Roudaia Eugenie, Bennett Patrick J, Sekuler Allison B, Pilz Karin S
Department of Psychology, Neuroscience, & Behaviour, McMaster University, Hamilton, Ontario, Canada.
J Vis. 2010 Dec 3;10(14):5. doi: 10.1167/10.14.5.
We used a random-dot two-frame apparent motion paradigm to investigate whether age-related declines in motion perception are caused by deficits in integrating spatial information, temporal information, or both. Two random-dot patterns were presented sequentially on a black screen, separated by a blank inter-stimulus interval ranging from 0.01 s to 0.240 s. From the first to the second pattern, all the dots were shifted to the left or right by an equal displacement ranging from 0.03 deg to 1.64 deg. The spatiotemporal range yielding good direction discrimination performance was greatly reduced with age. For ISIs longer than 0.04 s, older subjects performed less accurately than younger subjects across a wide range of spatial displacements. Older subjects also showed poorer performance for large spatial displacements across a wide range of ISIs. Age-related differences in performance were also found with small displacements; however, these were largely accounted for by age-related declines in visual acuity. Overall, the results show that the maximum temporal interval and maximum spatial displacement over which two frames can be integrated are reduced in older age.
我们使用随机点双帧表观运动范式来研究与年龄相关的运动感知能力下降是否由空间信息整合缺陷、时间信息整合缺陷或两者兼而有之引起。在黑屏上依次呈现两个随机点图案，中间有一个0.01秒至0.240秒的空白刺激间隔。从第一个图案到第二个图案，所有的点都向左或向右移动相等的位移，范围从0.03度到1.64度。随着年龄增长，产生良好方向辨别性能的时空范围大大缩小。对于长于0.04秒的刺激间隔，在广泛的空间位移范围内，老年受试者的表现不如年轻受试者准确。在广泛的刺激间隔范围内，老年受试者在大空间位移时也表现较差。在小位移情况下也发现了与年龄相关的表现差异；然而，这些差异在很大程度上是由与年龄相关的视力下降所导致的。总体而言，结果表明，老年人能够整合两帧图像的最大时间间隔和最大空间位移会减小。
