Lecture 8 Organism integrative activity and behavioral physiological bases (the higher nervous activity, behavioral congenital and acquired forms, memory, thinking and speech).

Human behaviour includes 2 reactions types:

1. genotypic – it is based on genetic proggramme;

2. phenotypic – it is linked with genotype, environmental conditions interactions or it may be individually aquired, based on study.

Hereditary behaviour forms

These are unconditioned reflexes, individual and of species, stereotypic organism reactions to external and internal stimuli performed by CNS. Main distinguishing feature of such reflexes – they determine reflexes expressed without preliminary study. For example, stomach juice releasing at food coming into oral cavity, hand taking off at noceoceptive irritation, winking while air coming into one’s eye. Try to check them up in new-borns and you’ll see that they are performed without any study.

Unconditioned reflexes – are instincts; they are fundamental phenomenon in highest nervous activity forming. One can differentiate 3 types of them:

1. Vital – they provide individual and species organism preserving:

• alimentary;

• drinking;

• dream;

• defence et al.

They are directed to organism forces economy; their disorders lead to individual’s physical death.

2. Zoo-social – they may be realized only by interconnection with other individuals of the same species:

• sexual;

• paternal;

• territorial;

• of groups et al.

3. Reflexes of self-development – they are oriented to new spatial-temporary environments discovery; addressed to future:

• investigations;

• reflex of freedom;

• plays;

• mimicry et al.

Instincts organization

It is rather complicated. External (key) stimuli are triggers in their realizing. Every stimule switches stereotypic reactions on as a rule consequent motor acts the result of which is any reaction performance. One can differentiate 2 categories of brain reflectory processes:

• Of preparation – triggering, motivational. Their activity are connected with less specific reactions and is controlled by organism internal needs in more extent. Motivational reflexes are also called drive-reflexes (from "drive”-“motive”). They are hunger, thirst, fear, fury. Their main peculiarity is motor activity general mobilization.

• Efferent – are linked with multiple specific reactions onto stimuli.

Each unconditioned reflex is characterized by definite behaviour. For example, hunger reaction initiates food-getting reactions expressing in motor anxiety and sensor systems activation. Ending phase of food-getting behaviour is efferent reflex – mastication and swallowing. Efferent reflex triggering (alimentary one in this case) is realized with participation of sensor (olfactory, gustatory) reception, emotional-motivational aspect is important for this. Food itself as unconditioned stimulus causes congenital emotinal reaction – gustatory and olfactory receptors excitement.

Unconditioned reflexes are congenital, species, relatively constant, reactions occuring as an answer to definite receptive field irritation. Brain stem and subcortical structures are essential for their realizing. They are remained after cortex removal although naturally they are realized at its participation under norma too.