THE HIGHEST

NERVOUS

ACTIVITY

Questions:

• The Highest Nervous Activity

• Cerebral of cortex

• Conditioned reflex

• Inhibition

• Sleep

• The highest nervous activity type

• Memory

2

THE HIGHEST NERVOUS ACTIVITY

THE HIGHEST NERVOUS ACTIVITY (НNA) is activity

of higher departments of the central nervous system, which

provide the adaptation of animals and the human to environment.

BASIS

OF HNA=

Cortex of the

Hemispheres+

Subcortical

nuclei of a

forebrain

+ Diencephalon

3

Cerebral cortex

4

The basic zones of a cortex

5

6

Primary speech zones of a cortex

7

8

Motor cortex

9

10

Cerebral Cortex

11

Conditioned reflex

12

Classification of Conditioned reflex

By origin Natural and artificial

By character of an

unconditional reinforcement

Alimentary, defensive,

Sexual, research

By character of

prearranged signal

Light, sound, tactile,

Olfactory, temperature and est.

By character of

receptors

Exteroceptive,

Interoceptive, proprioceptive

By a parity of stimuli in time coinciding, set aside, late

By complexity degree 1, 2, 3… n of order

13

14

RULS for a conditioned reflex For a conditioned reflex to appear it is necessary that certain conditions are

fulfilled:

• (1) coexistence in time, several times repeated, of the indifferent agent and

the unconditioned stimulus (in the previous example, the sound of the bell

presentation of the meat);

• (2) the indifferent agent should somewhat precede the unconditioned

stimulus.

• If we first give the meat and then ring the bell, the conditioned response is

not established;

• (3) absence of other stimuli that could induce externally caused inhibition.

If we simultaneously whip the animal or splash it with cold water, we

provoke inhibition, setting loose defensive reactions;

• (4) in order to preserve the conditioned reflex, it is necessary to reinforce

it periodically. Once the reflex is formed, the mere sound of the bell

substitutes the presentation of the meat. But, if we repeatedly ring the bell

without showing the meat, after a certain time the animal stops reacting

with salivation and digestive secretion.

Conditions of development of conditioned reflexes

Time conditionConditional and

unconditional stimuli operate

preliminary or simultaneously

Force condition

The unconditional stimulus

should be stronger (is vitally

more significant) the conditional

Indifference conditionThe conditional stimulus

should be indifferent

Condition of sensory

restrictionAbsence of extraneous stimuli

Condition of cerebral activityActive condition of the

central nervous system15

Mechanism of conditioned reflex

by I.P.Pavlov

16

17

18

Mechanism of conditioned

reflex by I.P.Pavlov• The classic experiment of Pavlov is that of the dog, the bell and the

salivation to the view of a piece of meat. Whenever we present to

the dog a piece of meat, seeing and sniffing it and makes the

animal salivate. If we ring a bell, what is the effect on the animal?

An orienting reaction. It simply looks around and turns its head to

look for where that sound stimulus comes from. If we repeatedly

ring the bell, and immediately after show the meat and give it to

the dog, after a certain number of times, simply ringing the bell

provokes salivation in the animal, preparing its digestive system to

receive the meat. The bell becomes a sign of the meat that will

come later. The whole body of the animal reacts as if the meat was

already present, with salivation, digestive secretions, digestive

motricity, etc. An stimulus that has nothing to do with feeding, a

mere sound, becomes then capable to induce digestive

modifications.

Formation of time connection

19

Cortex

Center

of hearing

Center

of salivation

orientating reflex

excretion of saliva

foodsound

The basic characteristics of the conditioned

reflex (by I.P.Pavlov)

1. Can be formed conditioned reflexes

(Innateness of instinctive reflexes)

2. Individuality of a conditioned reflex

(Specific character of an instinctive reflex)

3. Variability and possibility of cancellation

(inhibition) of a conditioned reflex

4. Signal character and principle of advancing

reflection in a conditioned reflex

20

INHIBITION

21

TYPES OF INHIBITION OF

CONDITIONED REFLEX

External

External - it appears under the

influence of a new strong stimulus

which acts simultaneously with

the conditioned one (for example,

pain stimulation).

Conditioned-the-limit - the strength of

the conditioned stimulus increases

to some limit. It has a saving

importance, appears from the first.

It is peculiar to all section of the CNS.

Internal

Extinction is a conditioned stimulus,

which is not supported by the inborn one.

Differentiation is one of two relative in

nature stimuli not supported,

but another one is supported.

The conditioned inhibitor is when one

stimulus is supported, but its combination

with another one is not.

Delay is when tie interval between

the conditioned signal and inborn stimulus

increases.

22

Conditioned

stimulus (Light)

Differentiation

stimulus (for example

another color of light)

Conditioned

reaction

Other reaction

Differentiation inhibition

inhibitioncortex

23

Delay

а

50% Conditioned

reaction

а

0%

Conditioned

reaction

а

Conditioned

stimulus + meal

Conditioned

stimulus through time

+ meal

Conditioned

reaction Other reaction

Conditioned

stimulus

through a lot of

time time

+ meal

Other reaction 24

Conditioned inhibitorConditioned

inhibitor

а

а

Conditioned

stimulus

cortex

Other

reaction

together

Conditioned

reaction

If only

conditioned

stimulus

inhibition

25

The Highest nervous activity type is individual properties

of the nervous system caused by features of an

individual and its life experience.

The Highest nervous activity types

26

Properties of The Highest nervous activity

1. Force of processes of excitation and inhibition.

2. Mutual steadiness, i.e. parity of force of processes

of excitation and inhibition.

3. Mobility of processes of excitation and

Inhibitions, i.e. rate, with which excitation it can be

replaced by inhibition and on the contrary.

27

Characteristics of types of

The Highest nervous activity

Strong counterbalanced,

with the big mobility of

nervous processes (alive,

fast mobile type)

Strong counterbalanced,

with small mobility of

nervous processes

(Quiet, slow, inactive, inert

type)

Strong unbalanced,

with prevalence of excitation

over inhibition

(Impetuous type)

Weak, from the fast

the emaciation resulting

to working capacity loss

(Brake type)

28

Types of the Highest nervous activity

by I.P. Pavlov

The strong The weak

(Melancholic

person)

The steadyThe unsteady

(Choleric person)

The mobile

(Sanguine person)

The inert

(Phlegmatic person)

29

30

SLEEP

Sleep – a physiological condition of an immovability with

the weakened tonus of muscles and sharply limited sensory

contact to environment.

31

Sleep types

Monophasic and polyphasic sleep

Slow, or an orthodoxical sleep

Fast, or a paradoxical sleep

32

33

34

Fast, or a paradoxical sleep

1. Desynchronization test EEG

2. Fast movements of eyeballs

3. Decrease of a muscular tonus

4. Increase of threshold of cortical neurons - a deep sleep

35

The structures of the brain

centers a sleep formation

Synchronizing, or sleep brain structures - a nucleus of a solitary

tract, structure around Sylvain aqueduct and a back wall of III

ventricle, a medial thalamus, a nucleus having a tail, basal

departments of a forebrain.

Desynchronization (waking up) structures of a brain –

a reticular formation and a mesencephalon,

a pons nuclei - blue maculae and a seam nuclei, nonspecific

nucleus of a thalamus.

36

37

Memory

Memory is a property of the central nervous system (Accumulation, storage, reproduction of information).

38

Phases of work of memory

perception

repetition

storing

storage

forgeting

recognition

reproduction

39

Types of Memory

By duration of conservation and material fastening

Short-term – very short

conservation of a material after

one-fold very short perception and

immediate reproduction (in the first

seconds after perception of a

material).

Plays a role in functioning of

mechanisms of accumulation of

experience.

Operative – a kind of short-term

memory. Serves actual actions

immediately carried out by the

person.

Reading, writing.

Long-term – long conservation of a

material after its repeated repetition

and reproduction.

Role in functioning of mechanisms of

accumulation of professional

knowledge.

40

Types of Memory

By character of the mental activity

prevailing in activity

The impellent Storing and reproduction of

movements. Underlies training to

household, sports, labor skills, written

speech.

Emotional (for

the first time has

entered

Strongly keeps the feelings endured by

the person.

By

K.S.Stanislavsky

Storing, conservation and reproduction

of the read, heard or said words.

Semantic (verbal) Allows to remember visual and sound

images, the smells accompanying the

given situation.

41

Types of Memory

By character of the purposes of activity

Consensual (Voluntary) – storing

and reproduction in which there

is no special purpose something

to remember or remember

With it the basic part of life

experience of the person is

formed

Any (Involuntary) – storing and

reproduction at which there is a

special purpose something to

remember or remember.

With it the person receives

professional and other

special knowledge.

42

Literature

• Anatomy and physiology. - The

McGraw−Hill, Companies, 2003

• www.mhhe.com/seeley6