Investigating Speech Sequencing in Neurotypical Speakers and Persons With Disordered Speech
- Conditions
- Stuttering, DevelopmentalAphasia, Primary Progressive
- Interventions
- Device: Anodal tDCSBehavioral: Learning of novel multisyllabic nonwordsDevice: Sham tDCS
- 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
Recruitment & Eligibility
- Status
- RECRUITING
- Sex
- All
- Target Recruitment
- 2
Not provided
Not provided
Study & Design
- Study Type
- INTERVENTIONAL
- Study Design
- PARALLEL
- Arm && Interventions
Group Intervention Description Sub-syllabic learning and anodal tDCS of cerebellum Anodal tDCS 35 adults with neurotypical speech development will participate in this arm. Subjects will learn novel 1-syllable words formed by non-native phoneme combinations. During the training, continuous anodal transcranial direct current stimulation (tDCS) will be applied to the the subject's right cerebellum. Sub-syllabic learning and anodal tDCS of inferior frontal sulcus Anodal tDCS 35 adults with neurotypical speech development will participate in this arm. Subjects will learn novel 1-syllable nonsense words formed by non-native phoneme combinations. During the training, anodal transcranial direct current stimulation (tDCS) will be applied to the the subject's left inferior frontal sulcus. Multisyllabic learning and fMRI in adults Learning of novel multisyllabic nonwords 30 adults persistent developmental stuttering (AWS) and 30 adults with neurotypical speech development (ANS) will participate in this arm. Subjects will learn nonsense words formed by novel combinations of 3 syllables that are legal in American English during 6 training sessions over 2 days. Following training, subjects will participate in a functional magnetic resonance imaging (fMRI) session on a third day to measure brain activity associated with producing the words formed by pairing 2 learned 3-syllable strings learned during training and those formed by pairing 2 unfamiliar 3-syllable strings. Behavioral measures extracted from the data will be used to compare performance before and after training and across the AWS and ANS participants. Multisyllabic learning in children Learning of novel multisyllabic nonwords 45 children with persistent developmental stuttering (CWS) and 45 children with neurotypical speech development (CNS) will participate in this arm. Subjects will learn nonsense words formed by novel combinations of 2 syllables that are legal in American English during 6 training sessions over 2 days. Behavioral measures extracted from the data will be used to compare performance before and after training and across the CWS and CNS participants. Sub-syllabic learning and sham tDCS Sham tDCS 35 adults with neurotypical speech development will participate in this arm. Subjects will learn novel 1-syllable words formed by non-native phoneme combinations. During training, Sham transcranial direct current stimulation stimulation (tDCS) will be delivered to the subject's brain.
- 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