Screen use during infancy may poorly impact executive function

Infant screen use may cause poorer executive function measured through altered cortical electroencephalography (EEG) activity in children aged under 2 years, according to a recent study published in JAMA Pediatrics.

Infants aged from 6 to 18 months are on average exposed to 2 to 3 hours per screen time per day, greatly passing recommendations from the American Academy of Pediatrics to avoid screen media use outside of video chatting for children aged under 18 months. This risks impairments to attention and executive functions, based on findings from prior studies.

Associations have been found between screen use in preschool aged children and changes to white matter tracts vital for executive functioning. However, while infants are the most vulnerable to executive functioning deficits, there is little data on possible neural correlates in this age group, or whether deficits last through school age. 

The neural correlates of many cognitive functions can be determined through EGG. Associations have also been recorded between screen exposure and greater functional connectivity in EGG theta waves.

Investigators conducted a study to determine the association between screen use when aged 12 months and neural signals indicating deficit attentional control when aged 18 months, along with analyzing whether any changes lead to different attentional and executive functioning when aged 9 years.

Data was gathered through a population-based cohort known as Growing Up in Singapore Toward Healthy Outcomes. There were 506 mother-child pairs who completed study measures when the child was aged 12 months and 9 years. Exclusion criteria included being born small for gestational age, part of a twin pregnancy, or having major neurological conditions.

Behavioral data of children aged 9 years was analyzed, and EGG data was collected in a subset of 157 children. Parents reported the screen time of their children aged 12 months in the prior month. Screen use time data for children on weekdays, Saturdays, and Sundays were reported.

At 5 other time points when the children were aged 12 months to 54 months, their parents answered the same question on their child’s screen time. Total hours of screen time per week were divided by 7 days to get an estimated hours of screen time per day.

To record resting EGG, investigators had children seated on the lap of a caregiver and watching bubbles being blown into the room. The Harvard Automated Processing Pipeline for EEG (HAPPE) was used to process data. According to authors of the study, “data were segmented into contiguous 2-second segments, and segment rejection was carried out via HAPPE criteria.”

Executive functions were measured as the main outcome. The 3 main executive function components were naming inhibition, shifting, and working memory. The Developmental Neuropsychological Assessment, second edition, was used to measure these categories, with higher scores indicating improved competency.

At 12 months of age, children had a mean recorded screen time of about 2 hours. When applied to regression models, each additional hour of screen time was associated with a decrease of 0.30 to 0.56 points in each task.

A linear correlation was observed between screen time at 12 months and neural correlates, with greater screen time leading to greater neural correlates, including theta ratios. Higher theta ratios were associated with poorer performance in executive function measured by EGG. This indicated longer screen time leads to poorer executive function in young children.

Reference

Law EC, Han MX, Lai Z, Lim S, Yan Ong Z, Ng V, et al. Associations between infant screen use, electroencephalography markers, and cognitive outcomes. JAMA Pediatr. 2023. doi:10.1001/jamapediatrics.2022.5674