Abstract
This paper investigates the memory disorder of Alzheimer-type dementia by comparing the performance of Alzheimer patients on selected memory tests with that of Korsakoff patients and healthy controls. Alzheimer patients have deficits in both primary and secondary memory, and this finding is compared with that which pharmacological studies predict would occur on the basis of cholinergic depletion. The deficits in primary memory are unlikely to be accounted for in terms of cholinergic depletion, and provide a possible explanation for the disappointing results of trials of cholinergic replacement therapy in this disorder. On the other hand, the pattern of deficit in secondary memory is entirely consistent with that expected from cholinergic depletion.