Effect of degraded viewing on visual asymmetry patterns in older adults.

Twelve young adults (18-23 years) and 12 older adults (62-79 years) were tested on a discrimination task under clear and degraded viewing conditions. Stimulus quality in the degraded viewing condition was manipulated by a spatial filtering process. Discrimination judgments were significantly slower and less accurate for right visual field trials than for left and central visual field trials under the degraded viewing condition. Although older adults exhibited slower reaction times and less accuracy than did younger adults, visual field patterns were independent of age. The present results provide additional support for the spatial frequency hypothesis and also support the hypothesis that hemispheric changes in processing with age are not selective but generalized across both hemispheres.