How do Preschoolers’ Brains Respond to Language That is Presented During Live Social Interactions?

• In Event: Infant learning and brain development

Abstract

Introduction: To date, only a handful of functional neuroimaging studies have sought to identify the neural bases of language processing in preschool-aged children (e.g., Redcay & Courchesne, 2008). In most of these studies, children listened to audio recordings of stories while they were asleep and/or socially isolated, which is not how children are exposed to language in everyday life. Functional near-infrared spectroscopy (fNIRS) is a neuroimaging method that is well-suited for measuring brain function while children are awake and interacting with a social partner. Despite the promise of fNIRS, no studies have used this method to measure how the brains of preschool-aged children function during live social interactions. Thus, the current study aimed to investigate how the brains of preschoolers respond to language presented via a live social partner compared to language presented via an audio recording, and to explore the relation between brain response to live language and children’s communication skills.
Methods: The current sample included N=13 English-speaking children (9M, 4F), 37 to 71 months of age. fNIRS was used to measure children’s brain function during two conditions – the live language condition and the recorded language condition (Figure 1). During the live language condition, an experimenter interacted with the child by reading them a scripted story from an illustrated book. During the recorded language condition, the child listened to an audio recording of a scripted story while viewing illustrations on a computer screen. Trials were 10 seconds long followed by a 10-15 second long intertrial period during which a fixation cross was presented. Each child received 18 trials of each condition; the order of conditions and story used in each condition were counterbalanced. Data were processed in Homer3 using standard procedures, including motion artifact correction (Huppert, 2016; Yücel et al., 2021). Average oxygenated hemoglobin (HbO) concentration (i.e., “brain response”) from 0 to 10 seconds was calculated from each channel on the fNIRS probe (Figure 2a). We conducted within-subject t-tests to determine whether HbO concentration differed between conditions. We also ran partial correlations to explore the relation between HbO concentration during the live condition and children’s communication skills, as measured by the Vineland Adaptive Behavior Scales-3rd Edition (VABS), controlling for chronological age.
Results: HbO concentration was significantly greater during the live language condition compared to the recorded language condition for channel 5 (t=3.021, p=.019; Figure 2b), which covered the left frontal gyrus. HbO concentration did not significantly differ between conditions for all other channels (ps≥.067). HbO concentration during the live language condition was positively correlated with children’s VABS communication domain raw scores (r=.786, p=.036; Figure 2c) for channel 8, which also covered the left frontal gyrus.
Discussion: Results demonstrated that the brains of preschoolers responded more strongly to language presented via a live social partner compared to an audio recording, particularly in the left frontal gyrus. Additionally, brain response to live language within this region was positively related to children’s VABS communication scores, suggesting that the function of this brain region supports development of communication skills during the preschool years.

Authors

• Meredith Pecukonis, Boston University
  Presenting Author

• Meryem Yücel, Boston University

• David Boas, Boston University

• Helen Tager-Flusberg, Boston University