You want to know something about how bullshit insane our brains are? (2018) | Hacker News Reader

You want to know something about how bullshit insane our brains are? (2018)

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468 pointsTomte255 comments

I have a (thankfully mild) inherited retina disorder. If you read the part about lasers and eye damage it’s basically that, but the “lasers” are faulty genes rather than anything external causing the eye damage. And I can verify that at first my brain did an incredibly good job at error-correcting over it, but in the last couple years it’s finally been able to “peek through”. One day I was hiking and suddenly had black spots in my vision. Then after that I woke up one morning and noticed large black halos in my vision that went away after a couple seconds of being awake. A couple weeks later and I started getting flashing visual artifacts in the edge of my vision.

Which is/was terrifying because I didn’t know this was a multi-decade process I was just becoming aware of and instead assumed that if I just noticed this much visual degradation in a couple weeks then surely I’ll be completely blind in a couple more? Thankfully that’s not how it works, the damage has been increasing at a slow steady constant, it’s just that the processes in place to correct for said damage do a _really_ good job at hiding it, until they don’t, so the rate of degradation seems much worse than it actually is.

That said, please if you notice any new visual artifacts get them checked up on _immediately_, while my case is a slow genetic issue sometimes it’s a detached retina, which can happen for any number of reasons and can usually be reversed quite easily with surgery if caught early. I was “lucky” mine was genetic rather than physical trauma, since I didn’t go see someone until things got noticeably worse.

I have self diagnosed (never saw a doc) Ocular Migraines, and the first time i encountered one it both amazed me and terrified me.

I was working and i noticed something was off with my vision, i couldn't read a label. I went to the bathroom and didn't see anything. I eventually realized i had a large deadspot in my vision that my mind was just... autocompleting. It looked flawless, but then i'd pass my hand slowly infront of the deadspot and there would be this strange artifact. My hand would be missing a finger, or this odd blending with the mirror behind it, etc.

It was like some poorly ML generated object removal. The scary thing was i had several, and had no idea. As i experimented with it further that day i was able to disappear entire vehicles (i wasn't driving thankfully), forklifts, etc.

I've only had ~half a dozen in my lifetime that i'm aware of, but i'm still quite fearful of experiencing one while i'm driving. As i likely would not realize what was wrong with me, immediately.

edit: Oh i should note, as the "migraine" clears, it turns the blindspots into this weird crystalline structure. Kinda like looking through a prism. It's a pretty crazy experience.

I get these as well, it seems very random. I might have one 3 days in a row, and then not have one for 3 months. About 15 minutes before the shimmering happens, I can already feel that something is off with my vision. The shimmer basically moves left to right/right to left until it dissipates in about 30 minutes to 1 hour. It started in high school, and back then the migraines were the absolute worst pain I had ever experienced. Now they are more or less just normal headaches(sometimes no headache at all even).

Have you checked if there's a correlation with caffeine? I get these too, and like one of the other replies to the parent mentioned, in my case it's definitely connected to drinking too much coffee.

I remember a recent-ish study that found a strong correlation at 3 or more (or was it more than 3?) coffees in a day, but was inconclusive below that amount. I don't know what the unit of coffee was (probably standard espresso) and I unfortunately no longer remember the source.

There are a bunch of different triggers though and they vary from person to person. Coffee is one I hear very often. For me, the worst is the combination of at least two of {hunger, dehydration, physical activity}.

Sounds about right, I drink a massive amount of coffee. The weird thing to me is that my routine is pretty consistent, but I get the auras pretty sporadically. I have also heard that dark chocolate can be a trigger, and some other things.

> About 15 minutes before the shimmering happens, I can already feel that something is off with my vision.

I've had only a couple of these in my life, both brought on by stress. For me they've both been preceded by about 15 minutes of a "feeling of impending doom" (which apparently is an actual medical symptom).

I get this kind of thing when I (very rarely) get a migraine. Interestingly, it comes on like 20min before the terrible crushing headache begins.

Migraine rescue medications that target CGRP receptors like Nurtec or Ubrelvy would help with this. They're modern migraine meds and have no side effects for me.

Same for me. It's a useful warning to immediately drop whatever I'm doing, cancel all my plans for the day and find a dark room to hide in.

That said, now that I've found a drug that works extremely well for me, I can often recover in less than an hour and continue my day with only something like a mild hangover. If you haven't already, definitely talk to a doctor and look into migraine-specific medication. They work like magic and the new stuff actually seems pretty safe. I never leave home without an emergency pill in my wallet.

This might sound weird, but I can often stop the headache from happening after getting aura by doing pushups or running on the spot to get some blood/adrenaline flowing and/or drinking a coke (I never drink coke normally). Sometimes it doesn't work, but mostly it does.

It wouldn't hurt to verify that these are harmless by seeing a doctor. It will probably be a 10' examination.

Good point. I'll bring it up on my next visit, though it's been .. boy, 8 years since i had one last? Nevertheless, doesn't hurt to ask on routine visits.

I have this too, when I drink too much coffee.

Back in those days i was quite heavily under sleeping and over coffee'ing, so quite possible. I haven't had an episode in ~8 years, but i also sleep and coffee intentionally these days.

I recently started having these as well. Only found out they were migraines when I asked my doc during an eye exam. Thankfully my eyes are otherwise fine

I have these as well, but what you describe a crystalline structure is there from the start and then it expands to encompass my right side vision before disappearing out of the edge of my eye sight.

If anyone is wondering what this looks like, this video gets quite close: https://youtu.be/qVFIcF9lyk8

That's close to what mine look like, though the crystalline part is much larger and can stretch across my entire vision. It's incredibly disturbing. Thankfully haven't had it in years.

Everyone normally has a small blind spot right off center (it is mentioned near the end in the tweet list), and can hide small objects, if you want to experience the same feeling at a small scale. There is a bright fluorescent bike helmet sitting in front of me right now, and if I close one eye and look slightly to the side it vanishes completely from my sight! Very weird feeling to know something is in my eyesight and cannot see it.

I had the same problem! Surprised to find the diagnosis on HN!

It’s always weird to hear someone describe migraines! I’ve had the exact same experience. At first it’s a weird feeling that I “missed” something, then I have trouble reading, then that sort of bad -ML-object-removal spot shows up with sparkly prism patterns around it. It grows until it’s half of my vision, and by the point I’m normally keeled over in pain if I didn’t take any triptans through that process.

When I was younger and had no idea what triggered them, I’d also get pretty bad aphasia and be almost unable to form sentences. It’s really a full-brain experience.

I can totally suggest going to a neurologist. Triptans (either as an autoinjector, or a tablet that dissolves under your tongue) have made a massive impact on my life. They’ve never stopped pain 100%, but I’ve come out of that aura long enough to get home.

I love your comparison with bad ML image inpainting. Not only does it kind of look like that, but it also feels like it. The picture looks fine until you focus on that one bit and it turns out there's no real information there. It's very hard to fully covey it to someone who hasn't experienced it, but this plus what happens when you look into a very bright light comes close.

It would be really interesting to look at different scenes and patterns to see how my brain reconstruct it, if it weren't for the crushing headache that I know will follow in 10-30 minutes from the first sign and wipe me out for at least the rest of the day.

Sounds like a scintillating scotoma. It's a kind of migraine that sometimes preceeds, or comes with or without the headache usually associated with migraine. I get them occasionally. Definitely don't want to be driving when it happens.

https://en.wikipedia.org/wiki/Scintillating_scotoma https://duckduckgo.com/?t=ffab&q=scintillating+scotoma&iax=i...

My migraines start this way then all that visual stuff stops and I get a killer headache following it. Thankfully I’m getting less and less of them as I get older.

I had these off and on over the years, and they somewhat seemed associated with stress, lack of sleep, to much/to little coffee etc, but recently they became more and more frequent. To the point of having them every couple of days. However, getting eyeglasses has dramatically reduced the occurrence.

I hadn't notice I needed eyeglasses, I could see things just fine, but apparently one eye is quite a bit worse than the other, and my brain was just doing some extra processing and making everything look OK. Eye doctor speculated that this extra processing was the cause of the ocular migraines.

Now, whenever I start looking a screen to program or whatever without my glasses, I can start feeling the impending tension building towards a migraine, and unless I put them on, will almost inevitability get the whole ocular migraine experience, and be useless for the rest of the day.

That reminds me a bit of tinnitus (chronic ringing of the ears).

You expose yourself to loud noises (e.g. at a club or party), damaging your hearing, and afterwards your ears ring for a while. Your brain adjusts and the ringing stops by the next morning, so you think to yourself, "well, this is fine".

Until the day comes that the damage is too much for your brain to compensate, and the ringing never stops.

Wait, is that actually how it works? Makes me sad about my hearing. Not sure how I wrecked it - must have been headphone use at loud volume as a kid.

I have the exact same symptoms you described, holy shit I'm scared. But I already know it's also a genetic issue because my father has this kind of genetic issue...

This is used to a very cool effect in Peter Watts' novel "Blindsight", about an alien species whose brains are so much faster than ours that they notice and exploit this deficiency in ours.

It's also free to read, e.g. at: https://bookmate.com/books/WiShbinL

There is also a audiobook on youtube. https://www.youtube.com/watch?v=_R55gdpgwQQ

Also check your library. I listened to it on Libby.

, as it says in the original post.

https://mobile.twitter.com/Foone/status/1014286291314270208

Many of Peter Watts books and short stories - including Blindsight, and the short story set in the same universe "The Colonel" - are free to read on his website: https://www.rifters.com/real/shorts.htm

There's also a non-free sequel novel - Echopraxia - together making the Firefall series.

Be sure to check out the "Vampire Domestication" multimedia presentation on that page, for some background on the "vampires" in the series.

Be sure to check out the "Vampire Domestication" multimedia presentation on that page, for some background on the "vampires" in the series.

Thank you, that was a fantastic read, really fills in the universe that Blindsight was set it. Here's a direct link to the PDF: https://www.rifters.com/real/shorts/VampireDomestication.pdf

Wow that took a couple of minutes to level set

(the pdf is a talk by the author above - so Inassumed it was a real talk, and it starts with how they started DNA therapy on an autistic child, who then experienced side effects, blood fixations and ... hang on what? This does not sound ethical ... oh look the logos in the images change, "FizerPharm - for the children", FizerPharm - better living for stock holders"

oh ok.

I get it - it's a low cost version of Resident Evil.

But boy it had me for a minute

This is probably the book I loved the most that was an absolute pain to read. I got no pleasure from reading the book but a lot of the concepts and ideas are great. It's just a slog.

I've heard the sequel is good but I've put off reading it for years because I don't want to go through it again.

I enjoyed Blindsight, but I really did not enjoy Echopraxia. It feels like it sort of undoes some of the conclusions in Blindsight. While at the same time failing to do very much with its own conclusions and ideas.

Watts' Freeze Frame Revolution (set in a different universe iirc) feels like a better book to follow up Blindsight with, personally.

Part of the whole point of Blindsight is that the reliability of the narrator is explicitly suspect on a couple of different levels.

The twist of Blindsight is that a fundamental assumption about the nature of intelligence is false. The book takes a very long time setting this up and then it hammers it into both the reader and the protagonist. It seems to be saying, "Hey this is a big deal and you're not going to accept it, so I'm going to shovel it down your throat with a snow plow."

In Echopraxia they have the same idea, but it's trivialized in a blink and you miss it throwaway line and accepted as fact by everyone. I get that the author didn't want to just retread the same ground over and over. However, I feel it's a mistake to trivialize something that a bunch of post human super savants were surprised by.

Will check out Freeze Frame Revolution. Thanks.

Hard same. I ended up spoiling myself on the entire plot and the "big concepts" to justify to myself that it's worth it to go see the execution.

The author watched too many "Cinemasins"-like teardowns/nitpicks of books/movies where characters have a conversation about something that wouldn't happen in real life because they would both know it already (but it's exposition for the audience) and thought "Yes, I will have NONE of that."

SO instead there is absolutely zero exposition or world-building. You're just dropped into a heavy jargon filled environment that has a narrator who refuses to explain any of the terms or concepts (which are frequently VERY interesting once you go read some wikis).

It's a great way to avoid being nitpicked by pedantic nerds, but it's no way to write an enjoyable work of fiction.

I highly disagree.

Peter Watts has lots of explanatory segments, but he uses them for building his world and characters, not for teaching you stuff you can already go learn about in this world.

I'm sorry you don't enjoy his work, but I really like his writing style and have read Blindsight multiple times.

I agree with you, but at the same time. Like, you have to admit that Blindsight is not going to be a book for everyone.

I think the book is fantastic. I've read it at least three times, and I expect that I'm going to read it at least a few more times.

However, I'm not showing it to anyone who hasn't already displayed an appetite for hard scifi.

I recommend Blindsight frequently. It isn't for everyone, but I think there are a wide variety of types of people who would enjoy it, including those who tend to read more non-fiction than fiction. In my opinion, the payoff from that book is high enough that it is worth recommending it to a few people who won't like it.

I also think that people too frequently don't try things because they or someone else thinks they won't like it. I'm a big fan of people pushing their comfort zone and trying new things.

I loved his work. It's a slog to get through. Both those things can be true.

It's not the explanatory segments. It's his entire writing style.

I feel exactly the same as you about the first book, I would say the sequel is actually much more engaging as well. I struggled to finish the first one, and finished the second probably 2x as fast.

Exactly the same here. And the sequel is even worse.

Oh, I thought it was just me being too dumb for that book. Which is a shame, because as a big fan of hard scifi, Blightsight aliens are truly alien. But the prose was so dense and abstract I could not visualise anything the author was trying to convey.

I read it right after attempting to wade through an impenetrable late-career Greg Egan science- textbook-masquerading-as-novel, so it was a breeze in comparison. Haven’t picked up the sequel, though.

I regularly recommend Blindsight here.

It's not an easy read by any means. But the ideas are too good to ignore.

> about an alien species whose brains are so much faster than ours

The reason _why_ they are much faster than ours is fascinating too.

To me, Blindsight is the gold standard for bleak scifi. It gives the same unsettled feeling one gets from watching, say, Alien for the first time.

SPOILERS

But there's a great bit of video/trailer for the book on youtube

https://www.youtube.com/watch?v=VkR2hnXR0SM

Luckily this only applies to vision and not at all to more abstract processes like world views and belief systems...

This will pass the average sarcasm detector I’m sure of it.

:-))))

But after they read your comment people will have always known it was sarcasm.

If it passes the average sarcasm detector then is the average observer any less or more certain sarcasm’s afoot?

Don't worry, it only applies to everyone else's world views and belief systems. Yours are accurate and reliable.

Mine too. In fact, seven years ago I decided to stop moving my eyes. Since then, both my world views AND my vision have been completely reliable.

It doesn't quite land the same way to have to explain it long-form, but...

I remember learning years ago about an experiment some researchers did where they anesthetized some test subjects' eye muscles (don't remember how), bolted them into a frame so their heads couldn't move, and positioned mirrors above that could be moved with a handle.

What this test setup found was that as long as the mirrors were constantly moving (even just a tiny bit), the participants could generally speaking see completely normally. But as soon as the mirrors stopped moving, the participants reported that their vision fairly rapidly went completely grey.

(The ba-dum-tss here is the "completely reliable" in your comment... :D)

I don't think the optic system in the brain is the only aspect that is "change-stimulated". A bit of a pet theory is that a lot of thought processes are quite similar at the low (and not so low) level.

I'm hoping to come across that study at some point, just not sure what to Google.

That sounds like a terrifying experiment!

https://en.wikipedia.org/wiki/Troxler%27s_fading

But my favourite one of these when your vision of something doesn't go away--viewing these test images for a few minutes can alter your visual perception involuntarily for months: https://en.wikipedia.org/wiki/McCollough_effect

Edit: this might be your study, https://doi.org/10.1016/0042-6989(76)90082-1

Edit:

wtf, I didn't know that waking total paralysis was something that's experimented on in humans. It's impossible to search for too, being camouflaged completely by sleep paralysis.

> Before the succinylcholine was administered an arterial tourniquet was placed on the right arm, thus preventing local blood flow and paralysis. This procedure made it possible for JKS to communicate by flexing his hand even during total paralysis.

They found lots of other weird effects when trying to move one's eyes that are partially or fully paralysed, like feeling that the entire world is moving in the wrong direction, being able to see during saccades, and afterwards consciously perceiving an object as being in one direction but reaching somewhere entirely different when trying to touch it.

Wow, thanks for finding that PDF! I would not have had the first clue where to start.

In the Fading section on page 5 there's actually a reference to "An Active Feedback System for Stabilizing Visual Images" (1975, DOI 10.1109/TBME.1972.324155), and going and reading *that* is actually making me question my memory of what I originally took note of - I remember a bit about mirrors, I think there might have been a mention of a person's head being secured, and the part with the handles was my own conjecture (I (again) think that the setup described that the mirrors were moved, but I'm not 100% sure). I'm wondering if this was the study that was being referenced??

Thanks! The linked paper and the reference paper are both extremely interesting *adds to collection*

And it makes total sense that local anesthetic would be used to achieve paralysis, that's one brute force method lol

Troxler's fading is infuriatingly annoying (mumbled in biology's general direction), like the "L R" blind-spot test; while I think need to go stare at the McCollough effect for a bit longer, the test pattern was ever so faintly blue O.o

Here's one from 2011- no mirrors in their method, but they cite a range of other relevant studies

Visual experiences during paralysis. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3232712

(What was that "humor-related task not presented here"? Why even mention it, and in the abstract too? Studying jokes so bad that they had to paralyse their subjects to tell them?)

Ah, the seventies.

> an arterial tourniquet was placed on the right arm, thus preventing local blood flow and paralysis

Don't cells begin to die off in seconds after blood flow stops? Did the researchers wire up an infusion to the arm?

You can do this any time. Just look at one point for a minute or two. It doesn't take very long to set in. I discovered this by myself back in primary school (christ, imagine how boring the lessons must have been).

It's somewhat difficult to avoid moving your gaze involuntarily, but it's ok if your eyes saccade just a tiny bit once in a while, the effect will still work.

Another interesting thing is that while everything fades to gray, if you offset your vision by a tiny bit, you'll see this weird emboss effect, where edges of objects are strengthened. It's hard to explain, but it somehow kinda makes sense to me in terms of an image transformation:

inputImage - troxlersFadingOffset = gray

inputImageWithTranslation - troxlersFadingOffset = edgeDetection

I can confirm this as well, discovered in a similar way. For me I notice objects start to fade into grey in the periphery. Another cool thing is that blinking seems to reset it for just a second or so and then things fade back to grey instantly.

> if you offset your vision by a tiny bit, you'll see this weird emboss effect, where edges of objects are strengthened.

That sounds like an FFMPEG stream with dropped keyframes, where you see a solid image then you see the changed parts of the next scene start moving but only the changed parts. It's the same mechanism in a way.

I've spent time staring as still as I can at things and tthis never happened for me. All I get is pulsating and artifacts like floating "invisible lines"

I know you’re joking, but this effect you described actually is just another trick our brains play to help us survive in the world. We believe that only we are free from this illusion.

I think it is not just plausible but likely that some world views are more accurate than others, and that various techniques/frameworks can provide not overly difficult means to improve one's approach....but, it is also very easy to wind up with a misleading one, often due to unrealized/unrealizable axioms.

Sounds like a false equivalence. The contradiction here is between our physical rendition of a phenomenon (like the image being rendered upside-down on the retina due to optics) and experience. We don't have a physical description of belief systems or philosophical views (nor we can), so I don't see how the sarcastic remark applies to those contexts.

Cognitive biases exist in a variety of contexts. The phenomenon of saccadic masking doesn't imply the existence of those other biases logically, but TheOtherHobbes makes a pertinent generalisation, imo.

Like I briefly mention in another comment, there is a point in claiming that what mind does is precisely to constantly deceive itself, yes. But the original comment sounds like hooking up to some factoids to bulk dismiss religious beliefs and meaning as illusions.

> upside-down on the retina due to optics

This is completely arbitrary when you think about it. Why would the physical orientation of the brain and its inputs necessarily have to have any correlation with anything? You don't expect it to have any meaning whether you plug in an HDMI cable vertically or horizontally, or what direction your RAM chips face. If someone turned your brain sideways or upside down while keeping the "cables" in tact you wouldn't even know it.

Well, there's nothing I disagree with in your statement, but am also not sure how to fit it within the previous exchange. OP was implying that, because there could be cases where the description of a phenomenon contrasts with the direct experience of it (such as the image being "flipped" due to the law of optics), then we are always deceived. I disagree with that characterization because either we say that mind always deceives itself (I can work with that statement) or you can't exclusively point out world views and beliefs, because in those cases we don't have a physical representation to contrast them with, therefore it's a non-sequitur.

I guess it doesn't contradict what you've said, but one of the tweets from the author of the main thread does repeat the cliche that our vision "should" be upside down because of the eye thing, which I've seen repeated a lot.

The idea that the image comes in "upside down" has always seemed incorrect to me. Isn't it more likely that this is essentially a configuration variable that is initialized undefined, and then set correctly based on comparing the input to other systems (inner ear etc.)? Is there any evidence that it is ever set "incorrectly"? i.e. a baby reaching up instead of down for something?

Edit: to clarify, I'm saying I don't see any reason to think anything in the vision system ever "expects" light from the world's up direction to come in at the top of the retina. Surely the developing brain doesn't know what orientation or flip to expect, and the whole system is constructed based on initial inputs. It was never upside-down.

If you wear glasses that invert the image, your eyes will adapt to the image after a few days. There is some information on the Wikipedia page of the guy who discovered it (https://en.wikipedia.org/wiki/George_M._Stratton).

Yes, I know. That's why I called it a configuration variable.

I think it has more to do with the content itself, and the elasticity and adaptability of neural networks. There is no "up" or "down" with inputs. I learned this when working with a machine vision problem. A model will adapt to the orientation or format of a given input. The orientation itself is never a variable, the network simply doesn't care and adapts to it. If you train a model to recognize input in a given orientation, any other orientation will give a high error rate. If you train the model with _every_ orientation, it will be able to classify inputs that are upside down, sideways, mirrored, etc., all relative to the original orientation.

Exactly. There is no "upside-down" unless you train one way and then flip it. So I wish people would stop saying "babies see upside-down at first."

To your point ... FWIW, young kids in cultures where they were carried in all different orientations as infants allegedly would not turn over a picture handed to them "upside down" to look at it - whereas kids who were held more upright as infants would. Presumably the former could make sense of objects in many more orientations. (Somewhat sure this was in Ashely Montegue's treatise on Touch.)

As for 'errors', yes, they are typically signs of trauma or dysfunction along the neurons that go into V1. You can have people that have blindsight or that can't tell faces apart in the upper half of their vision. You can get some pretty tragic stuff.

You can also have glaucoma or other 'typical' diseases of the eye. Things like blindspots from welding or lasers.

The visual system in healthy people is already a bit odd. You have the foveal blindspot, the differing distribution of rods and cones, the unseeing neurons that do light sensation for melanin production, etc.

Really, the whole sensory chain is one giant bag of 'wait, it does that? huh?'

https://en.wikipedia.org/wiki/Riddoch_syndrome

Above comment misplaced?

I had an eye surgery for strabismus when I was 5 or 6. They tightened some of the eye muscles. I was seeing everything rotated initially, and over a few weeks the angle gradually went from about 30 degrees back to zero.

I guess it was because the muscle adjustments resulted in my eyeballs getting rotated.

Sometimes I wish I could just forget about all the bizarre things our bodies do.

Yeah, ditto for glasses that change/remove colors ... after I few days your perception adapts and you see colors normally again.

It all proves how we don't directly see what's coming thru our eyes - we see the mental model that our brain maintains about the outside word, built/updated via what's coming in thru our eyes.

Please hint me to a source on this. I wonder since some time what will happen when you use a VR headset with see-trough cameras and change the color mapping.

Try warm-tinted sunglasses for a few hours - world becomes blue for a minute or two when I take mine off. I thought everyone noticed this at some point. I would be surprised if you couldn't replicate it with a VR headset, although that doesn't sound very comfortable. You would probably also experience a fleeting feeling of hyperrealistic vision, given how low-fi the see-through camera would be compared to your eyes.

I read this a long time ago .. don't remember the specific source. If I google for it I'm finding "The Innsbruck Goggle Experiments", but not sure if this was the same study I've seen before.

https://pubmed.ncbi.nlm.nih.gov/28521154/

http://users.sussex.ac.uk/~ezequiel/AS/Kohler_1962.pdf

What I've always wondered about this is what the experience is like during the transitionary period. Surely it doesn't instantly flip from completely upside-down to completely upright.

Another question I had is could you learn to instantly switch between them? If you alternated between wearing the glasses and not every few days, would the adaptation period shorten each time? Would it eventually become instant? This is usually the case for motor skills e.g. controlling something with an inverted vs. non-inverted axis.

As bit of trivia I’ve had procedure of laser ablation performed on one of my eyes upper edge of retina that detached. I’ve pink cloud from bleeding obfuse botton half of image in that eye for short time.

Rays of light travel in straight lines. Light enters your eye and hits the back of your retina inverted, not just upside down. Left is right. Up is down.

[1] https://www.schoolphysics.co.uk/age11-14/Light/text/Pinhole_...

Right, but how is this any different than a camera? Nobody goes around saying Nikon designed their cameras upside down and then had to hack around the mistake in software. It's just how lenses work.

> Right, but how is this any different than a camera?

The commenter above argues the image isn't upside down.

> Nobody goes around saying Nikon designed their cameras upside down and then had to hack around the mistake in software. It's just how lenses work.

That's an oddly specific statement. A camera inverts an image using any combination of lenses, mirrors, and software. And if you were building an eye, you would be meticulously poring over these implementation details and discussing all your options. Should you revert the image by adding another lens? Or, do an inverse affine transformation? Maybe you can cross the optic nerves so that the brain gets the correct image? Or program a reward function to individual neurons guided by the vestibular system... etc.

The screen you are looking at right now has gone through at least two transformations - due to the physical nature of light. The fact that you can look around and not realize all this is happening is pretty amazing. There are a few leaky abstractions as noted in the twitter thread.

No - if you were creating a lens or sensor you wouldn't even think about the orientation of the image relative to the real world. It's irrelevant - only that the pixels can be read off in an orderly manner. This is even true for analogue processes (but if the method of converting negatives to photos was different I can see it'd be a factor).

Maybe people in this thread are talking past each other but imo I agree with the commenter arguing that the image is ever "upside down", there is no image.

Because our brains form true stereo vision processing which requires two images that are combined into one.

Digital cameras do not do that, it's ho we get our true depth perception among other features.

Yes. It was never upside-down.

The fact the cells are not aligned with our visual representation doesn't mean it's "upside-down". Like you said, it's undefined, and the brain figures out what these cells represent.

There's no flipping going on.

It is upside down in the sense that if you built a lens system like the eye, the image produced would be upside down.

The system evolved that way so it is never set "incorrectly" or "expected" to be the other way.

But that's kind of the point -- the orientation of the image on the retina is irrelevant, unless it's being looked at by a little man sitting right-side-up inside your head.

Fortunately, his eyes have their own set of lenses that flip the image the right way up again.

I've noticed the second hand "freezing" on a quartz watch when I glance at it since I was a kid. When I asked adults about it they didn't understand what I'm talking about and had no explanation at all. Weird, fascinating stuff.

I also played around with this, making seconds go faster or slower.

I understood something glitchy was going on with my perception.

So it is funny to get an explanation.

This is the "stopped-clock illusion", an example of https://en.wikipedia.org/wiki/Chronostasis

Wondering whether watched kettles never boiling is a similar effect, only at a larger scale.

Time as we experience it is an illusion bordering on insanity, actually everything we perceive seems to be such a freaking illusion it's mind boggling the whole thing works at all.

wow this is crazy. I had forgotten until now but, as a child, I remember looking at my watch and when the second hand finally ticked thinking "that was way longer than a second".

Same here. I remember seeing this as a kid and being perplexed, but haven't thought about it until reading it now. This is sooo interesting, I wonder how much stuff like this we have hidden away.

If you can hear the tick, is it misaligned with the motion or does the tick time shift as well?

You know the craziest thing? That experience might vary based on whether you are familiar with the concept of a ticking clock, or not.

Sometimes it's amazing to me that kids trust grownups at all. Those plastic little brains don't filter out dozens or hundreds of things that adults just stopped thinking about because they're so overloaded with other worries. Everything from the sensory, to cultural 'norms' that may not make sense, like casual racism or sexism.

This shows up time and again in media where there are magical creatures that only interact with children. Everything from adults losing the ability to see them (Totoro has two separate classes of invisible creatures), to happenstance (Arrietty is accidentally seen by the boy, because she makes a bad assumption).

Do you think it might be possible for adult humans to simulate the curiosity that young minds are capable of? Perhaps even in short bursts?

I think Michael Pollan might be actively engaged in suggesting some options there...

Ya, psychedelics are certainly "in the neighborhood" of this problem, but I'm thinking quite a bit different scope. Most people would probably think I'm insane for thinking about it in the way I do, as opposed to "Oh, well that's just the way people are, there's nothing you can do!". It's kinda one of those "fish don't realize they are swimming in water" types of things.

I can say that part of my litany on expanding your horizons is that the more things I try to learn, the more I learn about learning. Some skills are a lot like software, or sometimes I feel software should be more like them. But then there are things like tai chi that is just nothing like the intellectual pursuits I’ve occupied myself with. Those are “safe” in some ways that as I get older I see as a trap.

I would sometimes catch the seconds hand of our bathroom clock going backwards - but it only ever happened the moment I looked at it.

Nowadays I know why - the seconds hand would vibrate a bit after every movement, and if my eyes "saw" it going backward for a fraction of a second after focusing on it, the brain would complete that to "yep, it just went back a second".

Ok, I've noticed the same effect with music and yawning. I'm musically inclined and have pretty good rhythm and it seems to me that songs seem to change tempo when I yawn. Maybe the same type of thing is in effect here; my brain is time traveling somehow.

The most verifiable part if you want to check it out yourself:

Look at a mirror (not your phone camera), and look at your eyes. Now move your eyes, and try to see the movement of your own eyes. You can't.

It's amazing how much our brain does in the background to smooth out processing because it can't handle all of the data coming in. This example several others (the one where you look at the center dot and all others disappear - briefly mentioned in this twitter thread also, the one where you stare between two sets of rapidly updating photos of celebrities..but after a few, your brain gives up and just sort of makes them all look like ogres, etc).

Awesome stuff and I will always do every one of these silly things.

This phenomenon made me convinced I was unable to move my eyes as a child. I thought I had some strange condition where I could move my focus without my eyeballs moving.

I remember my elementary school teacher saying "don't roll your eyes at me" and me trying to explain I couldn't move my eyes and her awkwardly going "right..." Then continued to believe it for another few years.

> move my focus without my eyeballs moving

This is a thing!

https://en.wikipedia.org/wiki/Visual_spatial_attention

I discovered this when I accidentally performed an experiment that showed how paying attention to a bright light in my peripheral vision without moving my eyes caused my pupils to constrict. That was after I became aware that my pupil size affected how blurry things were from nearsightedness (the same effect as in cameras).

https://en.wikipedia.org/wiki/Pupillary_light_reflex#Cogniti...

If I get really close to the mirror, so close I can barely focus, look at my dominant eye, then look at the general direction of my non dominant eye, but trying to focus some distant object, I can see it moving.

If you watch your eyes in the mirror and move your head, your eyes appear to do an incredible job of tracking using eye muscles. Are they actually? Or are they actually tracking jerkily and it appears smoothed due to saccadic masking?

Tracking smoothly. Copied from my other comment in this thread:

When you're focusing/tracking something your eyes do a different type of movement called smooth pursuit [0].

To see this in action, look around normally - notice your eyes move and then stop, taking in "still frames".

Next, look at your finger and move your finger around. Notice that your eyes smoothly follow the finger around.

[0]: https://en.wikipedia.org/wiki/Smooth_pursuit

That's cool! I really can't track around the room smoothly, despite "trying" hard to do so! Grr....

Haha yes this has annoyed me since I was a kid!

It is possible to train yourself to do that. I'd suggest starting with the corners of the room, horizontally, where the ceiling meets the wall. Taking your eyes slightly out of focus helps too. You will fail often. The goal is to minimize saccades.

If you are not following a pre-existing "line", it gets exponentially harder.

Thanks for the info. The part about needing catch-up saccades above a certain speed is particularly interesting.

I used to play with this as a kid. I have eye floaters[0] that tend to drift down to the bottom of my eyes, so I would saccade my eyes up to bring them to the center of my vision, then focus on the floaters and smoothly watch them on the way down (which actually just kept them centered since I was matching the tracking rate to their falling speed). I was kind of a weird kid.

[0]: https://en.wikipedia.org/wiki/Floater

I did the same thing in much the same way … So there’s at least two of us mate.

As a follow up, watch someone else doing the same thing. You'll be able to see their eye movements, but not your own.

This fits with (not sure the term) the model of our brains constantly doing projection/simulation. Your consciousness is at the abstract level and the brain projects successive levels of detail, then compares to actual input at the lower levels looking for differences to correct the simulation.

In the abstract this is very similar to how a Kalman filter works. There is a prediction component and a correction, with a (possibly time varying) adjustments for how much weight to give to measurements. The equivalent here would be to simply ignore the measurements when the eyes move since the input will be known to be messy, and just rely on the prediction.

This turns out the be a very effective (and in some ways mathematically optimal) way to process sensor input even in human-engineered systems.

This fits with my personal model of the brain composed of a distributed system made of millions of dumb organisms screaming in coordination to create a bigger, more intelligent being.

Kinda like an ant colony, CUDA and Kubernetes mixed together

> Kinda like an ant colony, CUDA and Kubernetes mixed together

Thanks for the nightmare fuel.

No shit. Excuse me briefly while I go calm down on the demonic spaceship from Event Horizon.

I think the author of these tweets is falling in to a common trap of trying to reverse engineer why our brains do what they do and try to ascribe intent to randomness. Everything our brains do is the product of a billion years of random evolutionary events leading up to a system that does something useful for our survival. Trying to explain how our brain processes "images" like a camera is the first mistake. The universe is a wild cacophony of matter and energy and what we see in our brains is just a rendition of the salient bits of data gathered from that noise. Looking at a second hand on a clock or a mirror was never an evolutionary selector. Neither was seeing infrared or ultraviolet. At least, not for humans.

If you want to compare it to a system, then a neural network is actually pretty apt (no coincidence there). Data goes in, conclusions come out. The mechanism takes thousands of byzantine shortcuts to get from A to B and the result is a small number of egregious blindspots in an otherwise highly efficient system.

Right. We are constantly sampling the environment in small amounts, but we perceive a much larger, more stable and detailed space than we can directly sense in recent moments because our consciousness is based on a simulation integrating a lot of information already gathered.

https://youtu.be/NTnbnw01HHY

For folks who want further info the wikipedia page on this phenomenon is

https://en.wikipedia.org/wiki/Saccadic_masking

Gets hundreds of poor devils to confess to "running somebody over cause i was frozzen up" in court, meanwhile its simply you were driving to fast for your visual system and it made up a plausible story after your drove into a poor guy.

Guilttrip included.

Here be privatpersons posting about how actions must have consequences.

I think that'd be called driving with undue care and attention here in the UK. Generally it's on you when you crash into someone without some super specific exception.

If you want to read more on this though it looks like there's been a study specifically on saccades while driving: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6536025/

https://e-lawresources.co.uk/R-v-Whoolley.php

"The defendant lorry driver, was travelling on the M62 in a queue of slow moving traffic. He suffered a sneezing fit, losing control of his vehicle he knocked into the car in front. This car in turn knocked into the car in front causing a domino effect involving 7 cars. The Magistrates allowed the defence of automatism. The appeal court held that the Magistrates were right to do so and that an attack of sneezing could amount to an involuntary action for the purposes of the defence of non-insane automatism."

Almost ten years ago now I found a site that would help show you all these visual inaccuracies. It was like a more interactive version of the wikipedia article on our blind spot. I haven't been able to find it for years, but it was an awesome exposé into how non-objective our vision is.

If anyone knows of this, please remind me! I've been looking for it for years.

Possibly this: https://michaelbach.de/ot/

Not what I had in mind, but just as good (or maybe better, this has a lot more content)!

I just happened to be reading the article on my tablet at the exact distance needed to make the blind spot test work without needing to adjust.

I've seen the effect before, but this time when I closed one eye, before I moved another muscle, the letter disappeared as completely and instantly as if it was done digitally. I knew what to expect and it was still amazing. A truly "holy shit" moment.

This is just the brain correcting for inputs and it does it all the time.

My friend had a stroke which damage the occipital lobe (vision) and he had an "empty space" there (about 20% of the field of vision).

After a couple years it was gone. It wasn't really gone, it was just "filled in" by the brain to an extent it wasn't noticeable at all.

If you tested them using accurate equipment to see field of vision you could catch it. But if you asked him, there was no "empty" spot any more.

I’ve noticed that the speedometer or rpm gauge can sometimes move erratically when I’m making eye movements while driving. At first I thought the engine or the instruments were broken (I drive a crappy car). Since first reading this thread, it makes sense that’s saccadic masking instead. It’s pretty cool!

Isn’t that the purpose of heads-up displays - to make that eye movement unnecessary?

To an extent it should reduce eye movement, yes. My cheap ass car doesn’t gave that though :’)

The user experience of vision is just great, good engineering all around.

All the bugs start really showing up after 40 years of uptime.

Proof that software doesn't need to be "well-designed" or "clean", it needs to be functional. What you think of as "insane design" is actually just functional design (or polymorphism, depending).

yes exactly! i thought insane design was such a weird way to describe it... the fact that it is functional and emergent means is has a satisfying cleanliness, even if we don't fully understand it yet.

another natural phenomenon that gets me like that is the balance of the innate/adaptive immune systems. the fact it all works on chemical physics (don't know the right word here) just blows my mind in the best way possible.

It's typically human to classify something we've just begun to understand as insane before time and deeper thought yield appreciation and in some cases, awe. Though I may just be describing dunning kruger here.

That being said I don't agree with anything the OP said about these being "ugly hacks". As another poster said, the UX of the visual system is exceptional, we've built no system as elegant or functional.

When you look at eyes and visual system from a systems design perspective they don't look randomly generated, they look purposefully engineered the way they are. Making educated tradeoffs against the limits of physics and organic chemistry.

The craziest thing about this is that it’s effectively an attack vector for any adversary to be active within that time window given it can measure eye movements or predict it. I’ve come across some material that shows some ML/NN stuff was trained on it to validate if it could pass human perception (yes, easily).

There's a pretty common street fighting move of stomping with the forward foot while you throw a punch. An untrained opponent will glance down and you pop them during the saccade. It's even explicitly part of the "proper" technique in some martial arts that allow both hand and foot strikes.

After it gets you a few times you just learn not to look but there's no general defense against the idea I don't think, just specific applications of it.

I'm admittedly having a hard time figuring out practical attacks that could make use of this.

Screen content manipulation (eg a desktop)? Exceedingly unlikely to be the simplest strategy. Real-world manipulation? Not sure what could be achieved.

Hmm, information suggestion (displaying an onscreen message just outside the field of view, and changing it to something else when the user looks at that area of the screen) comes to mind, but that's not really up there either.

Thoughts?

Not all people driving cars look left and right thoroughly before turning (but you can learn! [0]) This already leads to crashes and claims of 'coming out of nowhere'. So, practical attacks could be causing crashes. Could cause anxiety, injury, death, monetary loss, etc

[0]: https://www.portsmouthctc.org.uk/a-fighter-pilots-guide-to-s... (been some past HN discussions, searching for fighter pilot got quite a few)

I’m picturing an automated turret of some kind with the ability to track saccades and aim and track their human target during those periods. Turret is placed in the corner of a room, for example, engineered in a non-obvious shape. The target it’s tracking can move around briefly as the turret continues to track the target and in the meantime it can analyze the situation, maybe even phone home for authorization to fire. The human target would have no idea it’s being aimed at, right?

Could be useful for something like hostage rescue, maybe?

My problem with this is that once we have machines capable of tracking and exploiting saccades, humans have already lost completely and there’s no need for that kind of ability. I feel like our brains are too slow to compete with silicon.

Imagine perhaps exfiltration for any information within a saccade window. That wasn’t lag or a flicker of the imagination. Ghost in the shell relaying exfiltration semaphores.

It’s not just the amazing ways it exploits physical camouflage scenarios but also digital camouflage. It’s the perfect pair to steganography.

My favorite visual trick is the chess board illusion. People straight up think you're lying. Even when you draw a line between the boxes with the color and your eyes adjust in real time, I've had people tell me it's a gif or I'm doing some other trick.

IIRC, it takes time for the brain to synchronize the input of the ears, eyes and other senses. [eg sound reaches one ear before the other. The brain therefore gets two inputs, time shifts them to match, and gives you both sound and location based on the difference in time.] It then does the same to sync all the other senses. It also filters out the vast majority of inputs, so as not to overwhelm you, such as the tension from your socks.

All of which take up to 100th of a second for adults, less for children.

In order to not have a delay (which would totally impair regular actions such as catching a ball), the subconscious constantly sends imaginary scenes to the consciousness of what it expects to be happening in the real world, and updates them as things go along.

So, the clock ticking are not just timed backwards as described in this thread; instead all along you were getting "imagined" reality. In fact, our entire life we are living in a contrived reality, that are being updated with a lag, in the next incoming imaginary scenes.

(I have heard variations of the above from doctors, psychologists and magicians, and have read some articles, but am not actually knowledgeable - would love corrections if I am wrong)

I vaguely remember learning in school that the natives who saw ships arrive across the Atlantic for the first time saw the ships made of clouds because they had never seen anything like it before.

No idea if it was a fact or myth, but it’s always stuck with me that so much of our understanding and what we see is based on what we expect and not on reality.

I suppose a ship with a lot of large, white, billowy sails against a clear blue sky would look a lot like clouds.

Edit: I wonder, though, if native people didn't just use the word "cloud" because they did not have a word for "sail", and that was the closest thing they looked like.

the chicken and the egg, or the thought and the word.

Expectation and also language.

I've read that there are native languages out there with some large number of words for certain shades of color, and no words for other colors. Speakers of the language can very reliably distinguish the colors they have words for with high accuracy, but can't tell the colors they don't have words for apart very well at all.

Maybe because the ships came from over the horizon?

I’m confused how we can do thing like playing sports if our brains are mashing reality this much. How does a batter hit a 90 mph pitch if his vision can be delayed by half a second?

Prediction, operating at the limits of human ability in an extremely limited (but very impressive) application.

When you're focusing/tracking something your eyes do a different type of movement called smooth pursuit [0].

To see this in action, look around normally - notice your eyes move and then stop, taking in "still frames".

Next, look at your finger and move your finger around. Notice that your eyes smoothly follow the finger around.

When the batter is watching the ball, he is similarly tracking it.

[0]: https://en.wikipedia.org/wiki/Smooth_pursuit

To help the batter track the ball, MLB stadiums also have a darker, solid-color region called the "batter's eye" behind the pitcher and center field [0].

It's also why pitchers can't wear white sleeves or use white gloves (e.g., Eddie Butler getting his sleeves cut off before he pitches [1]).

[0] https://en.wikipedia.org/wiki/Batter%27s_eye

[1] https://www.youtube.com/watch?v=UR0nHFTWNnY

If the batter is not looking at the ball at the moment it's leaving the hand I doubt he can hit the ball.

Also as soon as the pitcher starts moving his body the brain probably starts creating all types of predictions of what will happen next.

He probably isn’t moving his eyes, at least not tracking the ball. Presumably his brain is using a basket of other tricks to let him know where the ball is going to be.

There's a range. Maybe his masking is less. Maybe his brain compensates in such ways that it makes it possible. Maybe he's not hitting the pitch, he's hitting where he believes the pitch is going to be.

90mph is 132 feet per second. The distance from the pitching mound to home plate is 60 feet, 6 inches. The ball will take under half a second to travel that distance. I think about 450ms.

The actual swing takes about 150ms. That gives the batter about 300ms total to identify the pitch and decide to swing.

They're basically watching the pitcher and determining where to swing based on the release. Once the bat is in motion, it's up to the baseball gods. That's why batting averages are so low. Even great batters are hitting the ball only about a third of the time.

You can estimate where the ball will pass based on how the pitcher moves their hands, before they have even released it (that's why people swing when you pretend to throw but don't release!)

Maybe that's why it's so important to "focus on the ball"? Vision isn't retroactivity updated if your eyes aren't shifting.

Maybe that's why you have to practice to be good at sports. I couldn't hit a 90 mph ball to save my life.

I read this tweet thread here a couple of years ago, and it was striking how much of our vision is done in the brain rather than the optics, similarly to modern digital cameras.

Since then I was diagnosed with amblyopia - a "lazy eye", which is not misaligned in my case but is simply not recognized properly by the brain. It's corrected easily when you are young, but not in adulthood. Apparently brain plasticity is the problem. The resulting double vision (diplopia) is quite annoying and sometimes debilitating when you are tired - and there is no surgery to fix your brain's learned behaviour.

It's pretty common - get your kids checked. My parents had no idea, and I always thought being "right eyed" was normal.

Apparently there are some promising new treatments for adults using VR headsets.

I've had cataracts since birth. It's a relatively dense area in the middle of my field of view. My brain interpolates information there as well as possible. Because of this I never see a stain. It's funny to spot the bugs in this process though. For example, objects may become visible because of eye movement that were previously invisible because they were completely obscured by cataracts.

You want to know something about how bullshit insane our brains are? (2018) - https://news.ycombinator.com/item?id=29769275 - Jan 2022 (3 comments)

“You want to know something about how bullshit insane our brains are?” (2018) - https://news.ycombinator.com/item?id=23591535 - June 2020 (200 comments)

You want to know something about how bullshit insane our brains are? (2018) - https://news.ycombinator.com/item?id=18850203 - Jan 2019 (12 comments)

You want to know something about how bullshit insane our brains are? - https://news.ycombinator.com/item?id=17724178 - Aug 2018 (2 comments)

This is why driving is the most dangerous activity most people usually do.

Pretty sure driving would be the most dangerous thing most people do without this

I highly doubt that, driving is dangerous because of: ego, technical failures, carelessness, sleep deprivation and other human factors. Probably our visual imperfections are the least important things to blame.

My meaning is that, for example, ego and carelessness are tied into our visual system. People believe they are more attentive and have better reactions than they actually have.

Why? The entire activity is within our simulated expectation of how time works vs how it really works.

To the aliens we are using bumper lanes for time. Like bowling.

It's not just saccades, it is the entire system of vision and all of the approximations that the brain is doing in order to process the information. The twitter thread only goes into a couple things. There is also inattentional blindness, which happens all the time in driving due to distractions.

We are using a system that was grown, trained and optimized for a ~80kg mostly-water biped with full proprioception and 5 senses to move a ~1900kg metal quadruped using only vision and hearing.

A car routinely reaches 120 km/h. The fastest human who ever existed, Usain Bolt, can only sustain a third of that for ~10 seconds.

Anecdata: Just a few days ago I was entering a road after checking really carefully for absence of traffic (I had a heavy trailer attached and knew I needed some more time). Visibility on the left was excellent, but on the right not so much, so I waited for the right side to clear... look left, also clear, great... quickly check right again, still all clear. I was surprised by the car coming from the right honking at me after I entered the lane, because I was 100% sure that it wasn't there before and could not have been "hiding" behind the A-pillar. Maybe they were too fast, but now I think it's realistically possible that my perception tricked me because the glance to the right was too quick. Will definitely adjust the timing for that.

Yes! This is why you need to look twice at everything, esp. at intersections, while also moving your head. If you do a simple glance, your brain will be perfectly happy to show you a nice empty road, ignoring the incoming vehicle that it didn't have time to properly see. (I was actually taught this when I got my motorcycle license.)

Not really, safe driving is not about split second decisions.

Cars have a lot of inertia, at highway speeds, it takes several seconds to stop your car, and your ability to avoid obstacles is limited. Even with instant reactions, it won't make much of a difference, the car can't do better.

So driving is more about planning what you are going to do for the next 10 seconds and making sure nothing bad can happen during that time period, if things are not sure, take defensive action (slow down, ...). In fact, most good drivers don't pay attention to what's just in front of them, they can't do anything about it anyways. Instead, they will continuously focus their attention on what comes next and act accordingly.

I wonder if this explains how I almost never see the minutes click over on a digital clock. I think of how often I check the time, say maybe 1 second at a time staring at the clock, it should at least every now and then be flicking over to the next minute, but it almost never seems to happen while I'm actually looking at it

If you normally glance at the time fir half a second, the switchover only happens every 120th time on average, which is infrequent enough that your brain simply doesn’t expect it in that context. Maybe it then just cuts out that “glitch” in the rare cases it happens.

The experiment whit the clock didn't work for me. I see no noticeable delay when looking back to the second hand. Maybe I do something wrong?

Small anecdote: long ago in my teens I had a period where I didn't sleep for days due to an illness. One of the more freakish thing I experienced was a moment where I was watching television on the couch, stood and walk away but for about a few seconds my vision was frozen. Still seeing a frame of the orientation of me sitting down looking at the tv even though I already had a completely different orientation.

a) I personally find that looking at the second hand just as it clicks into position - so I'm looking at the frozen second hand for a whole second - amplifies the effect for me. So I watch the clock for a bit to observe the seconds passing, then look at the wall while still counting the seconds in sync, then look back right at the start of a tick. Preferably while not really thinking about any of that, and paying attention to my eyes and vision.

b) Wow, that is really interesting, I have questions :) How long was everything frozen for? "A few" = 3, 4, 5 seconds? How did you stand and walk away without crashing into anything (or did you maybe stand up, take one step, and stop)? Were you somehow still able to know where everything was, or did you have to rely entirely on positional memory? Before you got up and you were watching TV, did the TV picture seem to be moving? Also, how did this fix itself? Did your vision switch like a saccade, like the replaced (correct) image was the most normal thing in the world (regardless that it happened late), or was it like waking up, or...?

It admittedly sounds kind of like the vision system went to sleep from exhaustion - then took a couple seconds to boot back up :P

I'm also very curious what the illness was, but it's quite reasonable that's irrelevant to the impact and this phenomena.

a) Your tip actually did make it work. It is really a crazy fun experiment!

b) It was maybe about 4 seconds. I stood up and actually only noticed it one second in. I took one more step just from memory. (Like I would for example walk to the toilet at night without turning the light on). The picture on the tv did not seem to move. It looked like a frozen frame. Yes, after those seconds I saw normal again. It was exactly like a video call that got stuck. Also I kept hearing the conversation on tv.

The illness was 'Lemierre's syndrome'. I had it very bad as doctors couldn't find out what was wrong we with me. Also I should have been in hospital much sooner but that is a whole different story. I could not sleep for an extremely long time because of the symptoms. Also many of my organs where infected. So I was both physically and mentally exhausted. It was not my only weird experience I got because of it. Most notably where the out of sync memories and what I can only describe as 'hallucinations inside memories'. I was not under medication at that time.

Your theory about my vision going to sleep seems very plausible.

a) Cool :) and I definitely agree with the crazy part, I think I remember stumbling on this by chance and not quite being able to sensibly reconcile/accept what was going on in my head (neurologically) lol ("well that's broken engineering, hmph")

b) Thanks for the info - really interesting! By "video call that got stuck" I presume you mean everything just jumped forward, do you remember how you integrated/perceived that? I guess you weren't surprised because there isn't really a "THAT wasn't supposed to happen" intrinsic response for this as it's a behind-the-curtain area there's no need for the brain to anticipate :P

Just read through https://pmj.bmj.com/content/80/944/328... wow you really fell a dozen miles through a can opener there :( I can only imagine trying to sleep dealing with all *that* D: aaagh. (Actually no I can't)

For what it's worth I'd *definitely* read through a long-form run-through of what happened (and it's quite possible that a few doctors might as well given the sparse section on neurological impact in the linked paper), although my curiosity is checked somewhat by empathy. I guess it's a tradeoff between deferring recall/contemplation of stronger impressions and catching the most long-tail/incidental memory fragments at the edges of the mental map - the kind of thing for which there's no wrong decision.

I'm only aware of one other clinically-"interesting" experience involving severe lack of sleep, caused by consuming slightly too much acid: https://www.stilldrinking.org/essays.php (this is the whole article list, everything prefixed with "The Episode" is listed halfway down the page; ctrl+click ftw?). At one point this person describes a moment at an early stage of the everything-falls-apart where he woke up then experienced falling asleep compressed into the span of ~a second while being consciously aware of the process (sounds uncomfortable :v). A bit of a mildly-orthogonal reference but potentially vaguely interesting.

Your mentioning about the TV picture being frozen, that you kept hearing the conversation, and having memories be out of sync and having hallucinations inside them, are also fascinating as well. Generally there is a fundamental separation between focus vs not-focus (trance? or vaguely in that direction) and a mutual distinction between awareness (central point) and daydreaming (drifting). (Might even say "daydreaming" is "map" and "awareness" is "reduce" a la MapReduce.)

It sounds like you were sufficiently exhausted that the crosstalk or general cohesion/interconnection that keeps things (subconsciously?) in lock-step had broken down, so when your vision got poked and woke back up again you were still able to discern that the TV picture had been frozen - thinking about it, it might reasonably be argued that the vision system being asleep is akin to daydreaming (where there is not particularly strong focus, recall, memory, etc), so when it woke up the logical answer (especially factoring in exhaustion) should have been "...wait, I don't know". But it seems the information about the picture being frozen was still being "recorded" in working memory (focus), kinda violating a theoretical distinction between not-focus and focus - or alternatively illustrating an interesting nuance between the frozenness being controlled by one system that was shut down, and awareness and memorization that this was what was going on being run by something else that was still running. The intuitive expectation would be that background crosstalk/interconnection would keep both of those systems activated.

Hmm, followup question that I should have asked before running off with theories: when you say you knew the picture was frozen, presumably you weren't focusing on that, right? I'm guessing you were maybe in some sort of half-asleep "I'm just staring in the direction of the TV and the picture isn't moving and that's perfectly normal" until you went to get up...?

Memories being integrated out of sync sounds like a bit of a delirium thing :(

I've occasionally had moments where I've wondered if something actually happened or if my brain just made it up on the spot. I think the same mechanism sometimes kicks in when I'm dreaming and narrates "and all this happened" by injecting the narration as a false memory of a sequence of things having happened and summary impressions of that. I've very occasionally been recalling the bits and fragments of dreams that make it to the next day and gone "...I... don't think that's exactly how that played out..." and come up with this vague theory of recursion. (I'm trying to figure what shape hole to put "hallucinations inside memories" through and this is all I can think of.)

Wait, do you maybe mean that the memories contained a sort of dynamic, changing, unresolved (ie unstable) component that your brain represented by expressing it visually and tying it into the memory itself? Hmm, that's almost a kind of perceptive synaesthesia!

Thanks again for the reply :)

Try the experiment a few times. It only works if you happen to look right after it changed to the number you see. Eg it changes to :57, 0.1s later you start looking at it, 0.9s later it changes to :58, 1s later it changes to :59. But to you the delay between :57 and :58 will seem noticeably longer than :58 and :59.

If you happen to look at :57 when it's already been on :57 for, say, 0.5s, then it'll change to :58 0.5s later. It might seem like 0.7s to you but you wouldn't have any way to know it was supposed to be 0.5s.

If you prefer blog format, Foone used to put their Twitter threads on their blog here: https://foone.wordpress.com/2019/03/01/the-eyes-have-it/

I've suggested that link be substituted to the HN mods (via email).

> and can even see polarization of light? our good friends the Cephalopods!

I’m sorry what?? That’s possible? That’s incredible. Anyone have any speculation on what that would look like?

This is a question which I don't think anyone can even speculate at. It's similar to the question 'what is it like to be a bat?', [1] or, what might a colour that no one's seen before look like?

Some people (such as myself) like to distinguish between the physical processes that are involved in the biology of (say) sensory perception, and then the phenomenology. The biology involves things like light waves, retinas, neurons, etc. The phenomenology is the "what it's like". The following is a controversial claim for reductive physicalists who believe everything reduces to the physical, but here goes: there is no way to go from the facts about the physical world alone to any statement about the phenomenology.

The problem with answering the question of what that would be like to see polarised light is hopeless. It's so hopeless that if we had two separate species that could "see" the polarisation of light, we would have no way of even telling if the "what it's like" for one of those species is the same as the next. Maybe for one it's similar to how we see colours, and for another it's similar to what it's like for us to hear sounds. Or maybe it's a completely alien kind of phenomenology with analogy to human experience.

The "easy" question is the biology. We can investigate whether an organism's sensory systems are sensitive to the polarisation of light or not, and if it's done via an eye-like organ, then we might say it "sees" light, even if we have no idea if the phenomenology is anything like our vision.

[1] https://en.wikipedia.org/wiki/What_Is_It_Like_to_Be_a_Bat%3F

It seems to be well established that bees see polarized light. For example:

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3049011/

Gamedevs have known for quite some time that theoretical math is too slow to simulate the universe in real time and sometimes this is what works best.

That book recommendation at the end seems really interesting. (edit: I was talking about the SciFi book, Blindsight)

There is a podcast call "You Are Not So Smart" that talks about all the ways our brain tricks us. https://youarenotsosmart.com/podcast/

Dennet's Consciousness Explained doesn't do what the title suggests, but it is great for stuff like this. I think there's at least one section on the brain retroactively time-stamping past events.

I've read about this many times, I don't really believe it.. If I move my gaze quickly from one spot to another I distinctly see the movement as blurry trail..

I'll believe that people ignore it, or do not pay particular attention to it, but I don't believe they _can't_ see it..

It sounds like you might be the exception. I certainly do not see it.

You can become aware of it, or ignore it. Just like you can become aware of your heartbeat, and even influence it.

When I was a kid, I was fascinated with trying to control my heart. Even nearly 40 years later, I’m aware of my heart and it’s beating 24/7 and I can’t turn it off. I’m curious if you maybe did something as a kid that made you hyper-aware of your vision?

It's probably from training it, I was pretty aware of my vision when I was a kid.

You can turn it off, but it only works once.

Everyone’s brain is a little different. It is possible the masking system in your brain is broken.

I know I have a lot of busted mental equipment. :)

If you move your gaze quickly, yes. Just start erratically moving your eyes and it seems your brain can't keep up and everything will be a blur.

But also keep in mind that even when you're looking at a stationary object, your eyes tend to move a lot. If you noticed the blur from tiny movements too, you'd have a very hard time seeing anything. Reading would be quite difficult, for example.

I believe you're wrong about your belief. As a kid I already noticed that, when looking at a watch, there is a chance that the first second takes too long. And my vision always stays sharp during movement, no blurry tails around anything when moving the eyeballs. Even when "looking" for it and making wild eye movements. But I feel like things become a little bit more detailed (left from me is a window, so that might just be the pupils adjusting).

That's not to say that you're lying about what you're seeing; but it is quite possible both perceptions are possible ;-)

I see the blurry trail once my eyes stop somewhere, not while it's moving. Specially if I was looking at a bright object.

I think for these basic universal perception stuff it's much more certain to refrain from thinking your brain is that different. Most likely it's also filling up your expected perception of a trail.

This isn't comparing like with like. You moving your gaze to something else on purpose is not a saccade. Those are unconscious.

Yes, chronostasis is my favorite "evolution hack" (probably thanks to this tweet).

The difference between a designed system and a "grown" one is that the Universe takes what works and discards what doesn't. It doesn't need for the thing to make any sense at all.

Wait, hold on. I somewhat recently discovered I can “see” pulse-width modulation on dimmable LEDs by moving my eyes quickly over the LED and then examining the trail of dashes left by the light.

How does this square with vision being “paused” during the movement?

Vision only seems to be paused briefly. If you repeatedly keep moving your eyes it seems to allow the blurriness through, there's probably a "timeout" mechanism. Probably better strategy to still see something in case your eyes are shaking for a long time for whatever reason than to not see anything

If you are following an object, the saccades routine itself is put on hold and you get more or less continuous eye motion, complete with smooth focus and field-of-view adjustments. I'm doing this for fun when walking alongside slow-rolling cars - the end result occasionally "looks like" a tracking shot straight out of a movie.

Edit: ...OK, field-of-view doesn't vary that much, unless you are Colonel Steve Austin with the telephoto augmentation.

Not following an object - this is the procedure:

1. Put LED at the bottom of vision 2. Look below LED, so now it’s at the top of vision 3. There’s a trail of light for a fraction of a second, seeming to start from the bottom of vision to the top.

I’m not smoothly tracking anything, just looking at one point and then another. I can clearly see the on-off duty cycles, and I’ve been playing with training myself to estimate frequencies with this method.

Hmm. I see something similar when looking quickly at or away from bright text (eg. end credits) on a DLP projector; it will get split into its constituent colors in the direction of my eye's movement. I guess the "double buffering" functionality does not completely shield one from experiencing the interim flashes.

That's what I do as well with tail lights of cars. There is a clear distinction between LED and normal lights: the LED's form a trail of dots.

I can see the color wheels of most projectors[1] by the colored light bleeding out through the ventilation on the side. I only notice it when I'm moving my gaze, stationary the light just blurs into a steady white.

[1] Except the pricier models, either with separate LCDs for three colors, or with very fast color wheels.

Another oddity: You can read text just fine even if everything except one word is blurred. With eye tracking, unblur only the one word in the focus point of the eyes. The area of your sharp vision really is that small.

i find that when i execute a saccadic eye movement while a dlp or similarly color strobed projector image is in view, at the end of the movement i'll see a brief artifact where the colors will briefly separate on certain edges. i've always assumed that this is probably the result of the inhibitory masking lifting with different response times for different rods and cones on the retina.

i suspect this is related to saccadic masking as it does not occur with smooth pursuit movements. (only darts to new targets as opposed to smooth panning)

If this happens every time your eyes move, what happens during REM sleep?

Huh. This is all about the impact on vision as opposed to imagination (or whatever it is that REM does), but that really does pose some interesting questions about long-tail impacts. Mirror neurons come to mind...

You can replicate the analog clock illusion without having to move your eyes. Open https://www.online-stopwatch.com/large-online-clock/ in a new tab and Ctrl+Tab, then Ctrl+Shift+Tab. It may take a few tries, but if you switch at the right time it will look as if the seconds hand freezes for more than a second.

And this is the reason why Elon Musk made a mistake by saying LIDAR was unnecessary for self-driving cars by assuming that cameras could fulfill the role of vision (He used first-principle thinking: our eyes can drive, so why do we need anything more than cameras?). Our eyes and brains do way more than any camera. The part about estimating the size of baseballs depending on one's intention to hit it also shows that our brain takes our intent into consideration when making moves, something no AI/ML-enhanced camera could ever do.

For those who hate Twitter threads as much as I do:

https://threadreaderapp.com/thread/1014267515696922624.html

Thanks

Serious question : why do publishers break down their blog posts into umpteen tweeted microblogs? Do the engagement web algorithms give preference to the number of tweets in a thread? I see this is becoming more of a trend (e.g. https://news.ycombinator.com/item?id=32296873).

If I tweet the 587,287 words of Tolstoy's War & Peace are more people inclined to read it, or at least have it come across their feed?

You jest, but I follow a bot which does this for the complete works of Shakespeare. A larger corpus, though by less than one might guess.

"Please don't complain about tangential annoyances—things like article or website formats, name collisions, or back-button breakage. They're too common to be interesting."

https://news.ycombinator.com/newsguidelines.html

The tone of this is grating. That aside, I don't think this mechanism is all that surprising. Inferring the previous state of things helps you better predict its next state.

Well, it is foone...no offence to them but it's kind of their hallmark

Written as though it's competing for the attention of fourteen-year-olds against meme scrolls, video games and online porn.

> Written as though it's competing for the attention of fourteen-year-olds against meme scrolls, video games and online porn.

Well, technically they are. Only not just teens. Attention spans have gotten shorter; I doubt that many of my friends can make it through that without checking their phone at least once.

That's quite literally the exact context, so yeah.

Archive of thread reader https://archive.ph/RsBpI

A much better way to read this: https://threadreaderapp.com/thread/1014267515696922624.html

Is anyone else bothered by the gratuitous and wrong usage of 'bullshit'?

English is not my mother tongue but bullshit would refer to a lie (horseshit would express disbelief, chickenshit - cowardice, dogshit - awful, etc..) while batshit would refer to something being crazy. Which would also make 'insane' redundant. 'Batshit crazy' would be acceptable as it's most commonly used.

"Batshit" is the measure of insanity. "Bullshit" is a measure of inaccuracy, "chickenshit" is a measure of obscurity, and "holy sheep shit" occurs, as far as I know, only in the film "Repo Man".

"So while I firmly believe we're basically just overgrown biological computers, we're apparently computers programmed by batshit insane drunkards in Visual Basic 5."

This explains... everything.

You want to know how fuckin wiiiiilldddd science is fellow kids?

Title should be changed.

They'll tolerate reading it on twitter?

Reply on news.ycombinator.com