NCT06181149

Brief Summary

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.

Trial Health

77
On Track

Trial Health Score

Automated assessment based on enrollment pace, timeline, and geographic reach

Enrollment
300

participants targeted

Target at P75+ for not_applicable

Timeline
20mo left

Started Jan 2024

Longer than P75 for not_applicable

Geographic Reach
1 country

2 active sites

Status
recruiting

Health score is calculated from publicly available data and should be used for screening purposes only.

Trial Relationships

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Study Timeline

Key milestones and dates

Study Progress59%
Jan 2024Dec 2027

First Submitted

Initial submission to the registry

December 7, 2023

Completed
19 days until next milestone

First Posted

Study publicly available on registry

December 26, 2023

Completed
6 days until next milestone

Study Start

First participant enrolled

January 1, 2024

Completed
4 years until next milestone

Primary Completion

Last participant's last visit for primary outcome

December 30, 2027

Expected
Same day until next milestone

Study Completion

Last participant's last visit for all outcomes

December 30, 2027

Last Updated

August 21, 2025

Status Verified

August 1, 2025

Enrollment Period

4 years

First QC Date

December 7, 2023

Last Update Submit

August 19, 2025

Conditions

Keywords

stuttering

Outcome Measures

Primary Outcomes (2)

  • 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

Study Arms (4)

Group 1

EXPERIMENTAL
Behavioral: Delaying speech initiation

Group 2

EXPERIMENTAL
Behavioral: Auditory errors and pre-speech auditory modulation

Group 3

EXPERIMENTAL
Behavioral: Contributions of the speech premotor cortex to pre-speech auditory modulation

Group 4

EXPERIMENTAL
Behavioral: Delaying auditory feedback

Interventions

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.

Group 1

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.

Group 2

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.

Group 3

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.

Group 4

Eligibility Criteria

Age3 Years+
Sexall
Healthy VolunteersYes
Age GroupsChild (0-17), Adult (18-64), Older Adult (65+)

You may qualify if:

  • 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)

Contact the study team to confirm eligibility.

Sponsors & Collaborators

Study Sites (2)

Arizona State University

Tempe, Arizona, 85287, United States

RECRUITING

Univeristy of Washington

Seattle, Washington, 98105, United States

RECRUITING

MeSH Terms

Conditions

Stuttering

Condition Hierarchy (Ancestors)

Speech DisordersLanguage DisordersCommunication DisordersNeurobehavioral ManifestationsNeurologic ManifestationsNervous System DiseasesSigns and SymptomsPathological Conditions, Signs and Symptoms

Central Study Contacts

Ayoub Daliri, PhD

CONTACT

Study Design

Study Type
interventional
Phase
not applicable
Allocation
RANDOMIZED
Masking
DOUBLE
Who Masked
PARTICIPANT, OUTCOMES ASSESSOR
Purpose
BASIC SCIENCE
Intervention Model
PARALLEL
Sponsor Type
OTHER
Responsible Party
SPONSOR

Study Record Dates

First Submitted

December 7, 2023

First Posted

December 26, 2023

Study Start

January 1, 2024

Primary Completion (Estimated)

December 30, 2027

Study Completion (Estimated)

December 30, 2027

Last Updated

August 21, 2025

Record last verified: 2025-08

Locations