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

Status

Indicates the current recruitment status or the expanded access status.
Recruiting

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

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

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Estimated)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
110

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • 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 Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.

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

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

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

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
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

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
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

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
VA Office of Research and Development

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • 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)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
June 3, 2024

Primary Completion (Estimated)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
April 3, 2028

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
August 5, 2028

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
February 20, 2024

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
February 20, 2024

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
February 28, 2024

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
April 24, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
April 21, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
April 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant 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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