The role of spatial selective attention in working memory for locations: Evidence from event-related potentials

We investigated the hypothesis that the covert focusing of spatial attentio n mediates the on-line maintenance of location information in spatial worki ng memory. During the delay period of a spatial working-memory task, behavi orally irrelevant probe stimuli were flashed at both memorized and nonmemor ized locations. Multichannel recordings of event-related potentials (ERPs) were used to assess visual processing of the probes at the different locati ons. Consistent with the hypothesis of attention-based rehearsal, early ERP components were enlarged in response to probes that appeared at memorized locations. These visual modulations were similar in latency and topography to those observed after explicit manipulations of spatial selective attenti on in a parallel experimental condition that employed an identical stimulus display.