[A neuropsychological index of aging--data from 9000 elderly people].

Cerebral functions degenerate at different rates in different people, and it is often necessary to measure these functions accurately: for example, to assess the condition of patients with senile dementia. We used newly developed tests and measured the functions of 9000 elderly people. The Kana Pick-out Test was one of the test used, in which the examinee is asked to circle only the 5 vowel-kanas as many as possible within two minutes and also to retain the meaning of the story. Functions of the prefrontal lobe was found to be similar among people of similar age. It was also found to be linearly and inversely associated with age. With the results of these tests, abnormal declines in function were relatively easy to detect.