAPH SHOWING COMPARISON OFTACTILE SENSITIVITY DURING TESTING PERIOD.

EXP. N o: 8FIG : 75

S°.C. SEA-WATER

t-Z 1-3 1-4 I S IS h7 2-3 2-4- 2-S 2-e 2-7 3-4- 3-S3-6 3-74-5 4-6 47 5-G 5-7 G-7

ORDER OF HNR PRESENTATION SUBJECT N°. 7

exp. no: a

S°C. SEA-WATER

72 t-3 7-4 IS I B 1-7 2-3 2-4 2-5 2-e 2-7 3-43-S 3-S 3-74-54-6 4-7 S-6 S-7 B-7

ORDER OF HAIR PRESENTATION SUBJECT N°8

GRAPH SHOWING COMPARISON OF: TACTILE SENSITIVITY DURING TESTING PERIOD.

EXP. N o : 8FIG : 76

SCORE

SCORE

E°0. SEA-WATER9

87654

3

2

1

12 13 h4 f'S J <S /-7 2-3 je-4 2-S S-B 2.1 3 4 35 3-6 3 74-5 4-64*7 5 6 5 7 6 7

ORDER OF HAIR PRESENTATION SUBUECT N°. 9

EXP. No: 8

E°C. SEA-WATER9

a7

654

3

2

1

" AS /3 /4 A5 /-<S f-7 2-3 2-4 2-5 2 6 Z-7 3'43-53-6 3-7454-6 47 5G 57 G-7

ORDER OF HNR PRESENTATION SUBUEGT NO JO.

GRAPH SHOWING COMPARISON OFSENSITIVITY -DURING TESTING PERIOD.

exp. no: aFIG : 77

Experiment ; 8, Compares performance in a controlled airenvironment with performance after hand immersion in Sea-U/ater at 5°C (dorsal).

Using the Mann UJitney U. Test.

U = S S C S 5 S S S S C C S C C C C C S C C

N. 1 a N. 2 = 10.

U = 2 + ( 8 x 2 ) + ( 9 x 5 ) + (10 x 2)

U = 83.

From Tables K, U is significant at P<0.01.

During this series of experiments, four subjects failed to complete the 20 minute immersion period due to feelings of nausea and one vomited after 12 minutes. A further subject complained of nausea at the end of the immersion period and during the test procedure, but managed to complete the test. His score however has- been deleted from the results.

Le Blanc (i960) also reports subjective observations of pain during immersion of hands in 2.5°C water for 10 minutes. In addition, the painful procedure caused three unacclimatized subjects to have fainting reactions and to become pale and clammy during which time blood pressure fell. The Admiralty Experimental Diving Unit have also shown an interest in the effect of cold on divers. This interest stems from 1962 when it was thought that two or three cases of collapse in divers were due to the cold. Barnard (1972) has reported that at water temperatures of 4°C only seven out of seventeen junior seamen starting a diving course persisted after the first day.(Ylouth temperature was down to about 33°C - 35°C whilst divers were waiting to enter the water and several complained of headaches, nausea and dizziness. This was considered to be due to breathing in cold air from a closed circuit breathing apparatus which tended to act as a heat exchanger.

Hand Immersion.

Experiments 9 and 10. Control with sea-water at 32°C and 14°C

Introduction:

The series of experiments 3 to 5 and 6 to 8 compared groups using different subjects making up a total population of 70 subjects including the control group.

Although statistically such a comparison is acceptable using the Mann UJitney U test, it was considered desirable to carry out a further series of experiments using the same group of subjects for the control group and for two experimental conditions in order to amplify the results of the previous series.

The groups mere as follouis:-

(a) A control group of 10 subjects in a controlled air environment maintained at a temperature between 18°C and 20°C. This mas a nem control group,

(b) An experimental group of 10 subjects immersing their non-preferred hands in sea-water at I4°c - i° c . same sub jects as (a ).

(c) An experimental group of 10 subjects immersing their non-preferred hands in sea-water at 32°C.same sub jects as (a ) e ( b ) .

Although the results of experiments 3 to 5 and 6 to 8 had produced no significant differences in tactile discrimination using distilled, isotonic and sea-water, it mas thought reasonable to continue using sea-water in this series, bearing in mind that the results obtained mould be more meaningful to the study of the may in which sea divers tactile discrimination may be affected by prolonged immersion.

fIn addition, it was considered that for experiment

10 a temperature of 14°C - 1°C could be used for the cold immersion,bearing in mind that the results of the last series of experiments had already showed significant differences between the control and the 5°C experimental conditions.

The temperature of 14°C ^ 1°C, mas selected as thismas the average annual temperature of the North sea and bore a more direct relationship to the sort of mater temperatures that divers are accustomed to (Bevan 1971), The palmar region mas also selected as the test site in order to cover more fully the area that mas dealt with in Experiment 1.

Subjects:

The ten subjects used for all three groups in this series of experiments mere taken from the student population of the Department of Architecture, and consisted of seven males and three females. Ages ranged from 19 to 40 years, see Fig# 78#

Results:

Experiment 9.

Control with 32°C Sea-UJater (palm).

It can be seen from Fig. 79 that although noticeable decrements in tactile sensitivity occur between the two conditions in the early part of the testing procedure, these are not so pronounced for the remaining period. The control score follows the presentation sequence of sutures as expected and is similar in many respects to the control graph in the previous series of experiments, although this deals with the dorsal region. Peaks occur generally in control when the presentation of sutures compares the lighter sutures with the heavier ones. The scores obtained following the experimental condition however, do not follow this presentation sequence, and are generally below those of the controls.

Comparing the experimental graphs for this experiment with Experiments 3 : 4 and 5, it is noticeable that there are similarities in their profiles although different regions of the hand were tested.

Statistical analysis using the ft* test showed the differences between the Control and Experimental condition to be significant, P<0.05.

SCORES . EXPER/MEA/T : 3

TEST/NB GOND/T/ONS

E m c o n ditio nsGOLD/WET IMMERSION

WETIMMERSION

CONTROLm

TEMPERATURE °G. *G. 3 2 ° C /8 °C TO20°0

IMMERSION RAND BODY\

RAND 1 BODY 1........

TVPE OP WATER s .m \ -..- ----:------ -

TEST SITE1

PALM\. ... I ...

p a l m

QljJi

/

SEX AGE SCOPE : N$ OF CORRECT RESPONSES

M /9 //z i fOZz M 2 ! /3 Z i 7 2 55 M 2 4 80 j 8 345

MP

2 5/9

■ '// ! 726S 3 J 72

6 P 2 5 86 | 8 57 P 25 S3 j 7/8 M 40 2 8 j

SZ |do ::

8 M 2 4 4 6/O M 2 0 Fo9 J 752

TOTAL SCOPES 7 8 / 8 4 2

MEAN SCOPES 78-T 84* Z

STANDARD DEVIATION 36 ■/ 3 0 '2

PE8ULT I SIGNIFICANT AT P = >05.

EXPER IM EN T NO ; 3 E /S : 78

KEY : D — 0/ST/LLED WATER/ - JSOTON/C SOLUT/CW S.W- SEA-WATER M — MAINSS.P. - SV/IMM/NG POOL WATER

WOR

E %

SCOR

E %

m 9 control

■0_ _ _ _ _ _ _ _ _ _ _ experimental.

CONTROL VERSUS 32°G SEA-WATER100 so 80 70 60 50 40 30 2.0 10

IZ l<5 h4 7-5 i <S i-7 23 2-4 2 -S 2-e 27 3-4- 3S3-G 3 74-5 4-6 4*7 S-G S-7 6-7

ORDER OF HAJR PRESENTATION /0 SUBJECTS

EXP, No: 9

CONTROL VERSUS N°C SEA-WATER100

soSO

6 090

70

60

403020

/-2 i-3 / 4 bS /-& 1-7 2-3 2-4- 2-S 2-G 2-7 3-43-S 3-0 3-74. 54-6 47 S-G 5-7 G-7

ORDER OF PAIR PRESENTATION 10 SUBJECTS

GRAPH SHOWING COMPARISON OFTAOr/LE SENSITIVITY -DURING TESTING PER/DD.

3 0

£XP. SJO

i r

exp. n o: /of i g : 73

% SC

ORE

\ %

SCO

RE

/o o

90

80

70

60

50

4 0

3 0

2 °

70

control

experim ental

CONTROL VERSUS 32°C. SEA-WATER

PALA,f

N v'N >— — / \

N V \ SL

\\ |. . - 4 r

sns

7-2 7-3 7-4 7-5 76 7 7 23 2-4 2-52-6 2-7 3-4 3-S 3-6 3-7 4 5’46 477 5-65-7 6-7

ORDER OR HAIR PRESENTATION . 70 SUBVECTS

E X P l 9

CONTROL VERSUS /4°C SEA-WATER700

90

80

70

60

50

40

30

20

70

PaLA*

%

s. \S>

rcr<y ” • —<\

■<*

*N <1**

7-2 7-3 7-4 7-5 7-6 7-7 2-32-42-52-62-7 3-4 3-53-6 3-74-54-6 475-6 £-76-7

ORDER OF HAIR PRESENTATION 10 SUBUECTS

EXP :/o

GRAPH SHOWING COMPARISON IN TACTILE SENSITIVITY FOR HAfRS 12'.27154 145 1 5-6167. FIG 1 80

32°C. SEA- WATEfl

PALM

hZ A3 1-4 I S I B 1-7 2-3 2-4 2-S 2-e 27 3-4 3S3-&3-7 45 4-647 S-6 5-7 6-7

ORDER OF HNH PRESENTATION SUBVECT N°./.

EXP. no: 9

3 2 ° C. SEA-IVATEEt

/■Z A3 7-4 IS AS 1-7 23 2-4 25 2-6 Z-7 3-43-S3-6 3-74-54-6 47 5-G S-7 e-7

ORDER OF RNR PRESENTATION SUBUECT N°.2

GRAPH SHOWING COMPARISON OFTACTILE SENSITIVITY DURING TESTING PERIOD.

EXP. N o: 9FIG : 31

SCORE

SCORE

32°G. SEA-WATER987

PAL A65432.I

AZ 13 14 I S A6 /• 7 2 3 2 4 25 2-6 27 34 2-S3 6 3 74-5 4-6 47 5-6 5-7 & 7

ORDER OF HAIR PRESENTATION SUBJECT No. 3

EXP. N o: 9

32*0. SEA- WATER

9

a7

PAL! A65432

1

AZ A3 A4 A5 AG (-7 2 3 24 25 26 27 3-43-53-G 3 74.546 47 56 57 67

ORDER OF HA/R PRESENTATION SUBJECT N0.4.

GRAPH SHOWING COMPARISON OF: TACTILE SENSITIVITY .DURING TESTING PERIOD.

EXP. N o: 9FIG : 82

*

SCORE

SCORE

3 2 ° C. SEA-WATS/?987

6

5432

1

i-Z /3 14 J S 1*6 /• 7 2-3 -4 2'5 «S-6 2-7 3-4 3-S 3-6 3-7 4-5 4-6 47 5-6 5-7 67

: ORDER OF HA/R PRESENTATION SUBOEOT m s

EXP. No: 3

32°C. SEA' WATER9

s

7

6

5432

1

f'2. /-3 /-4 t’5 J'G ( 7 2 3 24 25 2. 6 27 34 3 5 3-6 3 74,546 47 56 57 67

ORDER OF HNR PRESENTATION SUBVEOT N* 6

GRAPH SHOWING COMPARISON OFTACTILE SENSITIVITY DURING TESTING PERIOD.

EXP. n o : sFIG : 83

3E*G. SEA-WATER

I'Z 1-3 1-4 I S 7-6 h i 23 2-4 252-6 27 3-4 3-53-6 3-74*5 4-6 4*7 5-6 5 7 6 7

SUBJECT m 7ORDER OF HAIR PRESENTATION

EXP. N o: 9

BE°G. SEA- WATER

AZ h3 h4 h5 he 17 23 2-4 25 2 6 27 34353-6 3-7454 6 4-7 5-6 5-7 6-7

ORDER OF HA/R PRESENTATION SUBJECT W 8

GRAPH SHOWING COMPARISON OFTACTILE SENSITIVITY DURING TESTING PERIOD.

EXP. N o: 9f ig : 84

SCORE

SCORE

32°C. SEA - WATER9

87

654

3

2

1

t'Z 13 A4 AS AG 1-7 23 24 2-526 <2-7 34 3-5 36 374*54-6 4-7 5-6 5-7 67

ORDER OF HA/R PRESENTATION SUB3E0T m 3

EXP. N o: 9

3£°c. sea - Wa te r

9

a7

65

4

3

1

/2 A3 A4 15 AG f-7 23 24. 2-5 2-6 27 34353-6 374-546 47 56 57 67

ORDER OF HA/R PRESENTATION SUBSECT NO. 10

GRAPH SHOWING COMPARISON OFTACTILE SENSITIVITY .DURING TESTING PER/DD.

EXP. n o : 9f /g : 85

Statistical Method

Experiment : 9 Compares performance in a controlled airenvironment rnith performance after hand immersion in Sea-Ulater at 32°C (palm), (Same subjects).

Using the *tf test (one sided).

Z d = 161 Z d2 = 7583

sd = A (^Td2 - ( Z d ) 2

n - 1

sd2 = 554.5

let Xg = mean at 32°C

X2 = mean at control

d = X2 X3

t = 16.1/ 554.5 = 2’16J 10.

This is significant at P< 0.05,

63.

Discussion:

The results gained from this experiment confirm that immersing subjects hands in 32°C sea-water produced a significant decrement in tactile discrimination of the palmar region as compared to controls. This is in agreement with the decrements found in Experiments 3 : 4 and 5, for the dorsal region which used groups composed of different subjects* This experiment therefore amplifies the results of the previous series by using the same subjects for each group, and suggests strongly that a ’water* effect produces noticeable changes in the ability of subjects to discriminate between paired comparisons of graded nylon sutures for both the palmar and dorsal regions* This confirms Bowen’s provisional findings described earlier, that there was a difference between dry land and warm water performance although the testing procedure adopted for Bowen’s experiments was carried out whilst subjects were totally immersed.Bowen states that the hands are undergoing changes during warm water immersion and suggests "peripheral vasoconstriction."

Results:

Experiment 10*

Control with 14°C - 1°C Sea-UJater (Palm).

The mean hand skin temperature for the palmar region of the ten subjects during the cold immersion and recovery period is shown in Fig. 87.

A sudden drop of 14°C occurred during the first 5 minutes levelling out to a plateau around 16°C for the remaining period of immersion. No rewarming effect was noticeable during this period.

Reumrming occurred steadily for all subjects during the testing procedure but failed to reach normal hand skin temperatures after approximately 20 minutes of testing, see Fig, 87,

Fig, 79 shows the same control group used for Experiment 9, It can be seen that noticeably lower scores are achievbd for the experimental condition throughout the testing procedure except in the case of the comparison of suture 1 with 7, Statistical analysis using the *t’ test revealed a significant difference between control and the experimental scores P<0,01,

Discussion:

Provins and Morton (1960) found that there was little change in tactile discrimination after the index finger of five subjects had been immersed in a water bath at temperatures of 8°C and 15°C, and that decrements in two-edge thresholds using theMackworth 'I/1 test only occurred below a skin temperature of 8°C,They suggest that above 8°C "Sensory discrimination may be relatively unaffected,"

The results achieved in this present experiment using 14°Csea-water disagree with those of Provins and Morton, although on thisoccasion the palmar region was being tested and not the finger tip.The results show a significant deterioration in subjects ability to discriminate between paired comparisons of graded nylon sutures at a temperature well above the critical 8°C mentioned by Provins and Morton,

It is noticeable from Fig, 87 that almost all subjects hand skin temperatures during immersion came within 1,5°C to 2°C of the water bath temperature, whereas in all previous experiments at 5°C hand skin temperature of the test site seldom came within 5°D of the water temperature.

The lack of a rewarming effect attributable to vasodilatation Lewis (1930) may have been delayed on this occasion due to the relatively higher water temperature used, although there is little evidence to support this view as most other experimenters have generally used water temperatures ranging from 0°C - 5°C, Both Adams and Smith (1962) andLe Blanc (i960) used water at 0°C, and 2,5°Cj respectively, andrecorded vasodilatation for unacclimatized subjects after 7 minutes and 6 minutes, Glaser et al (l959)however, found no change in cold induced vasodilatation using a water bath at 4°C for 1 minute, repeated six times daily for nine days, Egan (i960) also failed to achieve a vasodilatation effect using 0°C water for an immersion period of 5 minutes, repeated six times daily for 17 days. Both these immersions are considerably less than those used by Adams and Smith, and Yoshimura and Iida (1952), On these occasions immersion was 20 minutes at 0°C, four times daily for one month, and 30 minutes daily for one month respectively. Evidence of changes in vasodilatation were found in both the studies of Adams and Smith and of Yoshimura dnd Iida,

The subjects used in this present experiment werenot acclimatized in the sense that they were not asked to immerse their hands repeatedly. Subjects No, 8 and No. 10 however were divers, and had some experience of total cold water immersion. Neither of these subjects obtained scores which were significantly different from the other subjects. The individual performance scores are shown in Figs, 93 to 97,

o U /V //V lr tn .r— U / - - -D u & u i^ u . f < j t i / r t s

scorns. e x p e r i m e n t : 70

TEST/NG GOND/T/ONS

ENV. GOND/T/QNSGOLD/WET /MMER3/0N

WET | CONTROL IMMERSION | AIR

TEMPERATUREi

14 °c \ °G..I

3 2 ° C. /8 °C TO 2 0 ° C

/MMERS/ON1

HAND \BODY\

RAND 1 BODY \

.....- .-..

TTPE OP WATER

\S.W. j

1!I .-...

..— --- ---- ...'•••

TEST S/TE1

PALM \ 1i1! PALM

sbot SEX ABE SCORE : NO OP CORRECT RESPONSES

/ M /3 104 j 1 /0 2z M 2 / 1 3 / j ( .......

1 /2 5s M 24 * 7 | " \

. J______ 6 JM 2 5 102 j ....1...... /2 6P /3 3 / \ 1.. j.. .. T2

a P 2 5 6 5 | 1 8 57 P 2 5 * 5 ! 1i. .. 7/8 M 40 65 \ 1 8 03 M 2 4 51 j 1 4 6 . ./o M 2 0 106 j 1

i /E Z

TOTAL SCORES 7 7 0 8 4 2

MEAN SCORES 7 7 -0 3 4 *2

STANDARD DEIUATION 3 0 -5 5 0 -2

RESULT I SIGNIFICANT AT P = 0 /

EXPER IM EN T AIO !0 P /S : 8 6

KEY : 0 — 0/ST/LLED WATER/ - ISOTONIC SOLUTION

. S.W- SEA-WATER /Yt - MAINSS.P. ~~ SWIMMING POOL WATER

TEMP

ERAT

URE

°C TE

MPER

ATUR

E

/4°C WATER TOTAL IMMERSION

--->VG PjER/OO/?A r- W A R M A ______ /A / A /R

. CGOL/A/G RER/OO /A/ WATRR30

20

PALMWATER TEMP

JO

35 ' 4025 • 305 70M/NUTES

HAND SKIN TEMPERATURE PURING IMMERSION ANEJ RECOVERK . fO. SUBJECTS

O 15

14°C HAND IMMERSION

COOL/NG RE RtOO /A / W A T IT R

RE-WARM/AG RER/O/D / / V A / R

30

20

/5PALMmrt'ft t e m p

35 403 02 515MINUTES '

5 JO 20O

HAND SKIN TEMPERATURE DURINGIMMERSION AND RECOVERY 10. SUBJECTS EXP'.NOJO

FIG : 87

SCORE

SCORE

CONTROL

987654

3

2PALM

1

/v? 1-3 74 I S IS 77 2-3 24 2 5 2 6 27 34 3-53-6 3 74-5 46 47 5-6 57 6 7

I ORDER OF HAIR PRESENTATION SUBUECT No: /

EXP. no: 9 £ to

CONTROL9

8

7

654

3

2

1

72 73 /-4 75 76 77 23 2-4. 2-5 2-6 2-7 3-43-53-6 3-74,54-6 4-7 5-6 5-7 6-7

ORDER OF HAIR PRESENTATION SUBUECTNO.E

GRAPH SHOWING COMPARISON OFTACTILE SENSITIVITY DURING TESTING PERIOD.

EXP. N o: 3 e 10F IG : 8 8

SCORE

SCORE

CONTROL

AZ t-3 A4 AS 16 /• 7 23 2-4- 2-52-6 27 34 3-S 3-6 3 7454-6 4-7 5-6 5-7 6-7

ORDER OF HAfR PRESENTATION SUBOECTMJ.

EXP No: 3 £ 10

CONTROL9

a7

65

4

3

2PALM

1

i-2 A3 A4 1-5 AtS f-7 2-3 24 2-5 2-6 2. 7 3-43-53-6 3-74,54-6 47 5-6 5-7 6-7

ORDER OF RA/R PRESENTATION SUBUEDT NO. 4

GRAPH SHOWING COMPARISON OF.TACTILE SENSITIVITY DURING TESTING PERIOD.

£X D N o:$eIOFIG : 89

SCORE

SCORE

CONTROL987

654

3

2.

i'Z t-3 14 IS J G 1-7 23 2 4 2 S 2-6 27 34 3 5 3 G 3 7 45 4-6 47 5-6 5 7 6-7

ORDER OF HA/R PRESENTATION SUBJECT No. 5.

EXP. N°L SefO

CONTROL9

a7

6

5

4

3

2

1

/ 2 1-3 /-4 1-5 1-6 17 23 2-4 2-5 26 27 3-4353-6 3-74,54-6 47 5-6 5-7 67

ORDER OF PAIR PRESENTATION SUBJECT NO. 6

GRAPH SHOWING COMPARISON OF: TACTILE SENSITIVITY .DURING TESTING PERIOD.

EXP. No : 9 e JOf ig : ao

CONTROL

t-Z t-3 t-4 t-S l-e 1-7 2-3 2-4 2-5 2-e 27 3-4 3-S 3-5 3-74-5 4-6 4-7 5-6 5-7 6-7

ORDER OF HA/R PRESENTATION SUBUECT N0.7

EXP. N °: 3 c 10

CONTROL

BA.

' f-Z t-3 /•<£ t-5 I-e t-7 2-3 2-4- 2-S 2-e 2-7 3-43-S3-3 3-74.54 0. 47 5-£ 5-7 6-7

ORDER OF HAIR PRESENTATION SUBUECT N0£

GRAPH SHOW/NG COMPARISON OFTACTILE SENSITIVITY DURING TESTING PERIOD.

£XP.m:.3c/ofig : 3/

CONTROL

lZ 13 14 J S 16 t-7 2-3 24 25 2-6 2.1 34 253 5 3 7 45 4-6 47 5-6 5 7 67

ORDER OF HA/R PRESENTATION SUBJECT NO. 3

EXP. N o: 3 e /O

"[■CONTROL

PALM

AZ 13 / 4 f’5 J-G 17 23 2-4 252G 2-7 3-43-530 3 74-546 4-7 56 5-7 6 7

ORDER OF HAIR PRESENTATION SUBJECTN°./0

GRAPH SHOWING COMPARISON OF. TACTILE SENSITIVITY DURING TESTING PERIOD.

exp. n o : se 10f is : 92

SCORE

SCORE

/4cC SEA-WATER9

87

654

3

2.

1

12 13 14 I S 1<S h i 2 3 24 2-5 BB 27 34 3-53-6 3 7 45 4-6 47 5-6 5-7 6-7

: ORDER OF HA/R PRESENTATION SUBUECT N° /

exp. no:/o

/4°C. SEA-WATER9

a7

6

5

A

3

2PALM1

AZ A3 A4 A5 A<3 17 2 3 24 25 20 27 3 4 3 S3-<S 3 74-54& 47 56 57 6 7

ORDER OF FAIR PRESENTATION SUBUECT m 2

GRAPH SHOWING COMPARISON OF: TACTILE SENSITIVITY ,DURING TESTING PERIOD.

EXP. m : /of ig : 33

/4°C . SEA-WATER

pa:m

i'Z 1-3 J-4 IS i-6 1-7 2 3 2-4252-6 2-7 34 253-6 3-745 4-6 47 5-6 5 7 67

ORDER OF HA/H PRESENTATION SUBJECT m 3

EXP, no: /O

/40D. SEA- WATER

PALA

/-2 /-3 f-4 1-5 J-6 f-7 2-3 2-4 25 2-6 2-7 3-4.3-55-6 3-74,54-6 47 5-6 5-7 6-7

ORDER OF PAIR PRESENTATION SUBJECT m 4

GRAPH SHOWING COMPARISON OFTACTILE SENSITIVITY DURING TESTING PERIOD.

exp. n o : 10f ig : 34

SCORE

SCORE

/4 °C SEA-WATER38765432I

AZ /-3 h4 hS hG 17 2 3 -4 252-6 2-7 3-4 353-6 3 74-54-6 4*7 5-G 57 G 7

ORDER OF HAIR PRESENTATION SUBUECT m 5

EXP no: 10

/4°G. SEA - WATER9

6

7PALM6

5432.

1

hZ h3 /-4 h5 h e f -7 2 3 2 4 2-5 2 6 2 7 3-43-53-6 3-7454-6 47 5-6 5 7 G-7

ORDER OF HA/R PRESENTATION SUBUECT N° 6

GRAPH SHOWING COMPARISON OF. TACTILE SENSITIVITY DURING TESTING PERIOD.

EXP. No: iof i g : 95

SCORE

SCORE

/4°0. SEA-WATER9

87

654

3

2

1

12 13 14 15 / <S /-7 2-3 .Z-4 2-6 2-7 3-4 3-S3-G 3 74-5 46 47 5-& 5-7 6-7

: "ORDER OF HAIR PRESENTATION SUBUECT N°. 7

EXP. NO: 10

14° O. SEA-WATER9

a7

6

S

4

3

2

1

AZ /-3 /-4 15 J-G f -7 23 24- 25 Z<5 2 7 3-43-53G 3 74,5 4& 4? 56 S-7 6 7

ORDER OF HNR PRESENTATION SUBUECT No. 8

GRAPH SHOWING COMPARISON OFTACTILE SENSITIVITY ,DURING TESTING PERIOD.

exp. n o : / oFIG : 86

SCORE

SCORE

/4°C. SEA-WATERs

87654

3

2I

/Z A3 14 IS 1-6 17 23 2 4 25 2 6 2-7 3 4 3-53 6 3 745 4*6 4*7 5-6 57 67

: ORDER OF HAJR PRESENTATION SUBUECT m S

exp no:/o

/4*C. SEA-WATER9

8

7

65

4

3

1

AZ A3 /•<£ 15/ 6 17 2 3 24 25 26 27 3-43-53-0 3 74.54-G 47 56 57 G 7

ORDER OF HAIR PRESENTATION SUBJECT NO. IO

GRAPH SHOWING COMPARISON OF; TACTILE SENSITIVITY DURING TESTING PERIOD.EXP. n o : iof ig : 97

Statistical Method,

Experiment : 10, Compares performance in a controlledair environment with performance after hand immersion in Sea-UJater at 14°C. (palm), (same subjects).

Using the ft' test.

2 d = 172 2 1 d 2 = 5782

Sd2 = 1 ( Z d 2 - ,(£d)2 )n " 1 N

Sd2 = 313.7

d = X2 - X1

t = 17.2 - 0

313.710

Using ft* tables, Result is significantPC0.01.

Experiments:9 and 10.

Using a two factor analysis of variance,estimates were obtained for the pooled variance,ie. the variance due to responses, and the variance due to the experimental units.

The results were:__

(a) That there was a difference between the experimental units and the pooled variance*

(b) That there was a difference between the responses and the pooled variance. This result was found to be significant at P <0.025.

Having confirmed that a variance existed in the responses,a1t* test was carried out to discover whether there were significant differences between the responses achieved for the three groups.

The results were as follows:-

(a) The response using 32°C water was significantlylower than that of the control group, P<0.05.

(b) The response using I4°C water was significantlylower than that of the control group. P<0.01.

(c) There was no significant difference between the means of the responses using I4°C water and 32°C water.

Total Immersion.

Experiment 11. Control with 14°C * 1°C (palm).

Introduction:

This experiment was designed to amplify the results of experiment 10 and was aimed at determining whether or not subjects1 tactile discrimination was significantly different to that of a control condition after being totally immersed.

Having dealt in some depth with hand immersion it was considered necessary to establish an experimental basis closer to the working condition of divers, bearing in mind the sparsity of literature in this context. The palmar region was used again so that results could be compared with Experiment 10.

Subjects:-

Subjects for this experiment were taken from the Sub-Aqua Club of the North East London Polytechnic, and consisted of 9 male subjects and 1 female subject. Ages ranged between 19 and 42 years.

Because of the need to select subjects from a different population for this experiment, bearing in mind that subjects needed to be experienced in S.C.U.B.A. (Self contained Underwater Breathing Apparatus) diving, it was considered useful to use tjie selected subjects for an additional control group. See Fig. 98.

Results:

Fig. 87 shows the mean hand skin temperature of the palmar region for the ten totally immersed subjects. An initial

fall in temperature of 14°C occurred, i.e. from 32°C to 18°C within the first five minutes. During the remaining 15 minutes of immersion, a further fall in temperature occurred of 1DC. Again as in Experiment 10, no rewarming effect was noticeable during this period. Generally speaking subjects maintained a hand skin temperature of approximately 5°C above water tank temperature. Rewarming during the testing procedure occurred steadily in much the same way as in Experiment 10, although subjects achieved a lower hand skin temperature than previously at the end of the experiment, the difference between the two being 2.5°C.

Fig. 100 shows there to be a noticeable difference between subjects1 tactile discrimination in a controlled air environment and that achieved following a total immersion in a water tank maintained at a temperature of 14°C i 1°C.

Statistical analysis using the *t* test revealed a significant difference between the control and experimental scores of Experiment 11. P < 0.025.

Discussion.

The results achieved in this experiment serve to amplify the results obtained in Experiment 10. Subjects were found again to suffer a loss in tactile discrimination following a total immersion in water at 14°C. Baddeley (1966) however, found no variation in the tactile sensitivity of 12 divers during immersion at 3 metres and 30 metres, as compared with a dry score on land, although no temperature for the water is given. Baddeley*s results disagree with those obtained by Bowen (1967) who found during preliminary experiments that four subjects totally

immersed in mater temperatures of 21°C, 19°C, 12°C, 9.5°C, and 6.5°C, suffered losses in tactile sensitivity during immersion. Larger decrements mere revealed for a later series of experiments using mater temperatures of 22°C, 16.5°C and 8°C. Subjects mere exposed to 'Short and Long Exposures' tuhen gloves were taken off for 2 minutes 15 seconds and 24 minutes 48 seconds respectively. The data indicated a fairly steady drop in tactile sensitivity with temperature,, and that long exposure combined with the lowest water temperature produced a dramatic decrease of 335/6 from the performance measured on dry land. Bowen suggests that thermal effects acting on top of the water effects, i.e. disorientation, reduced vision etc., are evidenced chiefly by the changes in performance occurring between the 16.5°C and the 8°C water temperature. He calls these "cold effects", and suggests that they may be considered to have a pronounced influence on performance at approximately 12.5°C.

Bowen's work in dealing with the effects of cold water immersion upon diver performance is more directly relevant to the present study, although the testing procedure was carried out whilst subjects were immersed. Baddeley’s studies however, are concerned not so much with cold or water effects, as the comparison between open sea testing procedures and pressure chamber testing, as is evidenced by there being no reference to the water temperature.

According to Bowen (1967) deterioration in tactile sensitivity occurs as a result of divers being totally immersed in water temperatures ranging from 8°C to 16.5°C. The results in this present study show that following immersion in water within this temperature range, in this case 14°C, tactile sensitivity continues to be significantly affected for a period of at least 20 minutes.P < 0.025.

As far as divers subjective experiences were concerned, most divers found the period in the water tank acceptable for about a quarter of an hour, but then commented subsequently on being generally cold and bored during this immersion. It was noted that ten divers were shivering on completion of the dive, although this generally ceased during the first 15 minutes of the testing procedure.

C)U/V//V//in Y Uf- OUD(J£ZLs f J EPEL / Y~ML-kJ f-l/VLJ

. SCORES : EXPERIMENT / //

TEST/NG GOND/T/ONS

ENV. CONDITIONSGOLD / W ET 7MMERS70N

W E TIMMERSION

CONTROLAIR

TEMPERATUREi

°c\ 14 cc..... I 32° C. !8°G TO 20 °C

IMMERSION(

HANO S BODY\

R A W 1 BODY ?- •;■■■ — .

TYPE OP WATER

\

j MJ. . . I . . . .1 .

. . . . . . . . :- - - -

TEST 8/TEm

iJPALM

11i PALM

S3JT SEX ARE SCORE : No OF CORRECT RESP07YSES

7 M 40 j 63 \ 80Z M /3 | 108 il 7523 M 20 | 98 i1 7724 M 79 | 98 . . 1i 704E M 24 ! * 5 1i 9 26 F 2/ j 1/8 ■ . . • . .1 ZOO7 M 26 | 107 r.. . . i . _____ //a8 M 2 3 I 3 7 i /oe3 M 42 ! 46 i 87/O M 24 | 74 !

......... . » 84

TOTAL SCORES 886 7,033

M E A N SCORES 88-6 -. . . . - 703-3 :

STANDARD DELATION 21-60 78-82 : : :

RESULT 1 SIGNIFICANT A T P = ■ 025

EXPERIMENT N O / / / PIG I 98

KEY : D — DISTILLED WATER/ - /SOTON/C SOLUTION

. S.W- SEA-WATERM - MAINS . S.P. - SWIMMING POOL WATER

% SCORE

! .

% SCORE

-o

CONTROL VERSUS TOTAL ZMMERSZON Z^C.WATERZOO

PALM

403020

/-2 /-3 1-4 AS AS A7 23 2-4 2-52-6 2-7 6-4 3-5 3-6 6-7 4-5 4 6 4 7 5-6 5-7 6-7

ORDER OP HAIR PRESENTATION ZO SUBUEC7S

E X P -' //

CONTROL VERSUS TOTAL ZMMERSZON S2°C.W ATER

8070

Z-2 A3 J-4 /-5 A6 A7 2-3 2-42-52-62-7 3-4 3-53-6 3-7454-6 475-6 576-7

ORDER OF ZZA/R PRESENTATION ZO. S U B U E C TS

e x p : z e

GRAPH SHOWZNG GOMPARZSON ZN TACTZLE SEAZS/T/V/TY for zzazrs /'Z:2'Z:S'4- :4--s: e g : 6-7. fzg: 99

SCORE

% SCORE

%

control

experimental

CONTROL VERSUS TOTAL IMMERSION. I4°C WATER

903 Z

80SO

no

6060

20

IZ IZ h4 t-B J <3 V-7 2-5 2-4- 25 2-G 21 3-4 3 5 3-G 3-7 4-5 4-& 4>7 5-G5-7 G'7

ORDER OF HAIR PRESENTATION 10 SUBJECTS

EXP No : I I

CONTROL VERSUS TOTAL IMMERSION 32 °C WATER100

90

80

70

605040

3020

10

--- COArm )L S /j 22 SO-- £X<O' SJO P4.7/

/sf> v*<

\ & \ 7*\v

V / y m>1.///\> -X \

\/r i <

% P a\u A

/Z /Z /-4 E5 EG ( 7 2-3 2-4 25 Z<3 27 3-4.

ORDER OF HAIR PRESENTATION

■74.-54 & 4-7 S G 5-7 G 7

/O SUBJECTS

GRAPH SHOWING COMPARISON OFTACTILE SENSITIVITY DURING TESTING PERIOD.

EXP. N o : 12f ig : 100

SCORE

SCORE

CONTROL

87

6

543

2.

1

IZ A3 /-4 / S AS A7 2-3 J?4 2-5- 2-6 2.7 3*4 3-S 3-6 3-74--5 4-6 <47 5-6 5-7 6-7

: ORDER OF HAIR PRESENTATION SUBtJEOT NO. /

exp . n o : h

control

9

6

7

654

3

J

/■2 A3 A4 /*3 A<S A7 2-3 2-4 25 2 G 2-7 3-4 3-S.3-6 3-74-S 4-6 4-7 5-6 5-7 6 7

ORDER OF HAIR PRESENTATION SUBUECT No.2

GRAPH SHOWING COMPARISON OFTACTILE SENSITIVITY .DURING TESTING PERIOD.

EXP. no : / /f ig : 10/

CONTROL

PALM

12 13 t'4 IS i <s 17 23 2*4 2 S 2 G 27 3-4 25 3 S 3 74*5 4& 47 S-& 5 7 G 7

ORDER OF HNR PRESENTATION SOBUECT m z

EXP. no: II

1-2 13 /•<£ 1-5 J*<5 f -7 2-3 24 2*5 ZG 2*7 3*43-53G 3 74*54& 47 56 57 G7

ORDER OF HAIR PRESENTATION SUBUECT N0.4

GRAPH SHOWING COMPARISON OF! TACTILE SENSITIVITY DURING TESTING PERIOD.

exp. n o : 11FIG : IOE

SCORE

SCORE

CONTROL987

6543

2

1

IZ 1-3 1-4 I S / <S 1-7 23 24 2 5 2-6 27 3 4 3536 3 745 4-6 4-7 5-6 57 6-7

ORDER OF HAIR PRESENTATION SUBJECT NUB

EXP.N°: //

CONTROL9

a7

65

4

3

2

I

/■Z A3 A4 i-5 J-iS 1-7 2-3 24 2-5 Z<3 2-7 3-43-S3-6 3 74,54-6 47 5-6 6-7

ORDER OF HA/R PRESENTATION SUBJECT No. 6

GRAPH SHOWING COMPARISON OFTACTILE SENSITIVITY DURING TESTING PERIOD.

EXP. n o : //f i g : 103

CONTROL

hZ /3 74 75 76 17 2 3 24 25 2 6 21 3-4 35 3-G 3 7 45 4-6 4-7 5-6 5 7 6 7

■ ORDER OF HAIR PRESENTATION SUBUEGT N°. 7

EXP. m : / /

CONTROL t

72 73 74 75 /■& 17 2-3 24 25 26 27 3-43-5 3-6 3 74,546 47 56 57 6 7

ORDER OF HAIR PRESENTATION SUBUECT m e

GRAPH SHOWING COMPARISON OF! TACTILE SENSITIVITY DURING TESTING PERIOD.

exp. no : i if i g : m

SCORE

SCORE

CONTROL9876543

2

1

I'Z f-3 14 f S / <S 1-7 2-2 2 4 2 5 2-6 27 3-4 2 53 6 3 745 4-6 &7 5-6 5-7 6-7

" ORDER OF HAIR PRESENTATION SUBBECT N°. 9

£XP.N°: //

9

a7

65

4

3PALM

2

1

/-2 /-3 /-4 t-5 /-iS /-7 2-3 2-4 2-5 2-6 2-7 3-43-53-6 3-74.-54-6 47 5-6 5-76-7

ORDER OF HAIR PRESENTATION SUBdECT Nojo

GRAPH SHOWING COMPARISON OFTACTILE SENS/TIV/TY DUPING TESTING PERIOD.

exp. no : / /F /6 : 105

SCORE

SCORE

/4 °C . WATER. TOTAL /MMERS/ON

9

87

654

3

21

IZ 13 14 I S AG 1-7 2 3 24 2-S 2 G 27 34 3S 3 G 3-7 4-5 4-6 4-7 5-6 57 6 7

ORDER OF HAIR PRESENTATION SOBOEOT No. I

EXP. n o : I I

14°C. WATER TOTAL IMMERSION9

a7

654

3

2PALM

1

AZ A3 A4 I'S AG A7 2 3 2-4 25 26 2-7 3-43-53-6 3 74 54 6 4-7 56 5-7 6-7

ORDER OF RNR PRESENTATION . SUBdECT N o.e

GRAPH SHOWING COMPARISON OF! TACTILE SENSITIVITY DURING TESTING PERIOD.

exp. n o : nF I6 : 106

SCORE

SCORE

/4°G . WATER. TOTAL /MMERSION98

654

3

2.PALM

1

!Z /*3 14 J-S AS t-7 2-3 .2-4 2-53-6 21 3 4 353 6 3 74-5 4& 47 5-6 5-7 6-7

: ORDER OF HAfR PRESENTATION SUBJECT N° 3.

exp. no: //

/4°G. WATER. TOTAL tMMERSJON9

a7

65

3

21

Z-2. A3 /-4 A5” AS A7 ^-3 -24 2'5 2S 2-7 34 3-S3-0 3-7454-6 47 56 5-7 G-7

ORDER OF RNR PRESENTATION SUBDECT N ° 4

GRAPH SHOW/NG COMPARISON OFTADT/LE SENSITIVITY DUF/NG TEST/NG PEP/DD.

e x p . n o : nF IG : 107

SCORE.

SCORE

/4*aWAT£R. TOTAL IMMERSIONs

87

6

5

4

3

2

1

I Z 13 h4 15 l <S 17 2 3 2-4 2: 5 S B 21 34 3-S 3-G 3-74-5 4-6 4-7 5-& 5-7 G-7

ORDER OF HAIR PRESENTATION SUBdECT n o . 5 .

EXP. n o : / /

/4 °G . WATER. TOTAL IM M ERSIO N

9

a

7.

654

3

2

1

/•2 / 3 / 4 15 J-iS f -7 23 2-4. 25 2-<3 2-7 3-43-53-6 3 74,5 4-G 4-7 56 57 6-7

ORDER OF HAIR PRESENTATION SUBUEDT N°. 6

GRAPH SHOWING COMPARISON OFTACTILE SENSITIVITY .DURING TESTING PERIOD.

exp. n o : 1/F IS : /O Q

SCORE

SCORE

/4 °C . WATER. TOTAL IMMERSION9

87

6S43

2 /SUAf1

IZ i-3 14 J'S / <s 1-7 2 3 24 2-5 2-6 21 3-4 3-53-6 3 74-5 4-6 4T 5-6 57 6 7

ORDER OF HAIR PRESENTATION SUBdECT no. 7

EXP No: //

/4°G . WATER. TOTAL IMMERSION9

e

7

654

3

2

1

/■2 /-3 /-4 A57-6 f'7 23 2-4 2-5 26 2-7 3-43-53-6 3 74-54-6 47 5-6 57 6-7

ORDER OF MNR PRESENTATION SUBdECT N°8

GRAPH SHOWING COMPARISON OFTACTILE SENSITIVITY DURING TESTING PERIOD.

EXP. N o: i i

F/G : 109

SCORE

SCORE

/4°G . WATER. TOTAL IMMERSION987

65

PALM4

3

2

1

IZ 13 14 I S / <3 / 7 2 3 24 25 2 6 2 7 3-4 3-53-6 3-745 4-6 <47 5-6 5 7 6 7

ORDER OF HNR PRESENTATION SUBVEGT No.9

EXP. no: II

/<4°C. WATER. TOTAL IMM ERSION

9

a

7

65

4

3

2

1

1-2 /'3 14 I’5 16 ( 7 23 24 25 26 27 34353-6 3 74,54-6 47 5-6 5-7 6-7

ORDER OF HAIR PRESENTATION SUBUECT m 10

GRAPH SHOWING COMPARISON OF •TACTILE SENSITIVITY DURING TESTING PER/DD.

EXP. N o: //p /s : NO

Statistical Method,

Experiment : 11. Compares performance in a controlledair environment ujith performance after total body immersion in water at 14QC i 1°C. (palm).

Using the ’t1 test.

I d = 149 I d 2 = 5037

5 c j 2 = - i — (Z d2 - (£d)2 N “ 1 N

— ( 5037 - 22201 )9 10

= 312.9

= d - 0312.9

14.931.29

10

t = 2.66

From the ' t1 tables result is significant P< 0.025

Total Immersion.

Experiment : 12. Control with 32°C Water, (palm).

Introduction;

This experiment was designed to amplify the results obtained from Experiments 3 ; 4 ; 5 and 9, which used water at 32°C for hand immersion only. Significant deterioration in tactile sensitivity had occurred after hand immersion for all three kinds of water at that temperature. It was necessary therefore to discover whether subjects totally immersed would experience a similar deterioration in tactile sensitivity following immersion, using on this occasion the palmar region as the test site.

Subjects:

Subjects were taken from the Sub-Aqua Club of the North- East London Polytechnic, and consisted of 9 male subjects and 1 female subject. Ages ranged between 19 and 48 years, see Fig.111.

As in experiment 11, the ten subjects selected for their diving capability were used also for an additional control group, thus enabling a more meaningful comparison of results.

Results:

Fig. 100 shows little variation in tactile sensitivity for the experimental condition as compared to the control for the first few minutes of the testing procedure. Scores are relatively closely matched until the presentation of suture 2 with 4. A noticeable deterioration in the experimental condition then occurs during the middle part of the procedure, lasting some ten minutes. Performance during the last few minutes of the testing procedure is similar for both the control group and the experimental group whereas in experiment 11, the comparable percentage difference at the end of the testing period was 10^,

Statistical analysis using the !t' test revealed a significant difference between control and experimental scores.

P< 0.025.

This result confirms the findings of Experiments 3 : 4 : 5 and 9, which used the same water temperature for hand immersion and used the dorsal region as the test site*

Discussion:

It is clear that total immersion of subjects in a water temperature of 32°C, for a period of 20 minutes, produces a significant deterioration in tactile sensitivity during the period immediately following the immersion. The results of both this experiment and experiments 3 : 4 and 5 and 9, confirm that both the dorsal and palmar regions are similarly affected following immersion in ^arm* water.

Water at 32°C provides a comfortable thermal environment for the diver especially when he is surrounded by a wet suit. Subjects used in this experiment neither complained of being chilled, or of being too warm, and most expressed regret at having to come out after the 20 minute period.

Bowen (1967) suggests that water at 22°C is comfortable for divers for periods of up to half an hour, and that although there is no sense of chilling, the "U" test performance makes it clear that the hands are experiencing changes. He further suggests that these changes are probably due to peripheral vasoconstriction although he is unsure whether such peripheral changes would be sufficient to explain the reduction in performance.

Five of the subjects used in the experiment described here were initially immersed in "indoor pool temperature" water, i.e. between 24°C-27°C for approximately half an hour. Four out of the five subjects wearing wet suits complained of feeling "shivery" and being chilled. It was therefore decided that it was necessary to increase the temperature of the pool to around hand skin temperature,i.e.between 30°C-32°C Provins and Norton (i960) to avoid chilling effects.

SU/v//v/rin y ut ouauti u / o lju //‘i/z.o ai/puSCORES. EXPER/MEA/T J /2

TESTING CONDITIONS

ENV, CONDITIONS COLD I'W ET IMMERSION

N ETIMMERSION

CONTROLAIR

TEMPERATURE\

°c \ °G. •

3 2 ° G. m°C TO 2 0 °G

IMMERSION■ i

HAND \ bODY\

HAND I BODYi.- ---- :T... -

TYPE O f WATER

i\

....i'i

I[ S.P. ---------:— ----

TEST SITEiii

11PALMi PALM

SPOT SEX AGE SCOPE : NO OF CORRECT RESPONSES

I M 26 \I 1 /o a 118

2 M 4 2 11 i 4 7 8 9

3 M 2 3 11 j 93 109

4 M 4 8 i1 ! 57 38& M 2 4 1

_________ 1.............................. 1 76I 66a M 2 3 1

.....I.-... | 36 907 P 30 1r \ eo ] 808 M 26 11 .

\ 7 T 563 AA 2 3 1I 1 81 92/O M 13 11 ! 9 7 104

TOTAL SCOPES 761 864

MEAN SCOPES TCP 8 6 -4

STANDARD DEVIATION 24171 2 2 -5 0 S

PEQULT I SIG NIFICANT A T P = -025

EXPERIA4ENT NO / /Z F IG : I I I

K£Y : O — 0/ST/LLED WATERI - /SOTOM/G SOLUTION S.W- SEA-WATER M — MAINS S.P. - SWIMMING POOL WATER

SCORE

SCORE

CONTROL­

'S

s

7

65

4

3

2

1

12 /-3 14 I S / <5 /-7 2S 2-4 25 2 6 2.1 3-4 ZS 3-G 3 745 4-6 4*7 5-& 5 7 6 7

; ORDER OF HAIR PRESENTATION SUBdECT m i

exp, mu z

CONTROL9

8

7654

3

2

1

/■2 / 3 f -4- t-5 /•<S t-7 2-3 2-4 2-5 26 27 34 3S3-6 3 74.54 6 47 5-6 57 6 7

ORDER OF HAIR PRESENTATION SUBdECT NQB

GRAPH SHOWING COMPARISON OF: TACTILE SENSITIVITY DUPING TESTING PERIOD.

EXP. NO: IBF/G : H Z

CONTROL

1'2 i-3 14 IS / <s 1-7 2-3 24 25 2 -G 27 3 4 3-53-6 3 745 4-6 4*7 5-6 5 7 G-7

ORDER OF HAIR PRESENTATION SUBJECTM 3

EXP. R o: /£

CONTROL

/-2 /-3 74 A5 /■& f-7 2-3 2-4- 2-5 2<3 2-7 3-43-53-2 3-7454-6 4-7 5-6 5-7 6-7

ORDER OF PAIR PRESENTATION SUBJECT NQ 4

GEAPH SHOWING COMPARISON OF: TACTILE SENSITIVITY DURING TESTING PEFIDD.

EXP. n o : izp /G : /IE

CONTROL

1-2 t-3 1-4 IS /-e /• 7 £-3 S .# 25 2-6 2 7 3-4 3-53-6 3-7 45 46 4-7 5-6 5-7 6-7

ORDER OF HAIR PRESENTATION SUBDECT N°.E

EXP.N°:i2

/■Z 1-3 /-<£ 1-5 !-G 1-7 2-3 2-4 Z-5 2-6 2-7 3-43-S3-G 3-7454-6 47 S-6 S-7 G-7

ORDER OF HAIR PRESENTATION SUBDECT N° 6

GRAPH SHOWING COMPAPISON OF. TACTILE SENSITIVITY DUPING TESTING PEPIDD.

EXP. NO'. 12.f /6 : //4

SCORE

SGORE

CONTROL987

zs:6S.4

3

£1

/•z /-3 14 i'S j-<s 1-7 2-3 2-4 2 5 2 6 27 3-4 3 S 3-S 3 745 46 47 5-6 57 67

ORDER OF HAIR PRESENTATION SUBJJEOT No. 7

EXP. Ho: /£

CONTROL

9

a7

6

S

4

3

2

I

/2 /3 /4 J-5 J-G /7 23 24 25 Z-G 27 3 -SJ-S 3-7454-6 47 5-6 57 G-7

ORDER OF HAIR PRESENTATION . SUBdECT m s

GRAPH SHOWING COMPARISON OFTACTILE SENSITIVITY DURING TESTING PERIOD.

EXP.NO'JZfig: u s

3VOQ5 3t/OOS

CONTROL

9a7

6543

1

J-Z J-3 J-4 J-5 J-G J- 7 -3 2-4 2-5 e-G 2 7 3-4 3-5 3-G 3-7 4-5 4-& 4*7 5-G 5-7 G-7

ORDER OF HAIR PRESENTATION SUBJECT N°.d

EXP. N °: /Z

CONTROLs

8

7

654

2.

J-2 J-3 /-4- f-5 J-G J-7 2-3 2-4 2-5 2-G 2-7 3-4 3-53-G 3-74. 5 4- G 4-7 3-G 5-7 G-7

ORDER OF HAIR PRESENTATION SUBJECT N°. 10

GRAPH SHOW/NS COMPARISON OFTACTILE SENSITIVITY DUPING TESTING PERIOD.

exp. n o : izF /6 : 116

SCORE

SCORE

32 ° c. w a te r9

8

654

3

2

1

IZ 13 1-4 1-5 l-e /7 2-3 24 2 5 2-6 21 3-4 353-6 3 74-5 4-6 4-7 5-& 57 6 7

ORDER OF HAIR PRESENTATION SUBUECT A/o. /

EXP. No: /2

3 2 ° G.WATER9

a7

65

4PALM

3

2

1

I Z 13 /-4 1-5 1-6 17 2-3 2-4 2-5 2.0 27 3-43-530 3-74-54& 47 5-6 5-7 6-7

ORDER OF FAIR PRESENTATION SUBdECT No. 2

GHAPH SHOWING COMPARISON OF: TACT/LE SENS/Tiy/TY .DUPING TESTING PEPIDD.

EXP. N o: 12f ig : 117

32°C . WATER

PALA4

i'Z /-3 h4 f-5 y-<S 17 2-7, 2-4 2 S 2-6 27 3-4 3 S3-G 3 745 4& 4-7 S-6 5-7 G-7

ORDER OF HNR PRESENTATION SUBUECT N °.3

EXP. no:/E

32°C. WATER

/-Z / 3 /-4 15 /-<S f-7 23 24- 25 2 <3 27 3-43-5 30 3-74546 47 56 5-7 G-7

ORDER OF MA/R PRESENTATION SUBUECT Al°. 4>

GRAPH SHOWING COMPARISON OFTACTILE SENSITIVITY DURING TESTING PERIOD.

EXP. NO: 12F !6 : U8

SCORE

SCORE

32°C. WATER987

6

5

4

3

2

1

I'2 /*3 /-4 /-s /-e /-7 2-3 24 2-3 2-6 -2-7 3-4 35 3*-6 3-745 4-6 4'7 5-6 5-7 6 7

1 ORDER OF HNR PRESENTATION SUBJECT No.5

EXP No: 12

32°C. WATER9

6

7PALM6

5A

3

2

1

AZ /*3 /•<£ /-5- /-S /-7 2-3 24 2-5- 26 27 3-43-S3-6 3 74.-54 6 47 5-6 5-7 6-7

ORDER OF NNR PRESENTATION SUBJECT N°.6

GRAPH SHOWING COMPARISON OFTACTILE SENSITIVITY DURING TESTING PERIOD,

EXP. N o: 12FIG : 119

SCORE

SCORE

32 °G W A TER

987654321

/•JZ 1-3 14 f -5 1-6 1-7 2-3 2-4 2-5 2-G 2. 7 3-4 3-5 3-6 3-7 4-5 4-6 47 5-6 5-7 6-7

ORDER OF HA!R PRESENTATION ~ SUBJECT M 7

£ X P N ° : / 2

3 2 ° G. WATER9

G

7654

PALM32?

AZ 1-3 /-4 1-5 1-G 1-7 2-3 24 25 2-6 2-7 3-4.3-S3-G 3-7454-6 47 5-6 5-7 6-7

ORDER OF HAIR PRESENTATION SUBJECTS N° 3

GRAPH SHOW/NG COMPARISON OF TACT/LE SENSmv/TY DUF/NG TESTING PEF/DD.

EXP. no: jzF/G : 120

SCORE

SCORE

J Z ° C . WATER9S7

6S4321

/vZ 13 i'4 IS J-G /• 7 <2-3 J2-4 2-5- <2*-<3 2-7 3-4 3-5 3-6 3-74--5 4-6 4-7 S-G 5-7 6-7

ORDER OF HAH PRESENTATION SUBUEGT W 3

exp. n o : /z

32°G . WATER

9

a7

654

1

I-Z 13 1-4. 1-5 J-G (-7 2-3 24 25 2-G 27 3-43-53-G 3-7 4 6 4-G 47 5-6 5-7 G-7

ORDER OF PAIR PRESENTATION SUBUEGT N<>. JO

GRAPH SHOWING COMPARISON OFTACTILE SENSITIVITY DUP/NG TESTING PERIOD.

EXP N o: iz

f/g : 121

Statistical Method:

Experiment : 12, Compares performance in a controlledair environment with performance after total body immersion in water at 32°C, (palm).

Using the ft* test.

Z d = 103 Z d 2 = 2429Sd2 = 152

t = 10.3 = 2.65152

From ’tf tables this is significant. P< 0.025.

Hand Immersion.

Experiment 13. Control with 32°C. Water, (end of middle finger).

Introduction:

Previous experiments in this study have given results for either the dorsal region or palmar region of the hand. It was proposed therefore to experiment further using the end of the middle finger.

Previous experimenters have shown that there is a significant deterioration in tactile sensitivity of the middle and index fingers after immersion in water temperature of 8°C and below. It was therefore considered more relevant to amplify the results obtained in this present study using warm water immersion at 32°C.

Subjects:

The ten subjects for this experiment were taken from the student and staff population of the department of Architecture and were aged between 21 and 46 years. They consisted of 6 males and 4 females, see Fig. 122.

Results:

Considerable variation in tactile discrimination occurs between the control condition and the wet condition during the early part of the testing procedure, see Fig.123. Little suggestion of a decrement however due to immersion appears until the presentation of suture 1 with 5, after which time there is a noticeable difference between the two conditions for the majority of suture presentations.

The results are similar in this respect to Experiment 12 although the test sites are different. It is also noticeable that during the end of the testing procedure the scores for both conditions remain within 10^ of each other for the last 4 presentations. This is again similar to the results of Experiment 12 and Experiment 9 both of which used the palmar region as a test site.

Statistical analysis using the ft* test revealed a significant difference between the control and experimental scores.

P< 0.005.

Discussion:

The results from this experiment indicate that a loss in tactile discrimination occurs to the finger as a result of the hands being immersed in water at 32°C, this confirms the findings in the previous experiments dealing with this temperature water.

The method used in this experiment for measuring tactile sensitivity was to make a 10mm x 10mm square - on the finger to be tested through a glove template. The test site was then presented with a series of "paired stimuli" according to Brown (i960) in the sequence 1 with 2 : 3 : 4 : 5 : 6 : 7 , to 6 with 7, This method differs from the method used for the other experiments insofar as the test site was smaller and therefore yielded less responses for comparison. Even so, it is clear that the responses gained during the testing procedure are sufficient to indicate that following immersion the finger undergoes peripheral changes sufficient to cause a lowered sensitivity, particularly during the mid section of the testing period. It is clear therefore that the finger as well as the palm and dorsal regions are similarly affected following a twenty minute immersion period.

Of the experimenters who have used water as a cooling medium, only Provins and Morton (i960) and Bowen (1967) have been concerned with using water at hand skin temperature. Provins and Morton used 30°C water as a control condition and found little change in two edge discrimination using the Mabkworth * V* test. On this occasion however, only the index finger was immersed. In addition, the testing procedure was carried out during the period of immersion, the subject having to take his hand out of the water bath in order to apply the finger to the apparatus.

The results from this study although indicating that tactile discrimination is significantly affected following immersion in water at hand skin temperature, that is during the recovery period, do not necessarily suggest that tactile discrimination is affected during immersion. It would be reasonable however, to assume that the sensitivity gradient would follow a downward curve as the period of immersion increases.

The 20 minute period used in the present series of experiments would seem to be sufficient to show a decrement in sensitivity. It is not clear however, whether a further period of immersion would affect discrimination to a more marked extent or whether the hand becomes saturated after a certain period of time, thereby preventing any further change in sensitivity.

SUMMARY OF SUBJECTS EETA/LS AND . '.SCORES . EXPEE/MENT / AT

TESTING CONDITIONS

ENV CONDITIONS COLD/WET IMMERSION

WETIMMERSION

CONTROLAIR

TEMPERATURE °C °C. 32° C. 13° C-20°C.

IMMERSION HAND BODY1

HAND 1 BODYi

TYPE OF WATERl

S.W [ - - - - - - ---------------------—

TEST SITEI

ENGERl

SBJT SEX AGE SCORE : NO OF CORRECT RESPONSES/ M 27 3 1 SZ M 23 6 \ 33 F 36 13 | /64 M 36 /4 ! /4S F 2 ! 6 | 46 F 45 7 | /O7 M 2 0 10 \ IO8 F IS & ! 123 M 46 // 1 1310 M 44 7 J 12

TOTAL SCORES as 105

MEAN SCORES 3 -S 10-5

STANDARD DEYIATION 3 2 6 3-53

RESULT : S/8N/F/CANT AT P < O- OOE

EXPERIMENT NO / /3 E /G : /2 2

KEY I D - DISTILLED WATER / -ISOTONIC SOLUTION S.W - SEA-WATER M - MAINSS.P. - SWIMMING POOL WATER

_ # co n tro l

experim entalo~

CONTROL VERSUS 32° C. SEA-WATERtoo

5 3

2 0

t'Z J-3 74 75 76. 77 23 24 2 5 2 6 27 3-4 25 36 37 4 '5464? 5-657 6 7

ORDER OF HAIR PRESENTATION A0. SUBJECTS

ERR PH SHOWING COMPARISON OF TACTILE SENSITIVITY WRING TESTING PERIOD.

/ oo

3 0

8 0

70

2 0

72 73 f-4 t-5 16 77 232-4252-6273-4 3-53-6 3 7 4 5 4'6 4-756 5-76-7

ORDER OF HAIR PRESENTATION

e x p: NO. 13

GRAPH SHOWING COMPARISON IN TACTILE. SENSITIVITY FOR HAIRS 11-2 2-3:3'414'5 :S-6 : 6-7. F/Gl 123

Statistical method.

Experiment : 13. Compares performance in a controlled airenvironment with performance after hand immersion in water at 32°C. (End of middle finger).

Using the !t’ test.

<Td = 20 f d2 = 80

sd2 = Z d 2 - (Xd)2 80 400 = 40

n - 1

10 9

Sd2 = 3.33

d - n 2. 0 2. 0S2 = 13.33 = /0. 333

3.4662

n / 10

t = 3.4662

From tables this is significant

P < 0.005.

7. GENERAL DISCUSSION

. Since 1962, approximately 60 habitats have been submerged in sea-water by countries such as Germany, Japan, U.S.A., France and Russia, at depths varying from 5 metres to 142 metres. Time spent by divers in these habitats vary from between two days for habitats such as Germany's Walter 1 to 60 days for the United States Tektite 11. In July 1968 at its fifth session, a working party of F.A.O. (Food and Agricultural Organisation), appraised the present and potential role of underwater vehicles and habitats and saw the use of such facilities as a development or extension of direct observation and work techniques in the oceans(Parrish et al ’1971).

The underwater habitat therefore, has been largely created out of a need to support man underwater in his quest todevelop oceanographic research in order to make the best use of theexisting mineral and biological resources in the sea. The situation therefore of the commercial diver or diver/scientist using such an environment for an extended period of time is of increasing relevance if seen against such a background.

The present study acknowledges this state of technological development and has attempted to look at the situation of a diver returning to an underwater habitat after a working operation in the sea. The specific nature of the study has been directed towards determining to what extent tactile sensitivity is affected after such an immersion, bearing in mind that the diver is likely to have spenta considerable period of time in the sea and is likely to be bothwet and cold.

The importance of such a study can be appreciated if it is realised that in addition to his being wet and cold, the diver will have been subjected to a number of unusual environmental conditions during his period in the water. These are also likely to contribute to a possible performance decrement after his return to the habitat.

Examples of these unusual conditions arej-

(a) A prolonged period of near weightlessness.(b) Experience of "tunnel vision" due to wearing

a face mask;(c) Altered visual experience due to the variation

in refractive index of water and air.(d) Lack of verbal communication.(e) Slowed movements due to increased viscosity of

water.

These additional factors, although being peripheral to this present study, point to the need to understand more fully the way in which the hands are affected by prolonged immersion, bearing in mind that these other senses such as hearing and vision may also require time to adjust from a near weightless environment to one where gravity is again present. Operational procedures requiring manual dexterity and good tactile sensitivity are commonplace in such a habitat in order to control and monitor equipment and machines for life-support as well as communication with control. It is therefore of importance that some attention be given to the way in which tactile abilities have been affected during the diver's period in the sea.

During the past few years considerable work has been carried out by such bodies as the Admiralty Experimental Diving Unit at Portsmouth together with many commercial companies related to the thermal protection of divers in order to conserve body heat and the need to provide additional diver suit heating. In order to explain the way in which this particular study is related to such a programme of work it is necessary to outline briefly some recent developments that have occurred in this field.

Common and Kettle (1972) have described thermal protection for the diver, that is, insulation provided by a wet suit as the "passive mode" and suit heating, that is the addition of heating elements or pipes into the fabric of the suit, as the "active mode".This suggests that the first priority to be considered must be the retention of heat available within the bodily system by means of insulating the outer layer, e.g. an insulated wet-suit, whereas the active mode suggests there is a need to supplement the divers heat supply by the addition of various heating devices to maintain normal bodily temperature during prolonged immersion. As far as the passive mode is concerned considerable work has been directed towards preventing the flexible insulated material from compressing under water pressure, thereby losing its insulation value. The trend at present is towards syntactic foams which by definition are cavities introduced into otherwise dense and homogeneous materials. Examples of these are rigid walled spheres of glass or resin which are evenly distributed in resins and then cured either in shaped moulds or extruded or rolled into sheet form. The problem at present is to secure bulk production of such foams in strong, flexible, elastic and low density sheet forms, suitable for tailoring into diving suits. The active mode includes systems which provide a hot water supply through an umbilical cord to a network of small bore flexible tubes covering the body. Alternative systems make use of a diver mounted power pack which distributes water through the suit in a similar manner but allows the diver to be autonomous.

Protection of the hands however is difficult whichever.'mode' is used. Gloves allowing water penetration, i.e. "wet" gloves, work on the same basis as the'wet suit' relying on the additional insulation value of the thin film of water surrounding the hands.Dry gloves tend to be cumbersome and are not suitable for work tasks requiring fine manipulation. At present the only acceptable compromise are wet-mitts which are removed for fine work, or insulated hot water containers into which the diver can plunge his hands at intervals.

the diver therefore still needs to expose his hands either to cold water conditions or to warm water conditions whatever method of insulation or suit-heating is adopted for a large proportion of his time in the water, The present study therefore has concerned itself essentially with three aspects:-

(a) Whether or not different kinds of water, i.e. sea-water, isotonic water, or distilled water, affect tactile sensitivity in a significantly different way, using water temperatures of 5°C and 32°C.

(b) Whether hand immersion or total body immersionin water temperatures of 14°C and 32°C significantly affects tactile discrimination as compared to a dry control performance.

(c) Whether hand immersion in the three kinds of waterat a temperature of 5°C shows significant differences in tactile discrimination as compared to a dry control score.

The results show that:

In (a) There are no significant changes occurring in tactile discrimination using the three kinds of water described.

In (b) That following the immersion of both hands and the total body in water at temperatures 14°C and 32°C significant differences were found in the following experiments when compared to a control group,

Experiment 3, Experiment 4, Experiment 5, Experiment 9,

Experiment ID,

Experiment 11,

Experiment 12,

Experiment 13,

using distilled water at 32 C

32°Cusing isotonic water at 32 C using sea-water at using sea-water at 32°C (same subjects) using sea-water at 14°C (same subjects) using mains water at 14°C (same subjects)Using swimming pool water at 32°C (same subjects) using mains water at 32°C

P< 0.05 P< 0.05 P< 0.01 P< 0.05

P< 0.01

P< 0.025

P< 0.025

P< 0.005

(See Tables).

In (c) That following the immersion of the hands in a water temperature of 5°C significant differences were found in the following experiments:-

Experiment 1, using sea-water P< 0.05Experiment 6, using distilled water P< 0.01Experiment 7, using isotonic water P<0.01Experiment 8, using sea-water P< 0.01

(See tables).

The results achieved in this study therefore, suggest the following:-

(1) That the varying osmotic pressure differences

resulting from immersing the hand in distilled, isotonic and sea-water at temperatures of 5°C and 32°C had little or no effect upon deterioration in tactile discrimination.

That a significant deterioration in tactile sensitivity occurs to the palmar region of the hand following a 20 minute immersion of the hand alone in sea-water at a temperature of 14°C.

That a significant deterioration in tactile sensitivityoccurs to the palmar region of the hand following a20 minute immersion of the whole body in water at a

otemperature of 14 C.

That significant deterioration in tactile discrimination occurs to the palmar region and dorsal region of the hand following 20 minute immersions in sea-water - isotonic water and distilled water at a temperature of 32°C, and further that a similar deterioration in sensitivity occurs to the end of the middle finger following immersion in a 32°C water bath.

That significant deterioration in tactile discrimination occurs to both palmar and dorsal regions of the hand following separate immersions of the hand in sea-water, isotonic water and distilled water at water temperatures of 5°C.

That significant deterioration in^tactile discrimination occurs to the palmar region of the hand following the total immersion of divers in a water temperature of 32°C.

The results of these experiments have a number of practical implications. These are:-

(1) That divers whose hands are exposed to water temperatures of 5°C and 14°C experience a deterioration in tactile sensitivity following a dive for periods longer than20 minutes. In the case of a diver returning to the habitat, such a deterioration may contribute an additional hazard to what is already a stressful situation, bearing in mind that he may be called upon to perform some critical manual operation requiring accurate judgement or sensitive control of life support and communication equipment. His dual role as both diver and scientist make it additionally important to understand the effect of these peripheral changes following cold water immersion,

(2) The results achieved from the use of water at 14° C for both hand and total body immersion suggest that average sea temperatures for example around the British Isles may also bring about a significant deterioration in tactile sensitivity following an immersion. The studyby Provins and (Tlorton (i960) has indicated that little or no change occurs above temperatures of 8°C, using.the fflackworth '\/f test.

(3) Whilst improved techniques for insulation and diver suit heating will clearly reduce the degree to which a diver is exposed to cold water conditions^ the evidence from this study suggest that he is still likely to experience a significant deterioration in tactile sensitivity following a dive in warm water due to a ’wet1 effect. His tactile discrimination therefore on returning to his underwater habitat is likely to be significantly impaired. In addition, the evidence

suggests that such a deterioration lasts for periods longer than 20 minutes, which was the average period taken for the testing period in this study. The necessary period for recovery is comparable to that required for cold immersion in 5°C at least as far as the hands were concerned.

Although Bartlett and Gronow (1952) failed to relate manual performance to losses in tactile sensitivity,Bowen (1967) found evidence of manual dexterity and tactile discrimination being similarly affected by water temperatures of 21°C, although the results were achieved whilst divers were underwater and are not directly comparable. They do indicate, however, that there are factors involved in losses in manual dexterity other than that cited by Bartlett and Gronow, who have suggested that the main contributing factor was the loss of dexterity in the thumb due to cold exposure.

It is clear from the results of this study that a deterioration in tactile sensitivity occurs after immersion in water at 5°C; 14°C; and 32°C; and is maintained for periods longer than 20 minutes. The diver returning to a habitat therefore is at a disadvantage during this period and is more likely to make errors when carrying out manual operations requiring accurate judgement or sensitive control of equipment.

It is therefore important that recognition should be given to these effects when considering the design of buttons, levers, handles, switches, dials, wheels, knobs, etc., within the habitat, particularly those operating critical life support equipment. Care should also be given to the positive nature of the operation for such equipment so that additional cues can be recognised when the correct position has been achieved, e.g. an auditory tone or flashing

lights, bearing in mind that the loss in tactile discrimination may affect a divers ability to determine whether a discrete manual movement has actually taken place.

The risk of power failure and subsequent loss of lighting inside a habitat, particularly if it occurs during a period of diver recovery, is an additional hazard that divers need to contend with and should be considered as an influencing factor when designing parts of control equipment that require accurate manual settings.

Clearly, an internal temperature within the habitat of between 18°C and 24°C would tend to prevent prolonged periods of deterioration in tactile discrimination after a divers return, although in practice such temperatures are difficult to achieve. Important too is the need to consider the temperature of metal or other control surfaces, such as wheels or levers, particularly those being held for prolonged periods, Russell (1957) showed that measurements taken immediately after a preferred hand was in contact with metal control surfaces revealed a lowering of hand skin temperature as compared to the non-preferred or control hand. This was followed by a re-warming of the preferred hand and then a cooling until the next re-warming took place,

Russell suggests that the increased loss of heat when subjects touched or grasped cold control surfaces served to trigger off a vasodilatation wave. This however only occurred when the temperature of the room was below 10°C,

It is suggested that following from this present study further work is required to establish:-

(a) Whether deterioration in tactile sensitivityfollowing immersion in cold and warm water contributes to losses in manual dexterity, as reported by Bowen.

Whether hands or fingers in direct contact with cold surfaces cause a significant delay in the recovery of tactile discrimination, following an immersion in cold water.

An investigation into the effects of cold water immersion with particular reference to nausea.

8. CONCLUSIONS AND RECOMMENDATIONS:

The following conclusions can be drawn from the results of the experiments carried out in this study*

1* Following separate immersions of the hand in sea-water, isotonic water, and distilled water at a temperature of 5°C, significant deterioration in tactile discrimination occurs to both the dorsal and the palmar regions during a 20 minute period after withdrawal of the hand from the water bath.

2. Following immersion of the hand in sea-water at 14°C, a significant deterioration in tactile sensitivity occurs to the palmar region during a 20 minute period after withdrawal of the hand from the water bath.

3. Following separate immersions of the hand in sea-water, isotonic water, and distilled water at a temperatureof 32°C, a significant deterioration in tactile discrimination occurs to the palmar and dorsal regions as well as to the end of the middle finger, during a 20 minute period after withdrawal. It can therefore be concluded that a "wet" effect rather than a cold effect is the main cause for such a deterioration.

4. Following the total immersion of divers in water temperatures of 14°C and 32°C, significant deterioration in tactile sensitivity occurs to the palmar region of the hand during a 20 minute period following a divers emergence from the water. It can be again concluded that as far as the immersion in 32°C water is concerned, a "wet" effect rather than a "cold" effect is the main cause for such a deterioration.

5. The varying osmotic pressure differences resulting from immersing the hand in distilled, isotonic, and sea-iuater at 5°C and 32°C had little or no effect upon deterioration in tactile discrimination.

Recommendations:

1. Divers returning to an underwater habitat after a prolonged immersion should be allowed a period of acclimatization before undertaking manual tasks requiring precision, irrespective of the temperature of the water in which they have been diving, and irrespective of whether their hands are cold.

2. Tasks involving the operation of criticial equipment should not be performed by the diver during the period of acclimatization following immersion in cold or warm water.

3. Critical equipment and controls which may need to be used before acclimatization has occurred should have large movements for relatively small effect, bearing in mind that a loss in tactile discrimination may affect a divers ability to determine whether a discr^ejt manual movement has taken place. Levers, buttons, switches, etc., should be designed for easy tactile recognition in the event of power and light failure.

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APPENDIX.

TESTS UNDERTAKEN FOR PhD STUDY r , _G.L.R. LEWiS

ENVIRONMENTAL BASE (A.P.E.)(INSIDE )

RECORD SHEET OF PERFORMANCE

RECORD SHEET OF TACTILE DISCRIMINATION TEST (FREY HAIR TEST)

OBSERVER'S NAME .................... ...

ADDRESS OF INSTITUTE ................. ..

SUBOECT'S NAME...................... ........ ........................

DATE OF OBSERVATION................. .................................

PLACE OF OBSERVATION ......... ....................

TIME OF OBSERVATION................. ..............am............... pm

ENVIRONMENTAL CONDITIONS ,°C Dry Bulb

...‘ ...°C Wet Bulb

SUBDECT'S CLOTHING WORN DURING TEST ................................

SUBOECT’S SEX....................... ..... .......................

OCCUPATION................................ ..........................

AGE................................. .................................

PREVIOUS EXPERIENCE IN TESTS......................... ...............

PERFORMANCE READINGS

HAND USED yV

PART OF HAND (ie Palm, Fingers etc)

HAND* IMMERSED

TEMPERATURE OF WATERi

TEMPERATURE OF HAND

DURATION OF IMMERSION FOR HAND

TOTAL BODY

PROTECTIVE CLOTHING (gloves etc)

AREA OF HAND INVESTIGATED

NO OF DIVISIONS OF TEST AREA

DIVISON CODE/REFERENCE SEE DIAGRAM

,hrs .............mins

.hrs ....... .rnins

sq inches

INDIVIDUAL STIMULI 1 : 7

1. RESPONSE I........... NO RESPONSE

2.3.

4.

6.7.

RESPONSE ........ NO RESPONSE

RESPONSE ...... NO RESPONSE

RESPONSE ....... NO RESPONSE

5........................ RESPONSE NO RESPONSE

RESPONSE ........... L .. NO RESPONSE

RESPONSE ..................... NO RESPONSE

PERFORMANCE READINGS

HAND USED ,

PART OF HAND (io Palm, fingers etc)

HAND IMMERSED

TEMPERATURE OF WATER

TEMPERATURE OF HAND

DURATION OF IMMERSION FOR HAND

TOTAL BODY

PROTECTIVE CLOTHING (gloves etc)

AREA OF HAND INVESTIGATED

NO. OF DIVISIONS OF TEST AREA

DIVISION CODE/REFERENCE (SEE DIAGRAM)

0,

h r s m i n s

• •eoe.t.ti.i.h rs...... mi ns

sq inches

MATCHED PAIR COMPARISON

Noted Difference

1:21:3

1:4

1:5

1:61:7

3:4

3:5

3:6

3:7

5:6

5:7

2:32:4

2:5

2:62:7

4:54:6

4:7

6:7

Noted Difference

SUBUECT'S RECORD SHEET DORSAL REG/ON E/e:

r \

SUBJECT'S RECORD SHEET PALMAR REG/OR.