Increasing Screen Exposure Time Harms Inhibitory-Control Network in Developing Children: A Two Years Follow-up of the ABCD Study

As virtual experiences are rapidly substituting a significant proportion of in-person interactions during the COVID pandemic, it is critical to monitor the effect of screen exposure time on developing children’s behavior and nervous system. Screen use boosts information accessibility and, therefore, may delay the development of the inhibitory control networks in children, who are vulnerable to immediate reward-orientated tendencies and not yet capable of controlling their impulsivity. Therefore, it was hypothesized that as children become more exposed to screens, the development of the inhibitory control network would be delayed and their reward sensitivity will be augmented. Using the ABCD Study Data Repository, 8,334 children’s behavioral and neural data (aged 9-11) were included. Robust mediation analysis and correlation analysis were used to investigate how Screen Time interacts with children’s reward-orientated tendency (e.g. Behavioral approach system, BAS) and the brain's inhibitory network. Intrinsic Frontoparietal Network-Striatum (FPN-Striatum) connectivity strength was used as neural indices of the inhibitory control quality in children. Results showed that Screen Time significantly mediated the relationship between BAS and both waves of the intrinsic inhibitory process. A higher BAS was linked to a longer Screen Time and weaker inhibitory network connectivity. This complete/full mediation model indicates that Screen Time negatively influenced the strength of FPN-Striatum connectivity. In conclusion, the study revealed specific behavioral and neural correlates of screen exposure using a large database, and suggested that increasing screen exposure time may impair the inhibitory capability and increase impulsivity in children.