Association of screen-based sedentary behavior with executive function in school-aged children: A functional near-infrared spectroscopy study.

Screen-based sedentary behavior (SSB) is a significant risk factor for the health of school-aged children, and guidelines recommend limiting SSB to 2 hr per day. This study aimed to examine association and potential mechanisms between SSB and executive function (EF) by comparing Stroop performance and frontal hemodynamic responses between children with and without excessive SSB. A total of 70 children aged 10 to 15 years were recruited and divided into two groups: excessive screen time (≥2 hr/day; n = 35; ES group) and normal screen time (<2 hr/day; n = 35; NS group). The Chinese version of the Adolescent Sedentary Activities Questionnaire was used to assess SSB, whereas EF was evaluated using the Stroop task. The frontal hemodynamic responses during the Stroop task were measured using functional near-infrared spectroscopy. The results indicated that the ES group had lower accuracy, longer reaction times, and greater activation in the bilateral dorsolateral prefrontal cortex (DLPFC) and left pre-supplementary motor area (Pre-SMA) compared with the NS group. Furthermore, significant correlations were observed between Stroop performance and cortical activation in the left DLPFC and Pre-SMA. These findings demonstrate that excessive SSB is associated with poor EF, which may be explained by a decrease in neural efficiency of the left DLPFC and Pre-SMA.

The association between sedentary behavioral characteristics and poor vision among Chinese children and adolescents.

Introduction: To understand the features of sedentary behavior of Chinese children and adolescents and its relationship with poor visual acuity, a self-administered "Questionnaire on Sedentary Behavior of Children and Adolescents" was used to survey 4,203 students in grades 4-12 in six administrative regions of China. Results: (1) The average time spent in sedentary behaviors (SB) of Chinese children and adolescents was about 8.1 h per day, of which the academic sedentary time was the longest, accounting for 79.2% of total sedentary time. The total time spent on SB and the time spent on studying SB were more in the upper grades and less in screen SB and cultural leisure SB, respectively. There were significant sex differences in total SB time (p < 0.05) and weekend sedentary behaviors time (SB-WD) (p < 0.01) among Chinese children and adolescents, with girls being more likely to be higher than boys. There were also significant differences in sedentary time across different regions (p < 0.05), and the longest total sedentary time in East China. (2) Reduction parents' sedentary time and limitation of sedentary behaviors and the use of electronics among children and adolescents can effectively reduce sedentary time among Chinese children and adolescents. (3) Sedentary time was significantly higher in children and adolescents with poor vision than in those with normal vision (p < 0.01), and study SB and screen SB were important independent factors affecting vision. (4) Timing of breaks in SB can play a positive role in promoting vision health. Conclusion: There were significant grade, sex, and regional differences in the SB of Chinese children and adolescents, and sedentary time was strongly related to the prevalence of poor vision detection rate.