MOTION AND SHAPE PERCEPTION IN CEREBRAL AKINETOPSIA
MOTION AND SHAPE PERCEPTION IN CEREBRAL AKINETOPSIA
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DOI：
10.1093/brain/118.5.1105
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发表时间：
1995-10-01
期刊：
影响因子：
14.5
通讯作者：
ZIHL, J
中科院分区：
文献类型：
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作者：
RIZZO, M;NAWROT, M;ZIHL, J
运动线索在灵长类视觉中有许多用途。因此，运动不能，一种由于大脑病变引起的运动知觉缺陷，预计将包括一系列运动相关的缺陷。为了解决这个问题，我们进一步探讨了视觉不能受试者L.M.由于背外侧视觉联合皮层的广泛双侧损伤而使初级视觉皮层VI区不受影响，该患者具有运动感知缺陷。我们使用了几种不同的实验程序。使用随机点运动刺激，我们表明，L.M.仍然可以感知全局相干运动和辨别运动方向，然而这些能力甚至在中等水平的背景噪声下也失效。L.M.还观看了称为Ternus显示器的两帧表观（phi）运动刺激。她在这项测试中的表现表明，有缺陷的“长距离”明显的运动机制。这些结果显然与以前的报告一致。其他实验表明，L.M.仍然可以感知二维形状和三维运动结构（SFM）。然而，就像运动方向辨别一样，这些能力在中等水平的移动和静止噪声下会崩溃。令人惊讶的是，M。也难以感知由非运动信号定义的2-D形状，包括“开”和“关”瞬变、动态和静态双眼视差以及静态纹理线索。我们的研究结果突出了视觉关联皮层在从噪声中提取显著信息中的作用。
Motion cues serve many purposes in primate vision. Consequently, akinetopsia, a defect of movement perception due to cerebral lesions, would be expected to comprise a range of motion-related defects. To address this issue we explored further the perceptual profiles in akinetopsic subject L.M. who has motion perception deficits due to extensive bilateral lesions of the dorsolateral visual association cortex that spare primary visual cortex, area VI. We used several different experimental procedures. Using random-dot motion stimuli, we showed that L.M. can still perceive global coherent motion and discriminate motion direction, yet these abilities fail even at moderate levels of background noise. L.M. also viewed a two-frame apparent (phi) motion stimulus known as a Ternus display. Her performance on this test suggests defective 'long-range' apparent motion mechanisms. These results are clearly in agreement with previous reports. Additional experiments showed that L.M. can still perceive 2-D shape and 3-D structure-from-motion (SFM). However; like motion direction discrimination, these abilities broke down at moderate levels of moving and stationary noise. Surprisingly, L.M. also had trouble perceiving 2-D shapes defined by non-motion signals including 'on' and 'off' transients, dynamic and static binocular disparity, and static texture cues. Our findings highlight the role of the visual association cortex in extracting salient information from noise.