taVNS on Pupillary Response and Perceptual Learning

Study Overview
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Brief Summary
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This study has two parts. The study team will evaluate transcutaneous auricular vagal nerve stimulation (taVNS) and two sham settings during a passive task while measuring pupillary response. Second, the study team will assign either taVNS, sham, or no intervention during a go/no-go task and evaluate perceptual learning over three sessions which will also include measuring the pupillary response and electroencephalogram (EEG).

Official Title
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The Effect of Transcutaneous Auricular Vagal Nerve Stimulation (taVNS) on Pupillary Response and Perceptual Learning

Conditions
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Pupillary Response

Intervention / Treatment
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* Procedure: Transcutaneous Auricular Vagal Nerve Stimulation (taVNS)
* Procedure: Sham Stimulation


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Healthy individuals 18 to 65 Normal audiometric testing Exclusion Criteria: Co-morbidities including cardiomyopathies, arrhythmias Implantable devices including vagal stimulators, pacemakers Presence of metallic implants Pregnancy

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 65 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

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


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Transcutaneous Auricular Vagal Nerve Stimulation (taVNS)<br> | Procedure: Transcutaneous Auricular Vagal Nerve Stimulation (taVNS)<br>* taVNS will be delivered by Digitimer DS7 Constant Current Stimulator (an FDA cleared medical device intended for human nerve and muscle stimulation). Stimulation is delivered via sticky pad electrodes all placed on the left side of the body (cymba concha, earlobe, and ulnar side of the wrist). Stimulation is delivered by a 3000ms pulse train (100us pulse width and 25Hz stimulation frequency). The current applied will be between 0.01uA to 9uA. The intervention will be delivered over the course of four sessions approximately one week apart.<br>|
| Sham Comparator: Sham<br> | Procedure: Sham Stimulation<br>* Sham stimulation will be delivered by Digitimer DS7 Constant Current Stimulator (an FDA cleared medical device intended for human nerve and muscle stimulation). Stimulation is delivered via sticky pad electrodes all placed on the left side of the body (either earlobe or forearm).<br>|
| No Intervention: No Intervention (Control)<br> | |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in Time It Takes to Reach 90% of Asymptotic Level Performance | Will be measured during performance on a go/no-go task. | Baseline, Month 3 | 
| Change in Overall Mean Peak (Pupillary Response) | Pupillary responses will be measured noninvasively using a video camera during a go/no-go task. | Baseline, Month 3 | 
| Change in Speed of Learning to Perform a Behavioral Task | Will be measured during performance on a go/no-go task. | Baseline, Month 3 |