Vol. 21, No. 2
Voxel-based Lesion Analysis of Category-Specific Naming on the Boston Naming Test
1 Center for Aphasia and Related Disorders, VA Northern California Health Care System
2 Department of Neurology, University of California, Davis
3 Center for Research in Language, University of California, San Diego
Case studies in the literature have reported individual patients who show striking dissociations in their ability to name items from distinct categories (e.g., living versus non-living things). Neuroimaging studies have attempted to delineate the brain basis of such category dissociations. Some of these studies have reported specific brain regions associated with discrete categories, while other studies have reported largely overlapping networks. In the current study, we analyzed naming performance in a large group of left hemisphere patients (n = 92), using voxel-based lesion symptom mapping (VLSM) to identify brain regions associated with specific categories of items (animals vs. tools, natural kinds vs. artifacts, and manipulable vs. non-manipulable items). The maps revealed very few dissociations across the three category comparisons but rather showed consistent regions in primarily left middle and superior temporal cortex associated with naming across categories. We also examined our dataset for individuals demonstrating a discrepancy in naming across categories. Out of 92 patients, there were four such individuals, but the lesion sites associated with impaired category naming were not consistent. The current findings are consistent with the notion of a distributed network in the left temporal lobe that underlies naming across different semantic and feature-based categories.