Prosopagnosia is the inability to recognize faces. There are varying degrees of impairment and in some cases only the recognition of familiar faces may be affected. There is usually preservation of other aspects of visual processing and intellectual functioning. With the most extreme impairment the sufferer cannot distinguish faces from other objects or their own faces. The ability to recognize faces is anatomically located in the fusiform gyrus and damage to this area leads to prosopagnosia.
Causes include 1: