Laboratory of Clinical and Behavioural Neurology, Santa Lucia Foundation IRCCS, Rome, Italy.
Neuroscientist. 2013 Apr;19(2):208-17. doi: 10.1177/1073858412447874. Epub 2012 Jun 4.
The human brain is characterized by the lateralization of cognitive functions. Multiple lines of evidence suggest the deployment of visuospatial attention is controlled by a frontoparietal network, with a right hemisphere dominance. Among cortical areas included in the network, the right posterior parietal cortex (PPC) has been proposed to be a crucial node and has also been implicated on clinical grounds. Here, the authors provide an overview of the existent literature giving evidence to a functional asymmetry of the parietal cortices in directing visuospatial attention, focusing on those studies seeking to characterize the causal role of PPC, applying transcranial magnetic stimulation and its combination with imaging techniques, such as electroencephalography and fMRI. First, the role of PPC and how this region exerts its control over remote areas of both hemispheres is discussed. The second part discusses studies involving neglect patients shedding light on the complex interplay between left and right PPC, strongly supporting the hemispheric rivalry theory. Finally, studies demonstrating changes of neglect disorders following the manipulation of the unaffected hemisphere activation will be discussed.
人类大脑的认知功能具有侧化特征。多条证据表明，视觉空间注意力的分配受额顶叶网络控制，右半球占优势。在包括在网络中的皮质区域中，右侧顶叶后部皮层（PPC）被提议为一个关键节点，并且也在临床基础上被牵连。在这里，作者提供了现有文献的概述，这些文献提供了证据证明顶叶皮质在引导视觉空间注意力方面存在功能不对称性，重点是那些试图描述 PPC 的因果作用的研究，应用经颅磁刺激及其与脑电图和 fMRI 等成像技术的结合。首先，讨论了 PPC 的作用以及该区域如何对两个半球的远程区域施加控制。第二部分讨论了涉及忽视症患者的研究，这些研究阐明了左、右 PPC 之间的复杂相互作用，强烈支持了半球竞争理论。最后，将讨论在操纵未受影响的半球激活后，忽视障碍的变化情况。
