Differential effects of age and cerebral atrophy upon span of immediate recall and paired-associate learning in older patients suspected of dementia.

Seventy-eight patients suspected of dementia, 50 years of age or older and without evidence of focal cerebral lesion or systemic illness, were administered the Digit-Span Forward and Paired-Associate Learning subtests of the Wechsler Memory Scale. Computerized axial tomography, allowing a visualization and measurement of the lateral ventricles and cortical sulci, was employed to measure cerebral atrophy. Four groups were defined as follows: (1) age 50-69, without atrophy (N = 27), (2) age 50-69, with atrophy (N = 17), (3) age 70-89, without atrophy (N = 18), (4) age 70-89, with atrophy (N = 16). Results of analyses of variance indicate that Digit-Span is affected by cerebral atrophy but not by age, while Paired-Associate Learning is affected by both age and cerebral atrophy. No interaction effect between age and cerebral atrophy was found for either task. These results are discussed within the context of previous research, and implications for both models of memory and theories of the effects of cerebral atrophy in different ag groups are suggested.