Aging and the perception of 3-D shape from dynamic patterns of binocular disparity

Abstract

In two experiments, we investigated the ability of younger and older observers to perceive and discriminate 3-D shape from static and dynamic patterns of binocular disparity. In both experiments, the younger observers' discrimination accuracies were 20% higher than those of the older observers. Despite this quantitative difference, in all other respects the older observers performed similarly to the younger observers. Both age groups were similarly affected by changes in the magnitude of binocular younger observers. Both age groups were similarly affected by changes in the magnitude of binocular disparity, by reductions in binocular correspondence, and by increases in the speed of stereoscopic motion. In addition, observers in both age groups exhibited an advantage in performance for dynamic stereograms when the patterns of binocular disparity contained significant amounts of correspondence "noise." The process of aging does affect stereopsis, but the effects are quantitative rather than qualitative.

Aging and the perception of local surface orientation from optical patterns of shading and specular highlights

“…The results of Experiment 1 support previous findings of age-related deficits in the stereoscopic perception of 3-D shape (Norman et al, 2000;Norman, Crabtree, et al, 2006), as well as the findings in those studies that have found reductions in stereoacuity with increasing age (Bell, Wolf, & Bernholz, 1972;Brown, Yap, & Fan, 1993;Haegerstrom-Portnoy, Schneck, & Brabyn, 1999;Jani, 1966;Wright & Wormald, 1992). It is interesting to note that whereas all of the studies to date in which the stereoscopic perception of 3-D shape has been evaluated have shown significant effects of age, the studies in which stereoacuity and aging have been evaluated have had mixed and contradictory results.…”

“…Previous studies have similarly shown that younger observers' performance is not adversely affected when their retinal illuminance is reduced by neutral density filters to match the lowered retinal illuminance that normally exists for older observers because of lens opacification or senile miosis (see Bennett, Sekuler, & Ozin, 1999, in which little or no effect of reduced retinal illumination for high-noise conditions was shown; see also Elliott, Whitaker, & MacVeigh, 1990;Habak & Faubert, 2000;Norman, Clayton, Shular, & Thompson, 2004;Norman, Crabtree, et al, 2006). The present results and those of the previous studies suggest that the various effects of age that have been obtained are not due to optical factors but, rather, to neurophysiological changes within the visual system.…”

“…Given the extensive amount of research that has been conducted to date, it is surprising that no studies have yet examined how aging affects older observers' abilities to perceptually utilize optical patterns of shading and highlights. Aging is known to affect the ability of older observers to extract information about 3-D shape from random dot stereograms (Norman, Crabtree, et al, 2006;Norman, Dawson, & Butler, 2000), patterns of motion parallax (Andersen & Atchley, 1995;Norman, Clayton, Shular, & Thompson, 2004), and kinetic depth effect displays (Norman et al, 2000). The primary purpose of our present set of experiments was to rectify this lack of information and evaluate the ability of older observers to utilize shading and Younger and older observers' ability to perceive local surface orientation from optical patterns of shading and specular highlights was investigated in two experiments.…”

“…Previous studies in which the effects of age upon the perception of 3-D shape have been evaluated have utilized sparsely sampled dotted surfaces (e.g., conventional random dot stereograms and kinetic depth effect displays; see Andersen & Atchley, 1995;Norman, Clayton, et al, 2004;Norman, Crabtree, et al, 2006;Norman et al, 2000). Such studies are important because their stimuli contained only a single source of information about 3-D shape.…”

Accounting for speed–accuracy tradeoff in perceptual learning

“…Within the diffusion model, response bias can be implemented in two different ways: as starting point bias, or drift rate bias (Diederich & Busemeyer, 2006; Ratcliff & McKooon, 2008; Voss, Rothermund, & Brandtstädter, 2008). Starting point bias refers to the whether the starting point is equidistant between the two response boundaries, whereas drift rate bias refers to whether the drift rates for signal (which are positive) and those for noise (which are negative) are equidistant from zero.…”