The effect of social media use on children is a tense area of research, as parents and lawmakers try to determine the results of a vast experiment already in full swing. Successive studies have added pieces to the puzzle, developing the implications of a nearly constant stream of virtual interactions beginning in childhood.
A new study by neuroscientists at the University of North Carolina tries something new, taking successive brain scans of high school students between the ages of 12 and 15, a period of especially rapid brain development.
The researchers found that children who habitually checked their social networks around the age of 12 showed a different trajectory, with their sensitivity to social rewards from their peers increasing over time. Teens with less social media engagement followed the opposite path, with decreasing interest in social rewards.
The study, published Tuesday in JAMA Pediatrics, is one of the first attempts to capture changes in brain function related to social media use over a period of years.
The study has important limitations, the authors acknowledge. Because adolescence is a period of expanding social relationships, the brain differences could reflect a natural turn toward peers, which could be driving more frequent use of social media.
“We cannot make causal claims that social media is changing the brain,” said Eva H. Telzer, an associate professor of psychology and neuroscience at the University of North Carolina, Chapel Hill, and one of the study’s authors.
However, he added, “teenagers who routinely check their social networks show these quite dramatic changes in the way their brains respond, which could have long-term consequences well into adulthood, setting the stage for the development of brain over time. .”
A team of researchers studied an ethnically diverse group of 169 sixth- and seventh-graders at a high school in rural North Carolina, dividing them into groups according to how often they reported checking Facebook feeds, Instagram and Snapchat.
Around the age of 12, the students already showed different patterns of behavior. Regular users reported checking their feeds 15 or more times a day; moderate users consulted between one and 14 times; non-regular users consulted less than once a day.
The subjects received full brain scans three times, at approximately one-year intervals, while playing a computerized game that delivered rewards and punishments in the form of smiling or frowning peers.
While performing the task, the frequent checkers showed increased activation of three brain areas: reward-processing circuits, which also respond to experiences like winning money or taking risks; regions of the brain that determine salience, selecting what stands out in the environment; and the prefrontal cortex, which helps with regulation and control.
The results showed that “adolescents who grow up checking social media more frequently are becoming hypersensitive to feedback from their peers,” Telzer said.
The findings do not capture the magnitude of the brain changes, only their trajectory. And it’s not clear, the authors said, whether the changes are beneficial or harmful. Social sensitivity could be adaptive, showing that adolescents are learning to connect with others, or it could lead to social anxiety and depression if social needs are not met.
Researchers in the field of social media cautioned against drawing sweeping conclusions based on the findings.
“They’re showing that the way you use it at one point in your life influences the way your brain develops, but we don’t know how much, or if it’s good or bad,” said Jeff Hancock, founding director of the Laboratory of Stanford Social Media, who was not involved in the study. He said many other variables could have contributed to these changes.
“What if these people joined a new team, a hockey team or a volleyball team, and they started having a lot more social interaction?” he said. It could be, he added, that researchers are “noticing the development of extroversion, and extroverts are more likely to check their social media.”
He described the paper as “very sophisticated work,” contributing to recently emerging research showing that sensitivity to social media varies from person to person.
“There are people who have a neurological status that means they are more likely to be drawn to checking themselves often,” he said. “We are not all the same and we should stop thinking that social networks are the same for everyone.”
Over the past decade, social media has remapped the core experiences of adolescence, a period of rapid brain development.
Nearly all American teens interact through social media, with 97% going online every day and 46% reporting being online “almost constantly,” according to the Pew Research Center. Black and Latino teens spend more hours on social media than their white counterparts, research has shown.
Researchers have documented a variety of effects on children’s mental health. Some studies have linked social media use to depression and anxiety, while others found little connection. A 2018 study of lesbian, gay, and bisexual teens found that social media provided them with validation and support, but also exposed them to hate speech.
The experts who reviewed the study said that because the researchers measured students’ social media use only once, at around age 12, it was impossible to know how it changed over time or to rule out other factors that might also affect performance. brain development.
Without more information about other aspects of students’ lives, “it’s hard to discern how specific differences in brain development hold up for social media verification,” said Adriana Galván, a specialist in adolescent brain development at UCLA, who did not participate in the study. to study.
Jennifer Pfeifer, a professor of psychology at the University of Oregon and co-director of the National Scientific Council on Adolescence, said: “All experience accumulates and is reflected in the brain.”
“I think you want to put it in this context,” he said. “Many other experiences that adolescents have will also change the brain. So we don’t want to get into some sort of moral panic over the idea that social media use is changing the teen brain.
Telzer, one of the study authors, described the increased sensitivity to social feedback as “neither good nor bad.”
“It’s helping them connect with others and get rewarded from the things that are common in their social world, which is engaging in social interactions online,” he said.
“This is the new norm,” he added. “It is important to understand how this new digital world is influencing adolescents. It may be associated with changes in the brain, but that can be for better or worse. We don’t necessarily know the long-term implications yet.”