Interbrain substrates of role switching during mother-child interaction.

Mother-child interaction is highly dynamic and reciprocal. Switching roles in these back-and-forth interactions serves as a crucial feature of reciprocal behaviors while the underlying neural entrainment is still not well-studied. Here, we designed a role-controlled cooperative task with dual EEG recording to explore how differently two brains interact when mothers and children hold different roles. When children were actors and mothers were observers, mother-child interbrain synchrony emerged primarily within the theta oscillations and the frontal lobe, which highly correlated with children's attachment to their mothers (self-reported by mothers). When their roles were reversed, this synchrony was shifted to the alpha oscillations and the central area and associated with mothers' perception of their relationship with their children. The results suggested an observer-actor neural alignment within the actor's oscillations, which was related to the actor-toward-observer emotional bonding. Our findings contribute to the understanding of how interbrain synchrony is established and dynamically changed during mother-child reciprocal interaction.

Types of On-Screen Content and Mental Health in Kindergarten Children.

Importance: Excessive screen time has been associated with a higher risk for mental health problems, but whether the associations differ by screen content types is unclear. Objective: To examine the allocation of and longitudinal changes in screen exposure across different content types and to explore their associations with mental health in children aged 3 to 6 years. Design, Setting, and Participants: This cohort study used 3-wave, lagged generalized estimating equation models to analyze data from the Shanghai Children's Health, Education and Lifestyle Evaluation-Preschool (SCHEDULE-P) study in Shanghai, China. The cohort was a representative sample of kindergarten children. Data were collected between November 2016 and May 2019 when children were aged 3 to 4 years (wave 1), 4 to 5 years (wave 2), and 5 to 6 years (wave 3). Data analysis was performed between June 2022 and May 2023. Exposure: Screen exposure (total daily time and time with each type of content, including educational programs, entertainment programs, non-child-directed programs, electronic games, and social media) was collected when children were aged 3, 5, and 6 years. Main Outcomes and Measures: Mental health of children at age 3, 5, and 6 years was reported by parents using the Strengths and Difficulties Questionnaire. Results: Of the 15 965 children included in the representative sample, 8270 were males (51.7%) and the mean (SD) age at wave 1 was 3.73 (0.30) years. As children developed from ages 3 to 6 years, the proportion of screen exposure to educational programs (≤1 hour per day: 45.0% [95% CI, 43.5%-46.5%] to 26.8% [95% CI, 25.3%-28.3%]) and entertainment programs (≤1 hour per day: 44.4% [95% CI, 42.8%-45.9%] to 32.1% [95% CI, 30.4%-33.9%]) decreased, whereas exposure to social media increased (≤1 hour per day: 1.5% [95% CI, 1.2%-1.9%] to 27.1% [95% CI, 25.5%-28.7%]). The associations between on-screen content and mental health varied. For a given total screen time, a higher proportion of screen exposure to educational programs was associated with a lower risk for mental health problems (adjusted odds ratio [AOR], 0.73; 95% CI, 0.60-0.90), whereas non-child-directed programs were associated with a higher risk for such problems (AOR, 2.82; 95% CI, 1.91-4.18). Regardless of the content, total screen time was consistently associated with mental health problems. Conclusions and relevance: Results of this study indicated that both total screen time and different types of content were associated with mental health problems in children aged 3 to 6 years. Limiting children's screen time, prioritizing educational programs, and avoiding non-child-directed programs are recommended.

Prevalence, co-occurring difficulties, and risk factors of developmental language disorder: first evidence for Mandarin-speaking children in a population-based study.

Background: Developmental language disorder (DLD) is a condition that significantly affects children's achievement but has been understudied. We aim to estimate the prevalence of DLD in Shanghai, compare the co-occurrence of difficulties between children with DLD and those with typical development (TD), and investigate the early risk factors for DLD. Methods: We estimated DLD prevalence using data from a population-based survey with a cluster random sampling design in Shanghai, China. A subsample of children (aged 5-6 years) received an onsite evaluation, and each child was categorized as TD or DLD. The proportions of children with socio-emotional behavior (SEB) difficulties, low non-verbal IQ (NVIQ), and poor school readiness were calculated among children with TD and DLD. We used multiple imputation to address the missing values of risk factors. Univariate and multivariate regression models adjusted with sampling weights were used to estimate the correlation of each risk factor with DLD. Findings: Of 1082 children who were approached for the onsite evaluation, 974 (90.0%) completed the language ability assessments, of whom 74 met the criteria for DLD, resulting in a prevalence of 8.5% (95% CI 6.3-11.5) when adjusted with sampling weights. Compared with TD children, children with DLD had higher rates of concurrent difficulties, including SEB (total difficulties score at-risk: 156 [17.3%] of 900 TD vs. 28 [37.8%] of 74 DLD, p < 0.0001), low NVIQ (3 [0.3%] of 900 TD vs. 8 [10.8%] of 74 DLD, p < 0.0001), and poor school readiness (71 [7.9%] of 900 TD vs. 13 [17.6%] of 74 DLD, p = 0.0040). After accounting for all other risk factors, a higher risk of DLD was associated with a lack of parent-child interaction diversity (adjusted odds ratio [aOR] = 3.08, 95% CI = 1.29-7.37; p = 0.012) and lower kindergarten levels (compared to demonstration and first level: third level (aOR = 6.15, 95% CI = 1.92-19.63; p = 0.0020)). Interpretation: The prevalence of DLD and its co-occurrence with other difficulties suggest the need for further attention. Family and kindergarten factors were found to contribute to DLD, suggesting that multi-sector coordinated efforts are needed to better identify and serve DLD populations at home, in schools, and in clinical settings. Funding: The study was supported by Shanghai Municipal Education Commission (No. 2022you1-2, D1502), the Innovative Research Team of High-level Local Universities in Shanghai (No. SHSMU-ZDCX20211900), Shanghai Municipal Health Commission (No.GWV-10.1-XK07), and the National Key Research and Development Program of China (No. 2022YFC2705201).