Prosopagnosia, or face blindness in layman terms, is a rare disorder of face perception where the ability to perceive and understand faces is impaired, although other basic perceptual skills, such as recognising and discriminating objects, may be relatively intact.
Face perception is the process by which the brain and mind understand and interpret the face, particularly the human face. The face is an important site for the identification of others and conveys significant social information. In view of the importance of its role in social interaction, psychological processes involved in face perception are known to be present from birth, complex, involve large and widely distributed areas in the brain.
Most cases have been reported following focal or localized brain injury, such as physical trauma (head injury), stroke, aneurysm or neurological illness, such as disorders of the central nervous system (brain, brainstem and cerebellum), the peripheral nervous system (neuropathy, including cranial nerves), or the autonomic nervous system (parts of which are located in both central and peripheral nervous system). More recently, cases of congenital or developmental prosopagnosia have also been reported.