Bedell Harold E, Chung Susana T L, Patel Saumil S
College of Optometry, University of Houston, TX 77204-2020, USA.
Vision Res. 2004 Apr;44(9):895-902. doi: 10.1016/j.visres.2003.11.006.
When the eyes move, the images of stationary objects sweep across the retina. Despite this motion of the retinal image and the substantial integration of visual signals across time, physically stationary objects typically do not appear to be smeared during eye movements. Previous studies indicated that the extent of perceived motion smear is smaller when a stationary target is presented during pursuit or saccadic eye movements than when comparable motion of the retinal image occurs during steady fixation. In this study, we compared the extent of perceived motion smear for a stationary target during smooth pursuit and vergence eye movements with that for a physically moving target during fixation. For a target duration of 100 ms or longer, perceived motion smear is substantially less when the motion of the retinal image results from vergence or pursuit eye movements than when it results from the motion of a target during fixation. The reduced extent of perceived motion smear during eye movements compared to fixation cannot be accounted for by different spatio-temporal interactions between visual targets or by unequal attention to the moving test spot under these two types of conditions. We attribute the highly similar attenuation of perceived smear during vergence and pursuit to a comparable action of the extra-retinal signals for disjunctive and conjugate eye movements.
当眼睛移动时，静止物体的图像会扫过视网膜。尽管视网膜图像有这种运动，且视觉信号在时间上有大量整合，但在眼球运动过程中，物理上静止的物体通常看起来并不会模糊。先前的研究表明，当在追踪或扫视眼球运动期间呈现静止目标时，所感知到的运动模糊程度要比在稳定注视期间视网膜图像发生类似运动时小。在本研究中，我们将平稳追踪和聚散眼球运动期间静止目标的感知运动模糊程度与注视期间物理上移动目标的感知运动模糊程度进行了比较。对于持续时间为100毫秒或更长时间的目标，当视网膜图像的运动是由聚散或追踪眼球运动引起时，所感知到的运动模糊要比由注视期间目标运动引起时显著更小。与注视相比，眼球运动期间所感知到的运动模糊程度降低，不能用视觉目标之间不同的时空相互作用或在这两种条件下对移动测试点的不平等关注来解释。我们将聚散和追踪期间所感知到的模糊高度相似的衰减归因于视网膜外信号对非共轭和共轭眼球运动的类似作用。
