Eye position-dependent activation of neurones in striate cortex of macaque.

Extracellular recordings were made in the striate cortex in awake, behaving monkeys to test the influence of the eye position on cellular activity. Two monkeys (Macaca mulatta) were trained to fixate a small spot at 25 different eye positions. About half (52%) of the studied neurones showed a selective gaze field (GF). The cells' activities increased significantly when the monkey fixated at this field of view. For the majority of these neurones, GFs were located at the contralateral field of view with respect to the hemisphere from which responses were recorded, and were usually found a few degrees peripheral to the related receptive field. Eye position-dependent neurones were found at different depths of cortex, but mostly in the superficial layers. The results indicate that some neurones in striate cortex may code information about eye position and could contribute to target localization in a head-centred coordinate system by combining retinal and afferent eye position signals.