Watching a screen more than an hour a day as a toddler is directly linked with poorer communication and daily living skills at age 4, but outdoor play may lessen some of the effects,suggests.
The results point to outdoor play as a potential targeted intervention to counter suboptimal brain development in young children who are watching screens at increasingly younger ages.
The findings were published online in JAMA Pediatrics.
The researchers first investigated whether higher screen time (more than 1 hour a day on a device or watching television) at age 2 years is associated with neurodevelopmental outcomes at age 4.
They found the 885 children in the sample from the Japanese Hamamatsu Birth Cohort Study for Mothers and Children who had more screen time had lower scores on communication and daily living skills than children who watched less than an hour a day.
Scores were based on the Vineland Adaptive Behavior Scale according to parent responses to questions. The children included were born between December 2007 and March 2012 and were followed from 18 months to 4 years.
After finding the connection between screen time and lower scores, the researchers investigated whether outdoor play (at least 30 minutes a day) introduced at a 2 years and 8 months made a difference. They considered 6 or 7 days per week frequent outdoor play.
Outdoor play mitigated poorer daily living scores
The researchers found that the outdoor play intervention mitigated 18% of the association between high screen time and lower daily living scores but did not mitigate the lower communication scores.
They also found that more screen time at age 2 was significantly linked with infrequent outdoor play at age 32 months (odds ratio, 2.03; 95% confidence interval, 1.48-2.76).
The associations were consistent after taking into account factors including a child’s sex, parental education, and any autism spectrum disorder symptoms at age 18 months.
The authors noted that neurodevelopment concerns with screen use are particularly troubling as the age for use is getting younger.
A recent meta-analysis found thatuse or watch screens, even though guidelines recommend against any screen time before 2.
In addition, the “COVID-19 pandemic led to children having more screen time, less outdoor play, and less physical activity, putting them at potentially greater risk for neurodevelopmental problems,” the authors noted.
“What is concerning is that data show screen time has not decreased after seclusion measures were lifted,” they added.
Proven benefits for outdoor play
Jennifer Cross, MD,* assistant professor and section chief for developmental pediatrics at Weill Cornell Medicine, New York, who was not part of the study, said the mitigation properties of outdoor play were something she hadn’t seen before but the concept makes sense.
“The overwhelming evidence is that screen time is not helpful for young children under the age of 2,” she said.
Outdoor play, on the other hand, has proven benefits.
“Physical activity has been shown to be good for physical and mental health so there’s no reason to believe it wouldn’t be good for 2-and-a-half-year olds,” Dr. Cross said. “It’s also good for developmental health. You want them to be engaged in imaginative play and be interactive.”
“[Outdoor play] gets them away from screens and gives them an opportunity to experience another environment and work on their motor skills and motor planning,” she added. “Exercise will change, briefly, the way our brains process information.”
Dr. Cross added that a lot of motor skills are involved in daily living skills, such as feeding, dressing, and toileting.
Screen time is increasing
The authors acknowledged that screen time may be underestimated by parents. They also noted that they did not have access to what children were watching on the screens.
“This should have been collected because the effect of high screen time differs depending on the type of program,” the authors wrote.
They added that children born in the 2020s may have been exposed to more screen time than the children reared in the early 2010s in this study.
Dr. Cross said screen use in the 2020s may be higher than estimated here and higher in certain populations globally, so it’s not easy to tell if the intervention in this study would have the same mitigating effect on a real-world population.
However, she said, the effect of outdoor play is always going to be helpful for brain development and there’s no downside.
“Exercise is just as important for little kids as it is for grown-ups,” she said.
The authors reported no relevant financial disclosures. Dr. Cross reported no relevant financial disclosures.
*Dr. Jennifer Cross is the correct name, not Dr. Jennifer Frost. The correction was made on Jan. 27, 2023.