Age-related changes in performance on a visual-closure task.

A sample of 645 volunteer subjects, 50-79 years of age, took part for two consecutive years in a neuropsychological study of perception and memory. The sample was divided into three age groups (50-59, 60-69, and 70-79) in order to examine any age-related changes in performance. On a visual-closure task, similar to that of Gollin (1960), all age groups showed significant improvements in performance (savings) with repeated exposure to the drawings, both after a 15-min, and again after a 1-year, time interval. There were significant differences, however, between the different age groups on all aspects of the task, including number of errors made during initial perceptual performance, percentage of savings over both short- and long-time intervals, and number of items recalled. These findings are contrasted with those from studies of implicit and explicit aspects of verbal memory in normal young and old people, which have found no age-related differences in implicit memory abilities. Implications of these findings, as they relate to the neuropsychological assessment of memory in older people, are discussed briefly.