Poster #15 - Bilateral posterior temporal brain connectivity is related to social communication in toddlers

• In Event: 3-003 - Poster Session 09
  In Poster Session: PS 09 Section - Biological Processes: Neuroscience and Genetics

Integrative Statement

Introduction
The second year of life is marked by dramatic gains in social-communicative abilities in typically developing children, but relatively slowed growth in those with language delay (Franchini et al., 2018). While the neural correlates of social communicative abilities have been examined in adults (e.g., Redcay et al., 2016), relatively little work has examined their neural bases during this critical developmental period for communication. In the current study, we examined how brain functional connectivity is related to social-communicative abilities in both typically developing children and children with significant early language delay. The inclusion of a language delay sample provides greater variability to assess the neural underpinnings of social communication using a dimensional approach.

Methods
Both functional (resting-state) and structural MRI data were collected from 34 toddlers with and without language delay (i.e., scores ≥2 standard deviations below the mean on the receptive and expressive language scales of the Mullen Scales of Early Learning). Data from two toddlers were excluded due to incomplete brain coverage and excessive head motion for a final sample of 32 (22 males, 18.69 3.25 months, 12-25 months; 12 language delay). Toddlers participated in the Communication and Symbolic Behavior Scales (CSBS) and parents completed questionnaires including the Mac-Arthur Bates Words and Gestures (MCWG). We used standard preprocessing for functional connectivity analysis including an infant pediatric template (Fonov et al., 2009) for segmentation and normalization.

To identify connectivity within brain networks associated with social communication we used regions of interest (ROI) from a study of joint attention (Redcay et al., 2012). We examined both average connectivity within joint attention regions and voxel-wise connectivity between the left posterior superior temporal sulcus (LpSTS) given that region’s role in language, social cognition, and gesture (Redcay, 2008; Redcay et al., 2016) and voxels within the default mode network (DMN) (Yeo et al., 2011), which is associated with social communication. Connectivity was regressed separately on five social-communicative behavioral measures including joint attention (initiating and gaze following) and the Social Composite score from the CSBS, and total gestures and total vocabulary (words produced and understood) from the MCWG.

Results
Mean connectivity across all ROIs within the joint attention network did not predict any behavioral measures once correcting for multiple comparisons. However, voxel-wise LpSTS to right pSTS connectivity was positively related to MCWG total gestures and the CSBS Social Composite score (p < .05, small volume corrected). These effects were present while controlling for general maturation (age), gender, and head motion.

Conclusion
We found that functional connectivity between bilateral posterior temporal regions was related to measures of gesture use and overall social ability across a sample of toddlers with a wide range of communicative abilities. These data suggest continuity in the role of the pSTS in social communication from infancy through adulthood. Further, an early marker of atypical or low communication abilities may be decreased connectivity between bilateral posterior temporal regions. Future longitudinal studies should examine whether this neurobiological feature is predictive of later diagnoses of communication disorders or autism spectrum disorder.

Authors

• Elizabeth Redcay, University of Maryland
  Presenting Author

• Yaqiong Xiao, University of Maryland, College Park
  Non-Presenting Author

• Stacy Shumway Manwaring, University of Utah
  Non-Presenting Author

• Elizabeth G. Smith, University of Maryland
  Non-Presenting Author

• Lauren Swineford, Washington State University
  Non-Presenting Author

• Jerry French, National Institute of Mental Health
  Non-Presenting Author

• Audrey Thurm, NIMH
  Non-Presenting Author