Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

The overfitted brain: Dreams evolved to assist generalization

cell.com

Post reply on HN
Print view View original

51–60 of 83 posts

Re: The overfitted brain: Dreams evolved to assist generalization

#51

Post by tayo42 »

nitrogen wrote: post #50
tayo42 wrote: post #39

Earlier quoted context omitted.

https://www.petmd.com/dog/general-health/do-dogs-dream This suggests that all mammals brain work simmiliar and are paralyzed durring rem. I'm not sure why your bringing up sleepwalking and night terrors, those don't occur durring rem, so it had nothing to do with paralysis disfunctioning And I'm not even sure what point your getting at with your comments? Just demanding sources. I feel like you can Google these thing…

I know someone who sleepwalks their dreams. People are demanding sources because you are claiming "always" when the reality is almost certainly just "usually."

I'm talking about general cases, not disorders. Sleeping walking doesnt occur durring rem, Google it. there's other disorders that allow for movement durring rem. What does disorders have to do with anything?

Re: The overfitted brain: Dreams evolved to assist generalization

#52

Post by canjobear »

toxik wrote: post #25
htrp wrote: post #4

> Notably, the techniques that researchers employ to rescue overfitted artificial neural networks generally involve sampling from an out-of-distribution or randomized dataset. The overfitted brain hypothesis is that the brains of organisms similarly face the challenge of fitting too well to their daily distribution of stimuli, causing overfitting and poor generalization. By hallucinating out-of-distribution sensory s…

And if the brain is overfitted, how can it generate out-of-distribution samples? Seems like wildly cyclical reasoning.

You'd have to posit multiple models in the brain. For example, one which simulates the world (call it the "world model"), and one which determines the best actions to take in the world (call it the "policy"). The policy might be overfit even while the world model is not. In dreaming, you are drawing samples from the world model and using them to train the policy.

Re: The overfitted brain: Dreams evolved to assist generalization

#53

Post by canjobear »

t-writescode wrote: post #18

I find it fascinating how a strong atheistic perspective and premise still tries to ascribe meaning to things. “Evolved to assist” and also most of the comments here that aren’t discussion of noticing animals dreaming.

There's nothing contradictory about using teleological language to describe evolution. Evolution is an algorithm that maximizes fitness in a changing environment over time. It does things "in order to" maximize fitness in the same way that you or a robot might do things "in order to" maximize utility.

Re: The overfitted brain: Dreams evolved to assist generalization

#54

Post by canjobear »

These theories are fun, but has it been shown that dreaming is an essential part of the function of sleep? If you could suppress dreaming but maintain sleep, would organisms still get the same benefit? Maybe what is required is simply a period of inactivity, and dreams are the effect of white noise cascading through the brain during that period.

Re: The overfitted brain: Dreams evolved to assist generalization

#55

Post by wpietri »

tayo42 wrote: post #39
wpietri wrote: post #37

Earlier quoted context omitted.

I'm not saying it isn't the general case. I'm saying it isn't absolute. I also am not saying sleepwalking is part of REM; I'm saying it is an example of how mechanisms for quiescence are not perfect. And since we're talking specifically about your claim about dogs, I'd like the dog reference specifically, please.

https://www.petmd.com/dog/general-health/do-dogs-dream This suggests that all mammals brain work simmiliar and are paralyzed durring rem. I'm not sure why your bringing up sleepwalking and night terrors, those don't occur durring rem, so it had nothing to do with paralysis disfunctioning And I'm not even sure what point your getting at with your comments? Just demanding sources. I feel like you can Google these thing…

I did Google and found a source contradicting your claim, as well as nothing supporting it.

As I've explained, I bring those up as examples that the sleep system is not 100% reliable, so I think it's a mistake to go from the general case of "most motor control is shut down during REM sleep" to "nobody in any species ever twitches during a dream".

Re: The overfitted brain: Dreams evolved to assist generalization

#56

Post by elliekelly »

maxrev17 wrote: post #12

Read something recently theorizing dreams are to prevent the visual processing part of the brain from being repurposed when we sleep...

Can you explain what that means? Being repurposed for what and why would that be something we’ve evolved to avoid?

Re: The overfitted brain: Dreams evolved to assist generalization

#57

Post by wiml »

canjobear wrote: post #54

These theories are fun, but has it been shown that dreaming is an essential part of the function of sleep? If you could suppress dreaming but maintain sleep, would organisms still get the same benefit? Maybe what is required is simply a period of inactivity, and dreams are the effect of white noise cascading through the brain during that period.

From what I remember, all of the phases of sleep are essential — if you suppress any of them, the person becomes unwell (possibly even dies). That includes the REM phase in which we sleep.

I don't know if you can arrange to have healthy REM with zero dreaming, though.

Re: The overfitted brain: Dreams evolved to assist generalization

#58

Post by fennecfoxen »

canjobear wrote: post #52
toxik wrote: post #25

Earlier quoted context omitted.

And if the brain is overfitted, how can it generate out-of-distribution samples? Seems like wildly cyclical reasoning.

You'd have to posit multiple models in the brain. For example, one which simulates the world (call it the "world model"), and one which determines the best actions to take in the world (call it the "policy"). The policy might be overfit even while the world model is not. In dreaming, you are drawing samples from the world model and using them to train the policy.

I can't remember what it was, but I've read something within the past 3 months, possibly on these pages, which very much suggested human cognition being derived from a series of overlapping partial models of the world, similar to what you described (but with more simulation models in that layer)

Re: The overfitted brain: Dreams evolved to assist generalization

#60

Post by tayo42 »

wpietri wrote: post #55
tayo42 wrote: post #39

Earlier quoted context omitted.

https://www.petmd.com/dog/general-health/do-dogs-dream This suggests that all mammals brain work simmiliar and are paralyzed durring rem. I'm not sure why your bringing up sleepwalking and night terrors, those don't occur durring rem, so it had nothing to do with paralysis disfunctioning And I'm not even sure what point your getting at with your comments? Just demanding sources. I feel like you can Google these thing…

I did Google and found a source contradicting your claim, as well as nothing supporting it. As I've explained, I bring those up as examples that the sleep system is not 100% reliable, so I think it's a mistake to go from the general case of "most motor control is shut down during REM sleep" to "nobody in any species ever twitches during a dream".

I think you need to work on your reading comprehension skills because I never said anything like that. Maybe your people interaction skills too. If my initial comment wasn't clear your free to ask for clarification instead of putting words in my mouth.

Ill recap for you, The parent post wonders if his dog is barking at things it dreams about

I join in after remembering that were paralyzed during rem, the stage when we sleep, implying the conclusion its probably just weird movements during other stages of sleep.

You then join in asking for sources about general sleep knowledge, then you actually say you don't know about sleep, your only suspicious, make a wild connection between the word "movement" being part of the acronym REM and so clearly we aren't paralyzed.

Then you make an incorrect conclusion about sleepwalking and night terrors as some point to refuting paralysis during REM. But you don't seem to understand that those don't happen during the REM stage. This point makes no sense, if anything actually strengthens the thing Im wondering about, because there are movements happening during non dream states of sleep.

I then read your post, you seem really confused, so I indulge you in your request for sources with a quick google search because you seem to not even have a general knowledge of sleep.

I'm confused why you latched onto my post, and then started arguing and what point you are arguing. Maybe you need to dream more?

Post reply on HN