How the New MIT Study Worked
The study, run by researchers at the Massachusetts Institute of Technology and
available online this month, split up participants into three groups, dubbed “LLM, Search Engine, and Brain-only (no tools).”
The groups were studied across three sessions of essay-writing, while their cognitive load was tracked with electroencephalography (EEG). Their essays were analyzed, and were also scored by human teachers and an AI judge. The results?
“EEG revealed significant differences in brain connectivity: Brain-only participants exhibited the strongest, most distributed networks; Search Engine users showed moderate engagement; and LLM users displayed the weakest connectivity. Cognitive activity scaled down in relation to external tool use.” -the study
The study also notes that LLM users “struggled to accurately quote their own work,” which makes sense, given that it was more the LLM’s work.
Previous Studies Also Found AI Makes Us Dumb
Scientific research is all about verifying results through repetition, so we’re happy to announce that this isn’t the first study that has indicated that AI use makes humans use their brains less.
One
January 2025 study titled “AI Tools in Society: Impacts on Cognitive Offloading and the Future of Critical Thinking” found that “Younger participants exhibited higher dependence on AI tools and lower critical thinking scores compared to older participants.” Using AI is a form of cognitive offloading, the study found — it saves the brain from completing cognitive tasks itself.
In
another study from February, researchers at Microsoft and Carnegie Mellon University polled 319 “knowledge workers” to find that participants with higher confidence in AI tools held lower confidence in their own critical thinking skills.
AI tools may be able to supplement critical thinking. Use them too often, studies indicate, and they’ll replace it instead.