Abstract
In order to investigate the possible role of the prefrontal association cortex (PFC) in the periphe ral visual attention, we examined the neuronal activities in the PFC while the monkey is performing a visual attention task (VAT) and a visual fixate a small spot was dimmed in the VAT. While recording sessions, these tasks were tested in blocks. It was confirmed that the monkey is using different attent ive state in two task conditions by measuring the reaction time of the very first trial of each block. Visual responses of 81 neurons were analyzed in detail. Of these, 53% were either enhanced (25%) or suppressed (27%) during the VAT. In 43 neurons, activities during saccade toward thestimuluspresented within the receptive field was also tested. Of these, 25 neurons showed pre-saccadic activities (saccadic neurons) and 18 neurons showed no pre-saccade activities (non-saccadic neurons). Among the saccadic neurons, activities of 68% were modulated during the VAT. Ammong the non-saccadic neurons, 61% were modulated during the VAT. These results suggests that the PFC is involved in the visual information processing, such as, selecting the relevant visual stimuli in the visual world without eye movement as well as with eye movement.
