A generation ago parents worried about the effects of watching television; before that it was the radio. Now it is about exposure to screens, the amount of time in which children – especially pubescents and teenagers – interact with televisions, computers, smartphones, digital tablets and video games.
It is an important age group because the interaction with screens increases drastically during adolescence and because brain development also accelerates at that age; Neural networks are defined and consolidated during the transition to adulthood.
The ABCD study (Adolescent Brain Cognitive Development or cognitive development of the adolescent brain) is a $ 300 million project funded by the National Institutes of Health (NIH), which aims to explain how much brain development is affected by various factors, including the consumption of fabrics, bruises and time for the screens. A recent report that is part of the study reported that spending much time on the use of screens is associated with lower scores on fitness tests and the natural process of "cortical dilution" in some children. However, the data are provisional and it is not clear whether the effects are permanent or even significant.
Does the addiction to the scenes change the brain?
Yes, but the same thing happens with every other activity practiced by children and several of their contexts: sleep, homework, playing football, discussing, growing up in poverty, reading or evaporating or smoking. The adolescent's brain changes constantly, or "reconnects", in response to daily activities, and that adjustment continues until the first half of the twenties.
What scientists want to know is whether there is a time limit on screens that cause measurable differences in the structure or brain functions of adolescents and whether they are significant. Do they lead to attention deficit, mood problems or delays in reading or their ability to solve problems?
Have there been any such differences?
Not convincing. More than a hundred reports and scientific analyzes have investigated the relationship between the way screens are used and the well-being of young people, looking for emotional or behavioral differences, as well as attitude changes with respect to aspects such as body image. In 2014, scientists at Queen's University in Belfast assessed 43 of those 100 studies; those that they considered better designed.
In a meta-analysis, they concluded that social networks enable people to increase their circle of social contacts in a way that can be both positive and negative when, for example, they expose young people to aggressive content. In the authors' review, however, it was concluded that there is "insufficient solid causal research into the impact of social networks on the mental well-being of young people".
To sum up: the results were diverse and sometimes contradictory.
Psychologists have also investigated whether playing violent video games is related to aggressive behavior. More than two hundred studies of this type have been carried out; in some, links are found and not in others. A challenge in studying these and other aspects of screen exposure is identifying the direction of causality: making children who play a lot of violent video games more aggressive or attracting that kind of content because they are more aggressive from the beginning ?
Even if scientists have found clear evidence of a measurable effect – for example, that three hours a day on screens was associated with an increased risk of being diagnosed with hyperactivity disorder with attention deficit – such a link would not necessarily mean that there is consistent and measurable brain structure.
Individual variation is a rule for the development of the brain. The size of specific brain areas such as the prefrontal cortex, the speed with which these regions consolidate their neural networks and the variations of these parameters between an individual and another, make it very difficult to interpret certain findings. Scientists must have a huge amount of research topics and a much better understanding of the brain.
The ABCD study, is not that just for that?
Yes, longitudinal research expects to follow 11,800 children in adolescence, with annual MRI examinations, to see if changes in the brain are related to behavior or health. The study began in 2013 with twenty-one academic research centers; The first focus was on the effects of drugs and alcohol use in the adolescent's brain. The project is extensive and now includes other topics, such as the effects of brain injury, screen exposure, genetics and a range of "various environmental factors".
The recently published article gives an early look at the results that are expected. A research team, based at the University of California, San Diego campus, analyzed brain studies of more than 4,500 adolescent people and correlated these with the amount of time children spend on screens (time reported by the same children in questionnaires), as well as their scores in tests of language and intellect.
The findings were varied. Some children who said that they spent a lot of time in front of the screens showed that they were getting cortical thinner at a younger age than expected; But thinning is also part of natural brain aging and scientists do not know what difference means. Some children who said they spent a lot of time on the screens scored lower than the curve in the aptitude test, while others performed well.
It is difficult to check the accuracy of the amount of time in front of the screens, because it has been reported itself. Moreover, the relationship between small differences in brain structure and the way people behave is even more ambiguous. It is very difficult to draw clear conclusions and this situation is complicated because the use of a brain scan is only a temporary capture: within a year some of the observed relationships could be reversed.
"The diversity of the results provides an important message for public health: this interaction with screens is not only harmful to the brain or brain-related functioning", the authors conclude.
In other words, the measured effects can be good or, more likely, not at all significant, until other studies prove the opposite.
But is screen addiction no harm?
It is probably both bad and good for the brain, according to the individual and their habits of screen use. Many people who are socially isolated – either as a result of abuse, personal eccentricities or developmental disparities, such as Asperger syndrome – record social networks through their screens that they could not find personally.
Separating the negative and positive effects in the physical development of the brain will be very difficult, given the many factors that may be at stake: the effects of marijuana use, alcohol, electronic cigarettes, genetic differences, changes at home or school to all emotional storms that accompany adolescence.
Most parents may already be aware of the biggest disadvantage of time for screens: the extent to which they can displace other experiences from childhood, such as sleeping, climbing, playing outside or getting into trouble. Although many parents – perhaps the majority – have certainly seen several hours of television when they were young. Perhaps your experiences are more similar than you think of those of your children.
Source: The New York Times