Dresp B, Salvano-Pardieu V, Bonnet C
Laboratoire de Psychophysique Sensorielle, Université Louis Pasteur, Strasbourg, France.
Percept Psychophys. 1996 Jan;58(1):111-24. doi: 10.3758/bf03205481.
The perception of brightness differences in Ehrenstein figures and of illusory contours in phase-shifted line gratings was investigated as a function of the contrast polarity of the inducing elements. We presented either continuous lines or line-like arrangements composed of aligned dashes or dots whose spacing was varied. A yes/no procedure was used in which naive observers had to decide whether or not they perceived a brightness difference in a given Ehrenstein figure or an illusory contour in a phase-shifted line grating. The results show that brightness differences are perceived to some extent in Ehrenstein figures with inducers of opposite polarity of contrast; however, the percentage of yes response was systematically lower and response times were longer than for figures with inducers of the same polarity. Phase-shifted line gratings with lines of opposite polarity of contrast yielded stronger illusory contours and shorter response times than those with lines of the same polarity. When the sign of contrast was not the same within a given line of induction, neither differences in brightness nor illusory contours were perceived. The results suggest that the mechanisms that lead to apparent differences in brightness are more sensitive to input of the same contrast polarity, the mechanisms generating illusory contours more sensitive to input of opposite polarity. The data are discussed in the light of a multistage approach to illusory form perception and some implications for cortical models of illusory contour integration are discussed.
我们研究了埃伦斯坦图形中亮度差异的感知以及相移线光栅中错觉轮廓的感知，并将其作为诱导元素对比度极性的函数。我们展示了连续的线条或由对齐的短线或点组成的线状排列，其间距是变化的。采用是/否程序，让未经训练的观察者判断他们是否在给定的埃伦斯坦图形中感知到亮度差异，或者在相移线光栅中感知到错觉轮廓。结果表明，在对比度极性相反的诱导元素的埃伦斯坦图形中，在一定程度上能感知到亮度差异；然而，肯定回答的百分比系统性地更低，且反应时间比具有相同极性诱导元素的图形更长。对比度极性相反的线条的相移线光栅比具有相同极性线条的相移线光栅产生更强的错觉轮廓和更短的反应时间。当在给定的诱导线内对比度的符号不同时，既感知不到亮度差异也感知不到错觉轮廓。结果表明，导致明显亮度差异的机制对相同对比度极性的输入更敏感，产生错觉轮廓的机制对相反极性的输入更敏感。根据错觉形式感知的多阶段方法对数据进行了讨论，并讨论了其对错觉轮廓整合的皮质模型的一些影响。
