Maus Gerrit W, Nijhawan Romi
Psychology Department, University of Sussex, Falmer, Brighton BN1 9QH, United Kingdom.
Psychol Sci. 2008 Nov;19(11):1087-91. doi: 10.1111/j.1467-9280.2008.02205.x.
The flash-lag effect, in which a moving object is perceived ahead of a colocalized flash, has led to keen empirical and theoretical debates. To test the proposal that a predictive mechanism overcomes neural delays in vision by shifting objects spatially, we asked observers to judge the final position of a bar moving into the retinal blind spot. The bar was perceived to disappear in positions well inside the unstimulated area. Given that photoreceptors are absent in the blind spot, the perceived shift must be based on the history of the moving object. Such predictive overshoots are suppressed when a moving object disappears abruptly from the retina, triggering retinal transient signals. No such transient-driven suppression occurs when the object disappears by virtue of moving into the blind spot. The extrapolated position of the moving bar revealed in this manner provides converging support for visual prediction.
闪光滞后效应，即一个移动的物体被感知到位于与其共定位的闪光之前，引发了激烈的实证和理论争论。为了检验一种预测机制通过在空间上移动物体来克服视觉中神经延迟的提议，我们要求观察者判断一根移入视网膜盲点的条状物的最终位置。人们感觉该条状物在未受刺激区域内的位置就消失了。鉴于盲点中没有光感受器，这种感知到的位移一定是基于移动物体的历史信息。当一个移动的物体从视网膜上突然消失，触发视网膜瞬态信号时，这种预测性过冲就会受到抑制。当物体因移入盲点而消失时，不会发生这种由瞬态驱动的抑制。以这种方式揭示的移动条状物的外推位置为视觉预测提供了相互印证的支持。
