Weidner Ralph, Fink Gereon R
Brain Imaging Centre West & Institute of Medicine, Research Centre Jülich, and Department of Neurology-Cognitive Neurology, University Hospital, Rheinisch-Westfálische Technische Hochschule, Aachen, Germany.
Cereb Cortex. 2007 Apr;17(4):878-84. doi: 10.1093/cercor/bhk042. Epub 2006 May 17.
Arrows terminating a line can distort the perceived line length. This so-called Müller-Lyer illusion can be used in healthy human subjects to mimic the performance of neglect patients in visuospatial judgments (e.g., in the landmark task). In this study, we investigated the neural mechanisms underlying the Müller-Lyer illusion, the landmark task, and their interaction. This was achieved by parametrically manipulating the magnitude of the Müller-Lyer illusion both in a landmark and in a luminance (control) task. As expected, the landmark task activated right posterior parietal cortex and right temporo-occipital cortex. In contrast, the neural processes associated with the strength of the Müller-Lyer illusion were located bilaterally in the lateral occipital cortex as well as the right superior parietal cortex. The data not only converge with but also extend neuropsychological data that indicate maintained line-length illusion in neglect patients. In addition, our results support the size-constancy scaling hypothesis as a putative mechanism underlying line-length illusions. Furthermore, activation that was driven by both the task and the strength of the Müller-Lyer illusion was observed in right intraparietal sulcus, thus arguing in favor of an interaction of illusory information with the top-down processes underlying visuospatial judgments in right parietal cortex.
线段末端的箭头会扭曲对线段长度的感知。这种所谓的缪勒-莱尔错觉可用于健康人类受试者，以模拟忽视症患者在视觉空间判断中的表现（例如在地标任务中）。在本研究中，我们调查了缪勒-莱尔错觉、地标任务及其相互作用背后的神经机制。这是通过在地标任务和亮度（对照）任务中参数化操纵缪勒-莱尔错觉的大小来实现的。正如预期的那样，地标任务激活了右侧顶叶后部皮层和右侧颞枕叶皮层。相比之下，与缪勒-莱尔错觉强度相关的神经过程位于双侧枕叶外侧皮层以及右侧顶上叶皮层。这些数据不仅与表明忽视症患者存在持续线段长度错觉的神经心理学数据一致，还对其进行了扩展。此外，我们的结果支持大小恒常性缩放假说，该假说被认为是线段长度错觉背后的一种机制。此外，在右侧顶内沟观察到由任务和缪勒-莱尔错觉强度共同驱动的激活，因此支持虚幻信息与右侧顶叶皮层中视觉空间判断背后的自上而下过程相互作用的观点。
