Making a Scene in the Brain

 

Russell Epstein
Department of Psychology
University of Pennsylvania

epstein@psych.upenn.edu

 Abstract

When we experience the visual world, we experience it in the form of objects embedded within a surrounding scene.  While considerable efforts have gone into understanding object recognition, the problem of scene recognition has garnered much less attention.  Neuroimaging data suggest that the human brain contains specialized systems for scene perception that are distinct from the more well-study systems involved in object perception.  In particular, two cortical regions -- the parahippocampal place area (PPA) and retrosplenial complex (RSC) -- respond more strongly when subjects view scenes such as landscapes, cityscapes, and rooms than when they view other stimuli such as faces or decontextualized objects.  These findings lead to the inevitable question: why do these regions respond so strongly to scenes?  In this talk, I will present evidence that the preferential response to scenes in the PPA and RSC reflects the engagement of mechanisms that extract navigationally-relevant information from visual input.  In particular, the PPA and RSC appear to support distinct but complementary mechanisms for place recognition, with the PPA encoding a viewpoint-specific "snapshot" of the local scene and RSC supporting processes that allow the local scene to be situated within the broader spatial environment.  I will also discuss results from fMRI adaptation studies that provide insight into how these regions encode scenes in order to mediate their distinct recognition functions.