Processing of perceived visual shape in the human lateral occipital complex

The human lateral occipital complex (LOC) has been implicated in visual recognition. Does the LOC represent higher-level shape information rather than low-level image features? To address this question event-related fMRI adaptation was used in which lower neural responses were observed for two identical than two different consecutively presented stimuli. Adaptation across a change between two stimuli implicates a common neural representation invariant to that change. A set of studies with stereoscopically defined displays showed that the sameness of perceived shape rather than of low-level contours is necessary and sufficient for adaptation in the LOC. These results indicate that the LOC represents perceived shape rather than low-level features of objects. Further studies addressed the question how abstract these shape representations are by testing for adaptation in the LOC across changes in the 3-D structure of objects. In particular, these studies tested adaptation (a) across rotations and changes in the 3-D configuration of objects, and (b) between 3-D shapes defined by binocular (ie stereo) or monocular (ie shading) depth cues and 2-D silhouettes of the same objects