Schedule of Events | Symposia

Sketchpad Series

Investigating structural differences between children with Developmental Language Disorder, Dyslexia, and controls

Poster Session E - Monday, March 31, 2025, 2:30 – 4:30 pm EDT, Back Bay Ballroom/Republic Ballroom

Olivia Baldi¹, Ted Turesky¹, Nadine Gaab¹; ¹Harvard Graduate School of Education

Developmental Language Disorder (DLD) is a neurodevelopmental disability characterized by difficulties comprehending and producing language and can lead to adverse social-emotional, academic, and vocational outcomes. A considerable number of children with DLD subsequently develop developmental dyslexia (DD), suggesting shared brain differences between DLD and DD. The DLD-DD Quadrant Model hypothesizes how individual differences in word recognition, affected in DD, and language comprehension, affected in DLD, contribute to reading comprehension deficits (RC). While this has been studied behaviorally, there are no current studies examining the underlying brain mechanisms of the model. To explore the neural underpinnings of the Quadrant Model, we acquired structural magnetic resonance imaging (MRI) data in children with DLD, DD, and typically developing children (TD). In a preliminary analysis, 5-6-year-old children were categorized as either DLD (n=18) or TD (n=21) based on measures of language comprehension, expressive language, receptive language, and syntactic processing. To identify differences in gray matter volume and cortical thickness between groups, a preliminary whole-brain analysis was conducted using FreeSurfer. The TD, compared to the DLD group, showed significantly greater gray matter volume in the inferior temporal cortex in the right hemisphere (vertex-wise threshold p < 0.005; cluster-wise threshold p < 0.05). This preliminary finding suggests structural differences between children with DLD and TD; however, future analyses will include a DD group and employ RC outcome measures to disentangle how deficits in word reading and/or language skills influence RC. Furthermore, implications will be discussed based on hypotheses within the Quadrant Model.

Topic Area: LANGUAGE: Development & aging