ChatGPT can harm an individual’s critical thinking over time, a new study suggests.

Researchers at MIT’s Media Lab asked subjects to write several SAT essays and separated subjects into three groups — using OpenAI’s ChatGPT, using Google’s search engine and using nothing, which they called the “brain‑only” group. Each subject’s brain was monitored through electroencephalography (EEG), which measured the writer’s brain activity through multiple regions in the brain.

They discovered that subjects who used ChatGPT over a few months had the lowest brain engagement and “consistently underperformed at neural, linguistic, and behavioral levels,” according to the study.

The study found that the ChatGPT group initially used the large language model, or LLM, to ask structural questions for their essay, but near the end of the study, they were more likely to copy and paste their essay.

Those who used Google’s search engine were found to have moderate brain engagement, but the “brain-only” group showed the “strongest, wide-ranging networks.”

The findings suggest that using LLMs can harm a user’s cognitive function over time, especially in younger users. It comes as educators continue to navigate teaching when AI is increasingly accessible for cheating.

“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,” the study’s main author Nataliya Kosmyna told TIME. “Developing brains are at the highest risk.”

However, using AI in education doesn’t appear to be slowing down. In April, President Trump signed an executive order that aims to incorporate AI into U.S. classrooms.  

“The basic idea of this executive order is to ensure that we properly train the workforce of the future by ensuring that school children, young Americans, are adequately trained in AI tools, so that they can be competitive in the economy years from now into the future, as AI becomes a bigger and bigger deal,” Will Scharf, White House staff secretary, said at the time.