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

Abstract

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.

Aging and perception of visual form from temporal structure.

“…Thus, for example, older individuals exhibit deficits in detection of low-contrast moving contours (Sekuler, Hutman, & Owsley, 1980), in perception of optic flow (Atchley & Andersen, 1998), in perception of self-motion from optic flow (Warren, Blackwell, & Morris, 1989), in detection of coherent motion in the presence of noise (Bennett, Sekuler, & Sekuler, 2007;Gilmore, Wenk, Baylor, & Stuve, 1992;Snowden & Kavahagh, 2006), and in the discrimination of differences in motion speed (Norman, Ross, Hawkes & Long, 2003;Snowden & Kavanagh, 2006). Could impaired motion perception be at the root of our older participants' performance on the TS task?…”

Gaze-eccentricity effects on road position and steering.

“…To this end, there exists evidence supporting the claim that neck position and head movements not only play significant roles in the handling of retinal flow, but that the information from these efferent signals is useful (and used) in making judgments of where one is going (Crowell, Banks, Shenoy, & Anderson, 1998). Finally, returning to the notion of gaze eccentricity in general, the stimulated area of the retina does not appear to be an important factor in the effectiveness of heading perception under laboratory conditions (Crowell & Banks, 1993; but see also Atchley & Andersen, 1998), thereby implying that this perceptual capacity is not impaired directly through presentation of stimuli away from the fovea.…”

The discrimination of heading from optic flow is not retinally invariant

“…Recently, Atchley and Andersen (1998) examined this issue by measuring differences between older and younger observers in sensitivity to optic flow components (including radial motion) at different retinal eccentricities. The observers were presented with radial flow fields in which the coherence of the motion pattern was adjusted until it was no longer detectable.…”

“…The average results for 20 college-age observers are presented in Figure 5, along with the data from Experiments 1 and 3. As is shown in Figure 5, the graph for sensitivity to radial flow is re- Atchley and Andersen (1998), in which motion coherence thresholds were derived for radial motion. markably similar to the heading thresholds observed in Experiments I and 3.…”