More Screen Time, Better Thinking? An 8-Year Study Finds a Surprising Link

Screen time was associated with better adolescent cognitive processing, while links between physical activity and cognition varied by sex, activity type, and measurement method.

A Finnish study following children into adolescence found an unexpected pattern: those who accumulated more screen time from childhood tended to show better cognitive processing as teenagers. Rather than treating all screen use as harmful, the findings point to the importance of balancing physical activity with screen activities that encourage active thinking.

Low levels of physical activity among adolescents remain an important public health concern. Sedentary lifestyles have been linked to poorer school achievement, while physical activity is known to support brain function, particularly in adults. Far less is known about how physical activity and sedentary time throughout childhood and adolescence relate to cognitive processing during the teenage years, even though these are critical periods of brain development. Cognitive abilities developed during these years can also influence later educational choices and working life.

The researchers examined whether physical activity, sedentary behavior, and screen time from childhood through adolescence were associated with cognitive processing during adolescence, including whether those relationships differed between girls and boys. They also investigated whether the intensity of physical activity made a difference.

Screen time tracks better cognitive processing

Greater screen time accumulated since childhood was associated with better cognitive processing during adolescence.

Doctoral Researcher Petri Jalanko from the University of Jyväskylä said the results suggest that screen use can support cognitive processing in children and adolescents, depending on what they are doing. He said parents and teachers should encourage uses of digital devices that involve active thinking, problem solving, creativity, and learning.

Jalanko emphasized that screen time should not automatically be considered harmful and that the goal should instead be a balance between physical activity and screen use that stimulates active thinking.

Activity benefits differed by sex

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 associated with better working memory.

Another result ran counter to expectations. Lower levels of self-reported unsupervised physical activity were associated with better cognitive processing in adolescence, while physical activity and sedentary time recorded with a combined heart rate and movement sensor showed no association with cognitive processing. One possible explanation is that such sensors record movement and heart rate but cannot identify what a person is actually doing during active or sedentary periods.

According to Jalanko, the findings indicate that relationships between physical activity, sedentary behavior, and cognitive processing are complex and can vary according to sex, the type of activity, and how activity or sedentary time is measured. He added that girls and boys may also benefit from different forms of physical activity when it comes to brain health.

Causality remains an open question

The researchers caution that intervention studies are still needed to determine whether these relationships are causal and to clarify possible differences between girls and boys. More detailed research is also needed to understand how different intensities of physical activity relate to changes in cognitive processing.

The results come from an eight-year follow-up of the PANIC study on children’s physical activity and nutrition. The analysis included 124 girls and 136 boys with an average age of 15.8 years. Physical activity and sedentary behavior were assessed using both questionnaires and a device combining heart rate and movement measurements, while learning, attention, and working memory were evaluated with the CogState test battery.

Reference: “Associations of Physical Activity and Sedentary Time From Childhood to Adolescence With Cognition in Adolescence: The PANIC Study” by Petri Jalkanen, Marja H. Leppänen, Bert Bond, Jari A. Laukkanen, Timo A. Lakka and Eero A. Haapala, 29 May 2026, Pediatric Exercise Science.
DOI: 10.1123/pes.2025-0083

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