A Finnish study has found an unexpected association between screen use and cognitive performance. Children who accumulated more screen time as they grew up tended to show better cognitive processing during adolescence. One of the researchers cautions against viewing screen time as entirely harmful and says the goal should be to balance physical activity with screen use that encourages active thinking.
Low levels of physical activity among adolescents remain a significant public health concern. Sedentary behavior has been associated with poorer academic achievement, while physical activity is known to support brain function, particularly in adults. Much less is known, however, about how physical activity and sedentary behavior during childhood and adolescence relate to cognitive processing later in adolescence.
These years are especially important because the brain is still developing. Factors that shape cognitive abilities during childhood and adolescence may have lasting effects that extend into adulthood, potentially influencing education and working life.
Researchers examined how physical activity, sedentary behavior, and screen time from childhood through adolescence were related to cognitive processing in the teenage years. They also looked for differences between girls and boys and investigated whether the intensity of physical activity played a role.
More Screen Time Linked to Better Cognitive Processing
The results showed that greater screen time beginning in childhood was associated with better cognitive processing in adolescence.
“The findings suggest that screen time can support children’s and adolescents’ cognitive processing. Presumably, the essential point here is what kind of things they do in their screen time. Teachers and parents should encourage children to use devices and screens in such ways that promote active thinking, problem-solving, creativity and learning,” states Doctoral Researcher Petri Jalanko from the University of Jyväskylä.
The findings suggest that the type of screen activity may be important. Digital activities that involve learning, creativity, problem-solving, or other forms of active mental engagement could potentially help explain the association observed in the study.
“We should not regard screen time solely as harmful but seek balance between physical activity and screen time that promotes active thinking,” Jalanko summarizes.
Physical Activity Showed Different Links in Girls and Boys
The relationship between physical activity and cognition was more complicated.
Among girls, greater amounts of light intensity physical activity since childhood were associated with better working memory during adolescence. Among boys, greater participation in guided physical activity from childhood through adolescence was linked to better working memory.
The researchers also found an unexpected pattern involving unsupervised exercise. Lower levels of self-reported unsupervised physical activity were associated with better cognitive processing in adolescence.
By contrast, physical activity and sedentary time measured using a device that tracked heart rate and movement were not associated with cognitive processing. One possible explanation is that these sensors can measure movement and physiological activity but cannot determine exactly what a person is doing during periods of activity or inactivity.
“Our study indicates that the connections of physical activity and sedentary behavior to cognitive processing are complex and depend on the sex, the type and assessment method of physical activity and sedentary time. Moreover, boys and girls may benefit from different types of physical activity in view of brain health,” Jalanko adds.
More Research Is Needed to Determine Cause and Effect
The researchers emphasize that the findings show associations rather than proving that screen time or particular types of physical activity directly cause changes in cognitive performance.
“However, we need more intervention studies to find out causal relations and sex differences in this respect. Moreover, it is important to examine more specifically the effects of the intensity of physical activity on changes taking place in cognitive processing.”
The results come from an eight-year follow-up of the PANIC study on children’s physical activity and nutrition. The current analysis included 124 girls and 136 boys with an average age of 15.8 years.
Researchers measured physical activity and sedentary behavior using both survey questionnaires and a device that combined heart rate and movement measurements. Learning, attention, and working memory were evaluated using the CogState test battery.
The research was published in the journal Pediatric Exercise Science.
