Search Abstracts | Symposia | Slide Sessions | Poster Sessions
Task-Modulated Functional Connectivity During Speech Processing in Adults with Developmental Language Disorder
Poster Session E, Friday, October 2, 11:00 am - 1:00 pm, Wangari Maathai
This poster is part of the Sandbox Series.
Noelle Abbott1, Gabriel Cler2; 1University of Washington, 2Basque Center on Cognition Brain and Language
Background & Motivation: Developmental Language Disorder (DLD) is a prevalent neurodevelopmental condition characterized by persistent difficulties in language acquisition and processing in the absence of known neurological cause (Bishop, 2017). Despite growing interest in the neural basis of DLD, functional connectivity (FC) remains almost entirely unexplored. To date, only one published study has examined FC in DLD (Doucet et al., 2025), using resting-state fMRI in children. Whether atypical functional network organization persists into adulthood, and how it manifests under the demands of speech processing specifically, remains unknown. Converging structural neuroimaging evidence from our adult DLD cohort motivates an investigation of functional coupling within and between speech and language perception networks. Design & Participants: Twenty-three adults with DLD and 27 TD controls (18-38 years) completed a block-design fMRI paradigm. Three conditions were presented: intact speech, degraded speech (low-pass filtered noise-masked speech), and a baseline silent condition. The two experimental conditions were 8 blocks each and the silent condition was 5 blocks. This design dissociates linguistic from low-level auditory processing; intact versus degraded speech isolates linguistic and phonological processing, while degraded speech versus silence isolates auditory processing in the absence of linguistic content. Data were preprocessed in FSL and first-level GLMs have been computed for each participant. Planned Analyses: Two complementary FC analyses will be conducted in the CONN toolbox. First, a whole-brain Generalized FC analysis (Elliott et al., 2019) will extract BOLD timeseries from 432 cortical and subcortical regions using the Schaefer-400 and Melbourne Subcortex atlases. Task regressors and standard nuisance signals (motion parameters, white matter, CSF) will be regressed from the full timeseries prior to computing pairwise FC matrices (Pearson r, Fisher z-transformed), yielding stable whole-brain connectivity estimates across the entire scan rather than within individual condition blocks. Group differences will be examined using Network-Based Statistics (NBS; Zalesky et al., 2010) with age, sex, and mean framewise displacement as covariates, enabling comparison with Doucet et al. (2025). Second, generalized psychophysiological interaction (gPPI) analyses will model condition-modulated connectivity by constructing interaction regressors for each task condition alongside the seed timeseries and task regressors, capturing how connectivity between regions changes specifically as a function of speech processing demands. Task contrast regressors (intact > degraded; degraded > silence) will be used to interrogate condition-specific coupling. A priori seeds will include inferior frontal gyrus and superior and middle temporal gyri parcels for the linguistic contrast, and bilateral auditory cortex parcels for the auditory contrast, targeting the core dorsal and ventral speech perception streams. Together, these approaches allow exploratory characterization of network-level FC differences alongside hypothesis-driven examination of connectivity within speech and language regions as a function of processing demands. Expected Contribution: This study will provide the first characterization of task-modulated functional connectivity in adults with DLD, extending the only existing FC findings from children to an adult population and moving beyond resting-state to examine how functional coupling tracks specific speech processing demands. We welcome feedback on analysis choices, ROI selection, and interpretation of anticipated outcomes.
Topic Areas: Disorders: Developmental,