Texture provides crucial information about the category or identity of a scene. Nonetheless, not much is known about how the texture information in a scene is represented in the brain. Previous studies have shown that the parahippocampal place area (PPA), a scene-selective part of visual cortex, responds to texture ensemble in simple patches. However, in natural scenes, textures exist in spatial context within a scene. Here, we tested two hypotheses that describe how textures within a scene context are represented in the PPA. The Texture-Only hypothesis suggests that the PPA represents texture ensemble (i.e., the kind of texture) as is, irrespective of its location in the scene. On the other hand, the Texture & Location hypothesis suggests that the PPA represents texture and its location within a scene (e.g., ceiling or wall) conjointly. We test these two hypotheses across two experiments using different but complementary methods. In Experiment 1, by using multivoxel pattern analysis (MVPA) and representational similarity analysis, we found that the representational similarity of the PPA activation patterns was significantly explained by the Texture-Only hypothesis, but not by the Texture & Location hypothesis. In Experiment 2, using a repetition suppression paradigm, we found no repetition suppression for scenes that had the same texture ensemble but differed in location (supporting Texture & Location hypothesis). Based on these results, we proposed a framework to reconcile contrasting results from the MVPA and repetition suppression and to allow for a more specific conclusion about how texture is represented in the PPA.
- multi-voxel pattern analysis
- Parahippocampal Place Area
- repetition suppression
- scene perception
- Copyright © 2016, Journal of Neurophysiology