Declining of memory functions of normal elderly persons.

Two studies examined the declining of memory functions in normal elderly persons using the Yokota memory test (YMT), which includes 15 items concerning verbal and non-verbal memory functions. In the first study, 552 subjects over 40 years of age in five age groups were examined. Factor analysis revealed that YMT consisted of two factors pertaining to short-term/working memory, and two factors pertaining to long-term memory. It is suggested that the former was more affected than the latter, with aging. In the second study, YMT was examined in relation to the revised version of Hasegawa dementia scale (HDS-R), which was the most popular intelligence scale for the elderly in Japan. As a result, memory functions differentially declined with the decreasing score of HDS-R, which suggests that memory functions differentially declined with progressive risk of dementia.