Inserm U975; UPMC-Paris 6, UMR_S 975; CNRS UMR 7225, Brain and Spine Institute, Groupe Hospitalier Pitié-Salpêtrière, Paris, France.
Cortex. 2013 Jul-Aug;49(7):1989-96. doi: 10.1016/j.cortex.2013.04.001. Epub 2013 Apr 9.
We studied the neural correlates of target omissions in five patients with right hemisphere damage and varying signs of left spatial neglect. Benefiting from the high temporal resolution of magneto-encephalography, we directly compared brain regional synchrony events of detected and omitted left-sided targets. Results showed that before stimulus presentation, a low beta synchronization activity was specifically increased within left frontal areas before pathological response omissions of left-sided targets. In the same pre-stimulus period, there were no such beta oscillations when patients correctly detected the target, or when no target was presented. Our findings emphasize the importance of neural activity during the pre-stimulus period on subsequent stimulus processing, and highlight the consequences of episodic interruptions of large-scale interhemispheric networks on target detection. Furthermore, our data suggest that prefrontal activity is not necessarily beneficial to target detection, but can be detrimental to it.
我们研究了五名右半球损伤且存在不同程度左侧空间忽略症状的患者在目标遗漏时的神经关联。得益于脑磁图的高时间分辨率，我们直接比较了检测到的和遗漏的左侧目标的脑区同步事件。结果表明，在刺激呈现之前，在病理性地遗漏左侧目标之前，左额区的低频β同步活动会特异性增加。在同一刺激前期间，如果患者正确地检测到目标，或者没有呈现目标时，则不会出现这种β振荡。我们的研究结果强调了刺激前期间神经活动对后续刺激处理的重要性，并突出了半球间大型网络的偶发性中断对目标检测的影响。此外，我们的数据表明，前额叶活动不一定有利于目标检测，反而可能会对其产生不利影响。
