Screen media exposure in the first 2 years of life and preschool cognitive development: a longitudinal study

Associations between screen media and child cognition are complex. This study aimed to examine whether age of onset of media exposure, cumulative effect of high media exposure, and verbal interaction during screen time in the first 2 years of life were associated with 4-year-old cognition by including parenting behaviors into the final construct.

There were 274 healthy participants who were followed up until age 4 years. Screen media data were collected at age 6, 12, 18 months, and 2 years. Cognition or early learning composite (ELC) was evaluated at age 2, 3, and 4 years, where the latter variable was the primary outcome. Positive parenting was obtained by Parenting Styles and Dimensions Questionnaire.

ELC at age 2 years was associated with later age of onset of media exposure (β = 0.113, p < 0.05), fewer months of high media exposure above the upper quartile (β = 0.282, p < 0.001), and more months of verbal interaction during screen time (β = 0.261, p < 0.001). ELC at age 4 years was associated with ELC and positive parenting at earlier ages.

Delayed introduction of screen media, appropriate screen time, and increased verbal interaction during media use in the first 2 years of life were associated with better cognitive development in preschoolers.

Associations between screen media exposure and children's cognitive development in existing literature mainly focused on duration of screen media viewing or the content of electronic media in which other factors are rarely explored. Earlier age of onset of media exposure, more months of excessive screen media exposure (>6.5 h/day), and fewer months of verbal interaction with children during media use in the first 2 years of life had associations with decreased preschool cognition. To mitigate undesirable effects of inappropriate screen media use on cognition, delayed introduction of screen media, appropriate electronic media exposure, and increased verbal interaction during media use with children should be recommended at health supervision visits. Lower positive parenting was a mediator for the relationship between cumulative months of high screen media exposure and decreased child cognition.