視覺消失、知覺填補、與運動引發視盲：從現象、心理物理、與神經生理的觀點談起

Fading, Perceptual Filling-in, and Motion-Induced Blindness: Phenomenology, Psychophysics, and Neurophysiology

為什麼我們會看到不存在的東西？視覺系統長時期固定不動時，物體即會由均質背景消失與從邊界處發生知覺填補。這表示視覺系統無法提供長時期且穩定的知覺感。另一個相關的例子是運動引發視盲。目前文獻看來這個三個現象間的關係還不是很清楚，然而當其物體尺寸比較小、呈現在邊緣視野、與具低對比時容易消失的結果顯示三個現象可能具有相似的運作機制。最近的研究結果也認為除了上述的刺激特性會影響外，物體的凸顯性與知覺組織特性也會影響視覺消失與知覺填補。更甚者，雙眼像差引發的深度感與單眼深度線索也是影響的因素。這些研究的發現顯示：除了由下往上的機制之外，由上往下的運作機制也可能是負責視覺消失與知覺填補中的物體消失的運作機制。本專刊的以下四篇文章將分別從現象與心理物理的研究來談亮度、色彩、與質地的視覺消失與知覺填補，並將提供相關的神經生理證據來連結現象的觀察與大腦運作的神經生理機制。

Why do we see what is not there? Fading of a target on a uniform background and perceptual filling-in from the edge are examples of the failure of the visual system to provide sustained vision under conditions of prolonged fixation. Another phenomenon that falls into this category is motion-induced blindness. The relationship between these three phenomena is not entirely clear, but the preference for small, peripheral, and low-contrast targets suggests that the mechanism underlying these effects may be similar. It has lately been shown that in addition to the above stimulus attributes, salience of the stimulus and perceptual grouping may also affect fading and filling-in. Furthermore, stereodepth and monocular depth cues have been proposed as relevant factors. These findings imply that in addition to bottom-up mechanisms top-down mechanisms are responsible for the perceptual disappearance of a fixated target by fading and filling-in. The following four articles in this special issue will summarize the phenomenological and psychophysical findings for fading and filling-in of brightness, color, and texture and correlate these observations with the presumed neurophysiological mechanisms.