健康与遗传心理学研究室知识库

经皮迷走神经电刺激（Transcutaneous Vagus Nerve Stimulation，tVNS）是一种非侵入性的神经调节方法，可以通过刺激颈部（tcVNS）或者耳部（taVNS）的迷走神经调节神经系统的功能。由于迷走神经和多个大脑区域之间的直接联系，tVNS 已被研究用于多种疾病的治疗，包括癫痫和抑郁症等。通过电刺激迷走神经可以调节神经系统的活动和神经递质的释放，从而纠正大脑异常功能。更重要的是，目前已有证据表明 taVNS 还可以改善健康人群的认知功能，例如调节认知灵活性、增强冲突引发的认知控制等。然而，这些结果的可重复性不高，这可能是由于研究者们忽略了个体生理状态对注意不同功能成分的差异性影响。基于此，本研究以同时考察注意警戒和执行控制功能的实验任务为研究范式，采用行为测量和脑电技术，通过三个循序渐进的实验探究了 taVNS 对不 同唤醒状态下（低唤醒疲劳 vs 高唤醒焦虑）健康人群的执行控制和注意警戒功能的影响。

具体而言，研究一以注意网络为理论框架，通过对经典 Flanker 范式与 Oddball 范式的结合，在行为反应层面同时考察了执行控制（Flanker 效应，即一致性效应）和注意警戒（Oddball 效应，即新异性效应）两种注意的主要功能。 该研究采用实验组对照组前后测实验设计，共采集了 16 名健康被试，随机分配到 taVNS 组和控制组（最后 15 名被试纳入后续分析）。其中，taVNS 组在认知任务前测后接受 20 分钟的持续个性化 taVNS 干预，而控制组则仅在开始干预的前 30 秒和第10分钟后的前 30 秒进行短暂 taVNS 干预。结果发现，前测中两组被试都成功表现出 Flanker 效应以及 Oddball 效应，证明了范式的有效性。此外， taVNS 组调控后反应时相比于控制组显著减少，提示了 taVNS 对注意功能的整体提升效果。

研究二采用一小时连续算数任务，迫使被试进入低唤醒疲劳状态，以探讨 taVNS 对低唤醒状态下注意警戒和执行控制功能的影响以及对疲劳的调节。随后采用研究一验证有效的研究范式进行行为测量，并同步记录脑电信号。该研究共招募被试 41 人，随机分配到 taVNS 组或控制组（最后 39 被试名纳入数据分析）。行为结果表明，在疲劳状态下 taVNS 对注意功能的行为调控效果未达到统计学显著，但脑电结果显示相比于控制组，taVNS 组调控后的额顶区晚期正向电位的振幅增加，提示 taVNS 可能调节了低唤醒疲劳被试对注意任务的认知资源投入。

研究三以焦虑这一典型的高唤醒状态为切入点，考察 taVNS 对高唤醒焦虑下注意警戒和执行控制功能的影响以及对焦虑的调节。首先通过问卷筛选高焦虑被试，然后在研究一的范式基础上加入一系列作用于脚踝的随机突发电刺激以保持被试高唤醒状态。此外，考虑到音乐是一种有效的焦虑调控手段，研究三在 taVNS组和控制组之外，增设了 taVNS+音乐联合调控组，即在 taVNS调控的同时播放音乐，以探讨结合方案的可行性。该研究共招募被试 70 人，随机分配到 taVNS 组，taVNS+音乐组和控制组（最后 68 名纳入数据分析）。结果表明， 在焦虑状态下，taVNS 和 taVNS+音乐联合调控均显著提升了被试的注意功能，表现为较控制组显著减少了任务反应时，然而仅 taVNS+音乐联合调控显著改善了被试的焦虑情绪，提示 taVNS 与其他手段相结合可以达到更好更全面的调控效果。

综上所述，taVNS 作为一种廉价便携的非侵入性电刺激手段，可以有效改善不同唤醒状态下的注意功能，表现为个体整体反应速度的提升；同时与其他非侵入性调控手段结合，会在调控注意功能的同时改善当下的生理状态。本研究不仅有助于我们更好地理解注意的功能机制，也为我们探索提升注意能力的新方法提供了理论与数据支持。

Transcutaneous vagus nerve stimulation (tVNS) is a non-invasive neural modulation approach that can regulate the functioning of the nervous system by stimulating the vagus nerve in the neck (tcVNS) or ear (taVNS). tVNS has been studied for the treatment of various conditions, such as epilepsy and depression, primarily due to the direct connections between the vagus nerve and multiple brain regions. Through electrically stimulating the vagus nerve, tVNS modulates neural activity and neurotransmitter release, thereby correcting abnormal brain functioning. Importantly, there is evidence suggesting that taVNS can also improve cognitive functions in healthy individuals, such as regulating cognitive flexibility and enhancing cognitive control triggered by conflict. However, the reproducibility of these results is low, possibly due to researchers overlooking the differential impact of individual arousal on various components of attention. Therefore, the present study employed an experimental task that is capable of testing executive control and attentional alertness functions at the same time. With behavioral measures and electroencephalography (EEG) recordings, this study investigated the effects of taVNS on attentional alertness and executive control functions in healthy individuals under low arousal (fatigue) and high arousal (anxiety) through three progressively designed experiments.

Specifically, Study 1 employed the attentional network framework and mainly focused on two primary functions of attention, namely executive control (the Flanker effect) and attentional alertness (the Oddball effect). Study 1 employed a pre-post experimental design with experimental and control groups, recruiting a total of 16 healthy participants who were randomly assigned to the taVNS group and the control group (with 15 participants included in the data analysis). In the taVNS group, participants received continuous taVNS intervention for 20 minutes after the pre-test, while the control group underwent brief taVNS intervention only for the first 30 seconds at the beginning of the intervention and for 30 seconds after 10 minutes. The results demonstrated both Flanker effect and Oddball effect for all participants in the pre-test, confirming the effectiveness of the paradigms. Additionally, in the post-test, reaction times in the taVNS group were significantly reduced compared to the control group, indicating an overall enhancement effect of taVNS on attentional functions.

Study 2 employed a 1-hour continuous arithmetic task to induce participants into a state of low arousal fatigue, aiming to investigate the effects of taVNS on attentional function under conditions of low arousal and its modulation on fatigue. Subsequently, the validated research paradigm from Study 1 was utilized for behavioral measurements, and simultaneous EEG signals were recorded. The study recruited 41 participants in total, who were randomly assigned to the taVNS group and the control group (with 39 participants included in the data analysis). The results indicated that under fatigue condition, the behavioral regulation effect of taVNS on attentional function did not reach statistical significance. However, EEG results suggested that compared to the control group, the taVNS group exhibited an increase in the late positive potential in the frontoparietal region after intervention, indicating the possibility of taVNS modulating participants' cognitive resource allocation during attentional tasks.

Study 3 focused on anxiety, a typical form of high arousal, aiming to investigate the effects of taVNS on attentional function under anxiety conditions and its potential for alleviating anxiety. This study screened participants with high trait anxiety using related questionnaires. Building upon the paradigm of Study 1, a series of abrupt electrical stimulations on legs were applied during the experimental procedure to maintain participants' anxious states. Moreover, considering music as an effective anxiety regulation approach, Study 3 included an additional taVNS+music group, in which music was played simultaneously with taVNS regulation, to explore the possibility to combined different approach with taVNS. The study recruited a total of 68 participants, who were randomly assigned to the taVNS group, taVNS+music group, and control group (68 included in data analysis). The results indicated that under anxiety condition, both taVNS and taVNS+music significantly improved participants' attentional function, as evidenced by significantly improved task reaction times compared to the control group. However, only taVNS+music significantly alleviated participants' anxiety, suggesting the possibility of combining taVNS with other regulation approach to achieve a comprehensive regulatory effect.

In conclusion, taVNS, as an inexpensive and portable non-invasive electrical stimulation method, can effectively improve attentional function under different arousal states, manifesting as an overall improvement in reaction time. This study not only contributes to a better understanding of the functional mechanisms of attention but also provides theoretical and empirical support for exploring new methods to enhance attentional ability.