Abstract
The recovery of perceptual functions that occur following cortical damage can offer key insights into the nature and plasticity of brain organization. In this respect, studies of individuals post-lobectomy/hemispherectomy offer a unique window into the nature and extent of cortical plasticity. First, in contrast with more common lesions, the extent of the damage in such patients can be extreme (i.e. an entire hemisphere in some cases) yet, at the same time, very well controlled - both cortical and subcortical structures of the remaining hemisphere are typically intact. Second, the extent of the recovery is often disproportionate relative to the extent of the damage - many compromised functions are regained partly or even completely. Using fMRI, our present work characterizes the changes in topography in extrastriate cortex in children who have undergone surgical lobectomy or hemispherectomy of ventral cortex in either hemisphere (compared with control participants who have undergone resections to other areas such as dorsal cortex). We also map language areas in each individual as an anchor for hemispheric dominance. We uncover atypicalities in the selectivity maps to common visual categories (face, object, and word) in the ventral patients and show changes in their development/reorganization over time. Overall, the current results suggest that extensive removal of visual cortex lead to atypical/diminished selectivity for common visual categories despite the absence of major recognition difficulties and that, in some cases, reorganization may result in somewhat more typical selectivity maps.
Meeting abstract presented at VSS 2015