Authors:

Gregory, C., Lough, S., Stone, V., ERZINCLIOGLU, S., MARTIN, L., BARON-COHEN, S. & HODGES, J.R.

Reference:

Year of publication:

2002

CBU number:

5053

Abstract:

A key aspect of social cognition is the ability to infer other peopleís mental states, thoughts and feelings; referred to as ìtheory of mindî (ToM). We tested the hypothesis that the changes in personality and behaviour seen in frontal variant frontotemporal dementa (fvFTD) may reflect impairment in this cognitive domain. Tests of ToM, executive and general neuropsychological ability and were given to 19 fvFTD patients, a comparison group of Alzheimerís disease patients (AD, n = 12) and matched healthy controls (n = 16). Neuropsychiatric assessment was undertaken using the Neuropsychiatric Inventory (NPI). Patients with fvFTD were impaired on all tests of ToM (first-order false belief; second-order false belief; faux pas detection; and Reading the Mind in the Eyes) but had no difficulty with control questions designed to test general comprehension and memory. By contrast, the AD group failed only one ToM task (second-order false belief), which places heavy demands on working memory. Performance on the faux pas test revealed a double dissociation, with the fvFTD group showing deficits on ToM-based questions and the AD group failing memory-based questions only. Rank order of the fvFTD patients according to the magnitude of impairment on tests of ToM and their degree of frontal atrophy showed a striking concordance between ToM performances and ventromedial frontal damage. There was a significant correlation between the NPI score and more sophisticated tests of ToM in the fvFTD group. This study supports the hypothesis that patients with fvFTD, but not those with AD, are impaired on tests of ToM, and may explain some of the abnormalities in interpersonal behaviour that characterize fvFTD.