Abstract
We examined the relations between three simple intelligence tests and the WAIS-III in patients with Alzheimer's disease (AD) , as well as changes in intelligence caused by the disease. The subjects were 78 AD patients (21 males and 57 females) who met the diagnostic criteria of DSM-IV and NINCDS-ADRDA. Their average age was 81.6 ± 6.0 years. We conducted three simple intelligence tests (HDS-R, MMSE, and RCPM) and the WAIS-III . Significant correlations (moderate to strong) were observed between each of the simple intelligence tests and the WAIS-III FIQ, VIQ, and PIQ, and we concluded that the concurrent validity observed with WAIS-R (the old version of WAIS) was maintained. From the correlations with the WAIS-III performance subtests, it seems that RCPM is strongly related to constructional ability and figure cognitive processes, but somewhat weakly related to analogical ability. As to the changes in intellectual function caused by AD, low scores for “ similarities” and “comprehension” implied a decrease of abstract thinking and common sense, while relatively high scores for “digit span” and “matrix reasoning” suggested that intelligence fields such as short verbal memory and convergent thinking are little affected by the disease.
