Socioeconomic Disparities in Language Input are Associated with Children’s Language-Related Brain Structure

• In Event: 1-127 - Resources Talk: A Closer Look at SES, the Home Environment, and Language-Related Outcomes

Integrative Statement

Introduction: Although socioeconomic disparities in children’s reading skills have been well-documented (Pace, Luo, Hirsh-Pasek, & Golinkoff, 2017), the proximal environmental and neural mechanisms underlying these associations are not well understood. Linguistic input in the home represents a key mechanism through which socioeconomic factors may impact children’s language-related brain structure and in turn reading outcomes. Higher socioeconomic status (SES) has been associated with higher quantity and quality of language input (Pace et al., 2017), which in turn predicts stronger language and reading skills in children (Hart & Risley, 1995; Hoff & Naigles, 2002; Hurtado, Marchman, & Fernald, 2008; Huttenlocher, Haight, Bryk, Seltzer, & Lyons, 1991; Rowe, 2012; Weisleder & Fernald, 2013). In this study, we examined associations among socioeconomic background, home linguistic input, brain structure, and reading skills in children.

Methods: A socioeconomically diverse sample of parents and children (5 – 9 years; N = 94; 61% female; 50% Hispanic/Latino; 31% African American) participated in this study. Linguistic input in the home was measured using the Language Environment Analysis (LENA) system (Ganek & Eriks-Brophy, 2017; Gilkerson et al., 2017), which combines naturalistic home audio recordings with automated quantification of the number of adult words, adult-child conversational turns, and child vocalizations in the recordings. Children completed high-resolution, 3-Tesla, T1-weighted MRI scans (n = 51 usable scans). Images were processed using FreeSurfer (version 6.0), and cortical thickness and surface area analyses were conducted using the QDEC surface-based analysis tool and cluster-wise correction for multiple comparisons.

Results: Children who experienced more hourly adult-child conversational turns or adult words had significantly greater surface area in the left perisylvian cortex (see Figure 1). Hourly child vocalizations were not significantly associated with brain structure. Hourly adult words significantly mediated the association between parental education and left perisylvian cortical surface area (see Figure 2). Left perisylvian cortical surface area significantly mediated the association between parental education and children’s reading skills.

Discussion: This work is the first to show significant associations between children’s language experiences and their gray matter morphology. The amount of conversational exchanges or adult words children experienced was associated specifically with a left perisylvian region spanning parts of the superior and transverse temporal cortices known to be involved in language production and comprehension (Friederici, 2011). Furthermore, differences in the number of adult words children experience may explain associations between parental education and brain structure in this left perisylvian cortical region.

Authors

• Emily Merz, Teachers College, Columbia University
  Presenting Author

• Elaine A. Maskus, Teachers College, Columbia University
  Non-Presenting Author

• Samantha A. Melvin, Teachers College, Columbia University
  Non-Presenting Author

• Xiaofu He, Columbia University Medical Center
  Non-Presenting Author

• Kimberly G. Noble, Teachers College, Columbia University
  Non-Presenting Author