[HN Gopher] The overfitted brain: Dreams evolved to assist gener...
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The overfitted brain: Dreams evolved to assist generalization
Author : hheikinh
Score : 101 points
Date : 2021-05-18 17:57 UTC (5 hours ago)
(HTM) web link (www.cell.com)
(TXT) w3m dump (www.cell.com)
| pacman2 wrote:
| Oh wow. Cell. Please also see previous dicussion:
| https://news.ycombinator.com/item?id=23956715
|
| I vaguely remember an Indian Paper (or an author with an Indian
| name) that made the same claims and it got destroyed on HN. But
| my memory may fail me.
| klimt wrote:
| It's Cell Patterns, a new open access journal from Cell Press
| that started in April 2021.
| prionassembly wrote:
| Ctrl-F "mania" says something. But on the level of barroom talk
| this sounds like a plausible explanation of the prodromal effects
| of sleep derivation.
| babelfish wrote:
| > Sleep loss, specifically dream loss, leads to an overfitted
| brain that can still memorize and learn but fails to generalize
| appropriately
|
| Curious where this claim came from. Obviously a lack of sleep
| will degrade your day-to-day performance, but I almost never have
| dreams.
| enneff wrote:
| Or you just don't remember them.
| azeirah wrote:
| From what I recall, everybody dreams an approximately equal
| amount of time every night, the only major difference is how
| much of it is forgotten when you wake up.
|
| I wish I recalled (..or saved) the paper, but waking up
| releases a chemical in the brain that makes you actively and
| quickly forget what you just dreamed about.
| quus wrote:
| They talked about this on an episode of Very Bad Wizards
| [deleted]
| dr_dshiv wrote:
| Seems like it isn't the randomization (high entropy) but rather
| the excessively low entropy. Sleeping brains are colder and more
| predictable (due to massive synchronization). REM sleep might be
| described as when our cortex turns on and tries sensemaking all
| the intrinsic oscillations.
| t-writescode wrote:
| 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.
| giantg2 wrote:
| I have too many dreams. It actually sucks since you don't get
| great sleep.
| reificator wrote:
| I have a sleeping disorder and if I wake up and remember having
| a dream I almost always also feel well rested.
| giantg2 wrote:
| I remember 1-3 dreams every night. All my dreams are vivid
| dreams, where I know they are dreams while they are happening
| and I even have some degree of control over the content.
| throw1234651234 wrote:
| Those are "lucid dreams". My experience is that lucid
| dreams do lead to you be tired, probably because we tends
| to wake up after lucid dreams, though we wake up
| momentarily in normal life too, we just don't remember it.
|
| Maybe lucid dreaming overrides the benefits of sleep since
| the mind is actively engaged again.
|
| It's all fascinating, and there are no real answers
| whatsoever.
|
| Also, side questions:
|
| 1. Is your working memory pretty good? What about your IQ?
| 2. How vivid are these dreams and how logically-sequential
| are they? I.e. can you remember a clear chain of events
| from the dream?
| giantg2 wrote:
| That's the term I was looking for.
|
| Memory is good. It used to be even better (I could recite
| important parts of meetings verbatim when I first joined
| my company 9 years ago). I think I'm still above average,
| but I'm not sure how to rule out bias on that.
|
| I've never taken an actual IQ test. When I was 5 my
| verbal/vocabulary skills tested on the level of a normal
| 10 year old. I was curious about IQ in college and took 2
| unofficial tests which turned out very consistent with
| scores of 121 and 124. I don't really see a lot of value
| in IQ tests, even the official ones.
|
| The dreams vary. Some are very detailed. Some might not
| be, or it's just that I don't remember as much detail
| except in the final dream of the night (I sometimes
| remember up to 3 dreams per night). Usually they are
| logical/realistic, but sometimes include unrealistic
| elements (that I know during the dream are unreal). I can
| usually remember the chain of events in the final dream
| of the night very well. I can usually remember the order
| that I had the dreams in too. The earlier dreams I can
| usually remember the high level chain of events for the
| other dreams, but maybe not the smaller details.
|
| Any reason for the questions?
| slfnflctd wrote:
| All I know is my dog sometimes yips in his sleep, and it can be
| fairly loud-- I will forever wonder what he's yipping at, or how
| that behavior could possibly be selected for. Brains are weird.
| tayo42 wrote:
| I thought dreams only happen durring rem and you are paralyzed
| durring rem stages. So you wouldn't be physically reacting to
| anything. I think those movements only happen in other stages
| of sleep
| wpietri wrote:
| What's your source for the paralysis being complete during
| REM and movements happening only during other stages?
|
| That seems suspicious to me given that a) REM is named for
| movement, and b) these mechanisms definitely aren't perfect,
| as things like night terrors and sleepwalking demonstrate.
|
| For what it's worth, the American Kennel Club claims that dog
| motions do happen during REM: "We can't know exactly what
| dogs dream about, but researchers have observed that certain
| breeds of dogs tend to perform breed-specific behavior in
| their sleep when the pons is inactivated. Pointers, for
| instance, point, and English Springer Spaniels exhibit
| flushing behavior during REM sleep."
| https://www.akc.org/expert-advice/lifestyle/why-dog-
| twitch-i...
| tayo42 wrote:
| This is fairly easy to google its pretty basic sleep
| info...
|
| https://www.sciencedaily.com/releases/2012/07/120711131030.
| h...
|
| sleepwalking isn't related to rem stage, most movement
| doesn't occur during rem stages
|
| https://www.mayoclinic.org/diseases-
| conditions/sleepwalking/....
|
| https://www.uofmhealth.org/health-library/hw48331
|
| I don't think its farfetched to guess this applies to other
| mammals
| Zircom wrote:
| Dogs and their ancestor's wolves are pack animals, maybe the
| sleep barking wakes the other pack mates making them more aware
| of their surroundings and better able to defend the pack from
| threats during the night? Maybe even The barking itself helps
| to ward off threats that would otherwise attack a sleeping
| animal.
|
| Is there even anything that preys enough on wolves where enough
| of them are being killed by it that the sleep barking would be
| selected against?
| zuzun wrote:
| I noticed mine seems to have vivid dreams with barking after
| being woken up at night. Interestingly, the paper claims:
|
| > It is notable that approximately 50% to 70% of the time
| subjects report having a dream upon a sudden waking during
| sleep.
| refactor_master wrote:
| It strikes me as rather unintuitive that the brain should be
| generating its own "out-of-distribution" data. It's training
| itself on itself? Compare with an adversarial network, which can
| be composed of two entirely separate entities, whereas the
| biological brain is know to have a lot of "bleed-through", e.g.
| our memories influence our perception and vice versa.
| bpiche wrote:
| Also here
|
| https://news.ycombinator.com/item?id=23956715
|
| https://news.ycombinator.com/item?id=27166536
|
| https://news.ycombinator.com/item?id=23922449
| im3w1l wrote:
| A theory of dreams should imo mention a few things:
|
| * Lucid dreaming. In particular does lucid dreaming prevent the
| generalization benefits?
|
| * Sensory deprivation hallucinations. It would seem this is
| connected to dreams, but is it?
|
| * Tetris effect. It seems that seeing a lot of a given pattern
| primes the brain the brain to look for it everywhere.
| maxrev17 wrote:
| Read something recently theorizing dreams are to prevent the
| visual processing part of the brain from being repurposed when we
| sleep...
| throw1234651234 wrote:
| That's a very interesting hypothesis actually.
| o_p wrote:
| Or sleep is needed to clean the toxins in the brain and dreams
| are just a funny consequence of disconnecting you from the world
| perl4ever wrote:
| Some researchers recently claimed to have determined that the
| fundamental purpose is to remove toxins in the gut. They
| actually caused shortened lifespan in fruit flies by keeping
| them awake and then extended it again by feeding them
| antioxidants. They also observed similar gut changes in mice.
| (hope I'm not overstating it) [1]
|
| Another thread on HN right now is about how creatures without
| brains also sleep, by the way.
|
| I would bet that mental illness in general will eventually be
| traced to the digestive system as well. I just have a gut
| feeling...
|
| [1] Sleep Loss Can Cause Death through Accumulation of Reactive
| Oxygen Species in the Gut Vaccaro, Alexandra et al. Cell,
| Volume 181, Issue 6, 1307
| FailMore wrote:
| For an alternative theory see https://psyarxiv.com/k6trz
| htrp wrote:
| > 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 stimulation every
| night, the brain is able to rescue the generalizability of its
| perceptual and cognitive abilities and increase task performance.
|
| Bit of jump there from randomized/out of sample data to dreams
| are for generalization.
| TaupeRanger wrote:
| Of course it is. But that wouldn't make a very interesting
| hyperbolic headline.
| toxik wrote:
| And if the brain is overfitted, how can it generate out-of-
| distribution samples? Seems like wildly cyclical reasoning.
| boardwaalk wrote:
| How can computers calculate more accurately than the human
| brain but also have PRNGs or even true hardware RNGs?
| DavidSJ wrote:
| The brain is a lot of different components working together.
| Perhaps the bits which do statistical learning are
| functionally distinguishable from the bits which generate
| permutations on the data.
|
| (This is in fact how modern neural network training often
| works: start with a set of 50,000 images, run them through a
| bunch of permutations -- translation, rotation, lighting
| changes, etc. -- and produce a training set of 1 million
| images which yield better generalization when trained
| against.)
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