Varghese Jessy Parokaran, Marlin Amanda, Beyer Kit B, Staines William R, Mochizuki George, McIlroy William E
Department of Kinesiology, University of Waterloo, Waterloo, Ontario, Canada.
Canadian Partnership for Stroke Recovery, Sunnybrook Research Institute, Toronto, Ontario, Canada; Department of Physical Therapy, University of Toronto, Toronto, Ontario, Canada.
Neurosci Lett. 2014 Aug 22;578:33-8. doi: 10.1016/j.neulet.2014.06.017. Epub 2014 Jun 23.
Cortical evoked potentials are evident in the control of whole-body balance reactions in response to transient instability. The focus of this work is to continue to advance understanding of the potential cortical contributions to bipedal balance control. Temporally unpredictable postural perturbations evoke a negative potential (N1), which has drawn parallels to error-related negativity (ERN) as well as visual and auditory evoked N1 responses. The mechanism underlying the generation of event-related potentials (ERPs) has been a matter of debate for the past few decades. While the evoked model proposes that ERPs are generated by the addition of fixed latency and fixed polarity responses, the phase reorganization model suggests that ERPs are the result of stimulus-induced phase reorganization of the ongoing oscillations. Previous studies have suggested phase reorganization as a possible mechanism in auditory N1, visual N1 and error-related negativity (ERN). The purpose of the current study was to explore the frequency characteristics of the cortical responses to whole-body balance perturbations. Perturbations were evoked using a lean and release protocol. The results revealed a significant power increase and phase-locking of delta, theta, alpha, and beta band activity during perturbation-evoked N1. This may suggest that the stimulus-induced phase reorganization of the ongoing electroencephalographic (EEG) activity could account for the features of cortical ERPs in response to perturbation of upright stability.
皮质诱发电位在对短暂不稳定做出反应的全身平衡反应控制中很明显。这项工作的重点是继续推进对皮质对双足平衡控制潜在贡献的理解。时间上不可预测的姿势扰动会引发一个负电位（N1），它与错误相关负电位（ERN）以及视觉和听觉诱发的N1反应有相似之处。在过去几十年里，事件相关电位（ERP）产生的机制一直是一个争论的问题。虽然诱发模型提出ERP是由固定潜伏期和固定极性反应相加产生的，但相位重组模型表明ERP是正在进行的振荡的刺激诱发相位重组的结果。先前的研究表明相位重组是听觉N1、视觉N1和错误相关负电位（ERN）的一种可能机制。本研究的目的是探索皮质对全身平衡扰动反应的频率特征。使用倾斜和释放方案诱发扰动。结果显示，在扰动诱发的N1期间，δ、θ、α和β波段活动的功率显著增加且相位锁定。这可能表明，正在进行的脑电图（EEG）活动的刺激诱发相位重组可以解释皮质ERP对直立稳定性扰动的反应特征。
