Screen Time May Alter a Teen’s Memory as Adults Are Already Exposing Ourselves to Brain Damage
There’s a public debate raging in the United States right now about the health effects of screen time on the development of teens’ brains, with healthy teens and those who spend excessive amounts of time in front of electronic screens getting flagged as “at risk.” Millions of parents have recently been told that their kids are particularly vulnerable to the effects of screen time. Adolescents spend a significant amount of time on screens – and not just now, but for years. They are highly susceptible to the increasing threats to their well-being posed by screen technology, from suicide to eating disorders to addictive gaming.
Yet it’s relatively uncommon to find adults worried about how screen time affects their brains, particularly in the U.S. Studies have shown positive or negative results for brain development in relation to screen time. This did not appear to be the case until recently, however, when neuroimaging studies began to unravel how screen time affects brain function and memory.
Some studies have found that adolescents’ brains are plastic and can adapt to new behaviors, and learn new skills and gain new insights. But those opposite results are too often seen in adults, too. Adults experience falling brain structure, reduced impulse control, and psychotic-like symptoms during their youth, when they may be more malleable and more prone to changing brain states in response to changes in their environment. Other studies have found that adolescents’ brains are not as plastic and have not yet evolved to develop and use technology for purposes beyond learning and play. These studies, however, also found a positive association between longer and more intense screen time in early life and better memory in late adolescence.
Neuroimaging studies have definitively established some of the connections between screen time and cognitive problems. Images show that the adolescent brain shrinks, slows, and changes over the first two years of life, in response to exposure to screens. But then those changes are reversed in the later years. As Adolescent Age Brain Changes, it looks like the brain changes throughout life, more or less at a gradual, incremental pace, as the child matures. Screen time can play a role in increasing the rate of this gradual change, by reducing the brain’s ability to adapt to the environment. Studies in this field have found stronger relationships between the periods of reduced activity in the teen brain and screen-related cognitive problems. Screen-related problems include depression, as well as other learning and emotional issues, such as attention disorders, social anxiety, learning disorders, and attention deficit disorder (ADD).
This research shows that screen time can be linked to factors like decreased attention spans, distractibility, impulsivity, and difficulties with depression and anxiety. If screen time does cause the adolescent brain to change during its critical period, that change in a child’s brain may be irreversible. Studies show that there is a set age point, called a “Mountain Threshold,” at which this irreversible change has been shown to occur. That age range is now between 16 and 17 years. In adult studies, brain changes in adolescents have been documented, suggesting that there is a complex web of impacts on developing brains from living in a multi-faceted world.
This Mountain Threshold developmental stage is also strongly associated with lower IQ, low memory recall, attention problems, and greater neuroticism. If screen time is having this effect in children, it is likely having the same impact on adults. If that’s true, then parents are clearly best advised to limit screen time for children, though children can access screens if this is the only way to learn valuable new skills. Adolescents who spend time on electronic screens as an alternative to attending school are at risk of struggling on cognitive tests in school. If they are also having trouble in school, there may be a greater chance of problems, including substance abuse, antisocial behavior, depression, and delinquency.
Neuroimaging is an extremely useful tool in helping to understand how our environment affects our brains, with implications for medical research and health policy. Unfortunately, it is common to find studies on one topic and not another. This lets us miss useful information. After all, common misapprehensions can lead to huge risks for our society and to major developmental problems. It is good for psychologists and psychiatrists to follow neuroimaging studies, which can tell us so much more about the health of our children and ourselves than what we learn from talking to parents and family members about their concerns.
Anya Kamenetz, Ph.D., is a doctoral candidate in the Department of Psychology at the University of Michigan.