Department of Psychiatry, Columbia University, College of Physicians and Surgeons, New York, NY, United States of America; New York State Psychiatric Institute, New York, NY, United States of America.
Department of Neurological Surgery, University of California, San Francisco, CA, United States of America.
Neuroimage. 2022 Feb 15;247:118746. doi: 10.1016/j.neuroimage.2021.118746. Epub 2021 Dec 4.
The ability to process and respond to external input is critical for adaptive behavior. Why, then, do neural and behavioral responses vary across repeated presentations of the same sensory input? Ongoing fluctuations of neuronal excitability are currently hypothesized to underlie the trial-by-trial variability in sensory processing. To test this, we capitalized on intracranial electrophysiology in neurosurgical patients performing an auditory discrimination task with visual cues: specifically, we examined the interaction between prestimulus alpha oscillations, excitability, task performance, and decoded neural stimulus representations. We found that strong prestimulus oscillations in the alpha+ band (i.e., alpha and neighboring frequencies), rather than the aperiodic signal, correlated with a low excitability state, indexed by reduced broadband high-frequency activity. This state was related to slower reaction times and reduced neural stimulus encoding strength. We propose that the alpha+ rhythm modulates excitability, thereby resulting in variability in behavior and sensory representations despite identical input.
对外界输入进行处理和响应的能力对于适应行为至关重要。那么，为什么在相同感觉输入的重复呈现中，神经和行为反应会有所不同呢？目前的假设是，神经元兴奋性的持续波动是感觉处理中试验间变异性的基础。为了验证这一点，我们利用神经外科患者的颅内电生理学来执行一项带有视觉提示的听觉辨别任务：具体来说，我们研究了刺激前阿尔法振荡、兴奋性、任务表现和解码的神经刺激表示之间的相互作用。我们发现，与无节律信号相比，alpha+波段（即 alpha 及其相邻频率）的强刺激前振荡与低兴奋性状态相关，表现为宽带高频活动减少。这种状态与较慢的反应时间和降低的神经刺激编码强度有关。我们提出，alpha+节律调制兴奋性，从而导致行为和感觉表示的可变性，尽管输入是相同的。
