ABSTRACT

We report the study of a woman who perceives 2D bounded regions of space (“shapes”) defined by sharp edges of medium to high contrast as if they were rotated by 90, 180 degrees around their centre, mirrored across their own axes, or both. In contrast, her perception of 3D, strongly blurred or very low contrast shapes, and of stimuli emerging from a collection of shapes, is intact. This suggests that a stage in the process of constructing the conscious visual representation of a scene consists of representing mutually exclusive bounded regions extracted from the initial retinotopic space in “shape-centered” frames of reference. The selectivity of the disorder to shapes originally biased toward the parvocellular subcortical pathway, and the absence of any other type of error, additionally invite new hypotheses about the operations involved in computing these “intermediate shape-centered representations” and in mapping them onto higher frames for perception and action.

摘要

我们报告了对一名女性的研究，她感知由中等到高对比度的锐利边缘定义的 2D 有界空间区域（“形状”），就好像它们围绕中心旋转 90 度、180 度，镜像在自己的轴上，或两者兼而有之. 相比之下，她对 3D、强烈模糊或对比度非常低的形状以及从一组形状中出现的刺激的感知是完整的。这表明构建场景的有意识视觉表示过程中的一个阶段包括表示从“以形状为中心”的参考框架中的初始视网膜主题空间中提取的相互排斥的有界区域。该疾病对形状的选择性最初偏向于小细胞皮层下通路，并且没有任何其他类型的错误，