Clavagnier Simon, Fruhmann Berger Monika, Klockgether Thomas, Moskau Susanna, Karnath Hans-Otto
Section Neuropsychology, Center of Neurology, Hertie-Institute for Clinical Brain Research, University of Tübingen, Hoppe-Seyler-Str. 3, D-72076 Tübingen, Germany.
Neuropsychologia. 2006;44(12):2330-6. doi: 10.1016/j.neuropsychologia.2006.05.012. Epub 2006 Jun 30.
One major function of parietal cortex is to direct our attention towards salient stimuli. The present data suggest that it also plays an important role in visual gestalt perception. Patients with simultanagnosia following lesions in this area are not able to extract the meaning of a visual scene whereas being perfectly able to recognise individual objects of this scene. We tested two patients with simultanagnosia with hierarchical Navon figures combined with eye movements recordings. The patients' performance allowed us to compare directly the scan paths in trials in which the global letter shape was recognised with trials in which the global letter shape was not recognised. We did not find any obvious differences in the eye movement pattern related to the two perceptual situations. The two patients did not show a significant problem in shifting their eyes (and thus possibly also their attentional focus) to all aspects of the complex visual stimulus when attempting to bind together the different elements of spatially distributed information. The results demonstrate that restricted ocular exploration cannot be the reason for the patients' inability to recognise the global shape of stimuli. Our data rather suggest a role of parietal cortex in visual gestalt perception that is beyond its role of directing attention towards relevant objects.
顶叶皮层的一个主要功能是将我们的注意力引向显著刺激。目前的数据表明，它在视觉格式塔感知中也起着重要作用。该区域受损后患有同时失认症的患者无法提取视觉场景的含义，而完全能够识别该场景中的单个物体。我们用分层纳冯图形结合眼动记录测试了两名患有同时失认症的患者。患者的表现使我们能够直接比较识别全局字母形状的试验和未识别全局字母形状的试验中的扫描路径。我们没有发现与这两种感知情况相关的眼动模式有任何明显差异。在试图将空间分布信息的不同元素结合在一起时，这两名患者在将眼睛（因此可能还有他们的注意力焦点）转移到复杂视觉刺激的所有方面时没有表现出明显问题。结果表明，有限的眼部探索不可能是患者无法识别刺激全局形状的原因。我们的数据反而表明顶叶皮层在视觉格式塔感知中的作用超出了其将注意力引向相关物体的作用。
