Activity of neurons related to eye movements during drowsiness in the frontal cortex of the macaca monkey

During our extensive study of the supplementary eye field (SEF) in relation to eye and arm movements, we had the opportunity to record the activity of 25 out of 315 cells during both saccade task and drowsiness states. All 25 cells showed a phasic, spatially selective postsaccadic activity that was not related to fixation. During drowsiness, the discharge was time locked with the onset of the slow movement, had increased duration, and was not spatially selective. These preliminary data suggest that saccade neurons present in SEF are also involved in the motor processes of slow eye movements during drowsiness.