Abstract
Neuroimaging studies in human adults have identified three cortical regions involved in scene processing: the parahippocampal place area (PPA), the retrosplenial complex (RSC), and the occipital place area (OPA). While the precise function each of these regions plays in scene processing is unclear, results from several studies suggest that scene processing may be divided into two distinct neural pathways: one for “active” navigation, including RSC and OPA; and the other for recognizing scene categories (e.g., “bedroom,” “playground,” “desert”), including PPA. Indeed, two recent experiments demonstrated that while RSC and OPA encode both direction (left/right) and egocentric distance (near/far) information – information crucial for navigation – the PPA does not, challenging its role in navigation. Furthermore, behavioral research has shown that human children and non-human animals rely more on direction and distance information during navigation tasks, but use length and angle information during object recognition tasks. Although length and angle information may not directly support navigation, they nevertheless define a scene’s overall shape and configuration of the extended surface boundaries and may thus be used for recognizing scene categories. We hypothesize then that PPA, if part of the scene categorization stream, will encode length and angle information in scenes. To test our prediction, we used fMRI adaptation in human adults to measure the sensitivity to changes in length and angle information in scenes in each of the three scene-selective regions. We found sensitivity to both length and angle in PPA and OPA, but not in RSC, supporting the hypothesis that PPA is involved in the recognition of scene category, but not in navigation.
Meeting abstract presented at VSS 2015