Brain, Behavior and Endocrine Effects of Transcutaneous Vagus Nerve Stimulation

Transcutaneous Vagus Nerve Stimulation Promotes Oxytocin Release and Increases Fixations on Nose

The main aim of the study is to investigate whether the transcutaneous vagus nerve stimulation(tVNS) promotes oxytocin release and the potential biomarkers of tVNS based on eye-tracking data

A randomized, single-blinded, sham-controlled, within-subject, crossover design will be employed in this study. In a randomized order, a total of 54 healthy subjects will receive transcutaneous vagus nerve stimulation via tragus and sham stimulation vis earlobe in the left ear (interval between these two stimulations will be 1 week). Eye-tracking and behavioral data will be collected before and after 30 minutes of stimulation, saliva samples will be collected before and after 30 minutes of stimulation, and the end of the experiment.

Some personal traits will be assessed using different kinds of questionnaires, such as the Autism Spectrum Quotient(ASQ), Social Responsiveness Scale(SRS), State-Trait Anxiety Inventory (STAI), Beck's Depression Inventory(BDI), and Toronto Alexithymia Scale (TAS-20).

Inclusion Criteria:

• Healthy subjects without past or current psychiatric or neurological disorders

Exclusion Criteria:

• history of head injury;
• pregnant, menstruating, taking oral contraceptives;
• medical or psychiatric illness.