Aging does not affect integration times for the perception of depth from motion parallax

Abstract

To successfully navigate throughout the world, observers must rapidly recover depth information. One depth cue that is especially important for a moving observer is motion parallax. To perceive unambiguous depth from motion parallax, the visual system must integrate information from two different proximal signals, retinal image motion and a pursuit eye movement. Previous research has shown that aging affects both of these necessary components for motion parallax depth perception, but no research has yet investigated how aging affects the mechanism for integrating motion and pursuit information to recover depth from motion parallax. The goal of the current experiment was to assess the integration time required by older adults to process depth information. In four psychophysical conditions, younger and older observers made motion and depth judgments about stationary or translating random-dot stimuli. Stimulus presentations in all four psychophysical conditions were followed by a high-contrast pattern mask, and minimum stimulus presentation durations (stimulus-to-mask onset asynchrony, or SOA) were measured. These SOAs reflect the minimum neural processing time required to make motion and motion parallax depth judgments. Pursuit latency was also measured. The results revealed that, after accounting for age-related delays in motion processing and pursuit onset, older and younger adults required similar temporal intervals to combine retinal image motion with an internal pursuit signal for the perception of depth. These results suggest that the mechanism for motion and pursuit integration is not affected by age.

Conspicuity of Various Colored Express Lane Delineators: Matching or Contrast?

“…In contrast, the results in Table 2 indicate that drivers in the youngest age group generally exhibit stronger scores in visual Optec tests (visual sensory function). Considering the relevant literature on aging, sensory performance, and driving performance ( 19 – 30 ), this reinforces the notion that time to notice is more dependent on age (experience) than on pure perceptual ability.…”

“…Based on an overview of the whole dataset, there was no statistically significant difference among the three age groups across most of the driving scenarios because of the effect of scenario presentation. However, a review of the literature ( 19 – 30 ) reinforces the notion that poor eyesight, in the context of old age, is generally associated with worse driving performance (higher crash risk, increased time requirement for motion processing, and pursuit latency). The experimental results verify that older participants indeed suffer worse eyesight (Table 2), but also suggest that experience (age) plays a role in noticeability of the delineators.…”

“…Furthermore, it is the CS of the most impaired eye that affects crash risk ( 23 – 26 ). The increased age-related risk may be because of concordant decreases in depth perception that also come with age ( 27 , 28 ) and result both from losses in CS and parallax ( 29 ). Holmin and Nawrot ( 30 ) also found that the increased time needed by older adults was because of increased time needed for motion processing and pursuit latency.…”