Time course of cross-hemispheric spatial updating in the human parietal cortex
Time course of cross-hemispheric spatial updating in the human parietal cortex
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DOI：
10.1016/j.bbr.2006.01.001
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发表时间：
2006-04-25
影响因子：
2.7
通讯作者：
Daum, I
中科院分区：
文献类型：
--
作者：
Bellebaum, C;Daum, I
在人类顶叶皮层中，当水平眼球运动将刺激的表征带入相反的视觉半场时，刚刚看到的视觉刺激的视网膜位置从一个半球更新到另一个半球。本研究旨在阐明这一过程的时间进程。十二名受试者执行更新任务，其中在水平扫视之前显示实心圆圈，需要更新刺激位置，并在扫视之前执行没有视觉刺激的控制任务。受试者执行任务时记录脑电图 (EEG) 和眼电图 (EOG)，并对事件相关电位 (ERP) 组件进行 LORETA 源分析。与两个潜伏期窗口中的控制条件相比，更新条件下的 ERP 幅度更正。早期正波始于扫视偏移后约 50 ms，起源于扫视方向对侧的后顶叶皮层，可能反映了扫视相关信息和视觉信息的整合，从而反映了更新过程。待更新刺激的表示向相反半球的转变反映在扫视偏移后大约 400 ms 开始的较晚分量中，这与记忆有关，起源于扫视方向同侧的 PPC，因此与更新的视觉刺激的空间位置相反。 (C) 2006 Elsevier B.V. 保留所有权利。
In human parietal cortex, the retinal location of a just seen visual stimulus is updated from one hemisphere to the other, when a horizontal eye movement brings the representation of the stimulus into the opposite visual hemifield. The present study aimed to elucidate the time course of this process. Twelve subjects performed an updating task, in which a filled circle was shown before a horizontal saccade, requiring updating of stimulus location, and a control task without visual stimulation before the saccade. Electroencephalogram (EEG) and electrooculogram (EOG) were recorded while subjects performed the tasks and LORETA source analysis was performed on event-related potential (ERP) components. ERP amplitudes were more positive in the updating condition in comparison to the control condition in two latency windows. An early positive wave starting at about 50 ms after saccade offset and originating in the posterior parietal cortex contralateral to saccade direction probably reflects the integration of saccade-related and visual information and thus the updating process. A shift of the representation of the to-be-updated stimulus to the opposite hemisphere is reflected in a later component starting approximately 400 ms after saccade offset, which is related to memory and originates in the PPC ipsilateral to saccade direction and thus contralateral to the spatial location of the updated visual stimulus. (C) 2006 Elsevier B.V. All rights reserved.