If you value critical thinking, you may want to rethink your use of ChatGPT.
As graduates proudly show off using ChatGPT for final projects, and with 89% of students admitting to using it for homework, have you ever wondered what effect this is having on our brains?
A new study conducted by researchers at MIT split 54 participants (aged 18 to 39 from the Boston area) into three groups. Each was tasked with writing 20-minute essays based on SAT prompts using either OpenAI’s ChatGPT, Google’s comparatively more traditional search engine, or their own brains.
Researchers then used electroencephalogram (or EEG) to record brain activity across 32 regions. Of the three groups, those assisted by ChatGPT engaged their brains the least and “consistently underperformed at neural, linguistic, and behavioral levels.”
The study found that using ChatGPT reduced activity in brain regions associated with memory and learning, as “some ‘human thinking’ and planning” was offloaded to the LLM. Unsurprisingly, ChatGPT users felt less ownership over their essays compared to the other groups. They also struggled to recall or quote from their own essays shortly after submitting them—showing how reliance on the LLM bypassed deep memory processes.
Over several months, those using ChatGPT became lazier with each essay. By the end of the study, their work amounted to little more than copy-and-paste. Two English teachers who assessed the essays called them largely “soulless.” The paper’s lead author, Nataliya Kosmyna, told Time: “It was more like, ‘Just give me the essay, refine this sentence, edit it, and I’m done.’”
By comparison, the group using their own brains showed the highest neural connectivity, were more engaged and curious, and expressed greater satisfaction with their essays. The Google Search group also showed high satisfaction and active brain function.
Given how frequently ChatGPT is now used in educational settings, these findings give cause for concern. A February 2025 OpenAI report on ChatGPT use among college-aged users found that more than one-quarter of their ChatGPT conversations were education-related. The report also revealed that the top five uses for students were writing-centered: starting papers and projects (49%), summarizing long texts (48%), brainstorming creative projects (45%), exploring new topics (44%), and revising writing (44%).
The MIT paper has not yet been peer-reviewed, and its sample size is relatively small. However, the authors believed it was important to release the findings to draw attention to the damaging long-term impact that use of large language models may have on our brains—as more and more people outsource everything from work tasks to texting.
“What really motivated me to put it out now before waiting for a full peer review is that I am afraid in 6–8 months, there will be some policymaker who decides, ‘Let’s do GPT kindergarten.’ I think that would be absolutely bad and detrimental,” Kosmyna told Time. “Developing brains are at the highest risk.”
Next time you are struggling with a writing task, stick with it. Your brain will thank you.
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