Investigating Speech Sequencing in Neurotypical Speakers and Persons With Disordered Speech

Not Applicable

Recruiting

• Conditions: Stuttering, Developmental; Aphasia, Primary Progressive

• Registration Number: NCT05437159
• Lead Sponsor: Boston University Charles River Campus

Brief Summary

Persistent developmental stuttering affects more than three million people in the United States, and it can have profound adverse effects on quality of life. Despite its prevalence and negative impact, stuttering has resisted explanation and effective treatment, due in large part to a poor understanding of the neural processing impairments underlying the disorder. The overall goal of this study is to improve understanding of the brain mechanisms involved in speech motor planning and how these are disrupted in neurogenic speech disorders, like stuttering. The investigators will do this through an integrated combination of experiments that involve speech production, functional MRI, and non-invasive brain stimulation. The study is designed to test hypotheses regarding the brain processes involved in learning and initiating new speech sound sequences and how those processes compare in persons with persistent developmental stuttering and those with typical speech development. These processes will be studied in both adults and children. Additionally, these processes will be investigated in patients with neurodegenerative speech disorders (primary progressive aphasia) to further inform the investigators understanding of the neural mechanisms that support speech motor sequence learning. Together these experiments will result in an improved account of the brain mechanisms underlying speech production in fluent speakers and individuals who stutter, thereby paving the way for the development of new therapies and technologies for addressing this disorder.

Detailed Description

Not available

Study Timeline

• Study First Submitted: 2022-06-01
• Study First Submitted QC: 2022-06-27
• Study First Posted: 2022-06-29
• Study Start: 2023-04-03
• Status Verified: 2025-04
• Last Update Submitted: 2025-09-15
• Last Update Posted: 2025-09-19
• Primary Completion: 2026-05
• Study Completion: 2026-05-01

Recruitment & Eligibility

• Status: RECRUITING
• Sex: All
• Target Recruitment: 2

Inclusion Criteria

Not provided

Exclusion Criteria

Not provided

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Primary Outcome Measures

Name	Time	Method
Change from baseline in production error rate	Evaluated at Baseline and immediately following intervention	Investigators will compare mean error rates when producing newly learned speech sequences versus novel speech sequences of the same length in each arm. This measure will be used to test hypotheses regarding speech motor learning and brain activity and how these compare in persons with persistent developmental stuttering and persons with neurotypical speech.
Change from baseline in utterance duration	Evaluated at Baseline and immediately following intervention	Investigators will measure changes in utterance duration before and after speech sequence training to test hypotheses concerning differences in the neural mechanisms responsible for speed/duration improvements compared to improvements in accuracy (i.e., reductions in error rate).
Change from baseline in reaction time	Evaluated at Baseline and immediately following intervention	Investigators will measure the time interval between the prompt to begin speech and the subject's speech onset. Mean reaction time will be compared for learned and novel nonwords in persons with persistent developmental stuttering and persons with neurotypical speech.
Percentage of words stuttered	Evaluated at Baseline and immediately following intervention	Investigators will compare the percentage of words stuttered under different experimental conditions. This measure will be used to test hypotheses regarding the effect of speech motor learning on stuttering rate and the relationship between stuttering rate and brain activity.
Brain activity measured with functional magnetic resonance imaging	Evaluated at Baseline and immediately following intervention	Investigators will measure blood oxygen level dependent (BOLD) brain activity when producing speech utterances in different experimental conditions in adults with persistent developmental stuttering and those with neurotypical speech.

Secondary Outcome Measures

Name	Time	Method
Cortical white matter connectivity	Evaluated during the MRI scanning procedure	Diffusion-weighted MRI will be collected and used to identify relationships between white matter connectivity and behavioral measures.
Stuttering Severity	Evaluated at Baseline	The Stuttering Severity Instrument, 4th Edition, will be administered to persons show stutter to identify correlations between stuttering severity and task performance and functional and structural brain measures.
Cortical morphometry	Evaluated during the MRI scanning procedure	Structural MRI will be collected and used to identify relationships between cortical morphometry and behavioral measures.
Working memory test scores	Evaluated at Baseline	The Comprehensive Test of Phonological Processing (CTOPP) Second Edition working memory subtest scores for each participant will be used to identify correlations between working memory capacity, task performance, and brain measures in all studies.
Forward digit span	Evaluated at Baseline	Scores from the Forward Digit Span task from the Uniform Data Set neuropsychological test battery will be used for each participant with PPA to identify correlations between phonological working memory and task performance.

Trial Locations

Locations (3)

Massachusetts General Hospital; 🇺🇸 Boston, Massachusetts, United States

Boston University; 🇺🇸 Boston, Massachusetts, United States

University of Michigan; 🇺🇸 Ann Arbor, Michigan, United States