Reflection of internal and external determinants of behavior in the neuronal activity of the neostriatum of monkeys.

It has been demonstrated that some neurons of the neostriatum of monkeys (Macaca nemestrina) participate in supporting the reaction of the animal to the appearance of standard situations in which a decision is made on the basis of already existing skills. Other neurons (primarily non-baseline active), by contrast, are activated in nonstandard situations, when the use of existing skills is ineffective. It is hypothesized that their activity is associated with the shift of the animal to a different activity which consists in the rejection of the use of existing skills for the formation of new skills.