As governments consider restrictions on social media for young people, researchers are examining how online habits may affect the developing brain. The evidence points to possible links with attention, sleep and brain development, but it does not settle what effects social-media use has or how they arise.
Adolescence is a period of significant brain development. Regions involved in social bonding and reward mature earlier than the prefrontal cortex, which supports decision-making and emotional processing. Researchers say features such as likes, notifications and endless scrolling may be especially compelling during this stage, when sensitivity to rewards is high and self-control is still developing.
Some studies have found associations between social-media use and attention problems. In one study of 79 children and adolescents, those who spent more time on their smartphones during school hours—mostly using social media—performed worse on a test of focus and attention. A separate four-year study tracking more than 8,300 children found a linear relationship between social-media use and symptoms of inattention.
Brain-imaging research has also reported a small but significant decrease in cerebellum volume among children with higher social-media use. The cerebellum is involved in movement and balance, as well as cognition, memory and communication. The researchers say this finding may be relevant to associations between heavier use and anxiety or depression, but it does not establish that social media causes those conditions.
Sleep is another area of concern. Researchers have suggested that social media may disrupt sleep, which is associated with the formation and maintenance of myelin, a material that helps nerve signals travel efficiently. A study of 976 children found associations involving shorter sleep, poorer white-matter organization, screen time and depressive symptoms. It also suggested that sleep duration and white matter could help explain the relationship between increased social-media use and depression-related symptoms.
Young people themselves report concerns about their habits: research cited in the article suggests nearly half of adolescents think they are addicted to social media. Scientists say that perception merits attention, while continuing to investigate the extent and Nature of potential effects. Meanwhile, some governments are pursuing restrictions; Australia has introduced a ban for under-16s, and the United Kingdom, France and Italy are among the countries attempting similar measures.
Sources: Nature.