Witzel Christoph, Gegenfurtner Karl R
Laboratoire Psychologie de la Perception, Université Paris Descartes.
Allgemeine Psychologie, Justus-Liebig Universität.
J Exp Psychol Hum Percept Perform. 2016 Apr;42(4):540-570. doi: 10.1037/xhp0000154. Epub 2015 Nov 16.
Recent studies suggest that the widely accepted evidence in support of categorical perception of color may be a confound of effects due to low-level sensory mechanisms that are unrelated to color categories. To reveal genuine category effects, we investigated the category boundary least prone to spurious effects of low-level mechanisms: the boundary between red and brown. We tested for low-level sensory and high-level cognitive effects of categories on color discrimination, while carefully controlling potential factors of color vision that are not related to color categories. First, we established the red-brown boundary through a naming task and measured just-noticeable differences (JNDs) for colors across the boundary. If low-level sensitivity to color differences was categorical, JNDs should decrease toward the boundary. However, this was not the case. Second, we measured performance in terms of response times and error rates in a speeded discrimination task with color pairs that were equalized in discriminability based on the empirical JNDs. There was a boost of performance (lower response times and error rates) for identifying color differences in equally discriminable color pairs, when the colors crossed the boundary. Given the particularity of the red-brown boundary, these results prove that the observed effects were due to color categories rather than low-level visual mechanisms. These findings support the idea that category effects are due to a shift of attention to the linguistic distinction between categories, rather than being a pure product of perception. These category effects do not depend on the hemispheric lateralization of language. (PsycINFO Database Record
最近的研究表明，广泛接受的支持颜色分类感知的证据可能是与颜色类别无关的低水平感官机制所产生的效应的混淆。为了揭示真正的类别效应，我们研究了最不容易受到低水平机制虚假效应影响的类别边界：红色和棕色之间的边界。我们测试了类别对颜色辨别在低水平感官和高水平认知方面的效应，同时仔细控制与颜色类别无关的颜色视觉潜在因素。首先，我们通过命名任务确定了红棕色边界，并测量了边界两侧颜色的恰可察觉差异（JNDs）。如果对颜色差异的低水平敏感度是分类性的，JNDs应该朝着边界减小。然而，情况并非如此。其次，我们在一个快速辨别任务中，根据经验性JNDs使颜色对的可辨别性相等，测量了反应时间和错误率方面的表现。当颜色跨越边界时，在辨别性相等的颜色对中识别颜色差异的表现得到了提升（反应时间和错误率更低）。鉴于红棕色边界的特殊性，这些结果证明观察到的效应是由于颜色类别而非低水平视觉机制。这些发现支持了这样一种观点，即类别效应是由于注意力转向类别之间的语言区分，而不是纯粹的感知产物。这些类别效应不依赖于语言的半球侧化。（PsycINFO数据库记录）
