Liu Careesa C, Ghosh Hajra Sujoy, Cheung Teresa P L, Song Xiaowei, D'Arcy Ryan C N
School of Engineering Science, Simon Fraser University, Burnaby, BC, Canada.
Health Science and Innovation, Surrey Memorial Hospital, Fraser Health Authority, Surrey, BC, Canada.
Front Hum Neurosci. 2017 Oct 11;11:489. doi: 10.3389/fnhum.2017.00489. eCollection 2017.
Spontaneous blinking occurs 15-20 times per minute. Although blinking has often been associated with its physiological role of corneal lubrication, there is now increasing behavioral evidence suggesting that blinks are also modulated by cognitive processes such as attention and information processing. Recent low-density electroencephalography (EEG) studies have reported so-called blink-related oscillations (BROs) associated with spontaneous blinking at rest. Delta-band (0.5-4 Hz) BROs are thought to originate from the precuneus region involved in environmental monitoring and awareness, with potential clinical utility in evaluation of disorders of consciousness. However, the neural mechanisms of BROs have not been elucidated. Using magnetoencephalography (MEG), we characterized delta-band BROs in 36 healthy individuals while controlling for background brain activity. Results showed that, compared to pre-blink baseline, delta-band BROs resulted in increased global field power ( < 0.001) and time-frequency spectral power ( < 0.05) at the sensor level, peaking at ~250 ms post-blink maximum. Source localization showed that spontaneous blinks activated the bilateral precuneus ( < 0.05 FWE), and source activity within the precuneus was also consistent with sensor-space results. Crucially, these effects were only observed in the blink condition and were absent in the control condition, demonstrating that results were due to spontaneous blinks rather than as part of the inherent brain activity. The current study represents the first MEG examination of BROs. Our findings suggest that spontaneous blinks activate the precuneus regions consistent with environmental monitoring and awareness, and provide important neuroimaging support for the cognitive role of spontaneous blinks.
自发性眨眼每分钟发生15 - 20次。尽管眨眼常常与其角膜润滑的生理作用相关联，但现在越来越多的行为证据表明，眨眼也受到诸如注意力和信息处理等认知过程的调节。最近的低密度脑电图（EEG）研究报告了与静息时自发性眨眼相关的所谓眨眼相关振荡（BROs）。δ波频段（0.5 - 4Hz）的BROs被认为起源于参与环境监测和意识的楔前叶区域，在意识障碍评估中具有潜在的临床应用价值。然而，BROs的神经机制尚未阐明。我们使用脑磁图（MEG），在控制背景脑活动的同时，对36名健康个体的δ波频段BROs进行了特征描述。结果显示，与眨眼前基线相比，δ波频段BROs在传感器水平导致全局场功率增加（<0.001）和时频谱功率增加（<0.05），在眨眼后最大值约250毫秒时达到峰值。源定位显示，自发性眨眼激活了双侧楔前叶（<0.05 FWE），并且楔前叶内的源活动也与传感器空间结果一致。至关重要的是，这些效应仅在眨眼条件下观察到，而在对照条件下不存在，这表明结果是由于自发性眨眼而非固有脑活动的一部分。当前研究是对BROs的首次MEG检查。我们的研究结果表明，自发性眨眼激活了与环境监测和意识一致的楔前叶区域，并为自发性眨眼的认知作用提供了重要的神经影像学支持。
