[The forms of cognitive activity in monkeys and apes]

Cognitive functions were compared in three species of primates (Cebus apella, Macaca mulatta, Pan troglodytes). Under identical conditions, studies have been made on the ability of identify two-dimensional natural images corresponding to three-dimensional objects basing on a modified "sample-to-sample" method. It was shown that monkeys learned to solve these tasks via multilevel combination of visual pictures with voluminous objects, being able to translate the principle elaborated from one set of stimuli to another. Apes exhibit the ability of direct translation of two-dimensional objects to three-dimensional ones using former experience in solving new tests of various complexity.