Centre for Brain and Mind, Department of Psychology, University of Western Ontario, London W6 8RP, Canada.
Cereb Cortex. 2011 Dec;21(12):2751-61. doi: 10.1093/cercor/bhr073. Epub 2011 Apr 20.
Recent evidence suggests the possibility that not all action modes depend on dorsal visual stream processing but that off-line nontarget-directed actions, such as antipointing, require additional and even distinct neural networks when compared with target-directed online actions. Here, we explored this potential dissociation in a group of 11 patients with left visual neglect, a syndrome characterized by a loss of awareness of the contralesional side of space. Ten healthy participants and 10 right hemisphere-damaged patients without neglect served as controls. Participants had to point either directly toward targets presented on their left or right (i.e., propointing) or to the mirror position in the opposite hemispace (i.e., antipointing). Compared with both control groups, neglect patients showed reduced accuracy when antipointing but not propointing. Lesion-behavior mapping revealed that the areas critically associated with these deficits were located in the middle and superior temporal and parahippocampal gyri. We argue that neglect patients present specific deficits only when the visuomotor task taps into more perceptual representations thought to rely on ventral visual stream processing and that our results indicate that right temporal brain regions are implicated in these off-line actions.
最近的证据表明，并非所有的动作模式都依赖于背侧视觉流处理，而是离线的非目标指向动作，如反指向，与目标指向的在线动作相比，需要额外的甚至是不同的神经网络。在这里，我们在一组 11 名左侧视觉忽略症患者中探索了这种潜在的分离，左侧视觉忽略症是一种以对空间对侧的意识丧失为特征的综合征。10 名健康参与者和 10 名右侧半球损伤但无忽略症的患者作为对照组。参与者必须直接指向他们左侧或右侧的目标（即指向），或指向对面半空间的镜像位置（即反指向）。与两组对照组相比，忽略症患者在反指向时的准确性降低，但在指向时则没有。病变-行为映射显示，与这些缺陷密切相关的区域位于中颞叶和上颞叶以及海马旁回。我们认为，只有当视觉运动任务涉及到更多被认为依赖于腹侧视觉流处理的知觉表征时，忽略症患者才会出现特定的缺陷，我们的结果表明，右侧颞叶区域与这些离线动作有关。
