The intense sensory stimulation provided by screens accelerates maturation visual and cognitive brain networks
Children exposed to high levels of screen time before the age of two showed changes in brain development that were associated with slower decision-making and increased anxiety in adolescence.
A study that has followed children for more than a decade also indicates that shared reading between parents and children can counteract these effects, according to a publication in .
From childhood to adolescence
Researchers from the Institute for Human Development and Potential () from the National University of Singapore used brain imaging at multiple time points to mapr a possible biological pathway from exposure to screens in childhood to mental health in adolescence.
This is the first paper to incorporate measurements spanning such a long period, “highlighting the lasting consequences of childhood screen time”, according to the University of Singapore in a statement.
Childhood is a period of rapid brain development and particular sensitivity to environmental influences.
Furthermore, the amount and type of time spent in front of screens largely depends on the awareness and practices of parents and guardians, which highlights the importance of early guidance and intervention.
The researchers followed 168 children, undergoing brain imaging exams at 4, 5, 6 and 7.5 years of age.
This made it possible to track the development of brain networks over time, rather than relying on a single assessment.
Children with the most screen time during childhood showed accelerated maturation of brain networks responsible for visual processing and cognitive control, which can be attributed to the intense sensory stimulation provided by screens.
The team noted that the screen time measured at three and four years of age did not show the same effectshighlighting why childhood is a particularly sensitive period.
“Accelerated maturation occurs when certain brain networks develop very quickly, usually in response to adversity or other stimuli”, highlighted researcher Huang Pei, one of the study’s authors.
Consequences of accelerated development of brain networks
During normal development, brain networks gradually specialize over time, but in children with high screen exposure, the networks that control vision and cognition specialize more quickly, before developing the efficient connections needed for complex thinking.
This can limit flexibility and resilience, making the child less able to adapt later in life, the university added.
Children with these altered brain networks they took longer to make decisions during a cognitive task at 8.5 years of age, suggesting a reduction in cognitive efficiency or flexibility.
Those who took longer to make decisions also presented higher levels of anxiety symptoms at age 13.
The findings suggest that exposure to screens in childhood may have effects that extend far beyond early childhood, shaping brain development and behavior years later.
