[The formation of conditioned reflexes to a complex signal in ontogeny under the conditions of an alternation choice].

Formation of conditioned reflex to simultaneous complex stimulus (light + sound) and its components was studied in alternation task (Go/Go) in kittens aged 1.5-10 months. Low percentage of correct reactions (48-57%) and preference of one of the two reinforced directions were shown in kittens aged 1.5-5 months. Successful learning in alternation task was attained in kittens which began to be trained at the age of 6 months. Extirpation of sensorimotor cortex in the trained animals aged 7 months and older induced a decrease of the level of correct reactions from 75-80% to 20-40% and preference of one direction. The problems of parallel development of interaction between the sensory and motor systems and sensorimotor cortex are discussed.