taVNS for Letter Learning in Dyslexia

Study Overview
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Brief Summary
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This is a pilot study to establish feasibility of transcutaneous auricular vagus nerve stimulation (taVNS) for improving letter-learning in adolescents with dyslexia. The main goals of the study are to 1) evaluate whether children in this age range will tolerate low level stimulation over the course of multiple sessions, 2) determine whether low level taVNS improves novel letter learning in dyslexia, and 3) evaluate the effect of low level taVNS on the brain's response to letters. Participants will complete fMRI before training, immediately after training, and a few weeks after training ends. Training will consist of six 30-minute lessons during which participants will learn novel letter-sound relationships while receiving either active or sham taVNS. Researchers will compare stimulation conditions to determine effect of this device on learning and neural plasticity.

Official Title
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Effect of Non-invasive Vagus Nerve Stimulation on Letter Learning in Dyslexia

Conditions
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Dyslexia

Intervention / Treatment
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* Device: active taVNS
* Device: sham taVNS


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Normal non-verbal IQ Reading scores above 90 on four single word reading measures (typical reader) OR reading scores below 90 on two or more single word reading measures (dyslexia) with or without ADHD Exclusion Criteria: Neurological diagnoses (e.g., autism, epilepsy, etc.) Medications other than those prescribed for ADHD Nonverbal IQ below 80

Ages Eligible for Study
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Minimum Age: 10 Years
Maximum Age: 12 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
Interventional Model Description: Participants will be randomly assigned to either active stimulation or sham stimulation groups.
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Active taVNS<br>Participants will receive custom current at 5 Hz to the left auricular branch of the vagus nerve while learning new letter-sound relationships. | Device: active taVNS<br>* low level stimulation to the auricular branch of the vagus nerve<br>|
| Sham Comparator: Sham taVNS<br>Participants will undergo current thresholding but device will be turned off without their knowledge during the training. | Device: sham taVNS<br>* device placed with no current administered<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Automaticity | Time taken to read a card of letters accurately | 3 weeks | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Letter ID | Percent correct of learned letter-sound relationships | 3 weeks | 
| Decoding | Percent correct of pseudowords read in 45 seconds | 3 weeks |