Large-scale visuomotor integration in the cerebral cortex. Cereb Cortex

Efficient visuomotor behavior depends on integrated processing by the visual and motor systems of the cerebral cortex. Yet, many pre-vious cortical neurophysiology studies have examined the visual and motormodalities in isolation, largely ignoring questions of large-scale cross-modal integration. To address this issue, we analyzed event-related local field potentials simultaneously recorded from multiple visual, motor, and executive cortical sites in monkeys performing a visuomotor pattern discrimination task. The timing and cortical location of four aspects of event-related activities were examined: stimulus-evoked activation onset, stimulus-specific processing, stimulus category--specific processing, and response-specific pro-cessing. Activations appeared earliest in striate cortex and rapidly thereafter in other visual areas. Stimulus-specific processing began early in most visual cortical areas, some at activation onset. Early onset latencies were also observed in motor, premotor, and pre-frontal areas, some as early as in striate cortex, but these early-activating frontal sites did not show early stimulus-specific process-ing. Response-specific processing began around 150ms poststimulus in widespread cortical areas, suggesting that perceptual decision formation and response selection arose through concurrent pro-cesses of visual, motor, and executive areas. The occurrence of stimulus-specific and stimulus category--specific differences after the onset of response-specific processing suggests that sensory and motor stages of visuomotor processing overlapped in time