Abstract
Prosopagnosia is an impairment in the recognition of faces which is known in two variants, congenital (cPA) as well as acquired prosopagnosia (aPA). Recently, it was shown that cPA often leads to a reduction of face specific processing in general and face specific configural processing in particular. In two experiments using a Thatcher illusion paradigm and a simultaneous matching paradigm with faces and houses, we tested 14 patients with cPA that is associated with impaired face recognition but with no macroscopic brain lesions. As a control group, normal participants with an adjusted age range were used. In Exp.1, for subjects with cPA the speed of a grotesqueness decision (RT) in a Thatcher illusion task (a highly demanding configural task) where faces were rotated in steps of 30° was strictly linearly related to the magnitude of the deviation from upright. In Exp.2, subjects with cPA showed face-specific reduction of face matching performance, but no reduction of performance when houses had to be matched. Moreover, the face-specific matching problems did occur most strongly when faces differed in relational aspects only. Results from both experiments indicate that cPA is tightly linked with reduced face-specific configural processing abilities.