Gerardin Peggy, Dojat Michel, Knoblauch Kenneth, Devinck Frédéric
Univ. Lyon, Université Claude Bernard Lyon 1, Inserm, Stem Cell and Brain Research Institute U1208, 69500 Bron, France; Université Lyon 1, 69003 Lyon, France.
Univ. Grenoble Alpes, Inserm, CHU Grenoble Alpes, GIN, 38000 Grenoble, France.
Vision Res. 2018 Mar;144:9-19. doi: 10.1016/j.visres.2018.01.003. Epub 2018 Mar 13.
Conjoint measurement was used to investigate the joint influences of the luminance of the background and the inner contour on hue- and brightness filling-in for a stimulus configuration generating a water-color effect (WCE), i.e., a wiggly bi-chromatic contour enclosing a region with the lower luminance component on the exterior. Two stimuli with the background and inner contour luminances covarying independently were successively presented, and in separate experiments, the observer judged which member of the pair's interior regions contained a stronger hue or was brighter. Braided-contour control stimuli that generated little or no perceptual filling-in were also used to assess whether observers were judging the interior regions and not the contours themselves. Three nested models of the contributions of the background and inner contour to the judgments were fit to the data by maximum likelihood and evaluated by likelihood ratio tests. Both stimulus components contributed to both the hue and brightness of the interior region with increasing luminance of the inner contour generating an assimilative filling-in for the hue judgments but a contrast effect for the brightness judgments. Control analyses showed negligible effects for the order of the luminance of the background or inner contour on the judgments. An additive contribution of both components was rejected in favor of a saturated model in which the responses depended on the levels of both stimulus components. For the hue judgments, increased background luminance led to greater hue filling-in at higher luminances of the interior contour. For the brightness judgments, the higher background luminance generated less brightness filling-in at higher luminances of the interior contour. The results indicate different effects of the inner contour and background on the induction of the brightness and coloration percepts of the WCE, suggesting that they are mediated by different mechanisms.
采用联合测量法，研究背景亮度和内部轮廓对产生水彩效果（WCE）的刺激配置的色调和亮度填充的联合影响，即一个摆动的双色轮廓包围一个外部具有较低亮度成分的区域。依次呈现两个背景亮度和内部轮廓亮度独立变化的刺激，并且在单独的实验中，观察者判断该对刺激中哪一个的内部区域具有更强的色调或更亮。还使用了几乎不产生或不产生感知填充的编织轮廓控制刺激，以评估观察者是否在判断内部区域而不是轮廓本身。通过最大似然法将背景和内部轮廓对判断的贡献的三个嵌套模型拟合到数据中，并通过似然比检验进行评估。随着内部轮廓亮度的增加，两种刺激成分都对内部区域的色调和亮度有贡献，在色调判断中产生同化填充，但在亮度判断中产生对比效果。对照分析表明，背景或内部轮廓亮度的顺序对判断的影响可忽略不计。两种成分的相加贡献被拒绝，而支持一个饱和模型，其中反应取决于两种刺激成分的水平。对于色调判断，背景亮度增加导致在内部轮廓较高亮度时色调填充增加。对于亮度判断，较高的背景亮度在内部轮廓较高亮度时产生较少的亮度填充。结果表明内部轮廓和背景对WCE亮度和色彩感知诱导的不同影响，表明它们由不同机制介导。
