To examine whether transcutaneous cervical and auricular vagus nerve stimulation (tcVNS & taVNS) could enhance second language vocabulary acquisition among career linguists in a realistic multi-day learning protocol.

Cognitive performance and skill proficiency are important in a wide variety of careers. Recently, transcutaneous vagus nerve stimulation (tVNS) has emerged as a promising technique to enhance learning and skill acquisition. tVNS efficacy in a realistic, multi-day learning protocol has not been demonstrated.

We conducted two double-blind controlled experiments examining the efficacy of tcVNS and taVNS on a 5-day second-language vocabulary acquisition protocol in career linguists at the US Defense Language Institute Foreign Language Center.

tcVNS produced statistically significant benefit during training (Day 2-4; model estimated mean performance: sham-37.5% vs ctVNS-46%, p = .025), and the training benefit was sustained on the final test conducted at a 24-hour delay where no stimulation was administered. Additionally, using pre- and post- training day mood rating as measured by Air Force Research Laboratory Mood Questionnaire, tcVNS promoted focus (p = .001) and mitigated fatigue (p = .036).

Our findings suggest that tcVNS promotes learning by inducing neuroplasticity as well as enhancing focus and mitigating fatigue. tcVNS training benefits are sustained for at least 24 hours after stimulation. Based on current and related demonstration of training enhancement, we believe tcVNS could be beneficial in language learning as well as acquisition of skills in intensive learning environments.

This research was developed with funding from the Defense Advanced Research Projects Agency (DARPA). The views, opinions and/or findings expressed are those of the author and should not be interpreted as representing the official views or policies of the Department of Defense or the U.S. Government.