Hemispheric efficiency in middle and later adulthood.
Right and left hemisphere efficiency, as measured by dichotic memory for numbers, was assessed in a sample of older adults in Experiment I. Right hemisphere efficiency dropped off sharply with age, while left hemisphere efficiency did not show a significant decline. A second group of subjects was tested on a musical note recognition task in Experiment II. Regression analyses revealed significant age decrements in performance, regardless of ear/hemisphere involved. The writers suggested that the reported decline with age in spatial ability may result from an age related decline in right hemispheric functioning, even on tasks that are right hemisphere dominant. The lack of decline reported for verbal ability may be a consequence of the lack of decline in left hemisphere efficiency with regard to left hemisphere dominant tasks.