Singapore Institute of Technology

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Auricular Vagus Nerve Stimulation for Stress Reduction: Evidence from Alpha Prefrontal Asymmetry

conference contribution
posted on 2024-04-03, 04:46 authored by Ramaswamy Palaniappan, Surej Mouli, Evangelia Fringi, Jane Ollis, Rahul Kanegaonkar, Suni Arora, Ian McLoughlinIan McLoughlin

This study explores auricular vagus nerve stimulation (aVNS) within the context of stress. Five healthy subjects underwent a pulsed mode aVNS (with a frequency of 25 Hz and pulse width of 200 μs) using a custom made current stimulation device. The device triggered the auricular vagus nerve branch through the tragus for 15 minutes, with prefrontal EEG data collected pre and post aVNS (each for 5 minutes) to capture stress indicators. Given that the frontal location is prone to noise, EEG signal pre-processing through independent component analysis (ICA) was used to reduce eye movements and other artifacts. Alpha (8-14 Hz) asymmetry in prefrontal location in both hemispheres was computed from locations Fp1 and Fp2 for one second segments of EEG; these asymmetry values were normalised by subtracting the post aVNS (or placebo) from pre aVNS (placebo). The normalised alpha frontal asymmetries were assessed for statistical significance using T-test. Results showed increased aVNS alpha prefrontal asymmetry compared to placebo, indicating reduced stress. This was statistically significant ( ) for all five subjects. It is therefore concluded that the pulsed mode aVNS stimulation at the tragus may represent a potential approach for stress relief.


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2020 IEEE-EMBS Conference on Biomedical Engineering and Sciences (IECBES), 01-03 March 2021, Langkawi Island, Malaysia.

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