Laboratory of Visual Neurophysiology, Lithuanian University of Health Sciences, Kaunas, Lithuania.
Institute of Biological Systems and Genetics Research, Lithuanian University of Health Sciences, Kaunas, Lithuania.
Acta Neurobiol Exp (Wars). 2020;80(2):139-159.
For most observers, the part of the stimulus that is filled with some visual elements (e.g., distractors) appears larger than the unfilled part of the same size. This illusion of interrupted spatial extent is also known as the 'filled‑space' or 'Oppel‑Kundt' illusion. Although the continuously filled‑space illusion has been systematically studied for over a century, there is still no generally accepted explanation of its origin. The present study aimed to further develop our computational model of the continuously filled‑space illusion and to examine whether the model predictions successfully account for illusory effects caused by distracting line‑segments of various lengths that are\r\nattached to different endpoints (i.e., terminators) of the reference spatial interval of the three‑dot stimulus. Our experiments confirm that the illusion manifests itself along a distracting segment located both inside and outside of the reference interval. In the case of two distractors arranged symmetrically with respect to the lateral terminator, we found that the magnitude of the illusion is approximately equal to the sum of the relevant values obtained with separate distractors. The results of experiments using vertical shifts of distractors supported the model's assumption regarding the two‑dimensional Gaussian profile of hypothetical areas of weighted spatial summation\r\nof neural activity. A good correspondence between the experimental and theoretical results supports the suggestion that perceptual positional biases associated with the context‑evoked increase in neural excitation may be one of the main causes of the continuously filled‑space illusion.
对于大多数观察者来说，充满某些视觉元素（例如，干扰物）的刺激部分看起来比相同大小的未填充部分更大。这种中断空间范围的错觉也称为“填充空间”或“Oppel-Kundt”错觉。尽管连续填充空间错觉已经被系统地研究了一个多世纪，但对于其起源仍然没有普遍接受的解释。本研究旨在进一步发展我们的连续填充空间错觉的计算模型，并检验模型预测是否成功解释了由各种长度的干扰线段引起的错觉效应，这些线段连接到三点点刺激的参考空间间隔的不同端点（即，终止符）。我们的实验证实，错觉会在参考间隔内部和外部的干扰线段上表现出来。在两个干扰物相对于横向终止符对称排列的情况下，我们发现错觉的大小大约等于用单独的干扰物获得的相关值的总和。使用干扰物的垂直移位进行实验的结果支持了模型关于假设的加权空间神经活动总和的二维高斯分布的假设。实验结果与理论结果之间的良好一致性支持了这样一种观点，即与上下文引起的神经兴奋增加相关的感知位置偏差可能是连续填充空间错觉的主要原因之一。
