On the potential of transcutaneous auricular vagus nerve stimulation to reduce visually induced motion sickness

Transcutaneous auricular vagus nerve stimulation (taVNS) is a potent therapeutic tool for a broad spectrum of diseases and disorders. Here, we investigated the effects of taVNS on autonomic function during visually induced motion sickness, through the analysis of spectral and time-frequency heart rate variability. To determine the efficacy of taVNS, we compared sham and taVNS condition in a randomized, within-subjects, cross-over design in 14 healthy participants. We found that taVNS reduced motion sickness symptoms by significantly increasing normalized high-frequency (HF) power and decreasing both normalized low-frequency (LF) power and the power ratio of LF and HF components (sympathovagal balance). Furthermore, behavioral data recorded using the motion sickness assessment questionnaire (MSAQ) showed significant differences in decreased symptoms during taVNS compared to sham condition for the total MSAQ scores and, central and sopite categories of the MSAQ. Our findings suggest that by administering taVNS, parasympathetic modulation is increased, and autonomic imbalance induced by motion sickness is restored. This study provides first evidence that taVNS has potential as a non-pharmacological neuromodulation tool to keep motion sickness at bay. Thus, this sheds new light towards protecting people from becoming motion sick and possible accelerated recovery from the malady.