After the injection of the antioxidant, oxymethacil (4-5 micrograms/kg), in an investigation in monkeys of the processes of delayed visual recognition, their cognitive characteristics were significantly improved.: the duration of the short-term storage of information increased (by a factor of 2-3) and the time of the motor reaction decreased. The improvement of the cognitive characteristics was accompanied by changes in the neuronal activity in the visual cortex at all stages of recognition. The activity of the majority of the neurons increased in the case of discrimination without delay, it decreased significantly in the case of delayed discrimination. The administration of oxymethacil induced an increase in the auto- and cross-correlation coefficients in the respondent reactions of the recorded groups of neurons. The results obtained suggest that oxymethacil possesses nootropic properties, and the participation of the visual cortex of monkeys in the realization of these properties for the improvement of cognitive characteristics.