Oxford University Press named "brain rot" its Word of the Year in late 2024 with more than 37,000 people voting.
Usage of "brain rot" had risen 230% in twelve months.
The definition Oxford gave was "the supposed deterioration of a person's mental or intellectual state, especially viewed as the result of overconsumption of material (now particularly online content) considered to be trivial or unchallenging."
(Emphasis on "supposed" is mine).
The term was coined for doomscrolling low-quality content, endless feeds - and it was adopted enthusiastically by those doing the scrolling.
Since then, brain rot has drifted onto AI. The claim is: use AI heavily and your thinking decays. I want to examine the concept a bit more closely.
What research actually shows
The short answer: yes there is something real in the concept of "brain rot", but it's a lot less than the name suggests.
The strongest finding I've seen comes from a study of students published in PNAS (Proceedings of the National Academy of Sciences). The paper is called "Generative AI without guardrails can harm learning: Evidence from high school mathematics"
Students given unrestricted GPT-4 access did better on practice problems while they had access. When the AI was taken away, they scored 17% lower on unaided maths than students who had never had access at all. A version of the tutor built with learning safeguards mostly removed the effect. Better with, worse without, design matters - that's the pattern in one sentence.
"students relying on the technology may underperform when access to AI is subsequently removed, indicating reduced skill acquisition. However, we also find that carefully designed safeguards, especially asking the AI tutor to provide teacher-designed hints instead of giving away answers, can mitigate these negative effects. Our findings highlight the need for thoughtful integration of generative AI in educational settings"
A Microsoft survey of 319 knowledge workers found that the more confidence people placed in AI, the less critical thinking they reported doing themselves - and that their thinking shifted towards checking and overseeing AI output rather than generating ideas.
That's self-reported and correlational, so it can't tell you what causes what. A widely reported MIT experiment measured brain activity while people wrote essays with and without ChatGPT, and found lower engagement and weaker recall in the AI group - suggestive, but it's a small preprint that hasn't been through peer review yet.
And on the flip side: a systematic review of 69 experimental studies found ChatGPT generally improved academic performance and motivation.
The picture is mixed, the effects are task-specific, and nobody has long-term data yet - these tools are too new.
So there is decent evidence that if you stop practising a skill because AI does it for you, your unaided performance on that skill drifts down. There is no evidence that AI use causes broad cognitive decline over years. One of those claims is "use it or lose it". The other is "rot". They are not the same claim.
Why the name bothers me
Rot is something that happens to you. Wood rots in the rain whether it likes it or not. But nothing in those studies describes damage being done to anyone. What they describe is practice that stopped happening. Mental arithmetic faded after calculators. Map-reading faded after GPS.
Nobody's brain rotted; they stopped doing the thing, and the skill did what unpractised skills have always done.
I think this distinction matters a lot. The two framings point to different responses. If AI truly rots your brain, the answer is abstinence and fear. If AI removes practice, the answer is deciding which practice you keep. One of those is useful.
The lazy truth
As usual it's more nuanced and less dramatic than the rage baiters would have you think ("rage bait" is Oxford's word of the year for 2025).
What I see in real life isn't brain decay. It's the temptation because an AI model hands you a plausible answer in five seconds, and the question is whether YOU do the work of judging it - or just accept it and move on.
Accept it often enough and the output gets worse, because unverified AI output is how slop gets made. And your own judgement gets less exercise, because "exercising judging" was the practice - it's right there in the phrase.
I've written before about the Verification Tax - the checking time you have to spend before AI output is safe to use, and the true cost that decides whether an AI workflow is worth it.
This "brain rot" conversation adds a second reason to pay it. Verification isn't just quality control on the machine. It's the remaining place in the workflow where your expertise still gets a workout. Skip the tax and you pay twice: slop now, impaired judgement later. (Maybe "impaired" is too strong here but you get my point)
This is not rot, it's simple laziness - or the age-old human preference for the easy answer. And AI helps make the easy answer very easy.
The fix
The fix is not giving up AI, and anyone telling you that has a different problem with their reasoning. The fix is deliberate practice.
Decide which skills you will not let fade and keep doing some of that work unassisted, on purpose.
Use AI as a sparring partner rather than a ghostwriter: have it attack your reasoning, find the holes in your plan, argue the other side. And on anything that matters, pay the verification tax in full, because that's where your judgement stays sharp.
I prefer the term "cognitive offloading", it's a less catchy name than brain rot admittedly, but feels more accurate to me.
P.S. The framework card is here: Cognitive Offloading - one page, with the Pipeline Problem as its organisational twin.