Sometime in the 1940s, a young man with a gun shot wound on the head woke up after treatment and suddenly realized he could not recognize any of his family, relatives and friends. He became one of the early medically treated cases of what is now medically and psychologically known as prosopagnosia or in lay man’s terms, face blindness.
Although there have been some early documented cases of prosopagnosia, it was not until 1947 that German neurologist, Joachim Bodamer coined the term prosopagnosia from the Greek words prosopon which means face and agnosia which means non-knowledge. A person suffering from this disorder has the ability to recognize objects but has an impaired ability to recognize faces.
The causes of this disorder have as yet to be determined but some researchers suppose that it might have something to do with damages on the fusiform gyrus which is regarded as that part of the brain which is related to face recognition. Another disorder closely related to prosopagnosia is prosophenosia in which patients who suffer damages in the temporal and occipital lobes become unable to recognize faces.
Prosopagnosia was at first thought of as solely resulting from damages to some parts of the brain resulting from injury but there is evidence that the disorder may also be congenital or hereditary, with some form of prosopagnosia occurring more commonly among ordinary people than originally imagined.
Since recognition of faces and associated memories of faces and other information on people are crucial in socialization, people with prosopagnosia also find it hard to relate normally among social circles.
To date there are three subtypes of prosopagnosia, Developmental, Associative and Apperceptive prosopagnosia. Developmental prosopagnosia may possibly be a kind of congenital prosopagnosia in which patients are born with selective impairment in face recognition.
Associative prosopagnosia occurs when patients cannot connect the faces of people and the mental information they have of these people. Persons with this disorder may be able to make sense of facial features and determine the sex and probable age of people but cannot associate their facial features with such data as name and occupation.
Apperceptive prosopagnosia is probably the most severe subtype. Those with this disorder simply cannot make any sense of faces at all, although they may be able to deduce a person’s identity by scrutinizing clothing, voice, mannerisms and movements.
While the study of prosopagnosia and its treatment is still at an early stage, the nature of the disorder itself has come to aid the medical and psychological fields in the study of perception. Somehow, studies in prosopagnosia point to the possibility that the human brain has specific areas in the brain responsible for perception.
In related studies on consciousness, it has also been determined through studies with patients with prosopagnosia that although patients with this disorder cannot recognize people just by looking at their faces, some form of recognition happens when an emotional prompt is used. This implies that in recognition, feelings, emotions and stored emotional memories may play a role in recognition.
