Abstract
It remains unclear which face-selective areas contribute to DP, whether areas outside the face processing system play a role in DPs' deficits with faces, and whether DPs show reduced selectivity in other category-selective areas. To address these issues, we scanned 22 DP participants and 27 controls with a dynamic localizer as well as areas selective for scenes, bodies, and objects. To avoid the complications inherent in comparing groups using typical threshold-based approaches, we analyzed each category-selective area by selecting a fixed percentage of the most selective voxels for each anatomical region that typically contains a category-selective response and then systematically probed the effect of ROI size on category-selectivity. DP face selectivity was reduced in all 12 face ROIs and was significantly reduced in four right hemisphere ROIs and left FFA. In all cases, the face-selectivity reductions were driven by weaker responses to faces. Selectivity differences in ventral and dorsal ROIs as well as anterior and posterior ROIs were comparable. Results for other category-selective ROIs were mixed. DPs showed reduced selectivity in all three scene-selective areas in the right hemisphere (PPA, OPA, RSC), and a signficiant reduction in left PPA. In body-selective ROIs, DPs showed marginally reduced selectivity in EBA bilaterally and non-significant reductions in FBA bilaterally. Object-selectivity in bilateral lateral occipital cortex (LO) and bilateral posterior fusiform (pFs) was normal. Selectivity reductions for faces and other categories were restricted to ROI that showed a preferential response to that category. In summary, DPs have widespread selectivity reductions throughout the face processing system. Reduced selectivity was also present in a number of areas selective for non-face categories. These findings suggest many DPs have broad impairments involved in visual recognition.
Meeting abstract presented at VSS 2018