Poster #27 - Microstructural Organization of the Arcuate Fasciculus is Associated with Better Social Communication Skills in Infants

• In Event: Poster Session 16

Abstract

Background
Social communication refers to the skills required to engage with others and includes verbal, nonverbal communication, socio-affective and symbolic skills (Watt, Wetherby & Shumway, 2006). Learning these skills begins in the first two years of an infant's life and supports later language acquisition (Watt, Wetherby & Shumway, 2006; Bates & Dick, 2001). Past research indicates that white matter tracts, such as the inferior longitudinal (ILF), inferior fronto-occipital (IFOF), arcuate (AF), and uncinate fasciculi (UF) are involved in social communication; however, existing studies have largely focused on older children and adults (for review see Ameis & Catani, 2015). One infant study found that structural coherence in the UF is associated with responding to joint attention (Elison et al., 2013).

Objectives
The current exploratory study aims to investigate whether white matter development of the ILF, IFOF, AF and UF at 12 months and/or 24 months of age is associated with social communication skills at 24 months of age in typically developing infants.

Methods
The study included typical developing infants from the Infant Brain Imaging Study. All participants had composite scores of ≥85 on the Mullen Scales of Early Learning (Mullen, 1995), did not meet the criteria for autism spectrum disorder at 24 months, and did not have a family history of autism. Using 25-direction diffusion tensor imaging data, fractional anisotropy (FA) was used to evaluate the structural organization of the ILF, IFOF, AF, and UF at 12 months (n=53) and 24 months (n=43-44, depending on tract) of age. The Communication and Symbolic Behavior Scales-Developmental Profile (CSBS-DP) behavioral sample was used to measure social communication skills, including social, speech, and symbolic skills, at 24 months (Wetherby, et al., 2002). Exploratory linear regression analyses were used to determine the association between the FA values (independent variable) and the CSBS-DP total weighted raw score (dependent variable). Covariates included chronological age at scan, data collection site, sex of the infant, and maternal education attainment.

Results
Exploratory analyses indicated a significant positive association between the FA values of the left temporofrontal AF at 12 months and the total CSBS-DP score at 24 months (F=4.16, p=0.04). The remaining tracts were not significantly associated with social communication skills at 24 months of age.

Discussion
Results indicated that greater white matter structural organization in the left temporofrontal arcuate fasciculus at 12 months was associated with better social communication skills at 24 months. Adult lesion studies have found that functional activation of left temporofrontal AF is central to language comprehension and production (Ivanova et al., 2021). The current study examined the broad domain of social communication which includes language skills but also social and symbolic skills. Future analyses will aim to determine if the association between white matter in the temporofrontal arcuate fasciculus and social communication is domain general or specific to language comprehension and production.

Group Authors

Infant Brain Imaging Study

Authors

• Bernadette Weigman, University of Texas at Dallas
  Presenting Author

• Shruthi Ravi, University of Texas at Dallas

• Kelly Botteron, Washington University in St. Louis

• Stephen Dager, University Of Washington

• Jed T. Elison, University of Minnesota - Twin Cities

• Annette Mercer Estes, Uniiversity of Washington

• Heather Cody Hazlett, University of North Carolina at Chapel Hill

• Natasha Marrus, Washington University in St. Louis

• Robert McKinstry

• Robert Schultz, Children's Hospital of Philadelphia

• Shoba S Meera, National Institute of Mental Health and Neurosciences

• Martin Styner, University of North Carolina at Chapel Hill

• Jason Wolff

• Lonnie Zwaigenbaum, University of Alberta

• Joseph Piven, University of North Carolina at Chapel Hill

• Meghan Swanson, University of Texas at Dallas