Age-related increases in right hemisphere support for prosodic processing in children

Abstract

Language comprehension is a complex process involving an extensive brain network. Brain regions responsible for prosodic processing have been studied in adults; however, much less is known about the neural bases of prosodic processing in children. Using magnetoencephalography (MEG), we mapped regions supporting speech envelope tracking (a marker of prosodic processing) in 80 typically developing children, ages 4-18 years, completing a stories listening paradigm. Neuromagnetic signals coherent with the speech envelope were localized using dynamic imaging of coherent sources (DICS). Across the group, we observed coherence in bilateral perisylvian cortex. We observed age-related increases in coherence to the speech envelope in the right superior temporal gyrus (r = 0.31, df = 78, p = 0.0047) and primary auditory cortex (r = 0.27, df = 78, p = 0.016); age-related decreases in coherence to the speech envelope were observed in the left superior temporal gyrus (r = - 0.25, df = 78, p = 0.026). This pattern may indicate a refinement of the networks responsible for prosodic processing during development, where language areas in the right hemisphere become increasingly specialized for prosodic processing. Altogether, these results reveal a distinct neurodevelopmental trajectory for the processing of prosodic cues, highlighting the presence of supportive language functions in the right hemisphere. Findings from this dataset of typically developing children may serve as a potential reference timeline for assessing children with neurodevelopmental hearing and speech disorders.

Figure 1

Regions supporting speech envelope tracking during a stories listening task. Ten perisylvian regions (parcels) showed significant coherence to the speech envelope (> 2 standard deviations above the mean). Each significant parcel is coloured in green and displayed on select axial slices. Corresponding statistical and anatomical information can be found in Table 1.

Figure 2

Age-related changes in speech envelope tracking (left) and corresponding scatterplot of coherence to the speech envelope as a function of age across the entire sample (n = 80) for each region of interest (right). Significant results passed an FDR of q = 0.1. (A) Age-related increases in coherence to the speech envelope were observed in the right superior temporal gyrus (r = 0.31, p = 0.0047), and (B) the right primary auditory cortex (r = 0.27, p = 0.016). (C) Significant age-related decreases in coherence to the speech envelope were observed in the left superior temporal gyrus (r = − 0.25, p = 0.026).