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Does mental imagery influence our food consumption?

Thesis submitted to the University of Plymouth for the Msc in Psychology

By Spiros Papageorgiou

202

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The !or" reported in this thesis received ethical approval from the #aculty of

Science and complies !ith the guidelines set by the British Psychological Society $

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ACKNOWLEDGMENTS

% !ant to than" my supervisor Professor &ac"ie 'ndrade for her continuous support

and encouragement to do my research (through !hich % learned so many ne! things

about psychology $

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Abstract

The goal of the research !as to investigate ho! mental imagery influences

real food consumption $The study !as based on the )laboration %ntrusion theory and

More!edge et al *200+ research findings and design $ The participants !ere ,2

males and females$ They !ere divided in - groups and each group had to learn and

e.ecute one particular mental imagery tas" $%n group participants had to put --

coins in a slot machine imaginary $%n the 2nd

group the participants had to imaginary

eat -- crisps from a bo!l and in the -rdgroup they had to focus for min in the

sensation of having crisps and che!ing them inside the mouth $ 'fter the e.ecution

of the tas"s the participants consumed freely from a bo!l !ith potato crisps $Their

crisp consumption !as measured in grams $/ne variable !as designed to test

More!edge theory * imagine you eat -- crisps from a bo!l + the second !as based

on )$% theory * imagine you have crisps in your mouth and focus on the sensation of

eating them + $The third variable !as used as a control factor$ The hypothesis !as

that the group of -- crisps !ill eat less ( the group !ith the crisps in the mouth !ill

eat more $The results !ere not statistically significant as tested by '/1' $o!ever

the groups consumption results sho!ed small numerical differences bet!een the

groups$

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Table of Contents

Page

%ntroduction 33333333333333333333333333 4

Method333333333333333333333333333335

6esults 3333333333333333333333333333$$ 2,

Discussion 33333333333333333333333333$ 25

6eferences 33333333333333333333333333 77

'ppendi.3333333333333333333333333333 78975

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List of Tables

Table Page

T'B:) $ Descriptive statistics of first '/1' 702 T'B:) 2$ #irst '/1' table 70- T'B:) -$ #irst '/1' Post hoc :SD test 7

7 T'B:) 7$ Second Descriptive statistics table 7, T'B:) , $Second '/1' table 7

List of Graphs

;raph Page

$ ;raph $;roup means of potato crisps consumption measured in grams 72

2 $ ;raph 2 $ #irst pilot study * replication of original More!edge et al 200 7-

research +$

Introduction

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/ne faculty of the human brain !hich is al!ays !ith us but !e don

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specifically the theories that have been developed regarding ho! mental and visual

imagination influences our food craving and real food consumption $

The role of ental ia!er" in ps"chotherap" and ps"cholo!ical disorders

%magination has been used from very early psychologists li"e #reud or &ung

as an important part of psychotherapy $'ccording to Scorr there are t!o different

types of visual imagery $The directed type !here the psychologists dictates to the

person !hat to imagine and thin" about $The second is the spontaneous type !here

the person focuses on their inner !orld and report !hat they

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sho!s ho! important are these images !hich are loaded !ith emotional =ualities

mainly of negative essence and ho! they influence the development of

psychopathology $So they concluded that the traumatic memory involves highly vivid

visual imaginary images of that traumatic e.perience $*olmes )$ 2004 +$

This has been sho!n by e.periments on cognitive interpretation bias $%n this

study by olmes C Mathe!s * 200,+the participants had to interpret negative or

positive events eg li"e @umping in a cliff by visualising it or by verbally describing it$

The results sho!ed that more visual elaboration lead to more emotional charged and

"ept longer in memory than the verbal accounts $%n another research by olmes et al

*2004+ !ith people !ho have tried to commit suicide the results !ere that these

patients had their suicidal e.periences imprinted as visual images and can recall

them in their memory $These findings suggest that visual imagery is stronger !ith

negative emotional states and that positive change can happen by using visual

imagination $

#isual ia!er" in applied ps"chotherap"

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The realiAation that visual imagination is involved in many clinical

psychological conditions and the influence it has lead psychologists to ma"e

research on it on ho! to apply visual imagination techni=ues in order to aid

psychotherapy $

1isual imagination has been used !idely on phobias $%n a techni=ue

developed by olpe !hich is called systematic desensitiAation the patient has to

imagine the fear stimuli very vividly but in se=uences $So if a patient fears dogs he !ill

imagine first that he loo"s at a magaAine !hich displays dogs ( then he might imagine

!atching a small dog from a distance ( then he !ill imagine a dog !ith him in a large

room and so one until the person imagine being !ith the dog from very close and

overcoming the traumatic phobic reaction $The patient has to vividly imagine these

se=uences and endure the emotional

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Simple as it may sound these techni=ues (!hich give a very important role on

mental imagery( are not so easy to be done but the results sho! reduction in distress

and improvement in the condition of the patients $*olmes )$ 2004+$

Mental ia!er" and cra$in!

So far research has sho!n that visual imagery is involved in various

psychological conditions of our life and the alteration of mental imagery can lead to

changes in the behaviour $ ith these findings various psychologists tried to

investigate the role of mental imagery on craving for food and other substances$

6esearchers have found that sensory imagery plays a big role on craving and

addiction on addictive and other substances (avanagh et al$( 2005+$

Mental imagery and its role on craving for tobacco has been demonstrated on

researchers Tifany et al *55+ $%n their research they as"ed participants to use their

imagination and imagine cigars related stimuli and situations versus neutral stimuli

and situations $The desire for smo"ing in the first group increased thus more vivid

imagery lead to more smo"ing desires *'ndrade 20+$

Since researchers have found that mental imagination is lin"ed !ith craving

and addictive behaviours ( researchers started investigating ho! mental imagination

is involved also in obesity and food craving in general $

Eatin! disorders % obesit" and ental ia!er"

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/besity is a serious health condition in modern !estern types of societies

mainly (!here food is abundant $%n US' only ( -F of men and -, F of !omen are

obese *Bro!n!ell($D 55,+$ ;enerally bad eating habits are !idely spread and

very detrimental for the national health services both financially and in human

casualties $/bese people have much higher ris" of various serious health conditions

such as heart disease ( diabetes (stro"es muscular problems etc $*Manson et al

2002+ $Modern psychology sees obesity under an evolutionary perspective $/ur

ancestor s lived in environment s !ere food !as not available all the time and in

sufficient =uantities so in periods of food

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research bet!een them and mental imagery $'lso the implications from mental

imagination and eating disorders could be gross $%t is possible that patients !ith

eating disorders could be taught mental imagery tas"s !hich could probably help

them !ith their eating habits and improve their conditions$

More&ed!e research on $isual ia!er" and their influence on food

consuption

More!edge et al *200+ did a series of e.periments to investigate ho! visual

imagination of eating a food influences the real food consumption of this food $My

first pilot research for the

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!hich involved putting coins in a slot machine$ The second group had to imagine

visually that they eat -0 mms from a bo!l and put - coins in a slot machine $The -

group they had to imaginary eat - mms and put -0 coins in the slot machine $'fter

the e.ecution of the tas"s the participants had to eat freely from a bo!l full of mms $

The consumption of each participant !as measured !ith a digital scale in grams$

The mean consumption of each group !as then compared statistically$ These

imaginary tas"s !ere meant to be done only imaginary and !ithout any real

movement from the participants$ *More!edge et al 200+ $The results sho!ed that

habituation happened and the participants of the high imaginary conditions that

imaginary ate -0 mms in reality ate less mms than the other t!o conditions $

My first pilot study !as an e.act replication of that e.periment by More!edge

and had the same structure and hypothesis $% had - participants in - conditions

*condition control group --coins ( condition 2 9-0 crisps and - coins ( condition -

-crisps and -0 coins + and the change !as that they had to consume potato crisps$

Potato crisps !ere selected for their ingredients> the fat and salt !hich they contain

and !e !anted to chec" if More!edge findings !ill again be continued !ith another

food $

.

The hypothesis that increased visual imagination !ill lead to reduced actual

consumption of crisps !as not supported in my pilot research $The results sho!ed

the opposite that the more imaginary repetitions of eating crisps made the

participants eat slightly more then the control and less crisps consumption condition

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See Graph 3 for results.

The participants !ho imagined eating -0 crisps ate more real crisps $This

reminds of the commonly accepted idea that the more you imagine something the

more you desire it$ This idea is e.plained by another theory on craving and mental

imagery the )laboration %ntrusion theory $

$Elaboration intrusion odel theor" and e'perients

The results of my pilot study sho!ed the opposite findings than !hat

More!edge e.periments have found $This lead my research to a different direction$

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The results sho!ed that more thin"ing and more imaginary repetitions of eating

crisps lead to increased real crisp consumption $ ' theory !hich deals !ith such a

finding and tries to e.plain craving and desire for food and other substances is the

)laboration %ntrusion theory !hich !as developed by my supervisor professor

&ac"ie 'ndrade (&ohn May and avanagh $The )laboration %ntrusion theory of desire

tries to e.plain the phenomenon of craving and addictive behaviour $hen !e desire

something a !hole se=uence of actions is happening inside our brain cognitive

system $)$%$ theory !as studied especially for food craving but also for other

substances *'ndrade et al 2004+ $

So !hen appetite is high for a food intrusive thoughts appear and these

thoughts are triggered by various cues or stimulus in the environment ( for e.ample if

you adore coffee and you listen in the radio sho! about a !onderful cup of coffee

(your cognitive system !ill get activated and your chances to crave and go and drin"

a coffee are increased $This se=uence depends a lot on ho! strong is the li"ing for

the particular food or drin" or substance $These intrusive thoughts if they elicit a

positive feeling they !ill further be elaborated or processed by the cognitive system

and further increase the desire to get the imagined ob@ect *'ndrade et al 202+$

'fter the cue the intrusive thoughts are represented by verbal or mental

images $*avanagh &$ 200,+$ 'ccording to the theory these mental images have a

emotional component !hich is very strong ( is lin"ed !ith past pleasurable

e.periences and have a po!erful effect on the elaboration of the thoughts in order to

obtain the pleasure from having the particular stimulus $Bac" in the e.ample of the

coffee in the radio sho! ( after the cue of listening about coffee (memory !ill bring to

consciousness the image of a cup of coffee along !ith other sensory representations

of it eg the smell or taste thus it !ill lead to elaboration of it and this !ill lead to

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actually thin" ho! to obtain a cup of coffee $ *Baddeley C 'ndrade(2000+

'lso the amount of ho! strong is the craving depends on ho! vivid the mental

images are$ 6esearcher avanagh et al$ *2005+ in his study !ith alcoholics found

that alcoholics reported having vivid mental imagery !hile on their strong craving

episodes . *avanagh &$ 200,+

The availability of the desired stimuli plays an important role in )$% theory $%f

its not in hand then this deprivation of not having the desired ob@ect !ill increase

negative moods and then recall positive one thus ma"ing the ob@ect more desirable *

'chtAiger '(2005+$

)$% theory seem also to fit !ell !ith the !or"ing memory model of Baddeley

!hich is divided in the visual s"etchial pad ( the phonological loop ( the buffer and

the central e.ecutive system $*)ysenc" et al 200,+.The )$% theory involves both the

long term memory of the pleasant stimulus from the past and the recall of it at the

present and the load it creates in the !or"ing memory at the present$

Since these intrusive thoughts are data or information they occupy resources

and influence the persons perception of that moment *li"e the buffer memory of a

computer system + and thus other tas"s have fe!er resources to be e.ecuted or

evaluated and generally the intrusive thought compete !ith other tas"s that moment

*avanagh &$200,+$

This lead researcher Baddeley and 'ndrade to try to create tas"s !hich

interfered !ith the mental imagery and see ho! these distractors influence the

imagery $ %n their series of e.periments the participants !ere smo"ers !ho !ere

trying to =uit smo"ing $The participants learned either a neutral visual imagery tas"

or an e=uivalent auditory tas" $%ndeed because the !or"ing memory consists of a

visual buffer and phonetic buffer the use of particular distractor tas"s of each type

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influences the vividness of the mental imagery due to sources competition and

overload $ 's a conclusion visual imagery competing memory tas"s reduced the

smo"ers cravings $* May9'ndrade 200+.$

6esearchers arvey et al *200,+ tried to investigate the nature of craving for

food and ho! mental imagery is involved$ There !ere 20 participants in total H0 in

diet H0 not in diet $The participants had to do imagine either a food induction tas" or

a holiday tas" $Then they had to perform either a visual imagery tas" or a auditory

tas" and their craving !as measured in a scale before and after the e.periment $The

results sho!ed that visual imagination of the food increased the craving for the

food (a conclusion !hich supports also the )laboration %ntrusion theory ( and since

the craving had visual imagery as a core the visual tas" reduced the craving $

*arvey $ et al 200,+$

%n this current research % had to e.plore ho! mental

imagination influences the consumption of a real food particulary potato crisps lightly

salted $ More!edge findings and )l theory have contrary results and predictions and

!e !anted to investigate ho! visual imagination influences ho! much you eat and

!hich hypotheses !ould prove stronger to influence food consumption $

Method

The e.periment used ,2 participants -2 females and 20 males (mainly

students of the Plymouth university and others !ho !ere eligible to participate

through the university psychology participation pool system $The participants had

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different ages (the mean age !as 28 years old $The e.periment procedures had the

follo!ing se=uence of phases >

+Gonsent form completion and information regarding the e.perimental procedures

to the participant

2+Mental tas"s learning

-+Mental tas"s e.ecution

7+'ns!er =uestions on crisps siAe estimation or coin siAe estimation

,+Gonsume potato crisps

H+'ns!er =uestion on crisps taste rates

4+Debrief I finish $

8+Measure the participants crisps consumption on a digital !eight scale in grams

5+)nter each participants crisp consumption in e.cel file for data collection

0+'ll data then !as analysed !ith SPPS !ith one !ay '/1' analysis

Materials

The current research has received ethical approval by the Psychology

department of Plymouth university on spring 202$The e.periments too" place in

:in" building psychology laboratories of Plymouth university during end of March

202 till the end of &une 202 usually from 0$00 till ,$-0 am $

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' laptop computer !as used to sho! the image of the coins and the image of

the crisps $ The laptop !as used also to "eep the data safe in an e.cel file and also

included participants number ( date and time ( place of e.periment ( group allocation

and crisps$

' digital !eight scale !as used to measure the real crisps consumption of

each participant $The standard full !eight of the bo!l !as al!ays 70 grams of potato

crisps and after the participants finished the remaining crisps !ere measured $ )ach

participants crisps consumption !as then put in an e.cel file and stored in a

separate hard dis" and all names !ere made anonymous in order to provide

confidentiality for the participants $

The e.periment used potato crisps as the mean to test visual imagery $The

potato crisps !ere of a high =uality brand and fresh $%n order to avoid taste

preferences a

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theory Ihypothesis to one independent variable and further to a specific group of

participants$ The research !as designed in such a !ay in order to include on

independent variable from More!edge result and combine it !ith another

independent variable !hich !as using the )% theory hypotheses$ The variable testing

More!edge hypothesis *eating -- crisps + !as used in his e.periments and has

sho!n to influence the participants consumption $#or this reason it !as used in the

current e.periment !ith the change that participants had to only focus on imagining

they eat -- crisps and no coins imagery !as as"ed in that group $

The variable testing )$% theory !as ne! ( has not been used in other research

and !as using multiple mental imagery * participants had to visualiAe the scene and

focus on the sensations they have !hen they eat crisps +$

The participants !ere told that they !ere participating in an e.periment !hich

!as measuring visual imagination and influence on siAe estimation and taste

preferences $This form of deceit !as used solely to provo"e the participants to

consume crisps !ithout any other influence e.cept from the mental imagery tas"s

!hich !ere being tested $The reasons for this tactic !ere e.plained in the debrief

phase $

)ach group had to learn a specific for the group visual imagery tas" then they

e.ecuted the tas" and then consumed freely potato crisps$ The participants !ere

divided in - groups *group J4 ( group 2 J8 ( group - J 4 + ( control group

!ith -- visual imagery coins insertion repetitions ( group 2 !as !ith -- imaginary

potato crisps eating based on More!edge theory and (group - !as based on )$%$

theory and !as using minute focusing on the !hole e.perience9sensation of

having crisps in the mouth and eating them $

%n the first group the participants had to visual imagine that they !ere in front

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of a slot machine and !ere inserting coins in the slot machine by imaginary

stretching their hand and putting the coin in *no actual movement only imagination+

This tas" !as irrelevant to the crisp consumption and !as used as the control group

baseline $

The group 2 had to consume imaginary -- crisps from a bo!l and use visual

imagery $This group !as using More!edge hypothesis that more visual imaginary

repetitions !ill lead to decreased real food consumption due to the habituation of the

participants !ith the food $

The group - had to imagine that they !ere eating crisps and they had crisps

inside their mouth for minute duration $Participants had to focus on the general

sensation and feelings that they usually have !hen they have crisps inside their

mouth and they are eating them and had to use not only visual imagery but also

taste imagery $This independent variable !as testing the )laboration %ntrusion theory

!hich claims that the more elaboration in the consciousness of a particular food

leads to increased food consumption due to the activation of memory

representations that further lead to craving and desire to eat the particular food

more$ *'ndrade et al 202+$

The -- coins independent variable !as used in the control group $ )ven if this

control group independent variable did not involve imaginary eating of a food it also

had high rates of consumption $ More!edge in his original study states that the coin

in the slot machine resemble the action of stretching the hand and ta"ing crisps from

the bo!l ( so the independent variable is not so disconnected from the other

variables that involve crisps imaginary eating$ *More!edge et al 200 +$

'fter the briefing the participants !ere taught their visual imagery tas"s $

Most participants did not find any difficulty to e.ecute the tas"s and no problems

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appeared during the testing procedure $The visual imagery tas"s in group and 2

usually too" around 92 minutes to be completed $%n group - the time for the

e.ecution of the imagery tas" of the crips sensation !as minute and !as

measured !ith a computer timer program$

hen the participants finished the e.ecution of the tas"s they had to ans!er a

=uestion about either the siAe estimation of 7 different pound coins images or to

estimate the siAe of 7 images of different siAes of potato crisps that they thin" they

consumed imaginarily $These siAe estimation tas"s scores !ere not used for data

analysis but !ere used to ma"e the e.periment more realistic in the eyes of the

participant $

The ne.t phase !as the crisp consumption !here participants !ere given a

bo!l of potato crisps *!eight 70 grams+ and !ere as"ed to eat as much as they

!anted freely $ hen the participants finished they !ere as"ed to rate the taste of

the crisps from terrible up to 0 very good $'lso this taste rating tas" !as not

measured and !as solely used to provo"e the participant to eat crisps $

The final part of the e.periment !as the debrief phase !ere all the details and

the aims of the research !ere e.plained to the participants and they !ere also payed

2 pounds for their time $Then the crisps consumption !as measured !ith a digital

scale and the data !ere put in an e.cel file for storing $

)ach group mean crisp consumption measured in grams !as the dependent

variable of the e.periment $'fter the full data collection the data !as put for analysis

in SPSS using the method of one !ay '/1' along !ith a :sd post hoc test $

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(esults

'fter the completion of the e.periments the data !as put in SPSS in order to

be analysed properly$ The preferred method !as one !ay '/1' analysis and a

post hoc test *:$S$D+ !as also used to establish further the credibility of the results $

%n this research the '/1' !as done and chec"ed !ith t!o different !ays$

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The first time '/1' !as used !ith all the values that !ere originally gathered $%n

this analysis all the values of very high and lo! crisps consumption !ere used $

%n the second time a data transformation filter !as used in order to eliminate

data entries that !ere much higher then the average mean of crisps consumption$

The second time (!ith this !ay of analysis (7 participants entries !ere e.cluded due

to very high crisp consumption above K2, or J2, grams $

Both results are reported here starting !ith the first '/1' !ith the full

original entries $

)I(ST ANO#A anal"sis *ALL #AL+ES INCL+DED,

#rom the descriptive statistics table !e see that the -rdcondition * minute

crisps sensation condition ()$%$ theory + had the highest mean !ith MJ5$4H and

SDJ8$50 $Second !as the rst condition * -- coins control group+ !ith MJ4$57 and

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SDJH$4, $:ast on crisp consumption !as the 2ndcondition * -- crisps More!edge

hypothesis + !ith MJ4$,, and SDJ 5$54 $#rom these results !e can see that the -rd

group of participants !hich !as using the )laboration %ntrusion theory had the

highest consumption in potato crisps $The 2ndgroup !hich !as testing More!edge

hypotheses had the lo!est potato crisp consumption $ The control group sho!ed

also high potato crisp consumption mean MJ4$57 even if in this group the visual

imagery tas" does not involve the imaginary eating of crips but only imagining of

inserting coins in a slot machine

See : Table 1 First ANOVA descriptive statistics table

#rom the '/1' table !e see that # *2(75+ J-$5 ( PJ$428 K0$0, $

The difference bet!een the - independent variables is not significant statistically $

ith a first glance at the results at the descriptive statistics table arithmetically there

is indeed a difference bet!een the conditions but statistically this difference is not

important meaning that the visual imagination tas"s !ere not influencing the potato

consumption as much as !as e.pected by the t!o hypotheses $

See : Table 2 First ANOVA table .

To further establish the credibility of the results a post hoc analysis test !as

used in this occasion :$S$D test !as chosen $

The post hoc test also did not sho! any significant differences bet!een the

variables $

See Table 3 ultiple !o"pariso#s $sd test table.

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Second ANO#A anal"sis *- DATA ENT(IES O) .A(TICI.ANTS C(IS.

CONS+M.TION WE(E E(ASED AND A )ILTE( WAS +SED ,

Some participants sho!ed very high crisp consumption for un"no!n reasons$

Their values deviated too much from the norm of consumption !hich !as 8$7

grams $%n order to ma"e the e.perimental analysis more credible a filter !as applied

L 8$7 *2 N 8$,H+J2,$,- O in the '/1' in order to e.clude participants values !ho

e.ceeded the limit $#rom the total ,2 participants !ith the application of the e.clusion

filter 7 participants !ere removed from the '/1' analysis$ #rom the descriptive

statistic table !e see that the 7 e.cluded participants had MJ- !hich is very high

compared to the rest of the population sample MJH$,2

See Table % Seco#d ANOVA descriptive statistics table.

The '/1' table did not sho! any significant values !ith #*(,+J42$75

(PJ$000K0$0, $Thus again even !ith the filter analysis the results did not sho! any

important differences bet!een the mental imagery tas"s $

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See table & Seco#d ANOVA .

%n both '/1's the results sho!ed that mental imagery tas"s did not

influence the potato crisp consumption significantly in statistical terms $The groups

had indeed arithmetically differences on the mean amount of crisps consumption but

not high enough to be important $

DISC+SSION

This research !as trying to see ho! visual imagery influences ho! much !e

eat a food $%n order to do this !e used hypotheses and findings from t!o other

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researches first of the More!edge and than on )$%$ theory $%n this current research

the results sho!ed again that strictly statistically the results !ere not significant (in

other !ords the 2 independent variables !hich used visual imaginary tas"s did not

prove strong enough to sho! a clear influence on them on ho! much crisps

someone consumed$ o!ever the - means of the variables sho!ed small

arithmetical differences bet!een them !hich still ma"e the sub@ect of mental

imagery and ho! it influences real food consumption more puAAling and demanding

more research$

The t!o theories are conflicting and predict different reactions$ More!edge

hypothesis says that more thin"ing about a food !ould lead to decrease in real food

consumption !hereas the )% predicts that more intrusive thoughts of visual imagery

and elaboration !ill lead to more eating$

The second group of the e.periment had to do the imagery tas" of consuming

-- crisps from a bo!l $'ccording to More!edge this group !ould sho! less

consumption than the other t!o due to the habituation of the individual !ith the food

!hich !ould then lead to a decrease in the crisp consumption due to reduction on

the craving for crisps $ This result even if not statistically significant appeared in this

research group 2 MJ4$,, $The second group ate less crisps than the other t!o

groups$

Probably More!edge findings that more thin"ing about the food leads to

habituation and than as a reduced desire to eat (could be e.plained !ith a more

cognitive approach $The elaboration of that food in the brain leads to increased

occupancy of the !or"ing memory buffer by that particular stimuli $%n such a situation

the system starts to habituate to it and then in the real appearance of the food stimuli

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reduced consumption happens $Since that data !as registered and processed in the

system for long this ma"es the system to not pay attention to it any more in order for

other processes to happen and the memory buffer to be used to the ne! ones $ %f our

memory and central e.ecutive !ere compulsively occupied by only a particular

stimuli then this might have survival conse=uences also $That

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having the crisps in the mouth and che!ing them so this combination of rich and

different imagery sensory sensations !ould according to )$% theory lead to

increased craving and more consumption of the food$ Participants !ill recall from

long term memory positive representations and thus eat more $

o!ever these long term memory representations can be of negative nature

as indicated by a participant comments$ ' female participant !ho !as assigned on

the -rdcondition !hen focused on the crisp sensation in her mouth recalled eating

crisps !ith a taste that she !as allergic to and recalled the negative reaction of her$

'fter focusing on this negative e.perience she focused on another taste and

continued her tas" $This account sho!s that mental imagery re=uires memory

(attention (s!itching bet!een tas"s and many more cognitive faculties $ The female

participant !as actively and consciously s!itching bet!een tastes (!as feeling the

sensation( so the elaboration process could be conscious and not absolutely

automatic $

The human brain has t!o systems of processing information ( system is

based on heuristic !ays its fast and frugal !hereas the system 2 is the analytical

system !hich processed information in a rich !ay $Mental imagery seems to be

based on both systems $The individuals seem to have differences in !hich system

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they use and under !hich circumstances (they can behave in automatic !ays based

on past memory representations and heuristics or be more conscious and analytical

in their process *)vans & 2008 + $

Since the system is based in t!o modes and uses also memory buffer

competing mental imagery tas" could be used a psychotherapy to patients !ho have

addictions and other conditions *May & et al 2007+$The occupancy of memory buffer

from competing mental imagery tas" !ill disrupt the elaboration of the not desired

=ue and reduce the undesired behaviour $'lso effort should be made on brea"ing the

automatic response by helping the person build up self control and self

management$ These results sho! that mental imagery seem to have at least a small

influence on the ho! much crisps participants consumed ho!ever both theories

could only possibly be supported if more research is done and these results appear

higher $

Confoundin! dactors

%n this current study despite all the efforts to design and control all the factors

in order to ma"e the research more reliable and valid there !ere some factors !hich

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need further investigation and notice $%t appears that possibly t!o factors should be

loo"ed at in the future research on this area >The first confounding factor has to do

!ith ho! much a person li"es the potato crisps and the second factor is ho! much

hungry they are at the moment of their participation in the e.periments $

Potato crisps are a favourite snac" for many $ The persons !ho li"e them

have positive memories associated !ith them and these can be recalled and induce

craving and desire for the potato crisps !hich !ere used in the e.periment $ %f you

li"e a food you usually eat more and the opposite if you don

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The taste sensation could further be influenced by biochemical mechanisms that

might influence ho! a particular taste influence the specific person food in ta"e$This

is an area !hich also needs to be chec"ed $)specially the fact that potato crisps

have a lot of fat and salt might be on influence on the satiation of the individual$

The other ma@or factor that possibly influences the research is the satiation

state of the person during the time of the e.periment$ %n other !ords ho! much

hungry is the person $ormally is e.pected for a hungry person to eat more in order

to reduce the craving for food especially if this hungriness state is associated !ith

positive memories of eating potato crisps using again the )$% theory $The research

did not use a measurement to chec" the satiation state of the person eg ho! many

hours ago they had food etc$ The future studies should include such a measurement

from the beginning and have as a re=uirement to not come hungry$ This factor of the

individuals satiation state if combined !ith a greater li"ing of the particular crisps

!ould also lead to increased food eating and thus

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analysed totally along !ith the t!o factors mentioned above$

'nother factor is the ability of vividness of the mental imagery by each

participant$ %n this research a visual imagery vividness scale !as not used $ ot all

people have the same ability for mental imagery and this had been found by creating

scales for visual imagery vividness and classifying people in various degrees of

capability on mental imagery *'ndrade 200+ $ Some seem to focus easily and

visualiAe !ith detail and good sensation !hile other may lac" attention to focus on

the mental imagery or might do it !ith less detail $' female participant commented

that she !as very easy to do the visual imagery tas" and focus and really feel it

imaginarily because she !as doing yoga meditation for many years and these

techni=ues stimulate visual imagination $' vividness scale could be used in future

research and categoriAe participants in groups of high and lo! visual imagery

vividness and than testing them each on one of the independent variables !ith

More!edge and )l theory variables $

Males and females consumption !as not measured for se. differences

bet!een them so this factor could also be included in future research$

%ts good to understand that the results of this current research are based on

laboratory e.perimentation $%ts highly probable that the participants !ill behave

differently !hen acting on their natural environment $More !or" is needed in order to

create the e.perimental methods to test participants mental imagery in their natural

environment s and !ith or !ithout the presence of others $Social pressure and the

specific circumstances of that moment are also factors !hich might influence ho!

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much food is ta"en$ )ating in front of other might be an issue of embarrassment or

discomfort for many people so in order to reduce this the e.perimenter stayed !ith

the participant inside the room but facing in a totally different direction and not

interfering !ith the participant in any !ay until heEshe said !as done eating$

.articipants coents

During the e.periment % !as trying to understand the participants opinion of

the t!o theories that

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very interesting $

The original comments follo! >

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conscious a!areness of the process $%magination can not only create mental states

that resemble the real ones in a great degree but it has been found by research on

visual imagery and #mri that 50F of the same brain areas are involved in real and

imagery vision *;anis et al 2007+ $

%magination can have a direct influence on the behaviour and this is also

found by the research on clinical psychology and the mental imagery on psychiatric

disorders !hich has been found to be involved in the conditions $Such types of

research could also sho! ho!

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and especially !ith )$%$ theory and ho! it affects each individual and in !hich

particular !ay $

%n a future study care should be ta"en to eliminate all the confounding factors

such as li"ing of crisps ( satiation state of the participant and even a =uestionnaire

!ere participants !ould be as"ed to describe their o!n understanding of mental

imagery and craving$

#inally the results of the current study !ere not significant and the original

hypotheses !ere not supported $The small arithmetical differences that appeared are

either an indication that mental imagery had a small influence on some participants

or that other factors created these results $)ven if not significant the results of the

study !ere interesting and open up ne! =uestions and challenges in order to further

understand ho! mental imagery influences our behaviour $The fact that mental

imagery is involved in so many parts of our life sho!s ho! important is for research

but also ho! comple. and difficult to e.plain !ould be $

TA/LES AND G(A.0S SECTION

Gondition MMMenmm mMean in grams SD

Gondition 9 -- 4 4$57 H$4,

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coins

Gondition 2 9 --

crisps

8 4$,, 5$54

Gondition - 9

minute mouth

sensation

4 5$4H 8$50

Total ,2 8$70 8$,H

Table 1 2 )irst ANO#A Descripti$e statistics table

ANO#A

Ghipsgrams

Sum of S=uares df Mean S=uare # Sig$

Bet!een ;roups 78$04, 2 27$0-4 $-5 $428

ithin ;roups -H50$777 75 4,$-,

Total -4-8$,5 ,

Table 3 2 )irst ANO#A table results

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Multiple Comparisons

chipsgrams

:SD

*%+ conditions *&+ conditions

Mean Difference

*%9&+ Std$ )rror Sig$

5,F Gonfidence %nterval

:o!er Bound Upper Bound

$00 2$00 $-8,H2 2$5-,07 $85H 9,$,2H H$28-8

-$00 9$82-,- 2$54HH8 $,7- 94$80,7 7$,8-

2$00 $00 9$-8,H2 2$5-,07 $85H 9H$28-8 ,$,2H

-$00 92$205, 2$5-,07 $7,, 98$04- -$H850

-$00 $00 $82-,- 2$54HH8 $,7- 97$,8- 4$80,7

2$00 2$205, 2$5-,07 $7,, 9-$H850 8$04-

Table 4 2 )irst ANO#A Multiple Coparisons .ost hoc Lsd test

Descripti$es

Ghipsgrams

Mean Std$ Deviation Std$ )rror

5,F Gonfidence %nterval for Mean

Minimum Ma.imum:o!er Bound Upper Bound

ot Selected 7 -$0000 H$0,,-0 -$024H, 2$-H74 70$H-,- 24$00 70$00

Selected 78 H$,208 ,$7888- $45227 7$5240 8$7H $00 2,$00

Total ,2 8$70-8 8$,H45 $84- H$0202 0$484, $00 70$00

Table - 5Second ANO#A Descripti$e statistics table

Table 6 2Second ANO#A table

(ESEA(C0 G(A.0S

41

ANO#A

Ghipsgrams

Sum of S=uares df Mean S=uare # Sig$

Bet!een ;roups 222$,70 222$,70 42$75H $000

ithin ;roups ,2,$545 ,0 -0$,20

Total -4-8$,5 ,

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0

2

4

6

8

10

12

Group 1 - coins 33

Group 2 - crisps 33

Group 3 - I min crisps mouth sensation

Graph 1 7Group eans of potato crisps consuption easured in !ras7

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con1 con2 con30

5

10

Crisps consumption mean

Crisps consumption mean

Graph 3 7)irst pilot stud" * replication of ori!inal More&ed!e et al 3818

research ,7

Gon 9 -- coins

Gon2 9 -0 coins - crisps

Gon- 9 - coins -0 crisps

Dependent variable mean crisps consumption $measured in grams

(E)E(ENCES

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' 1 ('chtAiger ' et al *2005+$Strate)ies of i#te#tio#for"atio# are reflected i# co#ti#uous *G activit+$ Soc eurosci$ 2005Q7>I24

R 2 'ndrade ( May ( avanagh *202+$ Se#sor+ ,"a)er+ i# !ravi#): Fro" !o)#itive-s+cholo)+ to Ne Treat"e#ts for Addictio#.&ournal of ).perimentalPsychopathology &)P 1olume - *202+( %ssue 2

R - 'ndrade &ac"ie *20+ Se#sor+ ,"a)er+ i# !ravi#): Fro" !o)#itive -s+cholo)+to Ne Treat"e#ts for Addictio#

' % (Bro!n!ell($D *55,+ $*/ercise i# the treat"e#t of obesit+ $)ating disordersand obesity andboo" (e! or" (;uilford Press

R , David &$ avanagh &ac"ie 'ndrade and &on May *200,+ $ ,"a)i#ar+ 0elish a#d*/uisite Torture:The *laborated ,#trusio# Theor+ of esire .Gopyright 200, by the'merican Psychological 'ssociation

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R H)vans &StBT*2008+ $ualprocessi#) accou#ts of reaso#i#) 4ud)"e#t a#dsocial co)#itio#$ 'nnu 6ev Psychol$ 2008Q,5>2,,I48

R 4 )ysenc" et al 200, $!o)#itive -s+cholo)+ 56 A stude#ts 7a#dboo8

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R - Manson et al *2002+ $ *pide"iolo)+ of health ris8s associated ith obesit+ $)ating disorders and obesity a comprehensive handboo" (e! or" ( ;uilford

R 7 May &( 'ndrade &$ et al *200+ $Visuospatial tas8s suppress cravi#) forci)arettes.Behaviour 6esearch and Therapy 78 *200+ 74HI78,

R , May &ohn et al *2008+7,"a)er+ a#d stre#)th of cravi#) for eati#)> dri#8i#)>a#d -la+i#) sport . Gognition C )motion /ctomber 2004$

R H May &$ C 'ndrade &$ et al *202+$ *laborated ,#trusio# Theor+: A !o)#itive*"otio#al Theor+ of Food !ravi#) .Springer ScienceBusiness Media( ::G 202

R 4 May &( Panabo""e ( 'ndrade &( avanagh D *2007+$ ,"a)es of desire:co)#itive "odels of cravi#)$ e"or+6774IH

$

R 8 More!edge et al 200 $ Thou)ht for food 1 ,"a)i#ed co#su"ptio# reducesactual food co#su"ptio# .

R 5 oreed)e> et al. 921 ; .,"a)i#ed co#su"ptio#

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reduces actual food co#su"ptio# .0 D)G)MB)6 200 1/: --0 SG%)G)

!!!$sciencemag$org

R 20 Schlundt D;( 1irts :( Sbrocco T$ Pope9Gordle *55-+ $A seue#tialbehavioral a#al+sis of cravi#) seets i# obese o"e#$ 'ddictBehav$ 55-Q8>H4I80

R 2 Schorr( & *547+ $ -s+chotherap+ throu)h i"a)er+ $ e! or"( >%ntercontinental Medical Boo" Gompany( 547

R 22 Tiggeman M( emps ) *200,+$ The phe#o"e#olo)+ of food cravi#)s: therole of "e#tal i"a)er+$ 'ppetite$ 200,Q7,>-0,I-

R 2- 1ol"o! D( ang ;&( #o!ler &S et al *under release in 202+$ Food a#d dru)reard: overlappi#) circuits i# hu"a# obesit+ a#d addictio#$ Gurr TopBehav eurosci( in press

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+ni$ersit" of .l"outh )AC+LT9 O) SCIENCE AND TEC0NOLOG9

0uan Ethics Coittee Saple Consent )or

G/S)T #/6M T/ P'6T%G%P'T) % 6)S)'6G P6/&)GT E P6'GT%G':STUD

ame of Principal %nvestigator> Spiros Papageorgiou

Title of 6esearch> Mental imagery and perceptual influences $

Purpose of research> To test ho! mental imagery influences a+the siAe perception ofcommon ob@ects and b the sense of taste of real food *potato crisps+$

Brief statement of purpose of !or"ello and elcome to my study My name is Spiros Papageorge and % am a student of the master program inpsychology $This is a research to see !hether by imagining something vividly ourperception gets influenced by $%n this e.periment % am loo"ing especially on siAeperception and taste $The e.periment is easy $% !ill as" you to imagine a se=uenceof actions and then as" you a couple of =uestions $Then you !ill try some potatocrisps and tell us your opinion and that

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participated in my former study on visual imagination $'lso if you are allergic topotato crisps you cant participate $Please if you have any =uestions as" me $The ob@ectives of this research have been e.plained to me$% understand that % am free to !ithdra! from the research at any stage( and as" for

my data to be destroyed if % !ish$% understand that my anonymity is guaranteed( unless % e.pressly state other!ise$% understand that the Principal %nvestigator of this !or" !ill have attempted( as faras possible( to avoid any ris"s( and that safety and health ris"s !ill have beenseparately assessed by appropriate authorities *e$g$ under G/S regulations+Under these circumstances( % agree to participate in the research$

ame> 333333333333333$ Signature> $$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$33333$$ Date> $$$$$$$$

Appendi'Ite 3

D!"I# #$"%

%enta& ima'er an) in*uence on si+e an) tasteperception

In,esti'ator piros /apa'eor'e

hans a'ain or our participation .o that e ha,e nishe) I i&&

ep&ain ou some )etai&s o the research .

In this research e ere trin' to see ho menta& ima'er in*uences oucrisps consumption an) not our si+e perception or taste . e to&) ou soto encoura'e ou eat ree&. his research is ase) on research a,ana'h: ;n)ra)e < %a (2005= an) %oree)'e et a& (2010= on ,isua&ima'ination an) rea& oo) consumption . e ante) to see i more or &essrepetition o ima'inar eatin' crisps i&& in*uence our actua& crisp eatin'./&ease e assure) that this sort o )eception is uncommon in pscho&o'eperiments. In most stu)ies: the researcher i&& te&& ou the truth aoutthe stu) an) it is important that: hen ou tae part in stu)ies in the

uture: ou are not epectin' to e )ecei,e). >our )ata cou&) e

49

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ith)ran rom the eperiment i ou ish )e&etin' our participationnumer an) the resu&ts rom m )ataase .

%ore research on this )irection in the uture i&& he&p man peop&e itheatin' )isor)ers : phoias : a))ictions etc . han ou a'ain or the

participation an) p&ease te&& me i ou ha,e an ?uestions@

I ou ant to contact me aout the stu): p&ease emai& piros/apa'eor'iou

spir)on.papa'eor'iouApost'ra).p&mouth.ac.u or

Committee ecretar %rs /au&a imson

emai& pau&a.simsonAp&mouth.ac.u

te& 01752 584503

mailto:spirydon.papageorgiou@postgrad.plymouth.ac.ukmailto:spirydon.papageorgiou@postgrad.plymouth.ac.uk