Ctrl+C, Ctrl+Forget

Why using AI for essays could be putting your brain in debt

You sit down in the library and stare at your essay title for ten minutes. Nothing. A few clicks later, ChatGPT has handed you an essay plan full of ideas you could only dream of coming up with that quickly. Now try closing the tab and going back to a blank Word document without peeking. With your evening plans looming, the quick option is the hardest to resist, even when you suspect it isn’t the best one. 

But new research from the Massachusetts Institute of Technology (MIT) suggests that this shortcut may come at a cost: 83% of people who wrote an essay with ChatGPT could not recall a single line of it just minutes after finishing. 

This matters for students. A Higher Education Policy Institute survey reported that 94% of UK undergraduates use artificial intelligence (AI) in some way. Yet because these tools only became widely available so recently, we know surprisingly little about how they affect the way we learn. If AI hands you the ideas, how much of the thinking is really yours?

Over four months, MIT researchers asked 54 participants to write essays across three sessions. Each participant used one of three methods: ChatGPT, Google, or nothing at all. While they wrote, researchers recorded their brain activity using electroencephalography (EEG), which measures electrical activity through electrodes placed on the scalp. 

The researchers focused on connectivity, meaning how well different brain regions coordinate during a task. The brain-only group showed the strongest connectivity, with regions linking up across wide networks. Google users fell somewhere in between, whilst ChatGPT users showed the weakest coordination, with up to 55% less connectivity than the brain-only group: same task, three very different ways of using the brain to do it.

Overall, the researchers reported that the ChatGPT group “consistently underperformed at neural, linguistic, and behavioural levels.” Alongside their poor recall and lower connectivity, ChatGPT users also reported feeling the least ownership of their essays. 

In a fourth session, the researchers gave the brain-only group access to ChatGPT for a final essay. This group remembered far more of their writing than the original ChatGPT group did, and their brains stayed noticeably more active. It looked as though they were evaluating the AI’s suggestions rather than simply accepting them. 

Only around nine people were in this group, so the result is far from conclusive. Still, it suggests that thinking through the material yourself first might change how you engage with AI afterwards. 

The researchers described the ChatGPT group’s pattern as “cognitive debt”: the hidden cost of repeatedly handing mental work to a tool. When AI does that work for you, your brain gets less practice doing it itself, and over time those abilities may weaken. Their concern is that relying on AI too early could stunt the very skills university is meant to build: critical thinking, creativity, and the ability to retain what you learn. 

They aren’t alone in raising the question. Writing in the British Journal of General Practice, General Practitioner Richard Armitage suggested that AI could be reshaping how our brains are wired to think. This study offers some of the first evidence that he may have a point. 

The findings come with important limitations. The sample is small, the study has not yet been peer-reviewed, and the long-term effects remain largely unknown. Even so, it is among the first attempts to measure what actually happens to the brain when we write with AI. With so many students now relying on these tools, understanding their effect on our long-term cognition matters more than ever.

None of this means abandoning AI altogether; it is a genuinely useful tool. But the effort it saves you now might cost your future more than you think.

Image from Wikimedia Commons