Perception and Eye Movement Laboratory, Department of Neurology, Department of Clinical Research, Bern University Hospital Inselspital, and University of Bern, Freiburgstrasse 10, 3010 Bern, Switzerland.
Neuroscience. 2009 Dec 29;164(4):1609-14. doi: 10.1016/j.neuroscience.2009.09.044. Epub 2009 Sep 24.
After a lesion of the posterior parietal cortex (PPC), the perception of a contra-lesional stimulus in presence of a simultaneous, ipsilesional stimulus may be impaired, a phenomenon referred to as visual extinction. In the present study, visual extinction was transiently induced in healthy subjects by interfering with the function of the right PPC by means of continuous theta burst stimulation (TBS). We investigated to which extent the horizontal and vertical position of visual stimuli influenced the extinction rate. A single TBS train over the right PPC induced a significant increase of left visual extinctions of at least 30 min. Left visual extinction rate was higher when the left sided visual stimulus was presented at a more eccentric position on the horizontal axis (irrespective of right sided visual stimulus position) and in the lower part of the visual field. The results are discussed within the framework of current explanatory models and of putative inter- and intrahemispheric mechanisms directing visuospatial attention.
在后顶叶皮层（PPC）损伤后，在同时存在同侧刺激的情况下，对侧刺激的感知可能会受损，这种现象称为视觉消失。在本研究中，通过连续 theta 爆发刺激（TBS）干扰右侧 PPC 的功能，在健康受试者中短暂地诱导出视觉消失。我们研究了视觉刺激的水平和垂直位置在多大程度上影响了消失率。在右侧 PPC 上进行单次 TBS 训练会导致左侧视觉消失的显著增加，至少持续 30 分钟。当左侧视觉刺激出现在水平轴上更偏心的位置（无论右侧视觉刺激的位置如何）以及在视野的下部时，左侧视觉消失率更高。结果在当前解释模型的框架内进行了讨论，并讨论了潜在的跨半球和半球内机制指导视空间注意力。
