Strong Samantha L, Al-Rababah Ayah I, Davies Leon N
School of Optometry, Aston University, Birmingham, UK.
J Vis. 2024 Dec 2;24(13):12. doi: 10.1167/jov.24.13.12.
Changes in contrast and blur affect speed perception, raising the question of whether natural changes in the eye (e.g., cataract) that induce light scatter may affect motion perception. This study investigated whether light scatter, similar to that present in a cataractous eye, could have deleterious effects on speed perception. Experiment 1: Participants (n = 14) completed a speed discrimination task using random dot kinematograms. The just-noticeable difference was calculated for two reference speeds (slow; fast) and two directions (translational; radial). Light scatter was induced with filters across four levels: baseline, mild, moderate, severe. Repeated measures analyses of variance (ANOVAs) found significant main effects of scatter on speed discrimination for radial motion (slow F(3, 39) = 7.33, p < 0.01; fast F(3, 39) = 4.80, p < 0.01). Discrimination was attenuated for moderate (slow p = 0.021) and severe (slow p = 0.024; fast p = 0.017) scatter. No effect was found for translational motion. Experiment 2: Participants (n = 14) completed a time-to-contact experiment for three speeds (slow, moderate, fast). Light scatter was induced as Experiment 1. Results show increasing scatter led to perceptual slowing. Repeated measures ANOVAs revealed that moderate (F(3, 39) = 3.57, p = 0.023) and fast (F(1.42, 18.48) = 5.63, p = 0.020) speeds were affected by the increasing light scatter. Overall, speed discrimination is attenuated by increasing light scatter, which seems to be driven by a perceptual slowing of stimuli.
对比度和模糊度的变化会影响速度感知，这就引发了一个问题：眼睛的自然变化（如白内障）引起的光散射是否会影响运动感知。本研究调查了类似于白内障眼中存在的光散射是否会对速度感知产生有害影响。实验1：14名参与者使用随机点运动图完成了一项速度辨别任务。计算了两种参考速度（慢；快）和两个方向（平移；径向）的最小可觉差。通过滤光片在四个水平上诱导光散射：基线、轻度、中度、重度。重复测量方差分析发现，散射对径向运动的速度辨别有显著的主效应（慢：F(3, 39) = 7.33，p < 0.01；快：F(3, 39) = 4.80，p < 0.01）。对于中度（慢：p = 0.021）和重度（慢：p = 0.024；快：p = 0.017）散射，辨别能力减弱。对于平移运动未发现影响。实验2：14名参与者完成了三种速度（慢、中、快）的接触时间实验。如实验1那样诱导光散射。结果表明，散射增加导致感知变慢。重复测量方差分析显示，中度（F(3, 39) = 3.57，p = 0.023）和快速（F(1.42, 18.48) = 5.63, p = 0.020）速度受光散射增加的影响。总体而言，速度辨别会因光散射增加而减弱，这似乎是由刺激的感知变慢所驱动。
