Aging and scanning of imagined and perceived visual images.

The authors examined adult age differences in the proficiency of visually scanning across perceived and imagined displays. Participants were asked to indicate whether an arrow in the central region of a square grid ring pointed to a target square. The distance between arrow and target was varied, and all participants showed the expected increase in response times and error rates as scanning distance increased. The arrow and grid display either remained visible until the participant responded (perceptual condition) or disappeared after 50 ms (imagery condition). In both conditions, older participants required more time to scan and made more errors as distance increased than did younger participants. These findings conflict with previous studies showing that perceptual and imagery scanning are preserved with aging. Although methodological factors may have contributed to these differences, further research is needed to elucidate effects of aging on visual scanning.