# Sequencing and Initiation in Speech Production

> **NIH NIH R01** · BOSTON UNIVERSITY (CHARLES RIVER CAMPUS) · 2022 · $631,982

## Abstract

PROJECT SUMMARY
The overall goal of this project is to develop and test a detailed neural and computational account of the brain
mechanisms underlying speech motor sequence planning and motor program initiation and their breakdown in
stuttering. 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. This project aims to remove this critical barrier to progress through an
integrated combination of behavioral, neurostimulation, and neuroimaging experiments and associated
neurocomputational modeling. The studies in Aim 1 will characterize the neural mechanisms underlying sub-
syllabic sequencing in neurotypical individuals. In Study 1.1, we will use functional magnetic resonance imaging
(fMRI) to test the hypotheses that (1) phonological working memory in left posterior inferior frontal sulcus utilizes
an onset-nucleus-coda representation rather than representing an entire syllable as a single item, whereas (2)
ventral premotor cortex uses a syllable-based representation in which a fully learned syllable is represented by
a single motor program. Study 1.2 uses non-invasive neurostimulation to directly test hypotheses concerning the
neural substrates of improved performance accuracy (hypothesized to involve the cerebellum in concert with
motor cortical areas) versus speed (hypothesized to involve left posterior inferior frontal sulcus) when learning
novel syllables. In Aim 2 we investigate sequencing at the multi-syllabic level, including the effects of word
learning in adults with and without stuttering (Study 2.1) and children with and without stuttering (Study 2.2).
These studies will test the hypotheses that (i) novel nonword repetition performance is impaired in both children
and adults who stutter compared to neurotypical speakers, (ii) learning a multi-syllabic word reduces working
memory load compared to producing the same syllables prior to learning them as a word, and (iii) this reduced
working memory load will reduce error rate differences between individuals who do and do not stutter and will
increase fluency in those who stutter. In addition, Study 2.1 uses fMRI to probe the neural mechanisms involved
in word learning, thereby testing the model-based hypotheses that (i) anterior inferior frontal sulcus is the site of
a word buffer whose load is decreased by learning a multi-syllabic word compared to producing syllables in a
novel nonword combination, and (ii) impaired initiation of motor programs, rather than impaired working memory
per se, is the central contributor to stuttering.
Together these studies will result in an improved neurocomputational account of the brain mechanisms
underlying the sequencing and initiation of speech ...

## Key facts

- **NIH application ID:** 10456231
- **Project number:** 5R01DC007683-17
- **Recipient organization:** BOSTON UNIVERSITY (CHARLES RIVER CAMPUS)
- **Principal Investigator:** FRANK H GUENTHER
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2022
- **Award amount:** $631,982
- **Award type:** 5
- **Project period:** 2006-04-01 → 2026-05-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10456231

## Citation

> US National Institutes of Health, RePORTER application 10456231, Sequencing and Initiation in Speech Production (5R01DC007683-17). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/10456231. Licensed CC0.

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