Auditory Prediction and Error Evaluation in the Speech of Individuals Who Stutter

Study Overview
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Brief Summary
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Stuttering negatively impacts communication and reduces the overall quality of life and well-being of individuals who stutter. This study will provide a strong foundation for developing neural and behavioral interventions for stuttering. Participants will be asked to name pictures, read words/sentences silently or aloud, and listen to speech and nonspeech sounds while their speech, muscle, and brain signals are collected. Some participants may also receive brain stimulation while reading and speaking.

Official Title
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Auditory Prediction and Error Evaluation in the Speech of Individuals Who Stutter

Conditions
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Stuttering, Developmental, Healthy Subjects

Intervention / Treatment
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* Behavioral: Delaying speech initiation
* Behavioral: Auditory errors and pre-speech auditory modulation
* Behavioral: Contributions of the speech premotor cortex to pre-speech auditory modulation
* Behavioral: Delaying auditory feedback


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: being a monolingual, native speaker of American English absence of developmental, psychological, neurological, or communication disorders (other than developmental stuttering) as confirmed by a certified research SLP normal (age-appropriate) binaural pure-tone hearing threshold (0.5-4k Hz; ≤25 dB HL for younger than 70 years, and ≤35 dB HL for older than 70 years) not taking any medications that affect the central nervous system absence of safety contra-indication for tDCS, TMS and MRI (for adults) scoring at the 20th percentile or higher on standardized speech-language tests (for children) Exclusion Criteria: -

Ages Eligible for Study
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Minimum Age: 3 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: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Group 1<br> | Behavioral: Delaying speech initiation<br>* This intervention will examine the effects of misalignment between prediction and auditory feedback in participants. We will use transcranial magnetic stimulation to induce a temporal misalignment between prediction and auditory feedback while participants produce speech.<br>|
| Experimental: Group 2<br> | Behavioral: Auditory errors and pre-speech auditory modulation<br>* This intervention will examine the contributions of auditory errors to pre-speech auditory modulation. Participants will receive auditory perturbations while speaking, and we will collect their brain activities throughout the study.<br>|
| Experimental: Group 3<br> | Behavioral: Contributions of the speech premotor cortex to pre-speech auditory modulation<br>* This intervention will examine the effects of stimulation of the left ventral premotor cortex on pre-speech auditory modulation. Participants will receive electrical stimulation while speaking.<br>|
| Experimental: Group 4<br> | Behavioral: Delaying auditory feedback<br>* This intervention will examine the effects of misalignment between prediction and auditory feedback in participants. We will use delayed auditory feedback to induce a temporal misalignment between prediction and auditory feedback while participants produce speech.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in brain activity before and during speaking | Participants will hear speech sounds in each trial before speaking or reading words. Participants' brain activity will be recorded while completing the speaking or reading tasks. The investigators will measure how the participant's brain activity in response to the played sounds changes during speaking and reading tasks. For this purpose, the investigators will measure the amplitude of the brain activity (in microvolts; µV) measured using a commercial electroencephalography system. The amplitude (µV) of the brain signals will be examined both before speaking and during speaking at two time points. | within each session of the study that may last up to 2 hours | 
| change in speech when participants experience auditory errors | In each trial, participants will experience an auditory error while they produce speech (e.g., they may say head but hear had). The investigators will measure how the participants' speech changes due to auditory errors that they experience in the current trial. For this p[purpose, the investigators will use commercial microphones to record speech signals and then examine the amplitude of the speech in specific frequency ranges (measured in Hertz; Hz). The frequencies (Hz) of speech in trials with auditory errors will be compared with those without auditory errors. | within each session of the study that may last up to 2 hours | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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stuttering