Congenital Prosopagnosia without Object Agnosia? A Literature Review

One of the longstanding controversies in the neuropsychology literature concerns the functional organization of high-level vision, and the extent to which

the recognition of different classes of visual stimuli engage a single or multiple, independent underlying mechanisms. We explore this issue in the context

of congenital prosopagnosia (CP), a neurodevelopmental disorder in which individuals, without a history of brain damage and with normal sensory and

cognitive abilities, are impaired at face recognition. Whereas many researchers have asserted that individuals with CP have face-selective deficits, others

have claimed that the deficit extends to the recognition of stimuli from other visual classes as well. This paper reviews 119 published reports of CP (a

total of 716 cases) from 1976 to 2016, and examines the evidence for associations or dissociations of face and object recognition behavior. The results

revealed that, of the 238 CP cases with data permitting a satisfactory evaluation of behavior, 80.3% had an associated face and object recognition deficit

whereas 19.7% evinced a dissociation between face and object recognition. We evaluate the strength of the evidence and correlate the face and object

recognition behavior where possible. We discuss the frequent pattern of an association between face and object recognition deficits along with the less

frequent case of dissociation, consider the implications for theories of functional organization of the visual system, and make suggestions for further

adjudication of the relationship between face and object recognition in prosopagnosia and object agnosia.