Abstract
Previous neuroimaging results indicate that reflective processes such as working memory and mental imagery can increase activity in category-selective extrastriate (CSE) cortical areas whose preferred category is that of the item held in mind. Recent classification studies also show that some CSE areas demonstrate exemplar-specific activity during perception for items of the preferred category, and that early visual cortex contains information about simple stimuli (e.g., oriented gratings) held in working memory. The aim of the present study was to determine to what extent item-specific information about complex natural scenes is represented in different human cortical areas (both in early visual cortex and several scene-selective extrastriate areas) during both perception and visual mental imagery. We used a multi-voxel classification analysis of moderately high-resolution fMRI data and found item-specific scene information represented in multiple areas including middle occipital gyrus (MOG), parahippocampal place area (PPA), retrosplenial cortex (RSC), and precuneus/intraparietal sulcus (PCu/IPS). Furthermore, item-specific information from perceiving scenes was partially re-instantiated during mental imagery of the same scenes. In addition, we examined voxels in the fusiform face area (FFA) and found that, despite the area's preference for face stimuli, item-specific scene information was represented there as well. These results suggest that 1) item-specific natural scene information is carried in both scene- and face-selective extrastriate areas during perception and 2) activity induced in CSE areas by reflective tasks such as mental imagery does carry information relevant to maintaining the specific representation in question.
National Institute on Aging, National Science Foundation.