[A neuropharmacological analysis of individual preference for the probability and quality of reinforcement].

Under the influence of diazepam in doses of 0.2-2.0 mg/kg in a situation of different probability and value of a reinforcement the dogs--sanguinics and melancholics change their strategy of behavior, from the preference at norm of a reinforcement of the low probability but the better quality to that of the high probability but the worse quality. Under the same conditions the strategy of behaviour of cholerics and phlegmatics practically does not change. The change of behaviour strategy under the influence of diazepam in sanguinics and melancholics is proposed to be connected with a depressing effect of the drug on the hippocampus and amygdala and simultaneous activation of the hypothalamus and the frontal cortex. The data obtained are discussed from the position of P. V. Simonov's concept on the four above-mentioned brain macrostructures as the basis of the type of the higher nervous activity and behaviour of animals and man.