Watching TikTok and Instagram deactivates the cognitive control network: Study
rathbiotaclan.com224 points by Akasci 2 hours ago
224 points by Akasci 2 hours ago
dlPFC deactivation is observed in a lot of immersive tasks. There are a lot of tasks that do this. Playing video games, as one example https://link.springer.com/chapter/10.1007/4-431-26797-2_11
Interpreting fMRI results like this article does is almost always wrong. Different activities produce different patterns of brain activity. You could put someone in an fMRI machine, have them do virtually any activity, and then write a headline saying that doing that activity turns of key brain regions that are important for something. The trick is that all brain regions are important for something. Having them be less active during a task doesn't imply that it's good or bad. It just shows you which parts of the brain are involved in that task.
This blogspam article isn't great. The study at https://www.sciencedirect.com/science/article/pii/S105381192... has more details, like the fact that those brain regions come online while viewing other less-preferred videos. The results aren't really indicative of anything by themself. It would have been more interesting if they compared to something, like watching a long involved movie or playing video games, but they didn't.
Also this post is coming from a fresh account that only spams links to this blog. Maybe the mods will want to switch the link to the actual study instead: https://www.sciencedirect.com/science/article/pii/S105381192...
I have seen a lot of reports of studies that imply completely different conclusions based upon the same reported data.
This could equally be reported as tiktok puts the mind at ease.
Or tiktok reduces brain activity related to anxiety.
"Related to" is a term that seems to be capable of supporting an unlimited load.
While this podcast episode is not about this particular research, it could have been.
https://www.changetechnically.fyi/2396236/episodes/17378968-...
And that's leaving aside the question of what it would affect. Elasticity/learning? Would it result in forgetting, or losing skill? Apart from the problem that I (and others with me) have with the "area X does Y" school of neuro-cognition, measuring changes in activity does not measure changes in connections, synapses, or tissue.
It is possible that inhibiting certain brain areas for a longer period will change e.g. cognitive skills. There is enough literature on losing skills after inactivity. But this approach can't bridge the gap.
It makes more sense to observer TikTok users' behavior over time. That can give more information about the actual effects, although without nice, colorful blobs.
Only thing I took away from it was, "No wonder the algorithm is the golden goose"
fMRI is incredibly noisy. Mandatory dead salmon study: https://www.wired.com/2009/09/fmrisalmon/
Why only TikTok videos. Other contenders are Instagram reels, Youtube Shorts, Snapchat, etc.
BTW its Social Media as per studies
https://pmc.ncbi.nlm.nih.gov/articles/PMC12329480/
Whole bunch of research,
https://pmc.ncbi.nlm.nih.gov/search/?term=Social+Media
But, my point is its normal Every generation behave differently. We shouldn't judge it even via these studies.
I haven’t read the study, but I’ve read the comments so far.
I wonder if this mechanism is the same mechanism that impacts, say, swipe-focused dating websites, as well? And Twitter feeds with super-short messages. A lot of the most viral modern tech has been bite-sized content feeds of various types.
They are all reward hacking, but tiktok is audiovisual immersion, dating apps are romantic validation and twitter is outrage/information foraging
https://news.ycombinator.com/item?id=16101310 (2018)
> "Matt Mayberry, who works at a California startup called Dopamine Labs, says it's common knowledge in the industry that Instagram exploits this craving by strategically withholding "likes" from certain users. If the photo-sharing app decides you need to use the service more often, it'll show only a fraction of the likes you've received on a given post at first, hoping you'll be disappointed with your haul and check back again in a minute or two."
https://news.ycombinator.com/item?id=28763413 also speaks to this.
(Dopamine Labs is now boundless.ai, only one example, the reward hacking mentioned is everywhere in socials, adult content, sports betting, for reward maxxing)
That's a weird old myth. I don't know why you dug up an old quote from a startup founder pumping his startup from 2018 in The Globe and Mail.
There were investigations into it after that the conclusions was that nobody believed it or could replicate it: https://nymag.com/intelligencer/2018/01/does-instagram-withh...
Either the person was making something up, or he just didn't understand how hyperscale apps work toward eventual consistency rather than having everything propagated the instant you press the button.
Additional citations:
US states accuse Meta of covering up research on teen social media addiction in pivotal trial - https://www.theguardian.com/technology/2026/aug/18/meta-chil... - August 18th, 2026
> Lawyers representing 29 US states have accused Meta of covering up internal research showing Instagram was addictive for teenagers. In a packed courtroom Tuesday, on the opening day of a landmark legal challenge, they said the company knew its products harmed children but hid that information from the public.
> The attorneys general disagree, saying Meta “developed and refined a set of psychologically manipulative” features designed to maximize people’s time on its apps. Those include an infinite scrolling recommendation algorithm, constant notification alerts, thumbs-up “likes” and visual filters for altering one’s image.
> “AGs are in the perfect position to get this done,” he added. “We did it with the tobacco settlement in the 1990s. We did it with the companies behind the opioid crisis. We’ll do it again with Meta.”
Meta and YouTube designed addictive products that harmed young people, jury finds - https://www.theguardian.com/media/2026/mar/25/jury-verdict-u... - March 25th, 2026
Sharpe BT, Spooner RA. Dopamine-scrolling: a modern public health challenge requiring urgent attention. Perspect Public Health. 2025 Jul;145(4):190-191. https://doi.org/10.1177/17579139251331914 Epub 2025 Apr 12. PMID: 40219910; PMCID: PMC12322333.
> This manuscript examines the emerging phenomenon of dopamine-scrolling and its implications for public health, particularly regarding mental wellbeing and digital behaviour patterns. While extensive research exists on Internet addiction, problematic social media use, and doom-scrolling, the authors of this paper identify dopamine-scrolling as a distinct behavioural pattern that warrants specific attention from public health professionals and policymakers.
De D, El Jamal M, Aydemir E, Khera A. Social Media Algorithms and Teen Addiction: Neurophysiological Impact and Ethical Considerations. Cureus. 2025 Jan 8;17(1):e77145. https://doi.org/10.7759/cureus.77145 PMID: 39925596; PMCID: PMC11804976.
> Does it matter how many hours we spend scrolling through Instagram? This article examines the neurobiological impact of prolonged social media use, focusing on how it affects the brain's reward, attention, and emotional regulation systems. Frequent engagement with social media platforms alters dopamine pathways, a critical component in reward processing, fostering dependency analogous to substance addiction. Furthermore, changes in brain activity within the prefrontal cortex and amygdala suggest increased emotional sensitivity and compromised decision-making abilities. The role of artificial intelligence (AI) in this process is significant. AI-driven social media algorithms are designed solely to capture our attention for profit without prioritizing ethical concerns, personalizing content, and enhancing user engagement by continuously tailoring feeds to individual preferences. These adaptive algorithms are designed to maximize screen time, thereby deepening the activation of the brain's reward centers. This cycle of optimized content and heightened engagement accelerates the development of addictive behaviors. The interplay between altered brain physiology and AI-driven content optimization creates a feedback loop that promotes social media addiction among teenagers. This raises significant ethical concerns regarding privacy and the promotion of personalized content. This review article offers a comprehensive and in-depth analysis of the neurophysiological impact of social media on adolescents and the moral concerns governing them. It also provides solutions for ethical social media use and preventing addiction among teenagers.
Addictive potential of social media, explained - https://med.stanford.edu/news/insights/2021/10/addictive-pot... - October 29th, 2021
What Makes TikTok so Addictive?: An Analysis of the Mechanisms Underlying the World’s Latest Social Media Craze - https://sites.brown.edu/publichealthjournal/2021/12/13/tikto... - December 13th, 2021
(I have provided subject matter expertise on this topic to federal policymakers, with peer reviewed citations in all cases, I hope I have helped improve your priors to bring them current)
I think that should be illegal. I don’t know how to legislate it in a way that makes sense and actually accomplishes the goal (or if that’s even possible), but I would support someone trying to figure it out.
Full social media ban, problem solved. There’s no point wasting more time discussing these things when they’re very obviously a large net negative on society.
Might be good to confirm that this is actually happening first :)
Hysteria typically doesn’t lead to particularly good policy
Call your state and federal representatives, it's the only way. Run for office if you have the appetite for it.
It’d be fairly easy to set up an experiment to validate if that were the case.
They definitely all play off emotions and have their own way to tapping into addictive behaviors. Youtube doom scrolling, reading endless reddits, etc. Lots of apps trying to get you hooked.
It's about the same amount of time that attention is given to any focus, most of those are less than a SFV length.
It really makes sense now. Emotional dysregulation comes into play and now I wonder that it's not just me who is quietly angry (at Match Group) all the time while still addicted to swipe based dating apps.
Leetcode became popular along the same time line.
Coincides with GenZ aging into adulthood after being educated in the debunked "3-cueing" or "whole language" reading education model. So far 40 states have pivoted away from it as states that switched first saw reading comprehension improve.
Whole lot of social experimentation without informed consent being put on people by 50+ year olds who run the world and never had to jump through the same thought policing.
Psychiatrist argues Americans have lost their grit for irrational reality we are forced to live in and actually are snowflakes: https://www.theatlantic.com/podcasts/archive/2024/02/how-we-...
You think people in their 50’s run the world? That’s adorable. Meanwhile people are living longer than ever, still going strong in their 80’s. You think they just retired or something?
Eeeh, Leetcode is older. I’m a millenial and it was popular when I was going through - 10ish years earlier.
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I don't think this comment is inline with community guidelines. "Be kind. Don't be snarky. Converse curiously; don't cross-examine. Edit out swipes."
This whole article is about the ills of falloff in brain activity as human agency is hyper normalized; stick to an experiential lane the brain does not further develop or keep active neuron clusters.
Broad sustained exposure being the known mechanism to activate and deactivate "key cognitive brain regions".
Perhaps you should activate more regions via exposure to that which so easily excites your brain due to lack of exposure. Snark won't trigger you so easily then.
It used to be that reading books made you an intellectual. In the age of TikTok and shorts being able to watch a movie for 2 hours makes you an intellectual.
What if I watch a movie in 56 two minute clips while someone extrudes playdoh in the corner?
Plus those shorts are out of order. So it’s gotta take more effort to piece the plot back together, right?
:)
I’d posit that we just puritanically glorify anything perceived as difficult, regardless of the correlation with “intellect.” I’m fine not having the same attention span as people who had to less stuff to do hundreds of years ago.
Watching a 2 hour movie is perceived as difficult?
> I'm fine not having the same attention span as people who had to less stuff to do hundreds of years ago.
Maybe, if we're really generous, there's a reasonable version of this argument that you've failed to adequately communicate here... But it really seems like you're trying to say that a short attention span is a good sign of progress, or something?
I know HN and SV in general has a culty addiction to contrarianism, and it rarely elicits more than an eye roll from me. Framing a short attention span as anything other than a bad thing is wild to me, and I honestly don't know how to respond to something like that (or if my sarcasm detector is off). Do we need scientific studies to show that goldfish brain == bad?
Reading might not make you intellectual, but if you read because you thought it made you intellectual, it definitely made you insufferable.
Headlines like this are tiring because they're always a vast simplification of an epidemic that has a much more complicated series of social and psychological causes than a simple "it turns ur brain off"
Isn't much of all this the modern couch potato and same as many research done being glued to the TV? It's channel surfing.
It's a lot worse. It's like comparing a bow and arrow to an M-16. Yes they both shoot projectiles, but...
The quantity is endless. You can run out of channels, sweep through them a few times, give up, and get bored, while doom scrollers give you an infinite stream of faux-novelty. It's entirely possible to scroll for eternity and never run out of what at least seems, to your limbic system, like information and social stimulation.
The content is generally much lower quality than TV. Even really bad dumb TV is high art compared to a lot of what's on the doom scrollers. It's hyper-optimized for narrow addictiveness and literally nothing else.
There's a closed feedback loop optimization system in place. The site knows you're scrolling. It knows how fast, where you pause, in some cases even where your eyeballs are going. It knows what makes you interact. It knows what you watched before you stopped watching vs what you watched and kept watching. It also has tons of third party data on you and sensor data that often even includes your location. It can optimize its addiction mechanism in a personalized rapid feedback closed loop way that television could never achieve.
It's like a smart drug that tries to keep you hooked. Imagine if the heroin had a learning algorithm that adapted its chemical structure in real time to keep you from quitting and it was powered by fleet-wide learning cross all heroin molecules in the world.
Oh, and only these two social media sites? Or we're only going to headline echo that it is TikTok? Why does this smell like out of control propaganda?
They’re the most popular short content ones?
Write this headline about Mastodon and no one would read it.
Yesterday someone showed a TikTok video where a friend of him was interviewed on the street. The question was, “What is your best fighting stance?”
I found it surprising how little depth the video had
I no longer get there. But when the algorithm gets really curated for me, 30 minutes on Tiktok is a fantastic good time.
I have deleted my Tiktok account 5 times. No longer a user.
Blipverts you say.
I never made that connection, and I am old enough to have seen Max Headroom when it came out. Thank you.
I would like to take this opportunity to state one of my core beliefs: we are all easily programmed meat machines. Accepting this fact is uncomfortable, but important.
Now that is what I call a series ahead of its time! Also saw it as it came out, had totally forgotten about that word.
I was young, and it was like a fever dream. I couldn't believe that was on TV. It was pretty darn subversive.
Like other really good satire it keeps predicting things it wasn’t trying to.
We’re living down to it.
I get the TikTok addiction, but before that it was fb, before that was the tv, before that the newspaper/magazines, before that the books, before that table games etc
I don’t know it seems that regardless of the technology the brain needs dozing off from reality.
You read the newspapers, books, watch a movie: eventually there is an end and you have to do something else
Also, books, TV, board games, newspapers didn’t disappear. So it’s compounded in some ways
I think there is something distinctly unique between dozing off from reality by letting your mind wander or twiddling your thumbs, and scrolling short form video.
Hmm... this doesn't quite add up. Do we have brain scans showing that critical thinking centers of the brain turn off when people read books or play table games?
In my personal experience short form content is easier to get sucked into for hours on end than those other ones and something I’m more likely to regret participating in. (Learning this early I stopped so I’m not the biggest consumer of it and may have an atypical opinion compared to 1-2 billion people actively watching tik tok for hours a day.)
This is just a nonsensically reductive argument.
Reading is obviously healthier than scrolling tiktok.
Exactly, should the "control regions" being deactivated be something that is activated all the time, or is that associated with burnout, or chronic stress?
"It's not that bad, everything was toxic befor so we can continue as if nothing was bad."
They are different categories. Brain rot isn’t an imagined thing and we aren’t confused about where it comes from
Something feels different with the short form, rapid fire stuff, at least to me
The Reddit tier mental gymnastics on display here to avoid any kind of acknowledgement of the dangers of short form video specifically is impressive.
The hyper normalization on technology fueled escapism is the difference.
Everyone had freedom to pick their poison so to speak. Now? All tech and screen based.
Hyper-social normalization always falls apart. It's unnatural; modern human biology evolved for thousands solving problems mostly in isolation. Tech fueled distribution of material goods humans need to survive is great as it removed risk to biology. But social normalization sucks.
Whether the socialized motive is appease gods by living up to scripture, keep a job/build career make money, or validate it just normalizes people and if we all know the same shit, why discuss anything with them? We already know the same shit.
I don’t have tiktok now, but years ago I downloaded it (i think before it was called musically), I used it for a day or two, and I remember after an hour or so of using it I get nauseous like how you might get on a boat, not severe enough to puke but still not comfy that you need to go for a walk or something to feel better. I deleted it and never used it again. And I don’t use any mainstream social media either since all bow have these shorts, if it’s not text based like rss or hn, it will be YouTube on videos at least 20min duration.
The brain is incredibly energy hungry so it evolved to detect situations that don’t require full attention and activates the Default Mode Network. This happens when you’re zoning out to pretty much anything, and indicates that you’re essentially in “low power mode”.
My question here is whether the framing of the content in question “shutting off brain regions” is an honest one compared to what I said above. fMRI is amazing to be sure, but what it tells us is limited.
So without endorsing crap content on any way, I’m very skeptical of this article’s conclusions based on the study in question.
This "low power mode" is a myth, the brain pulls a pretty constant amount of power (about 20% of metabolic energy), and most power isn't consumed by the action potential/neurons firing, but rather in keeping the neuron ready to fire.
And the regions involved in the default mode network are actually some of the metabolically most active regions in the brain, involved in memory consolidation, future simulation, theory of mind, and self-narrative; among other things.
I would postulate that it's even worse than this, given that default mode network activity is proven to be essential for a healthy mind. This is when engage in useful thinking even when we're not "doing anything".
I think screen activity/tiktok keeps us in some kind of purgatory where we can neither fully engage nor fully disengage.
This framing seems like the correct one, but I think that just like being physically sedentary leads to weakness of muscles and joints and health problems, so being mentally sedentary could also lead to a mind that is weakened in the long term, though the weakness could likely be reversed with exposure to exercise.
the article does note:
"The researchers caution against reading the deactivation as evidence of impaired cognitive function. As they put it in the paper, “this deactivation should not be interpreted as a failure of cognitive control capacity.” Instead, the team argues the pattern likely reflects an adaptive shift toward low-effort, automatic processing during passive, low-conflict viewing."
my take: if the study authors could qualify a subject's liked videos, they could qualify a subject's liked activities, and study activation thresholds prior to and post short form content exposure. this would provide a better substrate from which to draw such conclusions.
but I don't need a study to tell me that short form content fries the brain ... it fries my brain!
Today I found out that half my traffic on my apps are coming from bots. I am considering leaving the online world. Its becoming a hostile unpleasant place. This article report only fuels my devotion.
hell yeah it does, feels nice at the end of a long day
Worthwhile to note that “TikTok” here just means the format, not the platform. YouTube has its “shorts”, Facebook, insta, X, et all engage heavily in milking your doom scrolled eyeballs for time and profit.
I uninstalled basically all of these EXCEPT youtube, and that's what I struggle with sometimes now. I find so much great long- and medium-form content on Youtube that I want to keep it around. But I have to admit that I can sometimes fall down a time-wasting rabbit hole with shorts.
The Youtube app now has a "shorts feed limit" under "time management" that will limit your access to the auto-scroll shorts feed to a certain amount per day. Worth checking out!
By putting AI into every product I think Google has made a tactical error on YouTube, since the “summarize it this video” feature is helping me spend far less time watching rage bait political content.
Youtube is the only platform that has the potential to be actually positive for your life, which makes it hard to get rid of.
Yes, they don't even mention TikTok from the actual paper. It's a short form video app they custom created.
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the linked study effectively drills down on aspects of previous work ...
"High-frequency SFV [short form video] use was consistently associated with attentional disruption, reduced executive functioning, and emotional dysregulation."
"Neuroimaging results revealed reduced activation in the Dorsolateral Prefrontal Cortex (DLPFC) and Anterior Cingulate Cortex (ACC) regions ... when participants viewed personalised TikTok videos."
https://www.medrxiv.org/content/10.1101/2025.08.27.25334540v...
"(The ACC) is involved in ... higher-level functions, such as attention allocation, reward anticipation, decision-making, impulse control .. and emotion."
https://en.wikipedia.org/wiki/Anterior_cingulate_cortex
"The DLPFC is ... the highest cortical area that is involved in motor planning, organization and regulation."
https://en.wikipedia.org/wiki/Dorsolateral_prefrontal_cortex
by permitting unlimited short form content and not disallowing child access we are allowing corporations to destroy kids brains. therefore I posit the latest generation has been rendered retarded, which will pose a dire threat to continued stability unless addressed.
Absolutely baffling you’re being downvoted lmao. Social media Astro turfing teams working overtime I guess
see below comment by taurath for another great example of the truth being downvoted
very worrying study, essentially its a digital->neurochemistry chasm crossing substance that uses the 2 senses.
all more reasons to heavily discourage the usage of short form content , we might require regulations against what is essentially an invisible drug that rapidly replicate and distribute itself among the masses.
Full social media ban would be easier and more effective imo. Public spaces would come back to life in no time at all if social media was heavily curtailed or banned entirely. This would be an obvious win for everyone involved outside of the terminally online and corporations benefiting from their lack of self control.
define short form content as anything under an arbitrary time threshold, legislate all online providers of short form content to mandate an arbitrary time limit per day for all users, add a law that parents knowingly allowing children to exceed national daily short form content limits are subject to penalty. seems fairly straightforward. but uh, I guess we could all capitulate to giving corporations our biometric data ...
I don't think it's straightforward at all. What's considered "short form content".
Just video?
Does just audio count?
Does a gif count?
What if I make a website that uploads videos at 1/10th the speed, and the user plays it back 10x faster so it becomes short form?
What if i make a video aggregator website that pulls from multiple different sources so the user gets around the time limit per day per user?
What if users just make multiple accounts?
I don't think we are legally equipped to deal with this at all.
How about anything that tracks the user's behavior and changes its output based on that behavior specific to that user. If I have a table somewhere in my software that identifies a user and references behavior, not intentional settings, just behavior and that is used to determine what the software does. Make that illegal and a lot of problems go away. To me it is this feedback loop that is insidious.
It's fairly obvious what "short form content" is in context of discussions around TikTok, Reels, Shorts etc.
Let me add, it sound very much like 3D-prohibition for guns. The total demonization of anything, because it could be bad, given certain conditions, is a recipe for disaster. As you say, is extremely difficult to define where are the limits, and the extremely hard to apply the limits without screwing over millions.
study each proposed form of short form content regarding impact on cognitive function and select the most destructive forms for legislation.
if you make a website that provides short form content you are subject. why would an aggregator be excluded?
go ahead and let users make multiple accounts. the current, invalid, answer here is biometric provisioning (done not to protect anything but government and corporate interests). personally I don't care if an adult wants to fry their brain, provided that they have been adequately educated as to the extent of what they are doing to themselves. it's why I included the parental proviso, because protection from brain frying is most important during childhood.
LLMs and social media is 500+ PHD behavioral psychologists working together to make you do things at any price so they can make as much money as they can - in fact, if they don't try to make as much money as they can, everyone involved will be fired.
To me this is one of the final forms of our current laissez-faire capitalism - we are literally taking away our own agency in the name of "freedom" (of capitalists to maximize returns).
That’s a bad thing right?
Less brain, no thinking. Me thinks
Shocking that Zhejiang University didn't find this when TikTok was Chinese...