[Activity of neurons of the prefrontal cortex of monkeys during conditioned reflex activity]

Chronic experiments on macaques, trained to perform a delayed choice of the side of the conditioned signal, revealed the characteristics of unit responses in the prefrontal cortex to the stimuli, in relation to which the animals organized their behavior, i.e. warning, conditioned and triggering stimuli. The delay period differed from that of expectancy for the conditioned signal ("non-specific expectancy"): in the delay period the discharge frequency of 56 neurones depended on the lateralization of the conditioned signal. The connection between the rearrangements of neuronal spike activity and the process of the short-term memory and the formation of the programme of the adaptive behaviour is discussed.