Rapid Invariant Encoding of Scene Layout in Human OPA

Abstract

Successful visual navigation requires a sense of the geometry of the local environment. How do our brains extract this information from retinal images? Here we visually presented scenes with all possible combinations of five scene-bounding elements (left, right, and back walls; ceiling; floor) to human subjects during functional magnetic resonance imaging (fMRI) and magnetoencephalography (MEG). The fMRI response patterns in the scene-responsive occipital place area (OPA) reflected scene layout with invariance to changes in surface texture. This result contrasted sharply with the primary visual cortex (V1), which reflected low-level image features of the stimuli, and the parahippocampal place area (PPA), which showed better texture than layout decoding. MEG indicated that the texture-invariant scene layout representation is computed from visual input within ∼100 ms, suggesting a rapid computational mechanism. Taken together, these results suggest that the cortical representation underlying our instant sense of the environmental geometry is located in the OPA.

Keywords: MEG; fMRI; navigation; scene elements; scene perception; spatial layout.