The neural mechanisms of top-down attentional control

Selective visual attention involves dynamic interplay between attentional c ontrol systems and sensory brain structures. We used event-related function al magnetic resonance imaging (fMRI) during a cued spatial-attention task t o dissociate brain activity related to attentional control from that relate d to selective processing of target stimuli. Distinct networks were engaged by attention-directing cues versus subsequent targets. Superior frontal, i nferior parietal and superior temporal cortex were selectively activated by cues, indicating that these structures are part of a network for voluntary attentional control. This control biased activity in multiple visual corti cal areas, resulting in selective sensory processing of relevant visual tar gets.