The effect of age, retinal eccentricity, and speed on the detection of optic flow components.

Forty observers participated in a study examining the effect of age on the detection of motion in central and peripheral vision. Detection of lamellar (Experiment 1) and radial flow (Experiment 2) was measured for 20 younger observers and 20 older observers (10 men and 10 women in each group). Motion thresholds were measured for angles of 0 degree, 10 degrees, 20 degrees, and 40 degrees off fovea. The results indicated significant differences between older and younger adults for both motion types. The effect of age was mediated by the gender of the observer as well as the retinal eccentricity of the display. Older women showed higher thresholds for lamellar flow at fovea, consistent with previous findings. The findings suggest that age-related changes in visual information processing are affected by changes in the temporal characteristics of the motion processing system. A model is proposed in which 2 different streams of processing are used for the recovery and use of motion information.