The first studies on monkeys were carried out at the Leningrad Zoo. Then it became clear that the physiological parameters of the higher nervous activity of monkeys were very different from those established in dogs. This prompted Pavlov to the need for a systematic study of the behavior of monkeys at the Biostation on the shore of Lake Koltush. A year after the construction of Ivan Petrovich’s laboratory, the chimpanzees were transferred to a specially built "anthropoid" house. Thus, the first primatological nursery in Russia and the world’s northernmost primatological nursery was organized on the basis of the Koltush biological station, which served as the beginning of a systematic study of the physiological mechanisms of the complex behavior of anthropoids.
The main task of the academician in the study of anthropoids was to provide a physiological explanation of their intelligence. Therefore, the experiments were set up so that it was possible to trace the accumulation of life experience and its use in solving new problems by the monkey.
In 1933, Peter Konstantinovich Denisov brought two chimpanzees from France — Raphael and Rosa. From this moment, studies of motor conditioned reflexes in chimpanzees and their cognitive capabilities began. In 1935 Denisov conducted experiments in which chimpanzees had to get a highly suspended banana using a pyramid from boxes, pour fire, pull out oranges and open various boxes. Mikhail Petrovich Shtodin studied the behavior of anthropoids together with Denisov.
It turned out that in anthropoids, in comparison with lower animals, orientational-research activity is developed, there are more complex and long chains of conditioned reflexes used to solve problem problems. Pavlov concluded that the behavior of animals cannot be interpreted only on the basis of conditioned reflexes. He viewed this activity as an association of associations, that is, as a chain of conditioned reflexes formed due to the great motor abilities and perfect orientation of anthropoids in space.
In the postwar years, the study of complex forms of behavior of higher and lower monkeys began and their comparison with the behavior of normal children and oligophrenics. In those same years, a rigid maze technique was developed to study the cognitive abilities of chimpanzees when solving problematic problems.
Erasm Grigorievich Vatsuro studied the intellect and psyche of anthropoids. The scientist studied conditioned reflex reactions to relationships in animals at different levels of evolutionary development, and in children of different ages in health and disease.
In 1950, Leonid Grigorievich Voronin returned to Koltushi, and until 1954, under his leadership, comparative studies of the leading stream of nerve impulses (afferentation) of chimpanzees, positive and negative conditioned reflexes, a conditioned reflex for time and on a chain of stimuli were carried out.
Since 1954, research on monkeys has been carried out in two laboratories. One of them, the laboratory of comparative ontogenesis of higher nervous activity of lower apes, was headed by Boris Pavlovich Pavlov. Trace conditioned reflexes and the efficiency of the central nervous system were studied there.
The second laboratory, the physiology of higher nervous activity, was headed by Fyodor Petrovich Mayorov, who joined Ivan Petrovich’s research back in 1928. Under his leadership, research was carried out on active choice, motivation, memory, imitative activity on anthropoids.