Neuronal activity in the frontal eye field of the monkey is modulated while attention is focused on to a stimulus in the peripheral visual field, irrespective of eye movement

We tested the hypothesis that the frontal eye field (FEF) is involved in attention to the peripheral visual field (PVF). Neuronal activity was recorded in the FEF of two monkeys while they were performing three oculomotor tasks. In the visual attention task (VAT), the monkeys released a lever when a lest stimulus (TS) presented in the PVF dimmed while they were looking at a central fixation point (FP). In the visual saccade task (VST), the monkeys exhibited saccadic eye movements when the FP was extinguished. In the visual fixation task (VFT), the monkeys released the lever when the FP dimmed. Overall, the activities of 80 FEF neurons were examined. The responses to visual stimuli of 41 of these neurons (51%) were modulated during the VAT. Twenty-five neurons showed pre-saccadic activity. Of these, 13 neurons (52%) exhibited activity modulation during the VAT. Eighteen neurons showed no pre-saccadic activity. Of these, 10 neurons (56%) exhibited activity modulation during the VAT. These results suggest that the FEF is involved in selecting the visual stimuli relevant to performing a task irrespective of eye movements. (C) 1997 Elsevier Science Ireland Ltd.