PDF(Pubmed)
Abstract：
Following repetitive visual stimulation, post hoc phase analysis finds that visually evoked response magnitudes vary with the cortical alpha oscillation phase that temporally coincides with sensory stimulus. This approach has not successfully revealed an alpha phase dependence for auditory evoked or induced responses. Here, we test the feasibility of tracking alpha with scalp electroencephalogram (EEG) recordings and play sounds phase-locked to individualized alpha phases in real-time using a novel end-point corrected Hilbert transform (ecHT) algorithm implemented on a research device. Based on prior work, we hypothesize that sound-evoked and induced responses vary with the alpha phase at sound onset and the alpha phase that coincides with the early sound-evoked response potential (ERP) measured with EEG. Thus, we use each subject\'s individualized alpha frequency (IAF) and individual auditory ERP latency to define target trough and peak alpha phases that allow an early component of the auditory ERP to align to the estimated poststimulus peak and trough phases, respectively. With this closed-loop and individualized approach, we find opposing alpha phase-dependent effects on the auditory ERP and alpha oscillations that follow stimulus onset. Trough and peak phase-locked sounds result in distinct evoked and induced post-stimulus alpha level and frequency modulations. Though additional studies are needed to localize the sources underlying these phase-dependent effects, these results suggest a general principle for alpha phase-dependence of sensory processing that includes the auditory system. Moreover, this study demonstrates the feasibility of using individualized neurophysiological indices to deliver automated, closed-loop, phase-locked auditory stimulation.
摘要：
重复的视觉刺激后，事后阶段分析发现，视觉诱发反应幅度随皮层α振荡阶段而变化，该阶段在时间上与感觉刺激一致。在听觉系统中,这种方法尚未成功揭示听觉诱发或诱发反应的α相位依赖性.这里,我们测试了使用头皮脑电图（EEG）记录跟踪alpha的可行性，并使用在研究设备上实现的新型终点校正希尔伯特变换（ecHT）算法实时播放锁相到个性化alpha相位的声音。根据以前的工作，我们假设声音诱发和诱发反应随声音开始时的α相位和与EEG测量的早期声音诱发反应电位（ERP）一致的α相位而变化。因此，我们使用每个受试者的个性化α频率（IAF）和个体听觉ERP延迟来定义目标波谷和峰值α阶段，允许听觉ERP的早期成分与估计的刺激后波峰和波谷阶段对齐，分别。通过这种闭环和个性化的方法，我们发现在刺激开始后对听觉ERP和alpha振荡产生相反的alpha相位依赖效应。波谷和峰值锁相声音会导致刺激后α水平和频率的不同诱发和诱发调制。虽然需要更多的研究来定位这些相位依赖效应的来源，这些结果表明了包括听觉系统在内的感觉处理的α相位依赖性的一般原理.此外，这项研究证明了使用个性化神经生理指标来实现自动化的可行性，闭环,锁相听觉刺激。重要性陈述健康的成人大脑会产生alpha振荡，个体受试者具有不同的alpha振荡频率，这会影响他们动态处理和关注感官信息的方式。然而，关于感官事件和alpha阶段之间的精细尺度时间动态以及听觉输入处理的相应神经调节，人们知之甚少。在这里，我们使用一种新颖的闭环技术和个性化方法来播放特定额叶α阶段的声音。我们展示了对听觉诱发反应的新的α相位依赖效应，阿尔法水平，α相位相干性和频率。这种个性化的闭环方法在各种神经系统的研究和健康应用中具有潜在的应用，发育和临床疾病。
