Tan Gansheng, Adams Josh, Donovan Kara, Demarest Phillip, Willie Jon T, Brunner Peter, Gorlewicz Jenna L, Leuthardt Eric C
bioRxiv. 2024 Mar 27:2024.03.24.586365. doi: 10.1101/2024.03.24.586365.
Working memory is essential to a wide range of cognitive functions and activities. Transcutaneous auricular VNS (taVNS) is a promising method to improve working memory performance. However, the feasibility and scalability of electrical stimulation are constrained by several limitations, such as auricular discomfort and inconsistent electrical contact.
We aimed to develop a novel and practical method, vibrotactile taVNS, to improve working memory. Further, we investigated its effects on arousal, measured by skin conductance and pupil diameter.
This study included 20 healthy participants. Behavioral response, skin conductance, and eye tracking data were concurrently recorded while the participants performed N-back tasks under three conditions: vibrotactile taVNS delivered to the cymba concha, earlobe (sham control), and no stimulation (baseline control).
In 4-back tasks, which demand maximal working memory capacity, active vibrotactile taVNS significantly improved the performance metric ' compared to the baseline but not to the sham. Moreover, we found that the reduction rate of ' with increasing task difficulty was significantly smaller during vibrotactile taVNS sessions than in both baseline and sham conditions. Arousal, measured as skin conductance and pupil diameter, declined over the course of the tasks. Vibrotactile taVNS rescued this arousal decline, leading to arousal levels corresponding to optimal working memory levels. Moreover, pupil diameter and skin conductance level were higher during high-cognitive-load tasks when vibrotactile taVNS was delivered to the concha compared to baseline and sham.
Our findings suggest that vibrotactile taVNS modulates the arousal pathway and could be a potential intervention for enhancing working memory.
Vibrotactile stimulation of the auricular vagus nerve increases general arousal.Vibrotactile stimulation of the auricular vagus nerve mitigates arousal decreases as subjects continuously perform working memory tasks.6 Hz Vibrotactile auricular vagus nerve stimulation is a potential intervention for enhancing working memory performance.
工作记忆对于广泛的认知功能和活动至关重要。经皮耳迷走神经刺激（taVNS）是一种改善工作记忆表现的有前景的方法。然而，电刺激的可行性和可扩展性受到多种限制，如耳部不适和电接触不一致。
我们旨在开发一种新颖且实用的方法，即振动触觉taVNS，以改善工作记忆。此外，我们研究了其对通过皮肤电导和瞳孔直径测量的唤醒的影响。
本研究纳入了20名健康参与者。在参与者进行N-back任务的三种条件下，同时记录行为反应、皮肤电导和眼动追踪数据：将振动触觉taVNS施加于耳甲艇、耳垂（假对照）以及无刺激（基线对照）。
在需要最大工作记忆容量的4-back任务中，与基线相比，主动振动触觉taVNS显著改善了表现指标“ ”，但与假对照相比则不然。此外，我们发现，在振动触觉taVNS期间，随着任务难度增加，“ ”的降低率明显小于基线和假对照条件。以皮肤电导和瞳孔直径衡量的唤醒在任务过程中下降。振动触觉taVNS挽救了这种唤醒下降，导致唤醒水平对应于最佳工作记忆水平。此外，与基线和假对照相比，当振动触觉taVNS施加于耳甲艇时，在高认知负荷任务期间瞳孔直径和皮肤电导水平更高。
我们的研究结果表明，振动触觉taVNS调节唤醒途径，可能是增强工作记忆的一种潜在干预措施。
对耳迷走神经的振动触觉刺激增加总体唤醒。随着受试者持续执行工作记忆任务，对耳迷走神经的振动触觉刺激减轻唤醒下降。6赫兹振动触觉耳迷走神经刺激是增强工作记忆表现的一种潜在干预措施。
