Testing the Noradrenergic Hypothesis of Transcutaneous Vagus Nerve Stimulation

Study Overview
=================
Brief Summary
-----------------
This study investigates the capacity of non-invasive vagus nerve stimulation, applied at the ear, to alter to measures of locus coeruleus output pupil diameter and EEG alpha power. Non-invasive alteration in locus coeruleus output is of interest in regard to basic science and has potential clinical implications in a number of conditions.

Official Title
-----------------
Testing the Noradrenergic Hypothesis of Transcutaneous Vagus Nerve Stimulation

Conditions
-----------------
no Condition, Electroencephalography, Pupil Diameter

Intervention / Treatment
-----------------
* Device: Transdermal Vagus Nerve Stimulation (tVNS)


Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: Healthy, 18 years of age or older. Exclusion Criteria: self-report of mood disorders, prescription and non-prescription drug use which includes stimulants including caffeine and nicotine

Ages Eligible for Study
-----------------
Minimum Age: 18 Years

Sexes Eligible for Study
-----------------
All

Accepts Healthy Volunteers
-----------------
Accepts Healthy Volunteers

Study Plan
=================
How is the study designed?
-----------------

Design Details

Primary Purpose: Basic Science
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Active Stimulation 0.5<br>0.5mA, 30Hz intermittent transdermal vagus nerve stimulation of the auricle vagus. Stimulation 30 second on/30 seconds off for five cycles. | Device: Transdermal Vagus Nerve Stimulation (tVNS)<br>* Mild non-invasive transdermal electrical stimulation at the ear (0.0-1.0 mA, 0.0-30.0 Hz). Used in previous studies with no unexpected adverse events. Stimulator not considered a FDA regulated device in previous studies.<br>|
| Placebo Comparator: Lobe Control<br>0.5mA, 30Hz intermittent transdermal vagus nerve stimulation of the earlobe. Stimulation 30 second on/30 seconds off for five cycles. | Device: Transdermal Vagus Nerve Stimulation (tVNS)<br>* Mild non-invasive transdermal electrical stimulation at the ear (0.0-1.0 mA, 0.0-30.0 Hz). Used in previous studies with no unexpected adverse events. Stimulator not considered a FDA regulated device in previous studies.<br>|
| Placebo Comparator: Sham Stimulation<br>0.5mA, 5Hz intermittent transdermal vagus nerve stimulation of the auricle vagus. Stimulation 30 second on/30 seconds off for five cycles. | Device: Transdermal Vagus Nerve Stimulation (tVNS)<br>* Mild non-invasive transdermal electrical stimulation at the ear (0.0-1.0 mA, 0.0-30.0 Hz). Used in previous studies with no unexpected adverse events. Stimulator not considered a FDA regulated device in previous studies.<br>|
| Placebo Comparator: Nonstimulation<br>Placement of electrode without any stimulation. | Device: Transdermal Vagus Nerve Stimulation (tVNS)<br>* Mild non-invasive transdermal electrical stimulation at the ear (0.0-1.0 mA, 0.0-30.0 Hz). Used in previous studies with no unexpected adverse events. Stimulator not considered a FDA regulated device in previous studies.<br>|

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Pupil Diameter | Pupil diameter is measured via camera. | Within single one hour session | 
| EEG Alpha power. | Alpha power will be determined from EEG. | Within single one hour session |