Visual receptive fields and movement fields of visuomovement neurons in the monkey premotor cortex obtained during a...

Single-neuron activity in the premotor cortex of monkeys was examined while they performed a visually guided reaching task with their eyes fixated. We recorded a total of 177 visually responsive neurons that showed significantly enhanced activity after a presentation of visuospatial cue ('visual response'). Of these neurons, 57% (n = 101) also showed significantly enhanced activity after an onset of the go-signal and before movement ('movement-associated response'). These were designated as 'visuomovement neurons'. The visual response latencies of 81% of the visuomovement neurons were between 60 and 160 ms (median = 100 ms) and the response durations were less than 240 ms in 80% of the neurons. The preferred direction of the visual response (PDV) was toward the contralateral side in 57% and the ipsilateral side in 20% of the neurons. The preferred direction of the movement-associated response (PDM) was toward the contralateral side in 50% of the neurons. In most of the neurons (74/101, 73%), the PDV and the PDM corresponded to approximately the same direction. These results suggest that premotor visuomovement neurons play a role in receiving visuospatial information for visually guided reaching, and commanding reaching movements.