We used functional magnetic resonance imaging (fMRI) and electroencephalography (EEG) to measure neural changes associated with training configural processing in congenital prosopagnosia, a condition in which face identification abilities are not properly developed in the absence of brain injury or visual problems. We designed a task that required discriminating faces by their spatial configuration and, after extensive training, prosopagnosic MZ significantly improved at face identification. Event-related potential results revealed that although the N170 was not selective for faces before training, its selectivity after training was normal. fMRI demonstrated increased functional connectivity between ventral occipital temporal face-selective regions (right occipital face area and right fusiform face area) that accompanied improvement in face recognition. Several other regions showed fMRI activity changes with training; the majority of these regions increased connectivity with face-selective regions. Together, the neural mechanisms associated with face recognition improvements involved strengthening early face-selective mechanisms and increased coordination between face-selective and nonselective regions, particularly in the right hemisphere.

Neuropsychological, event-related potential (ERP), and functional magnetic resonance imaging (fMRI) methods were combined to provide a comprehensive description of performance and neurobiological profiles for K.W., a case of congenital prosopagnosia. We demonstrate that K.W.'s visual perception is characterized by almost unprecedented inability to identify faces, a large bias toward local features, and an extreme deficit in global/configural processing that is not confined to faces. This pattern could be appropriately labeled congenital integrative prosopagnosia , and accounts for some, albeit not all, cases of face recognition impairments without identifiable brain lesions. Absence of face selectivity is evident in both biological markers of face processing, fMRI (the fusiform face area [FFA]), and ERPs (N170). Nevertheless, these two neural signatures probably manifest different perceptual mechanisms. Whereas the N170 is triggered by the occurrence of physiognomic stimuli in the visual field, the deficient face-selective fMRI activation in the caudal brain correlates with the severity of global processing deficits. This correlation suggests that the FFA might be associated with global/configural computation, a crucial part of face identification.