Observers commonly experience functional blindness to unattended visual events, and this problem has fuelled an intense debate concerning the fate of unattended visual information in neural processing. Here we used functional magnetic resonance imaging (fMRI) to demonstrate that the type of task that a human subject engages in determines the way in which ignored visual background stimuli are processed in parahippocampal cortex. Increasing the perceptual difficulty of a foveal target task attenuated processing of task-irrelevant background scenes, whereas increasing the number of objects held in working memory did not have this effect. These dissociable effects of perceptual and working memory load clarify how task-irrelevant, unattended stimuli are processed in category-selective areas in human ventral visual cortex.
Bibliographical noteFunding Information:
This research was supported by National Institutes of Health (NIH) grant EY014193 (M.M.C.). It was also partly supported by a Vanderbilt University Discovery Grant (M.M.C.), NIH grant F32 EY015043 (G.F.W.) and National Science Foundation grant BCS 0094992 (R.M.).
All Science Journal Classification (ASJC) codes