Abstract
When we look at scenes, we notice not only what objects are in a scene but also how these objects are arranged in a scene. How do object identity and layout contribute to scene representation in the brain? Previous imaging studies have identified one object-selective cortical region in lateral occipital complex (LOC) and several scene-selective cortical regions, including the parahippocampal place area (PPA), the retrosplenial cortex (RSC) and the transverse occipital sulcus (TOS). Using an fMRI adaptation paradigm, we examined how activities in these four regions (LOC, PPA, RSC, and TOS) are modulated by object identity and object layout changes in scenes. In each trial, participants were shown a sequential presentation of two scene images. Compared to the first image, the second image was 72% in size and could be either identical to the first image, containing only object layout change, containing only object identity change (in which all the objects in a scene changed identity), or containing both object layout and identity changes. Participants judged whether there were any difference between the two scenes. Behavioral results show that people were more accurate and faster with object layout than with object identity changes. Using a regions-of-interest approach, preliminary fMRI results showed that PPA and LOC were sensitive to both object identity and object layout changes, with the effects from the two types of changes being additive; TOS and RSC, on the other hand, only showed sensitivity to object layout changes. These results suggest that the contribution of object identity and object layout to scene representation differ in different brain areas.
Meeting abstract presented at VSS 2012