The lesions associated with prospagnosia are found in the ventral occipitotemporal cortex and are usually bilateral(ref dam sergent) however there is evidence of cases of prosopagnosia associated with damage confined to the right hemisphere (Derenzi and Derenzi et al.) .
In addition to the neuropsychological support evidence from normal subjects suggests that face perception is dissociated from object recognition. For example, beginnging shorly after birth infants prefer to gaze at faces (Morton and Johnson). Infnats will also pefer to track faces rahter than other moving patterns soon after birth (Morton J jo). The effect of face inversion has been cited as evidence that face percepyion is mediated by a specialised system. It is markedly more difficult to identfy an upside-down face. The detrimental effect of inversion is moe marked for faces than for non face stimuli (Cog Neuro & Haxby in reader). Prosopagnosiacs do not show performance impairment fro inverted faces suggesting that faces may be processed more like objects within these individuals. Haxby et al suggests that given this evidence the face percetion system is not engaged effectively by viewing inverted faces but such reasoning seems dubious. For example it may be postulated that inverted faces are no longer faces but rather abstract objects that need discerning on a part based system before actual face recognition can occur. The account of prospagnosiacs not showing the inversion effect can then be accounted for by arguing that face recognition operates in an holistic manner involving neural systems whcich are collectively activated when faces are veiwed upright. During veiwing of inverted faces the necessary stimuli for the holistic response is momentarily absent until the part based system necessary for object recognition discerns that the image is a face. This information is then transferred to the neural system that participates in holisyic face perception and I=s thus the image is peceived as an inverted face.