May 2024   |   Volume 25 No. 2

Cover Story

Stuck on Scrolling

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Social media platforms bombard us with information in ways that can be addictive and possibly harmful to mental health. HKU scholars consider the consequences for young and old.

Facebook came in for a harsh grilling earlier this year when the CEO of parent company Meta, Mark Zuckerberg, was accused in a US Senate hearing of having ‘blood on his hands’. The reason was the mental health effects linked to the platform’s algorithms.

Social media algorithms are primed to keep us scrolling and exposed to more and more information. Multiple studies have found this to be associated with negative effects, such as depression and anxiety. But the question remains – what exactly is social media use doing to our brains? 

Neuroscientist Professor Benjamin Becker of the Department of Psychology and State Key Laboratory of Brain and Cognitive Sciences began looking at this issue a couple of years ago when he noticed features of social media overuse resembled those of drug addiction. “Usually, our behaviour is driven by seeking reward but in addiction, this becomes uncoupled from a positive experience and becomes automatic behaviour. In addition, when people try to stop or reduce their use, normally they fail. They have lost control over behaviour,” he said. 

Social media users can experience such symptoms but, unlike drug addiction, the mechanisms are unknown. Professor Becker and his German colleague, Professor Christian Montag from Ulm University, therefore have called on brain researchers around the world to look at what is happening in the brain when people engage with social media, especially adolescents. 

“Most researchers use questionnaires to study social media, which do not tell us what kind of brain changes go along with that, particularly during adolescence when the brain undergoes dramatic changes in reward processing and social processing. Adolescents are already very sensitive to the influences of friends, peers and the environment.

Now a new player has come along, which is social media use. How does that affect brain development and maturation?” he asked. 

Difficult to resist 

The only way to find out is to conduct long-term fMRI studies tracking adolescent brain development and social media use over two or more years. These are expensive, but they would provide insight about which brain systems get engaged with social media, which get people hooked, how this interacts with brain development, and how it affects or interacts with mental health. 

“We currently don’t know these things. Brain science could be critical to inform policymaking on social media use by minors and for developing new and specific treatment interventions,” such as education, regulation or restricting use, Professor Becker said. He and Professor Montag proposed in Nature in April that such studies could be funded through a proportion of the fines imposed under the European Union’s recent Digital Services Act. 

Meanwhile, he has already done preliminary work showing young users of WeChat experience brain changes related to emotional control and their reward system, similar to other addictions. Another study in Chengdu showed people are more likely to be distracted by social media notifications than other notifications. 

Professor Becker stressed that social media use is not overall a bad thing – many people use it without ill effects. But some people may be more vulnerable to addiction than others, particularly if they have higher reward sensitivity (as in drug addiction). Currently, it is unclear if reward-sensitive people are prone to heavy social media use, or if the use drives their reward sensitivity. 

In any case, the issue urgently needs addressing in young people because their brains are developing quickly and vulnerable to algorithms and content that keep them glued to the screen. Interestingly, the European Commission has launched proceedings against TikTok based in part on the negative effects on minors. “Social media can propel or enlarge problems because the information spreads very fast,” he said. 

Anxiety in older people, too

Older adults can also be vulnerable to anxiety from social media use, according to a study focussed on COVID-19 led by Professor Terry YS Lum, Henry G Leong Professor in Social Work and Social Administration. 

Professor Lum and his collaborators collected information from 3,421 adults aged 60 and over about their use of social media to obtain COVID-19-related information. Heavier use of social media was associated with more anxiety and lower social trust in information, particularly because users were more likely to encounter false information. However, social media use did not mediate their COVID-safe behaviours. 

“COVID-19-related information on social media was over-abundant and sometimes questionable, resulting in an ‘infodemic’ during the pandemic. Our results align with previous studies that suggest social media usage in general can increase the risk of developing anxiety symptoms. Importantly, we were able to show that social trust in information may be challenged by unverified and contradictory information online,” Professor Lum said. 

“The negligible impact on participants’ behaviours suggests social media may have caused more confusion in consolidating a consistent effort against the pandemic. Media literacy education is therefore recommended.”

Brain science could be critical to inform policymaking on social media use by minors and for developing new and specific treatment interventions. 

Professor Benjamin Becker