[Relation of the effect of psychostimulants on learning ability to internal and external factors].

It has been shown in rat experiments that the action of psychostimulants on the learning ability of rats in a T-shape maze and Dombrovskaya's maze depends to a greater degree on the problem complexity rather than on its type. The learning ability was enhanced in animals which responded to stress by the manifestations of the avoidance conditioned reflex. Sydnocarb and amphetamine were capable to abolish "passive" responding to stress and to enhance the learning ability. Individual level of the animals' investigative effort affected insignificantly the changes in the learning ability induced by psychostimulants (sydnocarb, amphetamine, caffeine, acephen, piracetam, euclidan).