Initiation of smooth-pursuit eye movements by real and illusory contours
- 作者：Ulrich Biber ; Uwe J. Ilg
- 关键词：Visual motion processing ; Direction error ; Vector averaging ; Elementary motion detector ; Anticipation
- 刊名：Vision Research
- 出版年：2008
- 期刊代码：268_00426989
- 类别：med
- 出版时间：March 2008
- 卷：48
- 期：8
- 页码：1002-1013
- 文件大小：263 K
摘要
It is well established that elementary motion detectors are only able to code for the movement of a contour perpendicular to its orientation. This shortcoming explains why the initial direction of smooth-pursuit eye movements is directed orthogonal to the orientation of a moving contour independent of its veridical direction of motion. Here, we replicated this finding and asked whether this directional error can be reduced by subjects’ prediction of upcoming target moving direction and whether this directional error also occurs during tracking of an illusory contour. Our results show that prediction did not abolish the directional error, it was only slightly reduced. On the other hand, the directional error was considerably diminished during pursuit initiation towards illusory contours and most likely reflected the amount of real stimulation defining the specific illusory contour. We conclude that pursuit initiation is driven by raw retinal image motion signals, which are not yet processed for figure completion.