[pcrh]

I can't pretend to understand how LLMs work, but I can be sure that anthropomorphizing their functions is not helpful to an objective debate over their abilities.

Does a motor vehicle get "sleep" when it is serviced? When I reboot a computer, is that equivalent to a nap?

[djeastm]

They provide an explanation for using the term "sleep":

> In animals, the transfer from short-term memory to long-term memory is thought to be supported by hippocampal replay [33], especially during sleep [41]; in this phase, short-term hippocampal memories are reactivated and consolidated into cortical synaptic weights. Sleep makes animals unable to respond to external stimuli, suggesting that it must provide enough cognitive benefit to justify this cost [41]. Inspired by these biological processes, we propose a method for transferring context-window memory into persistent weights. When the model’s context window becomes full during inference, the model enters a “sleep” in which it performs multiple forward passes over the accumulated context and recursively updates its fast weights via a learned local rule. As in animal sleep, the model receives no external input tokens during this phase. After consolidation, the context window is cleared, and the model resumes operation with updated fast weights. During training, the model is optimized end-to-end by backpropagating through the entire process to maximize task performance after sleep.

[pcrh]

The function of sleep in animals is largely obscure.

One thing we do know for certain is that it is necessary, it is needed in "dumb" animals as well as in you and I. If an animal can't sleep it will eventually die.

I don't think that applies to the activity described in the OP. Does their LLM "die" if it can't perform the function described?

[bayarearefugee]

> Does their LLM "die" if it can't perform the function described?

If you don't periodically clean the context, an LLM effectively goes insane in terms of outputs.

If the LLM were fully controlling a physical system (like a robot body) that contained it the resulting insanity of an ever-growing, never cleaned context would likely result in some sort of death-like event.

[pcrh]

That's probably the closest analogy posted here.

It's still weak, though. An LLM without constant human input is likely more similar to a bicycle that starts to lose its gyroscopic balance as it moves more slowly, a human can however keep a stationary bicycle upright (while riding it).

[adastra22]

There is a lot that is known about sleep. We don't know everything and there are large gaps in our knowledge, but there is also a lot that we do know. And this research explicitly tried to emulate the things we know that sleep does do. Calling it "sleep" is warranted, imho.

[rendx]

"Despite myriad studies, there is still no consensus on why sleep is needed for survival."

https://www.nature.com/articles/d41586-025-00964-w (2025)

[Earw0rm]

Probably because it evolved very early (like before bilateral symmetry, multi layer body cavity, or kidneys early... maybe even before multicellular animals early) and so has been incorporated as an essential pillar into multiple processes layered on top of that fundamental architecture.

[fc417fc802]

You've merely stated observations about the context and the process that led to it. That doesn't in any way answer the question of what it's actually doing that's so essential.

[DoctorOetker]

I've always assumed its spontaneous specialization of species: leaving the safety of their nest at those times of day when they are the fittest to occupy a niche.

Once energy conserving "sleep time" exists, the genome can postpone or schedule for activity during these times of day, if it turns out to be more effective somehow.

[crabbone]

I think sleep serves multiple functions. For example, anyone who works out in any-what systematic way knows that sleep is essential for muscle grow. You can't skip on sleep if you want to get fitter. And this probably has very little to do with the more sophisticated functionality of the brain, rather it allows for some process in muscle tissue to happen.

So, whether the LLM "dies" in any sense may or may not be important for what "sleep" is defined to be in this article. It's quite possible that sleep also affects endocrine system in animals or hormones etc... and that's what's causing death, not necessarily anything to do with how brain functions.

[ben_w]

> If an animal can't sleep it will eventually die.

Very few animals fail to eventually die even with as much sleep as they want.

But before death, there is a loss of cognitive function from sleep deprivation, and we observe this too with AI whose context windows get too full.

While we don't know very much about sleep, my understanding is that we do have a long list of things that we do during it, we just don't really understand if sleep is necessary for each of them or simply a convenient opportunity for it.

There's lots of things biology does in response to easy-to-detect proxy signals instead of the real thing they care about: Our sensation of needing to breathe more is based on too much carbonic acid in our blood, not lack of oxygen, which is why in general nobody is allowed in an elevator with a liquid nitrogen dewar; Our natural distaste for incest is based on who we grew up with, not our actual DNA; Get too cold and some people suddenly feel warm and want to (and some do) take all their clothes off even though that would just make them hypothermic even faster.

Being asleep may trigger the things we need to get done, but that doesn't mean sleep is *fundamentally* necessary for the things we need to get done. It could be just that it happens to be the way our biochemistry is wired, and we may find some other way to trigger those things.

The quotation given by djeastm would by my guess for what a dream is, and why we have them. But we don't spend all our time asleep, dreaming. And I'd be the first to say that my guess isn't worth much, as I'm not a brain scientist.

[jyounker]

> Being asleep may trigger the things we need to get done, but that doesn't mean sleep is fundamentally necessary for the things we need to get done. It could be just that it happens to be the way our biochemistry is wired, and we may find some other way to trigger those things.

We now have evidence for REM sleep in spiders(1). Our last common ancestor with spiders predates the development of nervous systems. This strongly suggests that sleep (and specifically REM sleep) serves some function important enough that it has independently evolved in both protostomes and dueterostomes. (And probably multiple times within the protostomes, being present in both cephalopods and jumping spiders.)

There may be some commonality in the origin of the ion channels, but I'll lay money that the requirements for sleep are more of a result of general information processing requirements.

(1)https://www.pnas.org/doi/10.1073/pnas.2204754119

[nextaccountic]

> The function of sleep in animals is largely obscure.

This just obscures the conversation IMO. We know a great deal of functions that sleeping performs. We don't know everything. For some reason this prevents us for using this word in a computing context? What do you think about sleep(1) in Unix?

Also..

> Does their LLM "die" if it can't perform the function described?

what "death" means in the context of a computer program?

[palmotea]

> The function of sleep in animals is largely obscure.

Also, there's different kinds/stages of sleep, which probably perform different functions.

For instance, REM may do something like the GP describes, consolidating memories and processing learning. Deep sleep may do something else (I vaguely recall some stage of sleep is used by neurons to clear certain waste products).

[Windchaser]

I don't think it's necessarily correct to think of sleep in terms of "it is necessary for animals or they will die". It might be more useful to think of it as "it was so useful that animals who slept outcompeted all the animals who didn't".

Meaning: it might just provide a big advantage.

I don't want to overextend and assume that any advantage extends to LLMs. That rest-and-recuperate advantage might also extend to LLM-based AIs. Or maybe not, and the rest-and-recuperate is mainly useful for biology-based organisms. But there is some logic to it.

> The function of sleep in animals is largely obscure.

In my understanding, it's well-understood that sleep is used to consolidate and store long-term memories (amongst other functions, like cell and muscle repair). They've found this memory-consolidation-during-sleep even in relatively simple animals like bees.

[pcrh]

Sleep-like states exist in animals with nervous systems with a complexity above that found in flatworms, even snails sleep. Sleep therefore appears to be an essential characteristic of more complex biological nervous systems, i.e. biological computers, should you care to stretch the analogy. The more complex the nervous system, the greater the requirement for sleep.

What is described in the OP is therefore not a specific characteristic of sleep. It may however be a "useful" rhetorical device.

I do however object to the extensive use of such rhetorical tricks in the conversations that surround LLMs. For example, why does a consumer-grade LLM display "thinking" while it is actually sending data from my computer to some datacentre, processing it, and sending the result back? Equally, why does it output human-emotive phrases such as "sorry" when such computation is revealed to be incorrect?

Such rhetorical tricks, and more, likely underlie to a large degree the popularity of LLMs, despite their actual performance being clearly below what the rhetoric implies.

[palmotea]

> I don't think it's necessarily correct to think of sleep in terms of "it is necessary for animals or they will die". It might be more useful to think of it as "it was so useful that animals who slept outcompeted all the animals who didn't".

You're talking about different things: biological necessity and evolutionary benefit.

You can find out about the former by preventing an animal from sleeping (but otherwise provide all other needed things), and seeing if it will eventually die.

[sillysaurusx]

> You can find out about the former by preventing an animal from sleeping (but otherwise provide all other needed things), and seeing if it will eventually die.

That is actually almost impossible to do. The rat study was as close as we’ve ever come, and it’s still debated whether the rats died due to lack of sleep or some other mechanism, since the autopsy couldn’t confirm a cause of death. (It could have been due to the way the experiment ran, for example, not the lack of sleep.)

[michaelmrose]

What about fatal familial insomnia in humans

[naasking]

> Does their LLM "die" if it can't perform the function described?

It dies in terms of usefulness if it can't stay up to date with new knowledge. That is, it will no longer be used and thus effectively die off.

[exe34]

LLMs also don't mate, but we can still talk about how they remember or forget things. The meaning of words change. Some of those changes are useful.

[libria]

Is a volcano described as dormant (dormire, literally sleep) also inaccurate and deeply problematic? BTW, it's not anthropomorphized as sleep has existed long before humans.

"Sleep" is just used in their context to describe a non-interactive mode and they didn't lean heavily into zoomorphic - I think you mean - parallels.

You're grinding an axe on a single term. What is your broader hangup with them using the term "sleep"?

> Does their LLM "die" if it can't perform the function described?

We're reaching an age where LMGTFY should now be Let Me LLM That For You. Have you tried asking an LLM this question about the article? I believe it answers it very well.

[sillysaurusx]

> If an animal can't sleep it will eventually die.

That turns out to be un-settled science. No human has ever died from lack of sleep.

People point to “fatal familial insomnia” as a counterexample. But they die to the disease, not the lack of sleep.

In a series of controlled experiments, rats and fruit flies did die from lack of sleep. But no one has yet proven that it holds true for vertebrates except for rats.

In other words, it could be true that “among vertebrates, only rats die of sleep deprivation.”

So “if an animal can’t sleep, it will eventually die” is actually quite hard to prove, and depending on how you look at it, somewhat easy to disprove by the fact that rats and fruit flies were so difficult to kill from sleep depravation alone.

Personally I’m skeptical of the rat study too. Claude amends this:

> What they did not establish: the mechanism. On autopsy, “no anatomical cause of death was identified.” The rats showed weight loss despite eating more, body temperature problems, and skin lesions, but nothing that pointed to a clean cause. So no, they could not say a rat “died from sleep deprivation alone” in the sense of identifying what sleep loss did to the body to kill it. They showed a strong association under tight controls, not a proven causal pathway.

[dijit]

> No human has ever died from lack of sleep.

As far as I understand it, there is a disease that destroys your brain's ability to produce sleep. Once you have it, you suffer total, progressive insomnia and die within roughly 6–18 months. Scientists debate whether it's the underlying brain damage or the sleeplessness itself that causes death, but the two are inseparable in practice, and sleep deprivation is considered the leading candidate.

Separately, the longest anyone has stayed awake under controlled conditions was 11 days, which produced severe cognitive impairment, paranoia, and hallucinations; suggesting the body deteriorates rapidly without sleep.

It's probably not wise to state your original claim as established fact.

[famouswaffles]

Fatal Familial Insomnia is an incredibly rare prion disease that causes widespread neurological destruction. It's not remotely a normal brain that has chosen not to sleep. It's such a highly non-trivial deviation of the brain that we've only identified a few dozen families in the entire planet that suffer from it. At this point, quite a lot of things have already gone wrong in your brain.

There is quite literally no prion disease that isn't fatal.

Sleep does a lot of very important things that we probably wouldn't live long without, but it really is unclear to what extent sleep is necessary for them. If we had enough knowledge, could we trigger all the things sleep does without invoking sleep itself ? Perhaps sleep is just a very convenient mechanism.

[sillysaurusx]

My second paragraph addresses that:

> People point to “fatal familial insomnia” as a counterexample. But they die to the disease, not the lack of sleep.

It’s a prion disease. It’s established fact that they don’t die from the lack of sleep.

[dijit]

Interesting that the scientific debate is settled, because you said so. Researchers who study prion diseases would probably be surprised to hear it.

[hajile]

They no longer accept world records for not sleeping because the record breakers have universally suffered lifelong cognitive damage.

We know more generally that people who get decreased amount of sleep suffer increased rates of physical and mental health issues.

It is not a very big leap from "causes permanent damage" to "enough permanent damage can cause death" and of course, keeping someone awake until they are hurt or killed is deeply unethical, so even if it could be proven in other species, you'd still be here arguing that 'they aren't humans".

[refulgentis]

It’s a bunch of Claude blather, and I love Claude. Just not worth copying over to HN, because the rush to get to a narrow answer to a narrow question elides the meaningful bits, ex. what does happen during sleep deprivation. Has a “not even wrong” air simply because you’re trying to get to true/false on a narrow question then pushing your research assistant to disavow what you’re quote unquote “skeptical” of.

[sillysaurusx]

This is little more than a fancy way of saying “Nu uh.” Such arguments are hardly convincing.

[refulgentis]

I don't understand this post. I can read it, but I don't understand it.

Why do you think I'm arguing something? Again, smacks of Pauli's not even wrong. You're confusing your headspace with everyone else's and rushed to copy pasta an AI you're browbeating into disavowing things you're skeptical of to...win an argument, I guess? Based on this post? Unclear to me what the argument is, or, if I'm understanding correctly, due to the narrow focus while being self-absorbed.

[burnte]

HIV doesn't kill you, but it creates circumstances where other things will. Sleep is the same. You may not die from lack of sleep, but you die from the things it can cause. Effectively there's no difference.

[sillysaurusx]

I’m shocked by how careless everyone here is about their definitions, and their science. Sleep isn’t the same as HIV. It’s in fact so hard to kill something with a lack of sleep that it’s never once been observed in vertebrates outside of one specific rat study, and that rat study couldn’t conclusively identify sleep as the cause of death.

For something so incredibly difficult to do (die from lack of sleep) it’s frankly crazy that most people here are saying it like it’s fact.

[burnte]

> I’m shocked by how careless everyone here is about their definitions, and their science. Sleep isn’t the same as HIV.

I do not believe this analogy really confused you. No one is saying they're the same and you're well aware of that.

As to the factual nature of the argument, I'll let you argue with Harvard Brain Institute, as I have no interest in this debate. https://brain.harvard.edu/hbi_news/why-severe-sleep-deprivat...

[bulbar]

A knife doesn't kill you, what kills you is the blood you lose after you get stabbed.

Lack of sleep doesn't kill you / does kill you in the same sense.

[nkmnz]

I'd probably kill myself after a couple of days without sleep. Would the lack of sleep be the cause of death or the cause of the cause of death?

[selfsimilar]

Bullets don’t kill you, it’s the bleeding that gets you. Wait, no, it’s not the bleeding since you could just put an IV in, it’s the loss of blood pressure. No wait, it’s not the loss of blood pressure since we can reattach severed limbs that have been at 0/0 for hours. It’s the lack of oxygen to the brain and other vital organs. Bullets definitely don’t kill you /s

[ambicapter]

So? You don't need a proven causal pathway to state that a glass heads towards the ground every time you brush it off a table.

[sillysaurusx]

Scientifically you do, otherwise you can’t claim that lack of sleep was the cause of death. It could be an artifact of how the experiment was run, or any number of other factors.

It’s not a small quibble to point out that the central argument (“animals need sleep or they’ll die”) may be mistaken.

[Kaliboy]

This is very interesting to me, I've been sleeping a lot lately.

I'm autistic and just went through massive changes that basically keep locking up my brain and I freeze.

I learned that sleeping helps, even if just 20 minutes. It helps that I can fall asleep "while awake". It's as if I relinquish control of responding to stimuli, which instantly brings so much rest to my mind. It is odd trying to move a limb and the brain basically responds with noop. But it works.

Afterwards I can generally make a decision and perform it.

So in a sense it seems similar to what you describe the model would have to do. I forget short term concerns that overwhelm and refocus on the long term goal.

[order-matters]

but isnt sleep an already defined technical term for significantly reducing power consumption while preserving its state until woken up?

i feel like its confusing to reuse the word for a process that aims to deliberately change state of the machine / process

[raincole]

This is why I object to sleep() from unistd.h. What an anthropomorphizing notion. Didn't early unix programmers understand that a computer isn't a living creature and therefore isn't capable of sleep? They must have been really stupid!

[not_a_bot_4sho]

Some of them were straight up psychopaths too, as evidenced by `kill()` !

[prerok]

Indeed and using SIGKILL is really cruel. At least with SIGTERM the process can say its goodbyes. /j

[famouswaffles]

Anthropomorphization is not inherently wrong, and in some instances, it actually lets you reason better about about complex behavior than whatever convoluted (and often wrong, especially in the case of giant neural networks) mechanistic description one might conjure.

Here the analogy isn't without reason.

[pfdietz]

We shouldn't anthropomorphize LLMs. They hate it when you do that.

[forshaper]

Wason Selection task performance improvements based on social framing suggest that it's easier for us to think about problems when some anthropomorphization is going on. https://www.cep.ucsb.edu/wp-content/uploads/2023/05/Cogadapt...

[DonHopkins]

Is it "Anthropicmorphization" when Claud treats human beings like LLMs?

[sillysaurusx]

Interesting question. Is there an actual term for that? It’s like inverse anthropomorphization, but not quite.

[incognito124]

Mechanomorphisation

[bouncing_bolete]

Dehumanization, assuming this wasn't sarcasm

[gabriela_c]

Feels like we're having a computer world Jane Goodall moment.

[CuriouslyC]

Saying something needs sleep isn't anthropomorphizing, since pretty much all complex living organisms need sleep.

Also, even when something is "specific" to humans, it might not be anthropomorphizing to observe it in something else, it could just be an emergent pattern of high intelligence.

[throw310822]

First, this is not a "debate over the abilities" of LLMs. It's a proposed method to improve their performance, and the authors are free to call it however they think it makes sense.

Second, explicitly avoiding things that sound like anthropomorphisation is equally not helpful- why avoid a metaphor that works?

Third, it's really a pity that this pointless nitpicking is dominating the thread.

[pcrh]

>this pointless nitpicking is dominating the thread.

What is dominating the thread are claims that the LLM operation in question is analogous to the function of sleep in humans. It obviously is not.

The anthropomorphization of LLMs has reached ridiculous proportions. Applying the same standards as used in this field to others would result in claims that laundry machines "hallucinated" that they had had sufficient water when they failed due to the faucet being turned off.

[gchamonlive]

Just like LLM sleep has nothing to do with animal sleep, the neuron in a neural network has nothing to do with an actual neuron, and nobody should pretend they do.

I agree we need to be mindful of our metaphores, but they do help both with inspiration for developing techniques as well as for naming things. The onus of keeping bias in check when using metaphores is on the reader, authors can't really do that for you. However once bias is in check you can have a very productive debate in terms of these namings given that everyone is aware of their ontology.

[ajs1998]

This is the struggle of naming papers. You could stretch definitions and make your own sexy headline or you could be precise and fewer people will read it.

[aaroninsf]

Very much agree that while it is is useful in description of motivation and inspiration,

it is very non-helpful—or worse—to use this language, this way.

One might as well say "need neural plasticity" which is as much an analogy and equally misleading and counterproductive in shaping the right model of the system.

One might even call this pernicious, what it encourages is already a social problem; and it doesn't aid understanding, it confounds it.

[cush]

I think it's interesting that folks are suddenly taking issue with "anthropomorphizing" language used in AI as if we haven't been doing this since the earliest days of computing (see "memory", "child", "parent", etc). It helps folks understand things at the correct level without needing domain knowledge

[ComplexSystems]

That's because the purpose of this article is not to have an objective debate over their abilities at all. Most interesting research in this field isn't. Instead, it's to present a new technique to improve LLM performance, which is much more interesting than (once again) rehashing the philosophy of LLM personhood.

[reaperducer]

Does a motor vehicle get "sleep" when it is serviced?

One of the mayors of New York in the 80's (Koch?) famously doubled the city's bus fleet for zero cost by running them 24 hours, instead of letting them rest at the end of their shifts, as was the previous policy.

[Dusseldorf]

Was it anthropomorphizing computers when they named "memory"? Seems to me like it's more analogizing for the sake of easy understanding. Sure, it's not literally the same exact mechanism, but it's certainly modeled after the biological concept.

[wat10000]

Just from the title, I’m assuming it refers to a period of downtime used to perform some sort of maintenance on the knowledge held by the system.

Clicking through, that’s exactly what it is. Seems like “sleep” is an excellent term to use here.

[lxgr]

If it works, it's called bionics, not anthropomorphization ;)

[skeledrew]

How do you concisely describe a low power state of an entity that processes, whereby when in that state it has little to no reaction to input and it may or may not be performing tasks in that state, for a mixed education audience?

Also keep in mind that most if not all devices with a chip have had a function called "sleep" for many years, without this argument.

[burnte]

> Does a motor vehicle get "sleep" when it is serviced?

That's more like a doctor visit and a workout. The sleep will be the part of the duty cycle when it's not operating.

> When I reboot a computer, is that equivalent to a nap?

Yes, it wakes up completely refreshed and in good working order, usually, and if there's still a problem you know you need a technician.

[eithed]

I assume compacting is the sleep here; so, yes

[colechristensen]

>we study a sleep-like consolidation mechanism in which a model periodically converts recent context into persistent fast weights before clearing its key-value cache

There is a strong, non-trivial connection here between what your brain does in sleep and what they are studying.

You wouldn't object to referring to robot eyes or robot legs.

[motoxpro]

One of the most common functions in programming is sleep(ms). There is wake, heartbeat, handshake, orphan, listen, starve, parent/child, etc.

This is not anything new, its just a word that fits the function.

[FarmerPotato]

>Does a motor vehicle get "sleep" when it is serviced? When I reboot a computer, is that equivalent to a nap?

Do androids dream of electric sheep?

[jonnyasmar]

When the goal of that function is to think (a notoriously human behavior), it's perfectly understandable to anthropomorphize it.

[madibo3156]

I find this annoying too. "Sleep" is okay, but the quippy headlines ("need sleep"—short, snappy and vague) infiltrating journals bother me. I've seen it well before LLMs, but as an example, there is a long list of title snowclones of the famous attention paper: https://github.com/vinayprabhu/X-is-all-you-need.

[tom_]

See also, perhaps: https://news.ycombinator.com/item?id=48273597

[genxy]

Please re-read up to the end of page 2 and then re-ask this question.

[zeckalpha]

Yet this is how "thinking" models got started.

[simonw]

> When I reboot a computer, is that equivalent to a nap?

I mean, you do put your computer into "sleep" mode and then "wake" it.

Analogies are useful. I think we need to learn how to continue to benefit from them despite the risk of anthropomorphication.

[cowlby]

The analogy is helpful, but yes we should be able to “intelligently design” something better than sleep analogues since we’re not constrained by evolution like in humans.

[SR2Z]

Evolution constrains the evolution of human beings, but it's also excellent at discovering elegant designs that work very reliably at a low cost.

Maybe someday we'll understand the way our minds work well enough to design from first principles but until then we've only got one template for how a thinking machine should look.

[lxgr]

We are however constrained by the complexity of any purported solution. That's the bitter lesson, in a nutshell.

At the very least, we know that sleep and dreaming do exist in biological brains. (Doesn't mean any of it is applicable to artificial neural nets, doesn't mean it'll work for our specific architectures etc. etc., but at least the idea requires fewer assumptions than a completely untested novel theory.)

[verisimi]

... and anyway, maybe it was hungry? Or getting the sniffles?