Our Brain on ChatGPT: Dementia Risk and the Future of Our Minds
A recent MIT study, Your Brain on ChatGPT: Accumulation of Cognitive Debt when Using an AI Assistant for Essay Writing Task, has found that relying on ChatGPT for writing dulls our neural networks, memory recall, creativity, and even our sense of ownership over our own work.
The reduction in cognitive load this creates poses serious questions for cognitive health, especially as we age.
We are only just beginning to understand how AI affects our minds. But the early signals are worth paying attention to. Especially if you care about brain health, cognitive longevity, and protecting your ability to think clearly.
This MIT study was interestingly fast-tracked and made media headlines suggesting something concerning: when you use ChatGPT to write essays or do thought-driven tasks for you, your brain quite literally switches off.
And the effects may persist even after you stop using it.
The Study: Groundwork and Key Findings
MIT researchers subjected 54 participants to three writing conditions: Brain‑only (no tools), with a Search Engine, and ChatGPT-assisted across three sessions, then altered conditions in a fourth session (MIT Media Lab).
What the EEG measurements revealed was:
Brain‑only group: Had the strongest brain network connectivity across alpha, beta, delta, and theta bands.
Search Engine group: Moderate engagement.
ChatGPT group: Weakest engagement, indicating under-stimulation of memory, attention, and executive functions (YourStory.com, MIT Media Lab).
They also found the essay content from the ChatGPT group tended to be more homogenous. Participants struggled to quote their own paragraphs. 83% of AI users couldn’t recall even one sentence, compared to almost full recall by the Brain‑only and Search‑Engine users (SciPublicHealthLaw).
In the fourth session, those who’d relied on ChatGPT continued to underperform when writing without assistance. They experienced persistent cognitive “de-skilling.” Whereas, participants who switched from Brain‑only to AI still retained stronger engagement patterns (Science News Today).
Why This Study Matters: Brain Health Isn’t Guaranteed
Currently 1 in 12 Australians aged 65 and over are living with dementia and 2 in 5 individuals aged 90 and above have dementia.
The best protection? Protecting our heart to protect our brain. This involves good blood pressure, cholesterol and diabetes prevention management. Eating a healthy diet, keeping active, sleeping well and staying socially connected.
The other important thing to do is stay mentally active. Lifelong brain activity needs to involve engaging our mind, solving problems, learning new things, and doing the hard mental reps that keep our cognitive pathways firing.
But if we’re outsourcing even basic thinking and we treat AI as a shortcut for writing, analysing, reflecting, then we’re starving our brains of the very challenges that preserve them.
AI is making life more efficient.
But that efficiency can be coming at a cost when it replaces the act of thinking itself.
What This Doesn’t Mean
This isn’t about fear or moral panic. The study isn’t claiming that ChatGPT causes brain damage. It doesn’t show AI leads to dementia. And it’s early research with limits like sample size and duration. It is important to note that the MIT study did not track long-term brain health or neurological decline, It was measuring immediate neural engagement .It is also important to know that dementia risk is influenced by genetics.
But it does point to something important:
The more you let AI think for you, the harder it becomes to think for yourself.
And that’s not just about productivity. It’s about agency. It’s about mental resilience. And over the long term, it’s about preserving your cognitive health in a world that increasingly nudges you to not think.
Use AI Like an Intern. Not a Brain Replacement
There’s a smart way to use tools like ChatGPT.
Treat AI like an intern: helpful, fast, good at drafts and structure. But you need to bring the strategy. You need to frame the question. You need to think critically, ask better prompts, refine what comes back, and decide what matters. And very importantly, question the answers it provides.
Use AI for:
Use AI for low-effort tasks and intentionally engage your own brain for high-value cognitive work.
Brainstorming angles or headlines
Outlining structure or talking points
Speeding up research gathering
Rephrasing or tightening what you've already written
Don’t use AI for:
Crafting the entire message for you
Making key decisions
Replacing your voice or perspective
Skipping the thinking entirely
This isn’t just a productivity principle. It’s a brain health principle.
Final Thought
If we want to protect our ability to think clearly, age well, and stay mentally sharp then we need to be intentional now.
The tools we use shape the minds we keep.
Use AI. But don’t let it use you.
