Abstracts

RATIONALE: Impaired discrimination and memory for newly presented faces of unfamiliar people has been well-documented in epilepsy patients with right temporal lobe lesions. The impact of these visual processing limitations on the ability to recognize faces of familiar people has not been studied as well.
METHODS: Left hemisphere language dominant temporal lobe epilepsy (TLE) patients who had undergone right (n=25) and left (n=16) anterior temporal lobectomy(ATL)and healthy controls were tested for their knowledge about 20 photographed people who had been very famous in the ten years or so preceding testing.
RESULTS: Both right and especially left ATL groups were significantly impaired in their spontaneous naming of photographed individuals. When allowed to demonstrate their knowledge of the famous people through verbal descriptions or responses to phonemic cues, left ATL patients[ssquote] performance improved to normal levels, but right ATL patients were still impaired. Whereas spontaneous naming of famous people correlated with verbal abilities (naming and recognition memory for words), knowledge of other characteristics of the famous people correlated with perceptual matching and recognition memory of newly presented unfamiliar faces.
CONCLUSIONS: Results indicate that right temporal lobe lesions impair the recognition of familiar faces (prosopagnosia), and that this is associated with defects in perceptual discrimination and memory for unfamiliar faces. Though this study only examined recognition of the faces of famous people, the pattern of relationships among measures leads us to expect that right ATL patients would show similar difficulties recognizing personally relevant familiar faces. Furthermore, preliminary data suggest that prosopagnosia is not simply a function of ATL, but is present in right TLE patients prior to epilepsy surgery. These findings have significant import for the social adjustment of TLE patients.