Department of Psychology, Carnegie Mellon University, Pittsburgh, United States.
Center for the Neural Basis of Cognition, Carnegie Mellon University and the University of Pittsburgh, Pittsburgh, United States.
Elife. 2017 Oct 5;6:e27576. doi: 10.7554/eLife.27576.
Although shape perception is considered a function of the ventral visual pathway, evidence suggests that the dorsal pathway also derives shape-based representations. In two psychophysics and neuroimaging experiments, we characterized the response properties, topographical organization and perceptual relevance of these representations. In both pathways, shape sensitivity increased from early visual cortex to extrastriate cortex but then decreased in anterior regions. Moreover, the lateral aspect of the ventral pathway and posterior regions of the dorsal pathway were sensitive to the availability of fundamental shape properties, even for unrecognizable images. This apparent representational similarity between the posterior-dorsal and lateral-ventral regions was corroborated by a multivariate analysis. Finally, as with ventral pathway, the activation profile of posterior dorsal regions was correlated with recognition performance, suggesting a possible contribution to perception. These findings challenge a strict functional dichotomy between the pathways and suggest a more distributed model of shape processing.
尽管形状感知被认为是腹侧视觉通路的功能，但有证据表明背侧通路也可以获得基于形状的表示。在两项心理物理学和神经影像学实验中，我们描述了这些表示的反应特性、拓扑组织和感知相关性。在两条通路上，形状敏感性从早期视觉皮层增加到外侧纹状体皮层，但随后在前部区域下降。此外，腹侧通路的外侧部分和背侧通路的后部区域对基本形状属性的可用性敏感，即使是对于无法识别的图像也是如此。这种在后部-背侧和外侧-腹侧区域之间的明显表示相似性得到了多元分析的证实。最后，与腹侧通路一样，后部背侧区域的激活模式与识别性能相关，这表明它们可能对感知有贡献。这些发现对两条通路之间的严格功能二分法提出了挑战，并提出了一种更分布式的形状处理模型。
