Category-selective deficits are the exception and not the rule: Evidence from a case-series of 64 patients with ventral occipito-temporal cortex damage

The organisational principles of the visual ventral stream are still highly debated, specifically the relative association/dissociation between word and face recognition. Reports of dissociations between word and face recognition stem from reports of category-selective impairments in single case-studies, and more recently neuroimaging investigations of healthy participants. Despite the historical reliance on single case-studies, more recent group studies have highlighted a greater commonality between word and face recognition. Studying individual patients with rare selective deficits misses (a) important variability between patients, (b) associations between task performance, and (c) patients with mild, severe and/or non-selective impairments; meaning that the full spectrum of deficits is unknown. The Back of the Brain project assessed the range and specificity of visual perceptual impairment in 64 patients with posterior cerebral artery stroke. Patients were recruited based on lesion localization and not behavioral performance. Group-level data-driven and single-subject case-series analyses revealed the full range of visual perceptual deficits. In both analyses, the general organisational principle was of associations between words and faces. Category-selective deficits were the exception and not the rule. This large-scale investigation of posterior cerebral artery stroke patients highlights the bilateral representation of visual perceptual function.