Refreshing and integrating visual scenes in scene-selective cortex.
Constructing a rich and coherent visual experience involves maintaining visual information that is not perceptually available in the current view. Recent studies suggest that briefly thinking about a stimulus (refreshing) can modulate activity in category-specific visual areas. Here, we tested the nature of such perceptually refreshed representations in the parahippocampal place area (PPA) and retrosplenial cortex (RSC) using fMRI. We asked whether a refreshed representation is specific to a restricted view of a scene, or more view-invariant. Participants saw a panoramic scene and were asked to think back to (refresh) a part of the scene after it disappeared. In some trials, the refresh cue appeared twice on the same side (e.g., refresh left-refresh left), and other trials, the refresh cue appeared on different sides (e.g., refresh left-refresh right). A control condition presented halves of the scene twice on same sides (e.g., perceive left-perceive left) or different sides (e.g., perceive left-perceive right). When scenes were physically repeated, both the PPA and RSC showed greater activation for the different-side repetition than the same-side repetition, suggesting view-specific representations. When participants refreshed scenes, the PPA showed view-specific activity just as in the physical repeat conditions, whereas RSC showed an equal amount of activation for different- and same-side conditions. This finding suggests that in RSC, refreshed representations were not restricted to a specific view of a scene, but extended beyond the target half into the entire scene. Thus, RSC activity associated with refreshing may provide a mechanism for integrating multiple views in the mind.
Park
Soojin
S
Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139, USA. sjpark31@mit.edu
Chun
Marvin M
MM
Johnson
Marcia K
MK
D000293:Adolescent; D000328:Adult; D001931:Brain Mapping; D002540:Cerebral Cortex / Q000502:physiology*; D003463:Cues; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D010775:Photic Stimulation; D021641:Recognition, Psychology / Q000502:physiology*; D013850:Thinking / Q000502:physiology*; D014796:Visual Perception / Q000502:physiology*