A2 Psychology Perception - Prosopagnosia

Condition where sufferers are unable to recognise familiar faces.Originally thought of as caused by acute brain damage, but a congenital form has been found that is inherited by 2.5% of the population.Specific brain area usually associated with Prosopagnosia is the fusiform gyrus.The right fusiform gyrus seems to be involved in making a more general appraisal of the face. Compares to the brains database to see if it is a familiar face. If a match is found then the anterior temporal cortex brings up a store of facts about that person. There is also the interior optical gyri which is sensitive to slight physical changes such as wrinkles.

Explanation oneThat it is a face specific problem and those with Prosopagnosia only have trouble recognising faces.EvidenceThis theory is supported by PET and fMRI scans which show that the right fusiform gyrus is more active when recognising faces.Barton et al believes that face recognition uses specific parts of the brain and the process involved is different to the process involved in other object recognition.case studies such as W.J provide further evidence for this theory.PET and fMRI scans are very scientific and give us hard evidence that the right fusiform gyrus is involved in face recognition.

ExplanationThat it is not a face specific problem and suggests that people with Prosopagnosia have difficulty recognising other objects.EvidenceGauthier and Tarr found that the Fusiform gyrus was activated in keen birdwatchers when identifying birds but not cars and activated in car enthusiasts when watching cars and not birds. This suggest that the FFA is activated when we are observing things that are important to us and faces are an important part of everyone's life.There is also evidence that shows people with Prosopagnosia have difficulty recognising other everyday objects.

Humphrey's et alStudies three patients with Prosopagnosia. All three were unable to recognise faces. However they were all as good as normal people at judging facial expression. This supports explanation one.Young et alInvestigated face perception in 34 ex servicemen who had received acute injury to the back of the head. Some were poor at familiar face recognition, some at matching unfamiliar faces and others found it difficult to read facial expressions. This supports the model that there are different parts of the brain used in different aspects of face recognition.McNeil and WarringtonW.J. A man who developed Prosopagnosia after strokes. He could not select the famous face when shown together with unknown faces. But he later went into sheep farming and could tell his sheep apart, but not faces. Supports the explanation one.

New ways of helping sufferers have been discovered because of research and prosopagnosics are now encouraged to use different cues when identifying people.A lot of the data is from case studies which can not be generalised because the results may be unique to that individual.Not always useful to compare face recognition with other object recognition. Face recognition may just be harder.Many of the studies lack ecological validity. Because participants are asked to recognise unfamiliar faces rather than familiar ones. It is more important to research the area of recognising faces of family and friends.