Seech Todd R, Funke Matthew E, Sharp Richard F, Light Gregory A, Blacker Kara J
Warfighter Effectiveness Research Center, U.S. Air Force Academy, Colorado Springs, CO, United States.
Naval Medical Research Unit-Dayton, Wright-Patterson AFB, Dayton, OH, United States.
Front Psychiatry. 2020 Jan 31;11:12. doi: 10.3389/fpsyt.2020.00012. eCollection 2020.
The ability to detect novelty in our environment is a critical sensory function. A reliable set of event-related potentials (ERP), known as the auditory deviance response (ADR), are elicited in the absence of directed attention and indexes functionally relevant networks. The ADR consists of three peaks: mismatch negativity (MMN), P3a, and reorienting negativity (RON) that are sequentially evoked in response to unattended changes in repetitive background stimulation. While previous studies have established the ADR's sensitivity to a range of pharmacologic and nonpharmacologic interventions and are leading candidate biomarkers of perturbations of the central nervous system (CNS), here we sought to determine if ADR peaks are sensitive to decreases in breathable oxygen. Participants performed a visuomotor tracking task while EEG was recorded during two 27-min sessions. The two sessions differed in the amount of environmental oxygen available: 10.6% O (hypoxia) versus 20.4% O (normoxia). ERPs were measured while a series of identical, or "standard," tones combined with occasional "oddball," tones, were presented. MMN, P3a, and RON were assessed in response to the oddball compared to the standard stimuli. Behavioral impairment during hypoxia was demonstrated by a deficit in tracking performance compared to the normoxia condition. Whereas no changes were detected in the MMN or RON, the amplitude of the P3a component was significantly reduced during hypoxia compared to normoxia, within the first 9 min of exposure. To our knowledge, this is the first study to demonstrate the effect of low oxygen exposure on passively elicited neural measures of early sensory processing. This study demonstrates that passively elicited EEG measures, reflecting preattentive auditory processing, are disrupted by acute hypoxia. Results have implications for the development of biomarkers for the noninvasive assessment of CNS perturbations.
检测环境中新颖事物的能力是一项关键的感官功能。一组可靠的事件相关电位（ERP），即听觉偏差反应（ADR），在没有定向注意力的情况下被诱发，并指示功能相关网络。ADR由三个峰值组成：失配负波（MMN）、P3a和重新定向负波（RON），它们是在对重复背景刺激中未被注意的变化做出反应时依次诱发的。虽然先前的研究已经确定了ADR对一系列药物和非药物干预的敏感性，并且是中枢神经系统（CNS）扰动的主要候选生物标志物，但在这里我们试图确定ADR峰值是否对可呼吸氧气的减少敏感。参与者在两个27分钟的时间段内进行视觉运动跟踪任务，同时记录脑电图。这两个时间段的环境氧气含量不同：10.6%O（低氧）与20.4%O（常氧）。在呈现一系列相同的或“标准”音调以及偶尔的“异常”音调时测量ERP。将与标准刺激相比的异常音调诱发的MMN、P3a和RON进行评估。与常氧条件相比，低氧期间的跟踪性能缺陷表明了行为损害。虽然在MMN或RON中未检测到变化，但与常氧相比，在暴露的前9分钟内，低氧期间P3a成分的幅度显著降低。据我们所知，这是第一项证明低氧暴露对被动诱发的早期感觉处理神经测量指标影响的研究。这项研究表明，反映前注意听觉处理的被动诱发脑电图测量指标会受到急性低氧的干扰。研究结果对开发用于中枢神经系统扰动无创评估的生物标志物具有启示意义。
