Project 5 The causal role of neocortical beta events in human sensory perception

β节律（15-29 Hz）是在人类中非侵入性测量的最主要的大脑信号之一， 磁图和脑电图（MEG/EEG）。它们是感知和运动的有力预测者 表现，并在疾病状态，如帕金森病中断。然而，β在函数中的因果作用 仍然未知。在这项提议中，我们将联合收割机结合人类脑电图，经颅磁刺激（TMS）和 生物病理学原则的神经建模，以调查β和感知之间的直接因果关系 并定义新的TMS范式，最佳地影响感知。 我们先前的研究表明，在人原发性肝癌中，用MEG测量的刺激前β活性 躯体感觉皮层（SI）“抑制”触觉检测，这样，平均刺激前β功率越高， 对象检测到对手指的阈值水平敲击的可能性就越小。此外，平均β功率增加， 非关注区域，大概是作为一种手段，以过滤分散注意力的信息，以促进知觉（琼斯等 等人，J. Neurosci. 2010年）。最近，我们报道了高功率β活动作为短暂的“事件”出现。 （<150 ms），主峰持续一个β周期~40- 60 ms（谢尔曼等人PNAS 2016）。初步数据表明，这种β事件是间歇性的，β事件的发生率是 β随注意力的变化以及对感知的影响。参加的患者中，刺激前β事件发生率降低， 非关注的躯体位置区域（分心区域）增加，对应于更高的 侦测 我们预测，当触觉刺激被抑制时，在被关注的位置中的触觉刺激的检测将被抑制。 在相应的躯体部位的自发性EEG β事件发生率较高后进行，以及 当在非关注的躯体部位（脑区）中的高β事件率之后递送时， 分散）（目标1）。我们进一步预测，模拟内源性β事件模式的TMS方案将影响 感知比非TMS条件和标准功能性“抑制”TMS协议更有效（目的 2）。我们小组专门设计的用于模拟宏观尺度EEG信号的计算神经模型将 用于解释观测数据背后的电路机制（目标3）。 !

Beta rhythms (15-29 Hz) are one of the most dominant brain signals measured non-invasively in humans with magento- and electro-encephalography (MEG/EEG). They are strong predictors of perception and motor performance, and disrupted in disease states, such as Parkinson’s Disease. Yet, beta’s causal role in function is still unknown. In this proposal, we will combine human EEG, transcranial magnetic stimulation (TMS) and biophysically principled neural modeling to investigate a direct causal relationship between beta and perception and to define novel TMS paradigms that optimally impact perception. Our prior studies have shown that prestimulus beta activity measured with MEG in human primary somatosensory cortex (SI) “inhibits” tactile detection, such that the higher the averaged prestimulus beta power the less likely the subject detects a threshold level tap to the finger. Further, averaged beta power increases in non-attended regions, presumably as a means to filter distracting information to facilitate perception (Jones et al J. Neurosci. 2010). More recently, we reported that that high power beta activity emerges as brief “events” (<150ms) in unaveraged data, with a dominant peak lasting one beta period ~40-60ms (Sherman et al PNAS 2016). Preliminary data suggests such beta events are intermittent and that the rate of beta events underlies beta’s shift with attention and impact on perception. Prestimulus beta event rates decrease in attended, and increase in non-attended somatotopic regions (areas of distraction), corresponding with a higher probability of detection. We predict detection of tactile stimulation in an attended location will be inhibited when tactile stimulation is delivered after high spontaneous EEG beta event rates in the corresponding somatotopic region, and enhanced when delivered after high beta event rates in the non-attended somatotopic region (area of distraction) (Aim 1). We further predict TMS protocols that mimic endogenous beta event patterns will impact perception more effectively than non-TMS conditions and standard functionally “inhibitory” TMS protocols (Aim 2). Computational neural modeling specifically designed by our group to simulate macro-scale EEG signals will be used to intepret circuit mechanisms underlying observed data (Aim 3). !