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Effects of External Ear Stimulation on Pain Perception and Mood

NCT02821741 · Status: RECRUITING · Phase: NA · Type: INTERVENTIONAL · Enrollment: 76

Last updated 2026-04-14

No results posted yet for this study

Summary

Background:

The vagus nerve runs from the brain to many organs. Stimulating it can affect the experience of pain. The nerve can be stimulated on the surface of the left ear. Researchers want to study how this stimulation affects the perception of pain. They also want to study how mood affects the experience of pain.

Objective:

To study the effects of mood and vagus nerve stimulation on the experience of pain.

Eligibility:

Healthy people ages 18 and older who are fluent in English

Design:

Participants will be pre-screened with a 15-minute phone call.

Participants will have three 2-hour visits.

At the screening visit, participants will be screened with:

Medical and psychiatric history

Physical and psychological exams

Questionnaires about physical and psychiatric health and mood

Urine tests

A heat probe on the forearm. The temperature will be increased until it is painful

but tolerable.

Participants will have 2 testing sessions within 7 days. Before the testing, they cannot do the following:

Eat, use nicotine, or exercise for at least 2 hours

Drink alcohol for 24 hours

Take certain medicines for 3 days

Testing includes:

Urine drug screening

Left ear stimulation: In one session, the vagus nerve will be stimulated. In the other, an area

of the ear away from the vagus nerve will be stimulated. This will be done with mild electric

shocks that cause a tingling, pricking, or itchy feeling.

Heat applied to the forearm until it is painful but tolerable

Completing several forms on a computer or on paper about how they are feeling

Monitors on the chest and a finger clip to monitor heart, breathing, and blood pressure

Conditions

  • Pain in Healthy Participants

Interventions

DEVICE

The Twin Stim Plus, 3rd Edition

Mild transcutaneous electrical stimulation will be applied to the cymba conchae of the left ear on day 1 and the left earlobe on day 2 (or vice versa) using a commercially available TENS unit (transcutaneous electrical nerve stimulator) attached to a pair of silver electrodes.

DEVICE

Medoc Pathway System

Device used to apply Thermal stimulation to both arms.

Sponsors & Collaborators

  • National Center for Complementary and Integrative Health (NCCIH)

    lead NIH

Principal Investigators

  • Alisa J Johnson · National Center for Complementary and Integrative Health (NCCIH)

Study Design

Allocation
RANDOMIZED
Purpose
BASIC_SCIENCE
Masking
TRIPLE
Model
CROSSOVER

Eligibility

Min Age
18 Years
Max Age
50 Years
Sex
ALL
Healthy Volunteers
Yes

Timeline & Regulatory

Start
2016-10-18
Primary Completion
2027-03-30
Completion
2027-03-30

Countries

  • United States

Study Locations

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Read the full study record

This page highlights key information. For complete eligibility criteria, study locations, investigator contacts, and the full protocol, visit the original record on ClinicalTrials.gov.

View NCT02821741 on ClinicalTrials.gov