Exploring the relationship between auditory processing characteristics and cognition in preschool children with developmental language disorder based on fNIRS.

backgroundAuditory processing (AP) is a fundamental function in speech signal processing. The ability to process speech signals in noisy environments is commonly used to assess AP capabilities. Research on the AP characteristics in Chinese children remains scarce, and the relationship between AP and language/cognitive development has not been explored. This study investigated the AP performance of children with developmental language disorder (DLD) in daily life and under the standardized speech-in-noise (SIN) comprehension paradigm. Using functional Near-Infrared Spectroscopy (fNIRS) to monitor brain activation in real-time during noisy environments, the study analyzed the functional modes of targeted brain regions in Chinese DLD children under noisy environments, while also exploring the relationships between AP behaviors, brain activation patterns, and cognition.

methodsThis cross-sectional study enrolled 34 Chinese preschool children with DLD and 43 age- and gender-matched typically developing (TD) children. Parents completed basic demographic information, the Preschool Auditory Processing Assessment Scale (PAPAS), and the Behavior Rating Scale of Executive Function-Preschool Version (BRIEF-P). A self-developed SIN comprehension paradigm adapted for Chinese preschool children with DLD was utilized, and fNIRS was employed to record brain activation patterns while the children performed the SIN comprehension task.

results1) AP Behavior: The DLD group scored higher than TD group on all dimensions of the PAPAS (P < 0.05); main effects of the group (F = 54.303, P < 0.001) and listening condition (F = 11.83, P = 0.001) were significant for the accuracy (ACC). 2) Brain activation characteristics during the SIN comprehension task: The DLD group showed significantly lower activation than the TD group in the left dorsolateral prefrontal cortex (DLPFC), left Broca's area, bilateral superior temporal gyrus and middle temporal gyrus (STG and MTG), and right Wernicke's area (P-corrected < 0.05). 3) The AP total scores, auditory decoding scores, and hyperactivity impulse dimension scores of both groups of children were negatively correlated with the scores on each dimension of the DREAM-C and the WPPSI-IV/WISC-IV (P-corrected < 0.05); the scores on each PAPAS dimension were positively correlated with the scores on each dimension of BRIEF-P (P-corrected < 0.05). 4) The activation levels in the left DLPFC, left Broca's area, right Wernicke's area, and bilateral STG and MTG in both groups of children were positively correlated with all dimensions of the DREAM-C (P-corrected < 0.05). The activation levels in the left DLPFC, left Broca's area, right Wernicke's area, and right STG and MTG were positively correlated with the full-scale intelligence quotient and verbal comprehension index scores (P-corrected < 0.05).

conclusionsChildren with DLD may exhibit AP abnormalities as early as the preschool years, as reflected by poorer performance on AP tasks and atypical cortical activation patterns.