Holmin Jessica, Nawrot Mark
Center for Visual and Cognitive Neuroscience, Department of Psychology, North Dakota State University, P.O. Box 6050, Fargo, ND 58108-6050, USA.
Center for Visual and Cognitive Neuroscience, Department of Psychology, North Dakota State University, P.O. Box 6050, Fargo, ND 58108-6050, USA.
Vision Res. 2017 Nov;140:81-88. doi: 10.1016/j.visres.2017.05.016. Epub 2017 Sep 5.
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.
为了在世界各地成功导航，观察者必须迅速恢复深度信息。对于移动的观察者来说，一个特别重要的深度线索是运动视差。为了从运动视差中感知明确的深度，视觉系统必须整合来自两个不同近端信号的信息，即视网膜图像运动和追踪眼球运动。先前的研究表明，衰老会影响运动视差深度感知的这两个必要组成部分，但尚未有研究调查衰老如何影响整合运动和追踪信息以从运动视差中恢复深度的机制。当前实验的目的是评估老年人处理深度信息所需的整合时间。在四种心理物理学条件下，年轻和年长的观察者对静止或平移的随机点刺激进行运动和深度判断。在所有四种心理物理学条件下的刺激呈现之后都紧接着一个高对比度的图案掩蔽，并测量了最小刺激呈现持续时间（刺激与掩蔽开始的异步时间，即SOA）。这些SOA反映了做出运动和运动视差深度判断所需的最短神经处理时间。还测量了追踪潜伏期。结果显示，在考虑了与年龄相关的运动处理延迟和追踪起始延迟之后，年长和年轻的成年人在将视网膜图像运动与内部追踪信号相结合以感知深度方面需要相似的时间间隔。这些结果表明，运动和追踪整合机制不受年龄影响。
