Does looking at screens damage your brain?

Question

I found several articles that warn of the dangers of too much computer time, especially for children.

• Oxford Learning, Jun 2010: Too much computer time can be bad for your brain

However, a recent article in the New York Times showed how, thanks to our rampant use of technology, scientists are now concerned that neuroplasticity can work against us to create bad learning habits.

According to the article, our brains can become addicted to the fast-paced, instantaneous give-and-take of the high-speed, connected, online world . This can become a problem where learning is concerned. It can cause issues in the parts of the brain that deal with deep thought, introspection, and reasoning.

• New York-Presbyterian: What Does Too Much Screen Time Do to Children’s Brains?

Early data from a landmark National Institutes of Health (NIH) study that began in 2018 indicates that children who spent more than two hours a day on screen-time activities scored lower on language and thinking tests, and some children with more than seven hours a day of screen time experienced thinning of the brain’s cortex, the area of the brain related to critical thinking and reasoning.

• Business Insider, Feb 2019: What staring at a screen all day does to your brain and body

But perhaps the most concerning changes we're starting to see from all this screen time is in kids' brains. An ongoing study supported by the NIH has found that some pre-teens who clocked over 7 hours a day on screens had differences in a part of their brains called the cortex. That's the region responsible for processing information from our five senses.

Usually, our cortex gets thinner as we mature. But these kids had thinner cortices earlier than other kids who spent less time on screens. Scientists aren't sure what this could mean for how the kids learn and behave later in life. But the same data also showed that kids who spent more than 2 hours a day on screens scored lower on thinking and language skill tests.

This seems inconsistent with the congitive abilities of programmers and engineeers who use computers daily (ie programmers and engineers).

Is it true that looking at computer screens for many hours causes damage to the brain?

Answer 1

It may delay development in childhood. It can cause depression in adulthood..

Findings so far are developpement lateness. I couldn't find a study showing these damages would be permanent, though. I'm going to assume here you mean media exposure and not just empty screen staring.

This paper gives convincing evidence that the brain structure could be affected by high media exposure during child brain developpement.

In this cross-sectional study of 47 healthy prekindergarten children, screen use greater than that recommended by the American Academy of Pediatrics guidelines was associated with (1) lower measures of microstructural organization and myelination of brain white matter tracts that support language and emergent literacy skills and (2) corresponding cognitive assessments.

Note that although the brain structure was previously not studied, lateness of developpement in cognitive assessments had been previously studied, in studies similar to this one. Here the content and parental behavior is being pointed out

The cognitive impact of television use on infants and toddlers (<∼2.5 years old) is related to the amount of exposure, the program content, and the social context of viewing. For children <2 years of age, associations with aspects of cognitive development are negative, especially for language and executive function6,7 largely because of exposure to programming produced for adults. Because children of this age pay little overt attention to such programs and likely have little comprehension of them, adult programming can be considered background television from the perspective of the child. Background television has been shown to disrupt 12- and 24-month-old children’s sustained toy play and reduce the quality and quantity of parent-child interactions compared with when the television is not on.8,9 In particular, background television reduces the quantity and quality of parental language addressed to their 12- and 24-month-old children.

Because of the reasons invoked and the specifical state that the child brain is in, it's difficult to imagine the same effect would apply to adults, but has been shown link to some negative effects such as depression, although no significant brain damage is observed here.

Approximately 25% of participants engaged in at least 4 hours/day of TVSE. In general linear models, TVSE time per week was independently associated with GHQ-12 score (higher scores represent worse mental health status) after adjustment for age, gender, physical activity, physical function, area deprivation level, smoking, alcohol, fruit and vegetable intake, and BMI. After full adjustment, participants in the group with the highest TVSE level (>4 hours/day) had an increase in GHQ-12 score of 0.28 (95% CI=0.05, 0.51) compared with participants in the group with the lowest TVSE level (≤2 hours/day). In stratified analyses, the association between TVSE time and GHQ-12 score persisted across all physical activity levels. Similar associations were observed using the MCS-12.

After a bit of research I couldn't find evidences of real permanent damage and remain skeptical there is any.