Verbal and visuospatial performance and aging: a neuropsychological approach.

The hypothesis that aging and hemispheric laterality interact to produce relatively greater decrements in older individuals in right hemispheric dominant (visuospatial) than left hemispheric dominant (verbal) tasks was examined in 24 early middle-aged (M = 37.6 yr) and 24 older (M = 71.2 yr) males equated for education. Participants performed structurally similar verbal and visuospatial paired-associated learning tasks (the Stark test) that have been found sensitive to left and right hemispheric dysfunction, respectively. They were also given the Shipley Institute for Living Scale and the Memory-for-Designs Test. No group differences were present on the Shipley verbal age scale, but the older group had significantly lower Shipley abstraction ages and memory-for-designs scores. They made more errors than the middle-aged group on both the verbal and visuospatial learning tasks. Similar patterns were found when the data were reanalyzed by decade cohorts. These data do not support the notion of a laterality effect associated with aging.