I remember this paper when it came out a couple months ago. Makes a lot of sense, the use of tools like ChatGPT essentially offshore the thinking processes in your brain. I really like the analogy to time under tension they talk about in https://www.theringer.com/podcasts/plain-english-with-derek-... (they also discuss this study and some of the flaws/results with it)
Like everything else in our life, cognition is "use it or lose it". Oursourcing your decision making and critical thinking to a fancy autocomplete with sycopantic tendencies and incapable of reasoning sure is fun, but as the study found, it has its downsides.
Anybody who has tried to shortcut themselves into a report on something using an LLM, and was then asked to defend the plans contained within it knows that writing is thinking. And if you outsource the writing, you do less thinking and with less thinking there is less understanding. Your mental model is less complete, less comprehensive.
I wouldn't call it "cognitive decline", more "a less deep understanding of the subject".
Try solving bugs from your vibe coded projects... It's pain, you haven't learned anything while you build something. And as a result you don't fully grasp how your creation works.
LLM are tools, but also shortcuts, and humans learn by doing ¯\_(ツ)_/¯
This is pretty obvious to me after using LLMs for various tasks over the past years.
"Studies" like this bite at the ankles of every change in information technology. Victorians thought women reading too many magazines would rot their minds.
Given that AI is literally just words on a monitor just like the rest of the internet, I have a strong prior it's not "reprogram[ming]" anyone's mind, at least not in some manner that, e.g. heavy Reddit use might.
When I'm really using AI, my mind is pushed to its very limits. I'm forced to maintain context that is much more complex than anything I had to keep in working memory pre-AI. But it also feels easier because you don't have to do nearly as much thinking to get every given task done. So maybe I get lazier, not in how much I accomplish, but in how much effort I put forth. So if my previous working intensity applied with AI would let me finish 10x as much work, now I'm content with exerting half as much effort and getting 5x as much work done as my pre-AI self.
1. This is arxiv - before publication or peer review. Grain of salt.[0]
2. 18 participants per cohort
3. 54 participants total
Given the low N and the likelihood that this is drawn from 18-22 year olds attending MIT, one should expect an uphill battle for replication and for generalizability.
Further, they are brain scanning during the experiment, which is an uncomfortable/out-of-the-norm experience, and the object of their study is easy to infer if not directly known by the population (the person being studied using LLM, search tools, or no tools).
> We thus present a study which explores the cognitive cost of using an LLM while performing the task of writing an essay. We chose essay writing as it is a cognitively complex task that engages multiple mental processes while being used as a common tool in schools and in standardized tests of a student's skills. Essay writing places significant demands on working memory,
requiring simultaneous management of multiple cognitive processes. A person writing an essay must juggle both macro-level tasks (organizing ideas, structuring arguments), and micro-level tasks (word choice, grammar, syntax). In order to evaluate cognitive engagement and cognitive load as well as to better understand the brain activations when performing a task of essay writing, we used Electroencephalography (EEG) to measure brain signals of the participants. In addition to using an LLM, we also want to understand and compare the brain activations when performing the same task using classic Internet search and when no tools (neither LLM nor search) are available to the user.
I expect this to replicate trivially. You would too if you had interacted with anybody who started using LLMs more and more recently. You can literally watch the IQs drop like a rock. People who used to be lively debaters now need to ask Grok or ChatGPT before saying anything.
I skimmed the paper and I question the validity of the experiment.
There was a “brain” group who did three sessions of essay writing and on the fourth session, they used ChatGPT. The paper’s authors said during the fourth session, the brain groups EEG was higher than the LLM groups EEG when they also used ChatGPT.
I interpret this as the brain group did things the hard way and when they did things the easy way, their brains were still expecting the same cognitive load.
But isn’t the point of writing an essay is the quality of the essay? The LLM supposedly brain damaged group still produced an essay for session 4 that was graded “high” by both AI and human judges but were faulted for “stood out less” in terms of distance in n-gram usage compared to the other groups? I think this making a mountain out of a very small mole hill.
I tried to see what the hype is about and translated one build system to another using "AI". The result was wrong, bloated and did not work. I then used smaller steps like the prompt geniuses recommend. It was exhausting, still riddled with errors, like a poor version of copy & paste.
Most importantly, I did not remember anything (which is a good thing because half of the output is wrong). I then switched to Stackoverflow etc. instead of the "AI". Suddenly my mental maps worked again, I recalled what I read, programming was fun again, the results were correct and the process much faster.
No, vibe science is not as powerful as to be able to determine "long-term cognitive harm", especially when such "technical wonders" as "measurable through EEG brain scans." are used.
> 83.3% of LLM users were unable to quote even one sentence from the essay they had just written
Not sure why you need to wire EEG up, it's pretty obvious that they simply did _not_ write the essay, LLM did it for them, and likely didn't even read it, so there is no surprise that they don't remember what didn't pass through their own thinking apparatus properly.
The future for humans worries me a lot. What evolutionary pressures will exist to keep us intelligent? We are already seeing IQ drop alarmingly across the world. Now AI comes in from the top rope with the steel chair?
Everyone is different. I don’t have a good grasp on the distribution of HN readers these days but I know for myself as a heavy user of LLMs, I am not sold on this for myself. I am asking more questions than ever. I use it for proof reading and editing. But I can see the risk as a software engineer. I really appreciate tools like cursor, I give it bite size chunks and review. Using tools like Claude code though. It becomes a black box and I no longer feel at the helm of the ship. I could see if you outsourced all thinking to an LLM there can be consequences. That said I am not sold on the paper and suspects it’s mostly hyperbole.
This does not mesh with my personal experience. I find that AI reduces task noise that prevents me from getting in the flow of high level creative/strategic thinking. I can just plan algorithms/models/architectures and very quickly validate, test, iterate and always work at a high level while the AI handles syntax and arcane build processes.
Maybe it's my natural ADHD tendencies, but having that implementation/process noise removed from my workflow has been transformational. I joke about having gone super saiyan, but it's for real. In the last month, I've gotten 3 papers in pre-print ready state, I'm working on a new model architecture that I'm about to test on ARC-AGI, and I've gotten ~20 projects to initial release or very close (several of which concretely advance SOTA).
The gap i see is the definition of "AI use" is not clearly delineated between passive (usage similar to consumption) vs active.
Passive AI use where you let something else think for your will obvious cause cognitive decline.
Active use of AI as a thought partner, and learning as you go yourself seem to feel different.
The issue with studying 18-22 year olds is their prefrontal cortex (a center of logic, will power, focus, reasoning, discipline) is not fully developed until 26. But that probably doesn't matter if the study is trying to make a point about technology.
The art of learning fake information from real could also increase cognitive capacity.
Personally, I don't think you should ever allow the LLM to write for you or to modify / update anything you're writing. You can use it to get feedback when editing, to explore an idea-space, and to find any topical gaps. But write everything yourself! It's just too easy to give in and slowly let the LLM take over your brain.
This article is focused on essay writing, but I swear I've experienced cognitive decline when using AI tools a bit too much to help solve programming-related problems. When dealing with an unfamiliar programming ecosystem it feels so easy and magical to just keep copy / pasting error outputs until the problem is resolved. Previously solving the problem would've taken me longer but I would've also learned a lot more. Then again, LLMs also make it way easier to get started and feel like you're making significant progress, instead of getting stuck at the first hurdle. There's definitely a balance. It requires a lot of willpower to sit with a problem in order to try and work through it rather than praying to the LLM slot machine for an instant solution.
110 comments
[ 4.0 ms ] story [ 69.3 ms ] threadLike everything else in our life, cognition is "use it or lose it". Oursourcing your decision making and critical thinking to a fancy autocomplete with sycopantic tendencies and incapable of reasoning sure is fun, but as the study found, it has its downsides.
I wouldn't call it "cognitive decline", more "a less deep understanding of the subject".
Try solving bugs from your vibe coded projects... It's pain, you haven't learned anything while you build something. And as a result you don't fully grasp how your creation works.
LLM are tools, but also shortcuts, and humans learn by doing ¯\_(ツ)_/¯
This is pretty obvious to me after using LLMs for various tasks over the past years.
> 83.3% of LLM users were unable to quote even one sentence from the essay they had just written.
> In contrast, 88.9% of Search and Brain-only users could quote accurately.
> 0% of LLM users could produce a correct quote, while most Brain-only and Search users could.
Reminds me of my coworkers who have literally no idea what Chat GPT put into their PR from last week.
Given that AI is literally just words on a monitor just like the rest of the internet, I have a strong prior it's not "reprogram[ming]" anyone's mind, at least not in some manner that, e.g. heavy Reddit use might.
https://youtu.be/omYP8IUXQTs?si=SgehtLWjnNho5MR6
But didn’t pocket calculators present the same risk / panic?
Don’t sugarcoat it. Tell us how you really feel.
1. This is arxiv - before publication or peer review. Grain of salt.[0]
2. 18 participants per cohort
3. 54 participants total
Given the low N and the likelihood that this is drawn from 18-22 year olds attending MIT, one should expect an uphill battle for replication and for generalizability.
Further, they are brain scanning during the experiment, which is an uncomfortable/out-of-the-norm experience, and the object of their study is easy to infer if not directly known by the population (the person being studied using LLM, search tools, or no tools).
> We thus present a study which explores the cognitive cost of using an LLM while performing the task of writing an essay. We chose essay writing as it is a cognitively complex task that engages multiple mental processes while being used as a common tool in schools and in standardized tests of a student's skills. Essay writing places significant demands on working memory, requiring simultaneous management of multiple cognitive processes. A person writing an essay must juggle both macro-level tasks (organizing ideas, structuring arguments), and micro-level tasks (word choice, grammar, syntax). In order to evaluate cognitive engagement and cognitive load as well as to better understand the brain activations when performing a task of essay writing, we used Electroencephalography (EEG) to measure brain signals of the participants. In addition to using an LLM, we also want to understand and compare the brain activations when performing the same task using classic Internet search and when no tools (neither LLM nor search) are available to the user.
[0] https://arxiv.org/pdf/2506.08872
There was a “brain” group who did three sessions of essay writing and on the fourth session, they used ChatGPT. The paper’s authors said during the fourth session, the brain groups EEG was higher than the LLM groups EEG when they also used ChatGPT.
I interpret this as the brain group did things the hard way and when they did things the easy way, their brains were still expecting the same cognitive load.
But isn’t the point of writing an essay is the quality of the essay? The LLM supposedly brain damaged group still produced an essay for session 4 that was graded “high” by both AI and human judges but were faulted for “stood out less” in terms of distance in n-gram usage compared to the other groups? I think this making a mountain out of a very small mole hill.
An equally valid conclusion is "People are Lazier at Writing Essays When Provided with LLMs".
Most importantly, I did not remember anything (which is a good thing because half of the output is wrong). I then switched to Stackoverflow etc. instead of the "AI". Suddenly my mental maps worked again, I recalled what I read, programming was fun again, the results were correct and the process much faster.
> 83.3% of LLM users were unable to quote even one sentence from the essay they had just written
Not sure why you need to wire EEG up, it's pretty obvious that they simply did _not_ write the essay, LLM did it for them, and likely didn't even read it, so there is no surprise that they don't remember what didn't pass through their own thinking apparatus properly.
https://www.ncbi.nlm.nih.gov/search/research-news/3283/
Rather than coming up with the right answers?
Maybe it's my natural ADHD tendencies, but having that implementation/process noise removed from my workflow has been transformational. I joke about having gone super saiyan, but it's for real. In the last month, I've gotten 3 papers in pre-print ready state, I'm working on a new model architecture that I'm about to test on ARC-AGI, and I've gotten ~20 projects to initial release or very close (several of which concretely advance SOTA).
Passive AI use where you let something else think for your will obvious cause cognitive decline.
Active use of AI as a thought partner, and learning as you go yourself seem to feel different.
The issue with studying 18-22 year olds is their prefrontal cortex (a center of logic, will power, focus, reasoning, discipline) is not fully developed until 26. But that probably doesn't matter if the study is trying to make a point about technology.
The art of learning fake information from real could also increase cognitive capacity.
This article is focused on essay writing, but I swear I've experienced cognitive decline when using AI tools a bit too much to help solve programming-related problems. When dealing with an unfamiliar programming ecosystem it feels so easy and magical to just keep copy / pasting error outputs until the problem is resolved. Previously solving the problem would've taken me longer but I would've also learned a lot more. Then again, LLMs also make it way easier to get started and feel like you're making significant progress, instead of getting stuck at the first hurdle. There's definitely a balance. It requires a lot of willpower to sit with a problem in order to try and work through it rather than praying to the LLM slot machine for an instant solution.