Abstract
Lesions to the ventral occipital lobe can produce severe deficits in color vision (achromatopsia) and face recognition (prosopagnosia). But because most studies focused on relatively few cases, uncertainty remains about precisely which cortical loci, when damaged, produce each syndrome. We attempted to localize the cortical regions implicated in both disorders using a meta-analysis of case reports from the literature. We identified all cases with either disorder that contained readable axial images depicting the lesion, 65 cases in total. Lesion locations were manually traced onto cortical templates in a standard stereotactic space and projected onto a 2-dimensional axial slice. Many patients had symptoms of both disorders: only 12 had impaired color perception with spared face perception, and only 8 had impaired face perception with spared color perception while 28 had both (17 did not report data regarding one of the syndromes). For achromatopsia, a voxel-by-voxel analysis revealed a single region of maximum lesion overlap in the ventral occipital lobe near Talairach coordinates (22, −76, −3). Of the 10 achromatopsic subjects with right-hemisphere lesions, 9 had a lesion at this location, while only 4 of the 7 prosopagnosic subjects with right-hemisphere lesions had a lesion at this location. Nearby locations showed similar patterns, and distant locations showed little overlap. For prosopagnosia, the most selective location was in the ventro-lateral occciptial lobe (34, −86, −12). This site was lesioned in 6/7 right-hemisphere cases and 3/10 right-hemisphere achromatopsia cases. However, many distant locations showed almost as selective a pattern, including near the Fusiform Face Area. Although rare, selective cases of achromatopsia and prosopagnosia provide evidence for a single region in cortex, that when lesioned, produces deficits in color vision. Face recognition appears to have a more distributed set of regions in which damage can produce a deficit.