There is a fundamental gap in our understanding of the temporal dynamics underlying the auditory-motor integration deficits consistently observed in children and adults who stutter. Fluent speech requires coordinated neuronal activity that is achieved through neural oscillatory synchrony across brain structures. This proposal will focus on the oscillatory synchrony facilitating neural communication within the speech network. Our long-term goal is to determine empirically-based neural markers for persistent stuttering, findings that may eventually inform the clinical diagnosis and treatment of childhood stuttering. The overall objective of the present application is to determine how children who stutter (CWS) differ from fluent peers in neural oscillatory synchrony across auditory-motor structures during speech perception and planning. Guided by EEG and MRI data collected from children who do and do not stutter, our central hypothesis is that beta oscillations, which control predictive timing of movements through coordination of motor to auditory systems, will show aberrant power, reduced inter- trial phase clustering, and reduced interregional oscillatory phase synchrony in CWS. A better understanding in this area has exciting treatment implications, since manipulation of synchrony within oscillatory patterns in auditory-motor systems may be possible through entrainment with external sensory stimuli and non-invasive brain stimulation. This project will thus allow us to lay the groundwork towards systematic, neurobiology-based intervention development for CWS. Guided by strong preliminary data, the central hypotheses will be tested by pursuing three specific aims: 1. Identify and characterize beta power and oscillatory synchrony in auditory- motor cortical areas during speech perception and planning in CWS. 2. Compare beta power and oscillatory synchrony in auditory-motor cortical areas during natural and entrained (paced) speech planning in CWS. 3. Determine how beta oscillation characteristics in auditory-motor areas relate to structural and functional connectivity among auditory, motor and striatal regions in CWS. The proposed work is innovative, as it will be the first series of studies designed to characterize neural oscillatory synchrony specific to speech processing in CWS, which may serve as a highly predictive neural marker for persistent stuttering during early childhood. Findings will be significant, because the expected results will elucidate, for the first time, causal mechanisms behind auditory-motor integration deficits in persistent stuttering. Such results will have an important positive impact, as the identified neural mechanisms underlying fluent speech will lay the foundation for effective early intervention for stuttering.
The proposed studies address an important and under-investigated area of childhood developmental stuttering pertaining to neural oscillatory synchrony underlying auditory-motor integration that supports speech perception and production. Using a multimodal imaging approach that combines both EEG and MRI data, the results of the proposed studies are expected to clarify for the first time the temporal dynamics of neural connectivity that are affected in children with persistent stuttering. These studies are expected to guide future intervention development that targets enhancing auditory-motor integration through manipulation of neural synchrony.