Examining Transcutaneous Vagal Nerve Stimulation as a Facilitator of Social Bonding (CtVNS)

This study aims to understand the role of the vagus nerve in promoting social bonding by using a non-invasive stimulation technique called transcutaneous vagal nerve stimulation (tVNS). The investigators will investigate whether tVNS can improve emotional, physiological, and behavioral experiences during and after social interactions. Couples will be randomly assigned to receive either tVNS or a sham stimulation during gratitude expression and problem-solving discussions. The investigators will measure their subjective evaluations of the interactions and capture their physiological and behavioral synchrony. This research will shed light on the processes involved in social connection and explore the potential of tVNS as a tool to enhance bonding in close relationships.

Study Overview

• Status: Completed
• Conditions: Vagus Nerve Stimulation
• Intervention / Treatment: Device: Transcutaneous vagal nerve stimulation

Detailed Description

As fundamental as the need to belong is to human survival and functioning, decades of research have shown that social connection is critical to emotional well-being. The current investigation seeks to use the knowledge and technological advances in the biomedical field to examine the causal role of the vagus nerve in promoting social bonding. Specifically, building on the recent evidence suggesting the effects of transcutaneous vagal nerve stimulation (tVNS) on improving social cognitive functioning, this study will examine the utility of tVNS in modulating emotional, physiological, and behavioral experiences during and after social interactions. The investigators will examine if romantic couple assigned to receive tVNS vs. active sham stimulation during two types of conversations (i.e., gratitude expression and problem-solving discussion) show differences in their experiences of the interactions. The study outcomes will include subjective evaluations of the interaction (e.g., felt emotions) and their physiological synchrony. This investigation will provide insights into the mechanistic processes that undergird social connection and, importantly, be the first to examine the potential utility of tVNS as an intervention tool for promoting social bonding within close relationships.

• Study Type: Interventional
• Enrollment (Actual): 160

Contacts and Locations

Study Locations

• United States
  • California
    • San Francisco, California, United States, 94107
      • UCSF Nancy Friend Pritzker Psychiatry Building

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• Fluent in English
• Having been in a relationship with the partner for at least a year
• Within the age range of 18-39

Exclusion Criteria:

• Major chronic disease. self-reported autoimmune disease; severe asthma; lung disease (such as chronic bronchitis; history of stroke, heart attack, epilepsy, brain injury); cardiovascular disease.
• Cancer: if not in remission.
• Substance dependence-current or long history (5 years of more).
• Current psychiatric diagnosis that is not being treated with medication
• Confounding medications, including those used to treat hypertension and cardiovascular conditions; psychoactive substances; and medications known to directly affect autonomic functioning.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Basic Science
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Single

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Active tVNS; We will use a research edition of an auricular vagus nerve stimulator (tVNS RE, Vagus.net™, UK) that sends current-controlled stimulation in symmetric biphasic waveforms. The tVNS RE conforms to EU directive 93/42/EEC medical device standards and ISO/IEC 17050-1. This device consists of a handheld stimulator and an electrode clip. We will deliver stimulation at the individually calibrated intensity continuously during the interactions, and the default device settings we adopted were as follows: frequency = 30Hz, phase duration = 250μs, interphase interval = 50μs, and max voltage = 65V. In the active stimulation condition, both partners will have the stimulation clip attached to the outer auditory canal.	Device: Transcutaneous vagal nerve stimulation; The intervention consists of neurostimulation device that is programmed to a stimulus intensity at 0.5mA with a stimulation frequency of 25 Hz at the outer auditory canal.
Sham Comparator: Sham tVNS; In the sham condition, both partners will have electrodes attached to the center of the left ear lobe. They will still receive stimulation but at a placement that should not activate the vagus nerve.	Device: Transcutaneous vagal nerve stimulation; The intervention consists of neurostimulation device that is programmed to a stimulus intensity at 0.5mA with a stimulation frequency of 25 Hz at the outer auditory canal.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Self-reported Positive Affect	During the conversation, overall, I felt… (1: not at all positive, 7: extremely positive)	Once, self-reported in a survey immediately following conflict interaction, up to 10 minutes
Self-reported Negative Affect	During the conversation, overall, I felt… (1: not at all negative, 7: extremely negative)	Once, self-reported in a survey immediately following conflict interaction, up to 10 minutes
Respiratory Sinus Arrhythmia	RSA was assessed continuously throughout the conversation.	Continuously throughout conflict conversation
Interbeat Interval	IBI was assessed continuously throughout the conversation.	Continuously throughout the conflict conversation

Collaborators and Investigators

• Sponsor: University of California, San Francisco
• Collaborators: National Institute on Aging (NIA)

Publications and helpful links

General Publications

• Chung JM, Harari GM, Denissen JJ. Investigating the within-person structure and correlates of emotional experiences in everyday life using an emotion family approach. Journal of Personality and Social Psychology. 2022;122(6):1146-1189.

Study record dates

Study Major Dates

• Study Start (Actual): February 17, 2024
• Primary Completion (Actual): July 31, 2024
• Study Completion (Actual): July 31, 2024

Study Registration Dates

• First Submitted: May 24, 2023
• First Submitted That Met QC Criteria: June 2, 2023
• First Posted (Actual): June 12, 2023

Study Record Updates

• Last Update Posted (Actual): May 4, 2025
• Last Update Submitted That Met QC Criteria: April 22, 2025
• Last Verified: April 1, 2025

More Information

Terms related to this study

• Other Study ID Numbers: 23-39189; U24AG072699 (U.S. NIH Grant/Contract)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO
• IPD Plan Description: There is currently no plan to make individual participant data available to other researchers.