Wertheim A H
TNO Institute for Perception, Soesterberg, The Netherlands.
Perception. 1987;16(3):299-308. doi: 10.1068/p160299.
During a pursuit eye movement made in darkness across a small stationary stimulus, the stimulus is perceived as moving in the opposite direction to the eyes. This so-called Filehne illusion is usually explained by assuming that during pursuit eye movements the extraretinal signal (which informs the visual system about eye velocity so that retinal image motion can be interpreted) falls short. A study is reported in which the concept of an extraretinal signal is replaced by the concept of a reference signal, which serves to inform the visual system about the velocity of the retinae in space. Reference signals are evoked in response to eye movements, but also in response to any stimulation that may yield a sensation of self-motion, because during self-motion the retinae also move in space. Optokinetic stimulation should therefore affect reference signal size. To test this prediction the Filehne illusion was investigated with stimuli of different optokinetic potentials. As predicted, with briefly presented stimuli (no optokinetic potential) the usual illusion always occurred. With longer stimulus presentation times the magnitude of the illusion was reduced when the spatial frequency of the stimulus was reduced (increased optokinetic potential). At very low spatial frequencies (strongest optokinetic potential) the illusion was inverted. The significance of the conclusion, that reference signal size increases with increasing optokinetic stimulus potential, is discussed. It appears to explain many visual illusions, such as the movement aftereffect and center-surround induced motion, and it may bridge the gap between direct Gibsonian and indirect inferential theories of motion perception.
在黑暗中对一个小的静止刺激物进行追随眼动时，该刺激物会被感知为朝着与眼睛相反的方向移动。这种所谓的菲勒内错觉通常被解释为，在追随眼动过程中，视网膜外信号（该信号向视觉系统告知眼睛的速度，以便能够解释视网膜图像的运动）不足。本文报道了一项研究，其中视网膜外信号的概念被参考信号的概念所取代，参考信号用于向视觉系统告知视网膜在空间中的速度。参考信号不仅会因眼动而产生，也会因任何可能产生自我运动感觉的刺激而产生，因为在自我运动过程中视网膜也会在空间中移动。因此，视动刺激应该会影响参考信号的大小。为了验证这一预测，研究人员使用具有不同视动潜力的刺激物对菲勒内错觉进行了研究。正如所预测的那样，对于短暂呈现的刺激物（没有视动潜力），通常的错觉总是会出现。当刺激物的呈现时间延长且其空间频率降低（视动潜力增加）时，错觉的程度会降低。在非常低的空间频率下（最强的视动潜力），错觉会反转。文中讨论了参考信号大小随视动刺激潜力增加而增大这一结论的意义。它似乎可以解释许多视觉错觉，比如运动后效和中心 - 外周诱导运动，并且它可能弥合吉布森直接运动知觉理论和间接推理运动知觉理论之间的差距。
