Selection of events in time enhances activity throughout early visual cortex.

Temporal selection poses unique challenges to the perceptual system. Selection is needed to protect goal-relevant stimuli from interference from new sensory input. In addition, contextual information that occurs at the same time as goal-relevant stimuli may be critical for learning. Using fMRI, we characterized how visual cortical regions respond to the temporal selection of auditory and visual stimuli. Critically, we focused on brain regions that are not involved in processing the target itself. Participants pressed a button when they heard a prespecified target tone and did not respond to other tones. Although more attention was directed to auditory input when the target tone was selected, activity in primary visual cortex increased more after target tones than after distractor tones. In contrast to spatial attention, this effect was larger in V1 than in V2 and V3. It was present in regions not typically involved in representing the target stimulus. Additional experiments demonstrated that these effects were not due to multimodal processing, rare targets, or motor responses to the targets. Thus temporal selection of behaviorally relevant stimuli enhances, rather than reduces, activity in perceptual regions involved in processing other information.