According to JAMA Pediatrics, infants with substantial screen time were found to be more vulnerable to poor brain function beyond age eight.
The Singaporean longitudinal cohort study, conducted by Yong Loo Lin School of Medicine, National University of Singapore, A*STAR’s Singapore Institute for Clinical Sciences (SICS), National Institute of Education, KK Women’s and Children’s Hospital, McGill University, and Harvard Medical School, revealed that prolonged screen time during infant years was linked with poorer consequences in terms of cognitive functions.
The research involved responses of 506 children from the Growing Up in Singapore towards Healthy Outcomes (GUSTO) cohort, which they were a part of since birth. Once the babies reached the 12 month mark, parents recorded their weekly screen time, falling into one of four categories:
- Less than one hour
- One to two hours
- Two to four hours
- More than four hours
At 18 months, the research team also gathered their brain activity using electroencephalography (EEG) that can track brain functioning. On top of EEG, children were also involved in cognitive ability tests to assess their attention span and executive functioning once they reached age nine. The researchers looked at the link between screen time and EEG brain functioning, and found that children who were exposed to greater screen time during infant years had larger low-frequency waves, which is linked with poorer cognitive ability.
To further see if screen time had greater impact throughout their childhood, the study examined data according to three age points in their lives — 12 months, 18 months, and at nine years. They found that greater screen time also heightened brain activity and impaired cognitive functioning. Children with executive function complications sometimes struggle with impulses or emotions, completing difficult tasks, or pursuing longer instructions.
From birth to early childhood, the brain grows relatively fast. Prefrontal cortex, which manages executive functioning, however, has a comparably prolonged growth. Executive functioning refers to the capacity of maintaining attention, grasping information and regulating emotions, which are all required to participate in school and social activities.
What other ways can screen time impact a child?
According to National Childbirth Trust (NCT) screen time can also impact children's physical health, from obesity to higher blood pressure. Screen time often replaces physical activity, where children opt out of physical and social activities and spend time staring at tablets.
With prefrontal cortex having a relatively slower growth, children can continue to grow their executive functioning through their school years. It is crucial that children are given appropriate and safe environmental spaces to grow in order for their brain to develop thoroughly. Unreasonable screen time is one of the environmental factors that can negatively influence function growth, so it is crucial to monitor their usage. Screens can be overwhelming to the infant’s brain, providing no space for their brain to develop cognitive skills.
Excessive screen time also points to other factors within the home. Researchers say screen time can correlate to problems within the family, such as housing insecurity or guardian mental health.
Dr. Evelyn Law of NUS Medicine and SCIC's Translational Neuroscience Programme said, "The study provides compelling evidence to existing studies that our children’s screen time needs to be closely monitored, particularly during early brain development."
- JAMA Network Open Associations Between Infant Screen Use, Electroencephalography Markers, and Cognitive Outcomes
- National Childbirth Trust (NCT) Screen time for babies and toddlers: the evidence