Pihlaja Mia, Failla Laura, Peräkylä Jari, Hartikainen Kaisa M
Behavioral Neurology Research Unit, Tampere University Hospital, Tampere, Finland.
Faculty of Medicine and Health Technology, Tampere University, Tampere, Finland.
Front Hum Neurosci. 2020 Oct 6;14:561780. doi: 10.3389/fnhum.2020.561780. eCollection 2020.
We have previously shown invasive vagus nerve stimulation to improve attention and working memory and alter emotion-attention interaction in patients with refractory epilepsy, suggesting that VNS might be useful in the treatment of cognitive impairment. The current research focuses on whether non-invasive, transcutaneous vagus nerve stimulation (tVNS) has similar effects to VNS. Furthermore, we aimed to assess whether tVNS has an impact on cognitive control in general or on underlying brain physiology in a task that mimics everyday life demands where multiple executive functions are engaged while encountering intervening emotional stimuli. Event-related potentials (ERP) evoked in such a task, specifically centro-parietal P3 and frontal N2 were used as biomarkers for attention allocation and cognitive control required to carry out the task. A single-blinded, sham-controlled, within-subject study on healthy subjects ( = 25) was conducted using Executive Reaction Time Test (RT-test), a Go/NoGo task engaging multiple executive functions along with intervening threat-related distractors while EEG was recorded. tVNS at the left tragus and sham stimulation at the left ear lobe was alternately delivered throughout the task. To assess the impact of tVNS on neural activity underlying attention and cognitive control, centro-parietal P3 and frontal N2 peak amplitudes were measured in Go and NoGo conditions. Task performance was assessed with RTs and different error types reflecting cognitive control in general and distinct executive functions, such as working memory and response inhibition.No significant effects due to tVNS on performance in the Executive RT-test were observed. For N2 there was a main effect of stimulator status and a significant interaction of trial type (Go, NoGo) and stimulator status. analysis revealed that tVNS resulted in a significant reduction of frontal N2 only in the NoGo condition. No significant effects were observed for P3 nor were there any effects of emotion. Diminished NoGo-N2 potential along with unaltered task performance during tVNS suggests fewer cognitive control resources were required to successfully withhold a prepotent response. Though caution is warranted, we suggest that tVNS may lead to more efficient neural processing with fewer resources needed for successful cognitive control, providing promise for its potential use in cognitive enhancement.
我们之前已经表明，侵入性迷走神经刺激可改善难治性癫痫患者的注意力和工作记忆，并改变情绪与注意力的相互作用，这表明迷走神经刺激可能对认知障碍的治疗有用。当前的研究聚焦于非侵入性经皮迷走神经刺激（tVNS）是否具有与迷走神经刺激（VNS）相似的效果。此外，我们旨在评估tVNS是否对一般认知控制有影响，或者在一项模拟日常生活需求的任务中对潜在脑生理学有影响，在该任务中，当遇到干预性情绪刺激时会涉及多种执行功能。在这样一项任务中诱发的事件相关电位（ERP），特别是中央顶叶P3和额叶N2，被用作注意力分配和执行该任务所需认知控制的生物标志物。我们使用执行反应时间测试（RT测试）对25名健康受试者进行了一项单盲、假对照、受试者内研究，这是一项Go/NoGo任务，在记录脑电图的同时，该任务涉及多种执行功能以及干预性威胁相关干扰物。在整个任务过程中，交替在左耳屏进行tVNS和在左耳叶进行假刺激。为了评估tVNS对注意力和认知控制基础神经活动的影响，在Go和NoGo条件下测量中央顶叶P3和额叶N2的峰值幅度。用反应时间和反映一般认知控制以及不同执行功能（如工作记忆和反应抑制）的不同错误类型来评估任务表现。未观察到tVNS对执行RT测试表现有显著影响。对于N2，存在刺激器状态的主效应以及试验类型（Go、NoGo）与刺激器状态的显著交互作用。分析表明，tVNS仅在NoGo条件下导致额叶N2显著降低。未观察到P3有显著影响，情绪也没有影响。tVNS期间NoGo - N2电位减弱以及任务表现未改变表明，成功抑制优势反应所需的认知控制资源更少。尽管需要谨慎，但我们认为tVNS可能导致更有效的神经处理，成功进行认知控制所需资源更少，这为其在认知增强方面的潜在应用带来了希望。
