Researchers report that brief bursts of transcutaneous auricular vagus nerve stimulation (taVNS) delivered during movement selectively increase motor-circuit excitability without producing extra autonomic effects. The study appears in the Journal of Neuroscience (25 May 2026; doi:10.1523/JNEUROSCI.2251-25.2026).
Thirty-six healthy adults (10 females, 26 males) took part in two experiments. The first used a randomized design with three stimulation conditions (taVNS, earlobe sham, no stimulation) and two behavioral contexts (go versus no-go). Investigators recorded heart rate, galvanic skin response, pupil diameter, and EEG spectral measures. The second experiment measured corticospinal excitability with TMS-evoked motor evoked potentials (MEPs) during 2-second taVNS bursts.
When taVNS coincided with active movement, TMS-induced MEP amplitudes rose, indicating transient facilitation of corticospinal output. Sensorimotor EEG activity also increased during movement with taVNS, but not during stillness. In contrast, pupil diameter showed a phasic response to stimulation in both movement and still conditions, consistent with engagement of central neuromodulatory systems independent of behavioral state. Autonomic indices (heart rate and skin conductance) showed no additional modulation from phasic taVNS beyond movement-related changes.
The authors conclude that brief, movement‑paired taVNS opens a temporally precise window that preferentially amplifies task-engaged motor circuitry rather than producing broad systemic or autonomic activation. They highlight MEPs, sensorimotor EEG, and pupil responses as sensitive biomarkers of phasic taVNS effects and note this mechanism supports timing stimulation to therapeutic movements in neurorehabilitation.
The paper lists Paulius Viskaitis, Dane Donegan, Olivier Lambercy and colleagues as authors. A footnote states that Viskaitis, Donegan and Lambercy later co-founded Skaaltec AG, and that the company was created after the manuscript was submitted and had no role in the study.
Photo credit: www.jneurosci.org
Tags: taVNS, vagus nerve, corticospinal excitability, EEG, TMS
Topics: Vagus nerve & taVNS, Neuromodulation, Non-invasive brain stimulation