轉不過去的面具-旋轉面具錯覺成因之探討

觀者能夠將二維剪影或網格影像看成是三維圖形旋轉,這種現象被稱為動態深度效果(Wallach & O'Connell, 1953)。由於 KDE 影像缺乏足夠的深度線索,因此觀者無法掌握圖形的旋轉方向,甚至會感覺到圖形在旋轉過程中發生反轉。Klopfer(1991)以人臉面具作為 KDE 影像的素材,發現面具在旋轉過程中有極高的反轉次數,並以 Gregory(1980)提出的熟悉度因素進行解釋,主張觀者對圖形的熟悉度與反轉次數是正相關,然而熟悉度因素並不能解釋非人臉 KDE 影像的反轉。本研究旨在驗證是否有影響 KDE 影像反轉的基礎因素,能夠廣泛人臉與非人臉圖形,作為旋轉面具錯覺的成因解釋。人臉面具是一種細節不均勻的物體,研究假設 KDE 影像的兩種深度表象會切換,而圖形細節均勻性會影響切換頻率,造成圖形更傾向於反轉或穩定旋轉。本研究以電腦繪圖的奈克方塊與人臉面具作為基礎材料,透過三個實驗來驗證圖形細節均勻性、複雜度、熟悉度、凹凸表現等變項是否能夠作為 KDE 影像反轉頻率的基礎解釋。實驗結果發現:圖形細節均勻性會影響到圖形的深度表象切換,並造成反轉次數的差異。當圖形的細節分佈不均,反轉次數就較高;當圖形的細節分佈均勻,則要考量對立面的競爭情形。此外,熟悉度因素也會影響圖形反轉,圖形越接近日常所見的人臉,就有越高的反轉頻率。考量以上二者的共同作用,可能更適合說明旋轉面具錯覺的成因。

關鍵字

動態深度效果；深度反轉；旋轉面具錯覺

並列摘要

A phenomenon that 2D wire-frame or silhouette figures are able to be perceived as 3D rotating objects is called Kinetic depth effect (KDE, Wallach & O'Connell, 1953). For lack of depth cue, observers are unable to determine rotation direction of these objects in KDE. Moreover, observers perceive the object reversing in rotation direction. Klopfer(1991) used masks of a face as stimulus in his experiment and found that mask appeared to oscillate rather than rotate, because observers are more familiar with convex faces than with concave faces. However, familiarity may not provide a explanation of non-face rotating object in KDE. The purpose of this study is to identify the general factors could explain reversal of rotating masks and non-face objects. We hypothesized that object in KDE reverse while two different depth appearances of a figure changing. A mask is an object with non-homogeneous features, and the homogeneity of an object would influences its reversal number. This study used Necker cubes and masks as stimulus in three experiments to identify the interaction between homogeneity of features, complexity, familiarity, and convex-concave shape would influence the reversal number of an object in KDE. The results of three experiments favor both homogeneity and familiarity of features influence the change of depth appearances.