Long G M, Homolka J L
Department of Psychology, Villanova University, PA 19085.
Perception. 1992;21(6):753-64. doi: 10.1068/p210753.
The contrast sensitivity functions of college students for grating targets presented at angular velocities of 0, 30, 60, and 90 deg s-1 were determined for target durations of 200 and 600 ms. The most pronounced effects of target movement were evident at the mid to high spatial frequencies in which sensitivity was markedly reduced as velocity increased. These adverse effects were greatest in the 200 ms condition, in which performance was largely limited to the saccadic eye movement system. In the 600 ms condition, in which both saccadic and smooth pursuit eye movements were possible, contrast sensitivity for the low-frequency target actually improved significantly for the 30 and 60 deg s-1 targets, whereas only adverse effects of target motion were found for targets of mid and high spatial frequencies. The results are discussed in terms of the limitations of traditional visual assessment procedures and the practical and theoretical benefits of conceptualizing the joint effects of target composition and target movement.
针对在0、30、60和90度/秒角速度下呈现的光栅目标，测定了大学生在目标持续时间为200毫秒和600毫秒时的对比敏感度函数。目标运动最显著的影响在中高空间频率处最为明显，随着速度增加，敏感度显著降低。这些不利影响在200毫秒条件下最为显著，此时表现很大程度上局限于眼球的扫视运动系统。在600毫秒条件下，扫视和平滑跟踪眼球运动都有可能，对于低频目标，30和60度/秒目标的对比敏感度实际上显著提高，而对于中高空间频率的目标，仅发现了目标运动的不利影响。从传统视觉评估程序的局限性以及将目标构成和目标运动的联合效应概念化的实际和理论益处方面对结果进行了讨论。
