chameleonseye/Getty Images/iStockphoto The team of researchers studied and performed regular MRI scans of the brains of 169 middle school students, aged 12 to 15. BRAIN - “Teenagers who grow up using social media the most become hypersensitive to feedback from their peers. This is one of the conclusions of the study conducted by neuroscientists at the University of Chapel Hill in North Carolina. His goal: to understand the impact of social media on their brain development. To do this, Eva Telzer, assistant professor of psychology and neuroscience, and her team studied the brains of 169 middle school students for three years, between the ages of 12 and 15. First conclusion: those who consult their social networks very frequently around the age of 12 show an increased sensitivity to the "social rewards" of their peers, which increases over time. Conversely, adolescents who are less addicted to social networks would develop a decreasing interest in these "social rewards", that is to say signs of approval, love or attention from others. The study, published Tuesday (January 3) in the medical journal JAMA Pediatrics, is believed to be one of the first attempts to capture changes in brain function correlated with social media use over a period of years. "Pretty dramatic changes" In the experiment, teens were divided into three categories: regular users, who check Facebook, Instagram, and Snapchat fifteen or more times a day, moderate users, who check between one and fourteen times, and non-habitual users. who go there less than once a day.