Search Abstracts | Symposia | Slide Sessions | Poster Sessions
Mapping Altered Coordination of Speech Motor Subnetworks in Children Who Stutter
Poster Session D, Thursday, October 1, 4:30 - 6:30 pm, Wangari Maathai
Yanni Liu1, Adriene Beltz1, Mike Angstadt1, Soo-Eun Chang1; 1University of Michigan
Fluent speech production depends on coordinated interactions across distributed cortical and subcortical networks. Computational models of speech motor control, including the DIVA and GODIVA frameworks, emphasize these coordinated interactions. Although developmental stuttering has been associated with abnormalities across speech-related cortical and subcortical regions, less is known about how these systems are coordinated at the network level in children who stutter (CWS). The present study used person-specific connectivity modeling to examine speech network organization in CWS and children who do not stutter (CNS). We hypothesized that group differences would be characterized by altered coordination among functional subnetworks. Resting-state fMRI data were obtained from 57 CWS and 74 CNS between 3 and 12 years of age. Eleven speech-related regions of interest were grouped into three theoretically motivated functional subnetworks: (1) cortical articulatory control (dorsal and ventral precentral speech areas [dPCS, vPCS], supplementary motor area, pre-supplementary motor area), (2) auditory–motor integration (Heschl’s gyrus, Sylvian–parietal–temporal area, parietal operculum, inferior frontal operculum), and (3) subcortical timing (putamen, thalamus, cerebellar lobule VI). Functional connectivity was estimated using Confirmatory Subgrouping Group Iterative Multiple Model Estimation (CS-GIMME). Subnetwork coordination was examined using within-network density, between-network density, node centrality metrics, and ROI-to-subnetwork connectivity profiles. Subgroup-level connectivity patterns differed between groups. CNS exhibited subgroup-specific connectivity linking dPCS with cerebellar lobule VI, whereas CWS exhibited subgroup-specific connectivity linking parietal operculum with vPCS. Within-network density did not differ significantly between groups, suggesting that coordination within functional subnetworks is broadly preserved in CWS. In contrast, CWS showed reduced integration between cortical articulatory and subcortical timing networks, accompanied by reduced node centrality in dPCS, putamen, and cerebellum. CWS also exhibited increased coupling between auditory–motor and cortical articulatory networks, along with greater centrality of vPCS. ROI-to-subnetwork connectivity profiles further revealed complementary dorsal–ventral patterns, with dPCS showing stronger subcortical timing connectivity in CNS and vPCS showing stronger auditory–motor connectivity in CWS. These findings suggest that persistent developmental stuttering is characterized less by disruptions within isolated speech subnetworks and more by altered coordination among cortical articulatory, auditory–motor, and subcortical timing networks. Reduced integration of subcortical timing circuitry, together with increased cortical auditory–motor coupling, suggests altered temporal coordination across distributed speech motor systems. Together, these findings highlight the value of person-specific modeling for characterizing heterogeneous functional network organization in developmental stuttering.
Topic Areas: Speech Motor Control, Disorders: Developmental