The researchers focused on the nucleus accumbens, a small but critical structure located deep in the center of the brain, because previous research has shown that rewards —including food, money, sex, and gains in reputation — are processed in this region.
“As human beings, we evolved to care about our reputation. In today’s world, one way we’re able to manage our reputation is by using social media websites like Facebook,” says Dar Meshi, lead author of the paper. Facebook is the world’s largest social media channel with 1.2 billion monthly active users. It was used in the study because interactions on the website are carried out in view of the user’s friends or public and can affect their reputation. For example, Facebook consists of users “liking” posted information. This approval is positive social feedback, and can be considered related to their reputation.
All 31 participants completed the Facebook Intensity Scale to determine how many friends each participant had, how many minutes they each spent on Facebook, and general thoughts. The participants were selected to vary widely in their Facebook Intensity Scale scores.
First, the subjects participated in a video interview. Next, the brain activity of the subjects was recorded, by using functional magnetic resonance imaging, in different situations. In the scanner, subjects were told whether people who supposedly viewed the video interview thought highly of them, and subjects also found out whether people thought highly of another person. They also performed a card task to win money.
Results showed that participants who received positive feedback about themselves produced stronger activation of the nucleus accumbens than when they saw the positive feedback that another person received. The strength of this difference corresponded to participants’ reported intensity of Facebook use. But the nucleus accumbens response to monetary reward did not predict Facebook use.
“Our study reveals that the processing of social gains in reputation in the left nucleus accumbens predicts the intensity of Facebook use across individuals,” says Meshi. “These findings expand upon our present knowledge of nucleus accumbens function as it relates to complex human behavior.”
Regarding the potential for social media addiction and the effects of social media on education quality, these results may provide important motivation for clinical research and for further research on learning. As Meshi says, “Our findings relating individual social media use to the individual response of the brain’s reward system may also be relevant for both educational and clinical research in the future.” The authors point out, however, that their results do not determine if positive social feedback drives people to interact on social media, or if sustained use of social media changes the way positive social feedback is processed by the brain.
The study was conducted at the Languages of Emotion Cluster of Excellence at Freie Universität Berlin. It was supported by the Excellence Initiative of the German Federal Ministry of Education and Research.
Dar Meshi, Carmen Morawetz, and Hauke Heekeren: Nucleus accumbens response to gains in reputation for the self relative to gains for others predicts social media use, in: Frontiers in Human Neurosience, DOI: 10.3389/fnhum.2013.00439.