Pupil-Indexed Noninvasive Neuromodulation

April 21, 2026 updated by: VA Office of Research and Development

Transcutaneous Auricular Vagus Nerve Stimulation: Motor Learning & Mechanisms

Vagus nerve stimulation (VNS) is thought to activate neural pathways that release chemicals which promote plasticity and learning. Previous work has shown that the auricular branch of the vagus nerve innervates landmarks on the external ear. Work from the PI's laboratory has shown that electrical current applied to the external ear modulates physiological indexes of brain states implicated in the therapeutic effects of VNS. The broad objective of this project is to better understand physiological mechanisms modulated by auricular stimulation to support possible therapeutic effects in the form of motor learning.

Study Overview

Status

Recruiting

Conditions

Intervention / Treatment

Detailed Description

Existing evidence supports the use of VNS to enhance the effects of traditional therapy on impairments due to neurological injury. It is known that the vagus nerve forms contacts with neuromodulatory nuclei in the brainstem that release of chemicals shown to be critically involved in attentional control and memory formation. It is also known that the auricular branch of the vagus nerve innervates portions of the external ear providing a possible means to engage similar neural pathways noninvasively via transcutaneous auricular vagus nerve stimulation (taVNS). Recent work from the PI's laboratory shows that electrical current applied to landmarks on the external ear elicits transient effects on pupil dilation, an established physiological index of brain states that support learning. Given the ability to engage the biomarker, the investigators aim to further investigate physiological mechanisms modulated by taVNS and possible effects on learning.

Study Type

Interventional

Enrollment (Estimated)

110

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Locations

  • United States
    • Pennsylvania
      • Pittsburgh, Pennsylvania, United States, 15240
        • Recruiting
        • VA Pittsburgh Healthcare System University Drive Division, Pittsburgh, PA
        • Principal Investigator:
          • Michael A. Urbin, PhD
        • Contact:
        • Contact:
          • Camona Beth
          • Phone Number: (412) 822-3700

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

Yes

Description

Inclusion Criteria:

ALL PROSPECTIVE SUBJECTS:

  1. 18-75 years of age

    PROSPECTIVE SUBJECTS DIAGNOSED WITH STROKE:

  2. Diagnosis of a single stroke resulting in hand impairment
  3. Diagnosis of stroke at least six months prior to the time of participation

Exclusion Criteria:

ALL PROSPECTIVE SUBJECTS:

  1. History of vestibular disorders or dizziness
  2. Difficulty maintaining alertness and/or remaining still
  3. Pregnant or expecting to become pregnant
  4. Diagnosis of neurological and/or musculoskeletal disorder(s) (other than stroke) that affect movement
  5. Ocular disease and/or impairment in more than one eye
  6. History of seizure and/or epilepsy
  7. Implants, devices, or foreign objects in the brain/body that are incompatible with MRI
  8. Body size that is incompatible with MRI scanner dimensions

  9. Anyone already enrolled and actively participating in another greater than minimal risk study.

    PROSPECTIVE SUBJECTS DIAGNOSED WITH STROKE:

  10. Other impairments secondary to stroke (e.g., attention, cognition, etc.) that would interfere with the ability to understand study goals or follow simple instructions, as judged by the investigators.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Sham Comparator: Sham
No stimulation
Other: Sham
Electrodes placed on the skin overlying putative sites of auricular vagal innervation but no current administered.
Experimental: Paired, Sub-Threshold Stim
Sub-threshold stimulation paired with successful task repetitions
Other: Transcutaneous Electrical Stimulation
Electrical pulse trains applied to the skin overlying putative sites of auricular vagal innervation.
Experimental: Paired, Supra-Threshold Stim
Supra-threshold stimulation paired with successful task repetition
Other: Transcutaneous Electrical Stimulation
Electrical pulse trains applied to the skin overlying putative sites of auricular vagal innervation.
Experimental: Unpaired, Sub-Threshold Stim
Sub-threshold stimulation after successful task repetition
Other: Transcutaneous Electrical Stimulation
Electrical pulse trains applied to the skin overlying putative sites of auricular vagal innervation.
Experimental: Unpaired, Supra-Threshold Stim
Supra-threshold stimulation after successful task repetition
Other: Transcutaneous Electrical Stimulation
Electrical pulse trains applied to the skin overlying putative sites of auricular vagal innervation.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Force Control Change
Time Frame: Pre, 1-week Post, 1-month Post
Subjects will be tested on the same task used for training that involves controlling finger forces.
Pre, 1-week Post, 1-month Post

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

VA Office of Research and Development

Investigators

  • Principal Investigator: Michael A. Urbin, PhD, VA Pittsburgh Healthcare System University Drive Division, Pittsburgh, PA

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

June 3, 2024

Primary Completion (Estimated)

April 3, 2028

Study Completion (Estimated)

August 5, 2028

Study Registration Dates

First Submitted

February 20, 2024

First Submitted That Met QC Criteria

February 20, 2024

First Posted (Actual)

February 28, 2024

Study Record Updates

Last Update Posted (Actual)

April 24, 2026

Last Update Submitted That Met QC Criteria

April 21, 2026

Last Verified

April 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • N4532-R
  • I0X1RX004532 (Other Grant/Funding Number: U.S. Department of Veterans Affairs)

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

product manufactured in and exported from the U.S.

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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