A deficit in covert attention after parietal cortex inactivation in the monkey.

Although the parietal cortex has been repeatedly implicated in controlling attention, the nature and importance of this contribution remain unclear. Here we show that inactivating the lateral intraparietal area in monkeys delays the detection of a visual target located in the contralateral visual field. This effect was observed using different visual scene configurations, e.g., with distractors that differ in number or that differ from the target by a conjunction of shape and color or by a single feature. Since eye movements were not allowed during the searching tasks, these results argue for an unambiguous role of the parietal cortex in the top-down control of attentional deployment in space.