Neural basis of saccade target selection in frontal eye field during visual search

Abstract

CONSPICUOUS visual features commonly attract gaze^1,2, but how the brain selects targets for eye movements is not known. We investigated target selection in rhesus monkeys performing a visual search task³ by recording neurons in the frontal eye field, an area known to be responsible for generating purposive eye movements^4,5. Neurons with combined visual- and eye movement-related activity were analysed. We found that the initial visual responses to search stimulus arrays were the same whether the target or a distractor was in the response field. We also found that the neural activity evolved to specify target location before the execution of eye movements, ultimately peaking when the target was in the response field and being suppressed when the target was beside but not distant from the response field. These results demonstrate a possible mechanism by which a desired target is fixated and inappropriate eye movements are prevented.