Identification of famous faces and famous names in early Alzheimer's disease. Relationship to anterograde episodic and general semantic memory.

We assessed remote memory in 33 patients with dementia of Alzheimer's type (DAT) with Mini-Mental State Examination (MMSE) scores between 17 and 30, and 30 matched controls using a Famous Faces Test and Famous Names Test designed to assess face recognition, identification and naming, and name recognition and identification, respectively, together with a range of anterograde episodic and semantic memory tests. Patients with DAT were impaired on all components of the remote memory tests, i.e. famous face recognition, identification and naming, and famous name recognition and identification. There was also evidence of a modest temporal gradient, with relatively greater impairment of more recent memory, which may be artefactual resulting from the very insidious onset of their anterograde amnesia. In contrast to the uniform impairment of anterograde memory, there was considerable heterogeneity in performance on remote memory. Although the DAT patient group's performance on remote memory measures was impaired with respect to controls, some patients had significant impairment on all measures, whereas others had intact remote memory. Overall, there was only a weak correlation between dementia severity and remote memory, and no correlation between performance on the Faces and Names tests and measures of anterograde memory. At a cognitive level, the deficit in face and name processing in DAT involved recognition, identification and naming. This would suggest that so called 'face and name recognition units', semantic knowledge of famous persons and post-semantic processing are all affected by the disease. There was also supporting evidence for the concept that recognition of famous faces and names both draw on common sources. Similar results were found for face and name identification. This suggests that face and name recognition units are closely linked, and that identification of a face or name accesses the same central pool of semantic knowledge regarding the famous person. Performance on famous names tests correlated, to a limited degree, with that on general semantic tests, suggesting that knowledge of famous people, at least as accessed by names, is associated with general semantic memory. By contrast, no correlation was found between performance on the famous faces and on other general semantic tasks.