A role for top-down attentional orienting during interference between global and local aspects of hierarchical stimuli.

Various models of selective attention propose that greater attention is allocated toward target stimuli when conflicting distracters make selection more difficult, but compelling evidence to support this view is scarce. In the present experiment, 15 participants performed a cued global/local selective attention task while brain activity was recorded with event-related functional magnetic resonance imaging. The presence of conflicting versus nonconflicting distracters during target processing activated regions of frontal, parietal, and visual cortices that were also activated when participants oriented attention in response to global- and local-task cues. These findings support models in which conflict between target and distracter stimuli is resolved by more selectively focusing attention upon target stimuli.