Abstract
Scenes are rich visual stimuli depicting places containing both spatial and identity associations. As such, associative processing should be fundamental to scene understanding. To test this hypothesis, we examined novel contextual associative processing in relation to scene processing using fMRI. Scene processing engages a network of brain regions: the parahippocampal cortex (PHC), the retrosplenial complex (RSC), and the transverse occipital sulcus. To the extent that associative processing is fundamental to scene processing, we expected: 1) differential BOLD activity within these regions related to associations; 2) a correlation between this activity and associative learning, reflecting a relationship between associative processing and brain function; and 3) the pattern of BOLD signal related to associative processing would be similar to the pattern related to scene categorical processing, suggesting associations are inherent to scene representation. Novel spatial and identity associations between meaningless novel shapes were taught to participants over a 30-minute training period. Afterwards, fMRI was used while participants viewed the trained associative shapes, scenes, and objects. ROI analyses in the PHC and RSC found significantly more activity for associative shapes compared with non-associative shapes. This differential activity correlated with learning, supporting our association hypothesis. However, these regions showed different patterns of correlation revealing complimentary roles: results from the PHC suggest a process that separates spatial and identity associations; in contrast, results from the RSC suggest a process of combining spatial and identity components into a holistic representation. Moreover, the pattern of activity coding for associations also coded for scene categories (hallways, roads, and intersections) in that identity associative activity discriminated semantically different scenes, whereas spatial associative activity discriminated scenes differing in spatial configuration. Results demonstrate that associative processing in different domains may be reflected in the complimentary information processing roles of PHC and RSC. This elucidates psychological and neural mechanisms underlying scene understanding.
Meeting abstract presented at VSS 2013