Timing of visuo-spatial information processing: Electrical source imaging related to line bisection judgements

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• 作者：Till D. Waberski ; René ; Gobbelé ; Kathrin Lamberty ; Helmut Buchner ; John C. Marshall ; Gereon R. Fink
• 关键词：Landmark task ; Visuo-spatial attention ; Neglect ; Posterior parietal cortex ; Hemispheric specialization
• 刊名：Neuropsychologia
• 出版年：2008
• 出版时间：2008
• 年：2008
• 卷：46
• 期：5
• 页码：1201-1210
• 全文大小：1593 K

文摘

This study deconvolves the temporal dynamics of the neural processes underlying line bisection judgements (i.e., the landmark task). Event-related potentials (ERPs) were recorded from 96 scalp electrodes in 10 healthy right-handed male subjects while they were judging whether horizontal lines were correctly prebisected. In the control task, subjects judged whether or not the horizontal line was transected by a vertical line, irrespective of its position. Using a current density reconstruction approach, source maxima in the time range from 50 to 400 ms after stimulus onset were localized and the time courses of activation were elaborated. Five regions, corresponding to those revealed by our previous fMRI studies (e.g., [Fink, G. R., Marshall, J. C., Shah, N. J., Weiss, P. H., Halligan, P. W., Grosse-Ruyken, et al. (2000). Line bisection judgments implicate right parietal cortex and cerebellum as assessed by fMRI. Neurology, 54, 1324–1331]), were identified as contributing significant source activity related to line bisection judgements: right middle occipital gyrus (Brodmann area; BA18); bilateral inferior occipital gyrus (BA19); right superior posterior parietal cortex (BA7) and right inferior posterior parietal cortex (BA40). Temporal deconvolution indicated sequential activation of these regions starting at BA18 as early as 90 ms post-stimulus onset, followed by the successive activation of the right superior posterior parietal (BA7), bilateral inferior occipital (BA19) and right inferior posterior parietal cortex (BA40). Three of these areas (BA18, BA17 and BA19) became reactivated within 250 ms of stimulus onset.