Scientists admit they don’t yet know the full effects of internet use on the brain — and they aren’t entirely comfortable with it.

A recent international review examined three areas of cognitive function: attention and concentration, memory, and social cognition. Researchers from Harvard University in Boston, Western Sydney University in Australia, and several U.K. institutions, including King’s College London, Oxford University, and the University of Manchester, analyzed previous studies to assess whether internet use is beneficial or harmful. Their findings appear in the journal World Psychiatry.

The team first considered digital multitasking. Evidence suggests that doing multiple things online does not improve multitasking abilities in other contexts. In fact, it may make individuals more prone to distractions. “The limitless stream of prompts and notifications from the internet encourages us towards constantly holding divided attention — which may decrease our capacity for maintaining focus on a single task,” explains Joseph Firth, senior research fellow at Western Sydney University’s NICM Health Research Institute. However, the immediate and long-term effects on young people require further study.

Next, the review focused on memory. While previous generations needed to store facts mentally, modern users can rely on the internet to access information. Researchers suggest this may free the brain to focus on more complex tasks. “Given we now have most of the world’s factual information literally at our fingertips, this could begin to change how we store and value knowledge,” the team notes. Still, more research is needed on long-term effects and on spatial memory, especially as people increasingly use digital navigation tools.

The final area was social cognition. The team found that online interactions are processed by the brain in ways similar to real-life interactions. This could benefit older adults facing isolation, but young people may be more vulnerable to negative social effects such as peer pressure or rejection.

The review did not find a causal link between internet use and poor mental health. In fact, social media may even serve as a form of therapy for some young individuals with mental health challenges.

Overall, researchers stress that future studies should focus on young people, as older adults appear to derive cognitive and social benefits from online activities. For younger users, the impact of internet use remains unclear.