
“You want to know something about how bullshit insane our brains are?” (2018) - notRobot
https://twitter.com/Foone/status/1014267515696922624
======
jonnypotty
So my visual system takes an image and projects it back through time to when I
started moving my eyes to present a consistent image of the world? Or,
alternatively, I have to be perceiving the past as time travel is impossible,
I am living in the past and my visual system can fill in the holes and make it
seem like I'm always perceiving the present.

Why this is presented as bullshit insane I have no idea. It seems like an
amazingly brilliant solution to me, much better than the 'engineering'
solution suggested where your vision flashes black every time you move your
eyes. Also worth mentioning this weirdness is repeated in human consciousness
all the time. Like the theory (tested as far as we can) that tall people
perceiving the world further in the past so they can reconsile nerve impulses
from their feet as happening at the same time as visual stimulus. We've known
about phenomenon like this for a long time as well as other deeper revelations
like, what is sometimes called, the illusion of free will. And yet we
constantly act surprised that our conscious experience of the world doesn't
correlate to what we find out is 'actually' happening.

So we are flawed meat bags with insane, non sensical brain mechanics, if only
our biological solutions were as well thought out as VR eh?

How glad am I that the incredible complexity and subtly of evolution created
my visual system and not Valve or Sony.

~~~
nwienert
Thanks for writing this. While the tweets have great comedic effect, they are
just really stupid.

You could very easily write a whole piece about how elegant and awe
inspiringly complex and effective they are on the exact same subject.

Except it wouldn’t get as many likes and retweets, of course.

Sort of made me sad just thinking about that. Twitter really does encourage
the worst forms of conversation - outrage, sarcasm, cheapness, drunk humor
dominates.

~~~
pmachinery
I wondered after a few posts why it was even on Twitter, and if it had been an
article/blog post there would definitely have been less motivation for the
author to play to the gallery.

> how bullshit insane our brains are

> but OH NO

> this shit works

> your freaking visual system just lied to you about HOW LONG TIME IS

> we're apparently computers programmed by batshit insane drunkards in Visual
> Basic 5

> your brain has EVEN MORE UGLY HACKS

Interminable shtick that just makes subject matter pointlessly longer and more
of a chore to read.

~~~
aeontech
This comes up any time @foone’s content gets posted.

TLDR; that’s authors choice both for stylistic reasons and personal. When the
choice is between “don’t blog at all” and “post on twitter” because that’s
what fits his mind process, I would rather read about it on twitter than not
at all.

Judging by the amount of discussion here, it seems like this was thought
provoking for a number of people despite the format.

I find twitter threads frustrating to follow also, but you could always...
skip clicking the link if you feel so strongly about it.

As an aside, criticizing the form of content rather than the substance is not
of particular interest in general, to be honest. It comes off as “I didn’t
really have anything to say about the subject, but at least I can comment on
perceived flaws in the style of presentation”.

~~~
nwienert
The critique is actually that this stupid YouTuber attention-desperate style
leads to Reddit level discussion. Especially because he just frames the whole
process as being dumb rather than... interesting. So no it’s not just a style
critique, he’s just making wild unfounded claims while trying to frame them as
obvious truths.

If _you_ like that style, then fine, why don’t you just not reply to this
valid sub-thread? I don’t see you adding any to the discussion. But the
discussion of the degradation of our ability to communicate due to social
media incentivizing stupid clickbait _is_ super important.

~~~
aeontech
Apropos of nothing, thanks for your work on Recoil, it’s awesome :)

I don’t think the discussion on this post here is reddit-level - for example,
I found the top level comment on the role of dreams, and the link to the
commenter’s paper on psyarxiv super interesting. As I said in my comment, I
too find the twitter thread format a bit frustrating to read.

What I was trying to say is that the author (Foone) has previously posted
about this - for them, the choice really is between “blog this way or not at
all” due to the way their mind works.

Of course the fact that this topic comes up every time is indicative, but I
think what it indicates is that Twitter UX is terrible, not that the author is
a bad person for choosing to share in this format.

~~~
nwienert
Thanks! I haven’t done much at all, not sure if you’re involved with it but if
so thanks right back, I do love Recoil and its potential.

I definitely should aim my criticism at the incentives more than the people,
that’s a good point. I specifically like HN because it seems to have figured
out pretty nice incentives (of course the lack of scale is the key).

------
FailMore
What you might not know is that your emotions can do this too (create feelings
which feel real but don't match with the reality of a situation, with the
purpose of fulfilling an underlying need of the brain - typically protection).

This is at the heart of mental health - the issue being that imagined feeling
patterns are formed during infancy. During that period you need to maintain
relationships with your caregivers in order to survive (so your feelings
organise around achieving good caregiver conditions). However when you are in
the wider world as an adolescent/adult things are very different (1. don't
need your caregivers to survive and 2. the rest of the world doesn't act the
same way that your caregivers do) and that's when things get bad-mental-
healthy. Your brain is imagining feelings to satisfy a different environment
to the one you are in.

Even more amazingly the brain knows it does this and has a built in correction
mechanism - dreams. They don't auto correct, but provide instructions (if we
listened). This isn't the Freudian-everything-is-a-penis/vagina vibe, but a
much more practical route to using dreams to diagnose false feelings. I wrote
a paper on this here: [https://psyarxiv.com/k6trz](https://psyarxiv.com/k6trz)

When you have spotted a false feeling it's very easy to get rid of it. You
have to catch yourself repeating the pattern and break it. Do that a few times
and your brain reconsolidates and no longer feels the inaccurate feeling as it
understands that the survival function of it is no longer required.

~~~
pier25
> _You have to catch yourself repeating the pattern and break it_

How do you recommend doing that?

~~~
FailMore
A therapist is very useful. It is difficult to see yourself clearly from the
inside out. It's easier for someone from the outside to help you spot
patterns, then you will gain some level of awareness of how they arise in your
life (because you will be discussing your life with the therapist).

The paper I link to on dreams should help too. Dreams are sort of an internal
mini-therapist, but again, it is easier with an outside perspective.

------
MauranKilom
When I first learned about this, especially the "Because your brain recognizes
it's moving and adjusts what you see to make sure it sees the 'right' thing"
part, it explained a phenomenon that really confused me as a child:

I would sometimes "catch" our bathroom clock (analog, with second hand) going
backwards for a second. But no matter how long I stared at it, it wouldn't
happen again. Only when I turned my attention to it would it sometimes seem to
go backwards for the first second.

With the "your brain extrapolates the movement backwards" this makes perfect
sense if the second hand will vibrate a bit on each tick. Apparently, if I
focused on the clock while the second hand was vibrating for a fraction of a
second after moving, it might be moving ever so slightly backwards at that
moment, which is extrapolated to a full second of backward movement. In the
end it's just another optical illusion.

~~~
Digit-Al
Have you ever noticed car wheels looking as if they are spinning backwards
instead of forwards?

~~~
malingo
This is due to the rotation rate of the structural elements of the wheels
being just above the flicker fusion threshold frequency, around 60 Hz [1]. As
the wheels spin faster, they just look like a blur.

[1]
[https://en.m.wikipedia.org/wiki/Flicker_fusion_threshold](https://en.m.wikipedia.org/wiki/Flicker_fusion_threshold)

~~~
Digit-Al
Thanks. Very interesting.

------
refurb
It's also fascinating when the other end of the visual system (the brain) has
issues.

My aunt had a very small stroke in her visual cortex. Incredibly it only
impacted the visual processing in the upper right quadrant of the right eye.
Everything else was fine.

She was telling me that the affected part of her field of vision wasn't black
(as you'd expect). She described it as "empty". It just wasn't there. There
were no good words to describe how that looked visually.

Interestingly as her brain recovered somewhat, the "empty" area got a bit
smaller, then her brain started to do "error correction" and to her, the
"empty" part is gone, but it doesn't provide any visual information. Similar
to the tweets, it's just filled with "background".

~~~
goblin89
10+ years back a handful of times I suffered from (what I think were, but
you’ve got me thinking) migraines that resulted in localized loss of visual
perception. In my case the spot was right in the center of my field of vision.

The loss manifested itself at first as trippy vibrating colors, which soon
changed to non-black nothing.

After that I would look straight at things not only to _not see_ them, but to
not even realize I am not seeing something.

~~~
dminor
[https://en.m.wikipedia.org/wiki/Scintillating_scotoma](https://en.m.wikipedia.org/wiki/Scintillating_scotoma)

~~~
zipwitch
I've had these several times myself. For me, they start as a small "blind
spot" at the center of my field of view, which was really scary, particularly
if I was trying to read or do screen-work at the time. After the first one,
the appearance of the rainbow zig-zags was actually comforting, because that
confirmed what it was. Since I was effectively incapacitated for the duration,
I'd just lie down and enjoy the light show.

It's been years since I had an occurrence, but the timing was pretty reliable.

~30 minutes: slowly growing blind spot at the center of my field of vision.

~15 minutes: rainbow zig-zags in a slowly expanding circle from the blind spot
until it encircled my whole field of view, after which it faded out and I
could focus pretty normally again. No headache during or after.

After multiple rounds, I figured out the, or a, trigger: absinthe. Drinking
absinthe reliably brought one on ~18 hours later. Only ever had one that I
couldn't tie to absinthe. Stopped drinking absinthe years ago, and the
scintillating scotoma stopped as well.

------
crazygringo
> _it seriously shows you the image at the new point, but time-shifts it
> backwards so that it seems like you were seeing it the whole time your eyes
> were moving... you can see this effect happen if you watch an analog clock
> with a second hand. Look away (with just your eyes, not your head), then
> look back to the second hand. It 'll seem like it takes longer than a second
> to move, then resumes moving as normal._

Is there a citation for this? I can't find any paper on it, the Wikipedia
articles on "sacaddic masking" and "transsaccadic memory" don't mention the
phenomenon at all, and I've been trying it with my own clock (where the second
hand moves in second increments, not continuously) and it simply doesn't
happen for me at all.

I can't figure out _why_ your brain would "rewrite past memory" instead of
simply persisting the old image either.

If anyone could point me to an actual name for this phenomenon, or a paper
proving it, I'd super appreciate it, because it seems so implausible that I'd
love to understand it more.

EDIT: found the actual term for it -- "chronostasis" \-- and the memory
phenomenon is "neural antedating" or "neural backdating". [1] And while it
appears to be a _reported_ phenomenon, it appears to be understandably
difficult to verify experimentally, since it is an inherently subjective
phenomenon and experiments involve potential sources of bias that could
alternately explain it.

[1]
[https://en.wikipedia.org/wiki/Chronostasis](https://en.wikipedia.org/wiki/Chronostasis)

~~~
jstanley
> it simply doesn't happen for me at all.

FWIW, I have noticed the effect many times, in particular with the second hand
of analogue clocks.

~~~
kqr
Even before I knew this was a thing, I know I've looked at my watch and for a
second being confused about why it seemed broken when it was working just
minutes ago, simply because the second hand didn't appear to move in time.

~~~
proactivesvcs
I had assumed that this was part of my watches' mechanisms that self-
calibrated but it never occurred to me that I just happened to notice this
self-calibration so often!

It's interesting that I casually came up with a complex explanation and didn't
even try to critically examine whether it was plausible or not.

------
AndrewKemendo
Studying computer vision and specifically the intersection of visual computing
systems and human vision in the context of Augmented Reality really cemented
to me how much "bubblegum and duct tape" human systems really are - and are
totally amazing.

Namely how flexible/fluid adaptive the brain is. The eye is pretty "dumb" but
the processing pathway of the optic nerve through the visual cortex (which is
hilariously on the complete other side of the brain) is a marvel of
processing.

------
tjalfi
Here is a Thread Reader view of this content.

[https://threadreaderapp.com/thread/1014267515696922624.html](https://threadreaderapp.com/thread/1014267515696922624.html)

~~~
nickthemagicman
Goodness that's long for a BLOG post! Much less twitter. Thanks for the link!

------
csomar
The wikipedia experiment is much easier to do and more pronounced. You'll need
a mirror and a reasonably good phone camera to take video. I just tried it and
it's amazing.

> This can easily be duplicated by looking into a mirror, and looking from one
> eye to another.

But you can't see your eyes move in the mirror. They seem strangely very
inert. If you play the video afterward, you'll see your eyes moving!

>
> [https://en.wikipedia.org/wiki/Saccadic_masking](https://en.wikipedia.org/wiki/Saccadic_masking)

------
aasasd
It's very easy to find the blind spot with the mouse cursor. Close one eye,
and with the other look at the opposite side of the screen. Move the cursor
around on the side corresponding to the open eye. You'll plainly see the
cursor disappearing and reappearing—meanwhile, your brain pretends that it
knows static content that's in the spot. Most probably, it will even
interpolate movement for videos—as it wont to do.

~~~
byteface
if ur on a mac shake the cursor really fast and the arrow grows massive. never
noticed that before. I was using my curosor to check the blindspot on my eye
and was wiggling it in and out at the edge and it freaked me right out. it
went in small, disappeared and came out 20x larger. I was like fuck me these
eye tricks are mental.

~~~
aasasd
Moreover, if you shake it _really fast_ for a bit of time, you'll get an
easter egg.

------
shariqm
As someone with a PhD in neuroscience I like the sentiment of this post but
it’s off the mark in some key ways.

From a high level @foone is right, our eyes and visual system are nothing like
a camera. Our visual system constructs an internal 3D model of the world, our
“perception”, given observations in the form of the electrical activity in our
photoreceptor (rod and cone) cells. It tries to do this in a way that balances
energy use and accuracy of the model. This simple concept can actually be used
to explain a lot things that may seem like ‘hacks’ as @foone put it. One
example: Saying Saccades are a problem is misleading, they likely evolved to
give us higher acuity (resolution) vision without having to pay the energy
cost of a larger fovea [1, 2, 3]. They also likely allow us to see color more
accurately outside of our fovea.

I also really don’t buy this time-shifting idea, although other
neuroscientists would probably disagree. As @foone said our eyes are not
cameras, our perception is our brain hallucinating an internal 3D model of the
world. It knows what data to incorporate into the model and what not to, i.e.
a blurry saccade is not a good representation of the world. If you want to
read about how this can be framed with bayesian statistics you can read one of
my favorite papers from my advisor [4].

[1]
[https://en.wikipedia.org/wiki/Saccade#Function](https://en.wikipedia.org/wiki/Saccade#Function)

[2] Ratnam, Kavitha, et al. "Benefits of retinal image motion at the limits of
spatial vision." Journal of vision 17.1 (2017): 30-30.

[3] Anderson, Alexander G., et al. "A neural model of high-acuity vision in
the presence of fixational eye movements." 2016 50th Asilomar Conference on
Signals, Systems and Computers. IEEE, 2016.

[4] Olshausen, Bruno A. "27\. Perception as an Inference Problem." The
cognitive neurosciences (2014): 295-304.
[https://pdfs.semanticscholar.org/bb00/42b5e48feff89a95182c63...](https://pdfs.semanticscholar.org/bb00/42b5e48feff89a95182c63bc400c6e6662fe.pdf)

------
elliottkember
I have a condition called nystagmus[1] which makes my eyes saccade constantly.
It mostly happens when I look to the left or right, with what's called a "null
point" in the middle. Having a null point in the middle is a lucky break.

It doesn't affect my day-to-day, which I think is surprising. In fact I have
very good hand-eye coordination and visual perception, which may be a side-
effect of constantly having to track moving objects.

It's also a symptom of being drunk, or a brain injury. Medical students are
always very concerned and ask whether I've hit my head, and I often get
breathalysed when I'm pulled over.

[1] [https://www.aoa.org/patients-and-public/eye-and-vision-
probl...](https://www.aoa.org/patients-and-public/eye-and-vision-
problems/glossary-of-eye-and-vision-
conditions/nystagmus#:~:text=Nystagmus%20is%20a%20vision%20condition,or%20in%20a%20circular%20pattern).

~~~
abiogenesis
I get nystagmus from time to time (maybe once a year) because of positional
vertigo, but I have since learned to "fix" it by applying the Epley manoeuvre
myself. I guess yours is not treatable though.

------
bonoboTP
This is an interesting write-up but doesn't go far enough. Yes you're not
watching an HD pixel based video when seeing.

But the phrasing of "your visual system shows you X" is still off. The visual
system is you, the eyes and the retina's neurons are you, etc. There is no
"you" hidden somewhere deep in the brain that watches what the brain shows it,
like a homunculus.

~~~
cmroanirgo
There _is_ the possibility to observe your thoughts, which strongly indicates
two "you".

~~~
dualogy
There _is_ the possibility that this is "just" memorizing / remembrance /
memory of the just-passed (now-past) instant. Meaning as you think about
"current" thought-X, the current instant is now thought-Y (thinking about X)
and X is no longer "your current thought". Hm. Impossible to measure or decide
because we can't ever possibly define "how long" is "now".

------
rags2riches
Do you ever see a cat or a bird move in the corner of your eye, but when you
look closer it was just a leaf or a shadow or something? I think you _see_
that cat just as much as you _see_ anything at all. The visual processing just
got a little too carried away in a way that was easily noticed, just like the
seconds hand on the clock.

~~~
bemmu
All the time. In that moment the leaf that used to be a cat also instantly
changes to having been a leaf all along.

Our experience is like a dream vaguely guided by reality.

------
akamoonknight
One of their examples about the balls appearing bigger when needing to hit
then reminded me of something from a YouTube video [0] about our senses lying
to us. The example brought up in the video is how a hill appears steeper to us
if we have a heavy backpack on!

Overall though, those were some cool new examples of eye limitations I hadn't
heard of before, like the accumulation of laser light damage.

And yeah similar to other commenters, some of these could just as easily be
explained as amazing adaptations required to work with the limited resources
available in addition to a description as ugly hacks. I guess the important
part is just to hopefully become more aware of our limitations with the goal
that that helps us maybe get a little better understanding of potential
difficulties we all face.

[0] [https://youtu.be/BMvgOjGPXyw](https://youtu.be/BMvgOjGPXyw)

~~~
ars
> how a hill appears steeper to us if we have a heavy backpack on!

I've reverse hacked this: When I'm tired and need to walk up a hill, I look
straight down at the ground such that it appears horizontal, this makes it
easier to walk.

~~~
akamoonknight
Come to think of it, that's kinda sorta what I do to! Stare at the ground
right ahead and just plow ahead. I always put it down to just saying well,
doesn't really matter what's further ahead too much, just follow the path and
we'll get there eventually. I like the idea of it as a reverse hack though.
Gotta look up occasionally to enjoy/watch out for stuff though.

------
aeturnum
In general, thinking about how we see using metaphors drawn from photographic
media (chemical or digital) will lead to deeply incorrect understandings.

We do not see images. Our brain does not have a frame buffer. Our minds
construct the visual experiences we have of the world around us. They
construct them from reality and we have developed technology that can make
recognizable facsimiles of how we see the world, but they have very little to
do with each other.

------
bobcostas55
A similar (and similarly good) thread on sensory and motor systems:
[https://twitter.com/analogist_net/status/1014397203450744832](https://twitter.com/analogist_net/status/1014397203450744832)

------
mirekrusin
It's not only vision. When you're sleeping and there's a sound that will wake
you up, you can have a dream fragment which would have to know the future to
compose itself this way.

I don't know if it has a name but I've noticed this many times.

~~~
samueloph
I also noticed that and couldn't find any name for this phenomenon, seems like
there are somethings on the internet about "Sensory Incorporation in Dreams"
but I failed to find anything related to this specific behavior of dreaming
with something that led to the noise.

[https://biology.stackexchange.com/questions/56798/what-is-
th...](https://biology.stackexchange.com/questions/56798/what-is-the-term-for-
awareness-of-or-inclusion-of-real-sounds-within-a-dream)

------
Gatsky
I thought I was going crazy when I first noticed the chronostasis effect on my
watch (that is where the ticking second hand seems to stick in place when you
first glance at it). Years later by chance I came across a paper explaining
the mechanism.

~~~
proactivesvcs
I would often "see" the second hand tick, but not move forward by a second.
More like a "flick" than a tick.

------
ganstyles
I started reading and immediately thought of Blindsight. The tweet thread
mentions it later, make sure to check it out if you like hard sci-fi, it's one
of the best.

~~~
Merg
It was my first though as well. Idea of aliens, which can just "skip" the
sight of humans is pretty cool. The same goes with concept of consciousness as
a parasitic/optional part of inteligent species.

Blindsight is one of the best, 10/10 on Mohs Scale of sci-fi hardness. I love
the description of scientific concepts behind sci-fi story at the end. Such a
shame, there is so little books with that kind of deep research.

One of the best written, first contact novels out there. I have the luck of
hearing Watts lecture on one of the Cons. He is even better in person.

If you are from Canada, it is good idea to check, where he is speaking.

Authors blog, filled with pop-scientific concepts and ideas [1], is well worth
it.

[1] [https://www.rifters.com/crawl/](https://www.rifters.com/crawl/)

------
LoSboccacc
> It'll seem like it takes longer than a second to move, then resumes moving
> as normal.

shit I knew it was real! adolescent me noticed this and had a hard time to
explain or figure out information about it (this was about the excite era)

~~~
magnio
Ohhhhhhhhh! So that's why whenever I stop and look up at a traffic light with
a timer, the first second always seem longer than the subsequent ones.

This is so cool. It's one of those mundane things that you think only occur to
you, when in reality it's way more common and intriguing. Like those eye
floaters.

~~~
sukilot
Why would you assume that your experience isn't common to others with the same
evolutionary history and environment?

~~~
LoSboccacc
it's an effect that's very hard to describe - john: "hey jim did you notice
that last second was longer" it's very personal, if jim was not looking or
already looking at the timer from before john's assertion would just sound
absurd and it also require being attentive enough to the clock and the sense
of time in general.

and personally I kinda had a general feeling that could be at best described
as 'the first second of a timer always look longer than the others' which
roughly matches what magnio said, and that was it, it's not something I'd
widely share unprompted, people already think I'm enough of a nerd as it
stands.

------
vanderZwan
So do we have examples of people for whom these hacks are not functioning
quite as well, and what the consequences of that are? Because a lot of these
visual hacks he describes remind me of issues people with Auditory Processing
Disorder have to deal with, except that it's vision instead of audio.

[0]
[https://en.wikipedia.org/wiki/Auditory_processing_disorder](https://en.wikipedia.org/wiki/Auditory_processing_disorder)

~~~
rzzzt
I have one for you: the vestibular system works in concert with the eyes for
"image stabilization" purposes, so when you are eg. walking around, all that
up-down head motion is canceled out. Visual vertigo occurs when the two
systems fall out of sync for some reason.

[https://www.sciencedirect.com/science/article/pii/S030698771...](https://www.sciencedirect.com/science/article/pii/S0306987718301324)

~~~
wruza
The same when you play a videogame with a heavy “view bobbing”. Someone
decided that it would be more realistic if your camera shook by 15 degrees
both axis at every move (looking at you, cod:mw), but it only makes a scene
feel sick and you can’t turn it off.

------
toss1
Another insane property is a type of blindsight in people who are cortically
blind, i.e., their eyes are intact, but have damage to the visual cortex so
they cannot form or process images.

However, parts of our visual system other than forming images are handled in
other parts of the brain. For example, managing the tracking of objects by the
eye - it's a completely separate group of control neurons (vs the visual
cortex) that drives where the eye looks (and it's actually different for
vertical vs horizontal tracking).

So, it turns out that if you present images with, say, vertical or horizontal
stripes and ask a person with cortical blindness (developed after they could
see) person which it is, they'll tell you of course that they can't see &
don't know. However, make it a forced-choice question where they must guess
one or the other, and they'll get a high percentage right, far greater than
chance. The information is exfiltrating from the centers controlling the eye
motion even though there is no cortex to form an image.

------
Wistar
A little tangential: If you hard lock your eyes, say, all the way to the right
and rotate your head slowly to the left, you can defeat the saccade mechanism
and get a smooth pan, complete with motion blur.

~~~
just-ok
This is basically because (one of?) the only times our eyes don’t do saccades
is when they’re tracking motion. In other words, you can’t move your eyes
smoothly unless you’re following something (like prey or a finger). In this
case, you’re tracking the boundary of your periphery!

~~~
Wistar
It seems to me it is more because your eyes can't move if they are locked all
the way to one side.

~~~
mbeex
[https://en.wikipedia.org/wiki/Smooth_pursuit](https://en.wikipedia.org/wiki/Smooth_pursuit)

" Smooth pursuit eye movements allow the eyes to closely follow a moving
object. It is one of two ways that visual animals can voluntarily shift gaze,
the other being saccadic eye movements. "

~~~
Wistar
Ah, now I understand. Thanks. Makes perfect sense.

------
vincvinc
> There was an experiment back in 1890 where someone wore glasses made with
> mirrors in them to flip their vision. After about 8 days, they could see
> just fine with them on.

Schience youtuber Kurtis Baute did this as well: his video "I Spent 7 Days
Upside-Down" documents it... a very fun watch!

[https://www.youtube.com/watch?v=2HaXUCQKBjs](https://www.youtube.com/watch?v=2HaXUCQKBjs)

------
sukilot
Why do people sprinkle curse words pointlessly over otherwise useful
information?

~~~
tombert
I can’t speak for anyone else, but I like to sprinkle in swear words as a way
of “grounding” the subject.

A lot of my friends will bother me for help with compsci or math stuff for
some reason, and I usually try to help. Math and programming are hard,
especially to someone who doesn’t already know it, and people can quickly get
frustrated as a result of it being confusing. Throwing in a swear can be
useful to signal to the person to relax, and to tell them that it’s ok to
think of this stuff in goofy terms, and in my experience it can help lower the
tension.

It’s not the best tool for every scenario, I don’t use that tactic when
teaching kids, but I do think there’s utility in it.

------
saurabh20n
Most informative takeaway for me: an amazing experiment to "see" saccades: (1)
mirror, vs (2) iphone selfie camera, vs (3) macbook photobooth.

Scanning my own face, for each of these 3, i tried to see my own saccade, and
(1) I am blind to it in the mirror; (2) barely see it on the iphone, and (3)
very visibly see it on the macbook.

------
wwwwewwww
I think a similar effect was described by Daniel C. Dennet. Imagine a row of
lights next to each other. The leftmost one blinks, then the one to the right,
then the one to the right, creating an effect of a smoothly moving light dot
from left to right (similar to how animation works).

What does your brain see in the period between the blinks? Because it
perceives the light as a smooth motion, and not as discrete jumps, it must
"see" a virtual non-existent light in between two real lights. But if
everything in your brain happens chronologically, how would it know if the
light to the right would light up or not? It must have "backfilled" that
information into your memory/perception after seeing the right light blink.

~~~
vlasev
It probably extrapolates, much like how when you stare at those videos of a
moving background and look away, your environment appears to shift in reverse
of the motion you were observing.

------
highfrequency
I'm a bit suspicious after spending 5 minutes trying to replicate the frozen
clock phenomenon and having no success. Often, the second hand ticks within a
very short window (<150ms) of looking at the clock, consistent with what I
would expect.

When you shift your focus to look at an analog clock, the time to the next
tick of the seconds hand should follow a uniform distribution between 0 and 1
seconds if there are no visual bugs. It seems likely that people experience
some confirmation bias, where the delays above 0.9s stand out more in their
memory.

I really don't buy the claim that there's a 500ms delay in perception here. At
the very least, this should be bounded by the time it takes to move your eyes
(~100ms).

~~~
xwdv
I too was unable to replicate that experiment. I took it a step further by not
only having an analog stop watch, but also having other things close by that
were constantly moving. Even though my timing resulted in variable durations
to the next tick, some longer than others, I did not notice any “paused”
effect from other things.

------
wwwwewwww
Does the same chronostasis effect with the second hand on the clock work if
you can hear the clock tick?

I'm having a hard time visualizing this. If it still happens, would you sense
a longer time between clicks? Or does the effect go away?

------
Thorentis
> you can see this effect happen if you watch an analog clock with a second
> hand. Look away (with just your eyes, not your head), then look back to the
> second hand. It'll seem like it takes longer than a second to move, then
> resumes moving as normal.

Woah, woah, woah. I'd noticed this before when sitting around waiting for
something (reception rooms, etc.) but never thought much of it. Thought it was
just my mind playing tricks. I am so happy to know this is a consistent
phenomenon for everybody, and there is a concrete reason for it. The human
brain is facinating.

------
spicymaki
This is great write-up. I love learning things about perception and how the
manipulates data behind the scenes. Are there any good layman books about the
this?

------
sandoooo
Think about streaming a live video from Youtube inside your browser. There's a
lot of complicated stuff going on underneath: layers upon layers of
compression, error correction, buffering, etc. Many ugly, crazy hacks to
squeeze the signal into a system not built for it. The end result is a lossy
approximation of the original and definitely not in real time.

The visual system is a lot more like videos than people think.

------
adventured
I was unfamiliar with the Ted Turner black & white movie colorization
controversy (circa 1980s), interesting cultural conflict:

[https://www.latimes.com/archives/la-
xpm-1986-10-23-ca-6941-s...](https://www.latimes.com/archives/la-
xpm-1986-10-23-ca-6941-story.html)

[http://archive.is/LAkOO](http://archive.is/LAkOO)

------
jrobn
I don’t think these are hacks. They aren’t bubble gum and duck tape. They are
well tested solutions for current physical limitations.

------
hoppla
Today, I noticed that when I open my eyes, the vision quickly fill from the
perifer vision to the center. Like a shrinking black bubble, disappearing in
the middle. It was easier to see it in a dimly lit room after staying there
for a while.

------
StavrosK
Hmm, how does saccadic masking jive with the fact that if you "roll" your eyes
and keep rolling them, you still see an image? It's blurry, but it's there,
and you're never holding your eyes in one position.

------
qqj
Why oh why do people abuse twitter to post entire blog posts. Do they also
drink from plates, and shower in the sink? Write kernels in Javascript? smh

~~~
ufmace
I don't really get the beef with this. Twitter's UI for reading these tweet-
streams is pretty decent these days.

~~~
gorkish
See that's where

gorkish 1 hour ago | parent |on "I don't really get the beef with this..."

you and I have very markedly

gorkish 1 hour ago | parent |on "I don't really get the beef with this..."

very different ideas about what

gorkish 1 hour ago | parent |on "I don't really get the beef with this..."

"pretty decent" means

gorkish 1 hour ago | parent |on "I don't really get the beef with this..."

because I actually think this kind of

gorkish 1 hour ago | parent |on "I don't really get the beef with this..."

nonsense is really quite bullshit.

------
chadcmulligan
Here's another one (apologies if I missed it below) - when you are in an
accident it seems like everything is in slow motion - no, its your memory is
more complete, at least you think it is, but its not really. An experiment was
performed to validate this effect, to see if you actually can see things
faster when you're in an accident :- [https://www.livescience.com/2117-time-
slow-emergencies.html](https://www.livescience.com/2117-time-slow-
emergencies.html)

------
codeulike
Saccades are a great demonstration of the idea that consciousness is actually
very different to what we intuitively imagine it to be.

------
jayd16
This make no sense to me. If I turn to look at speeding cars they don't appear
frozen for some brief moment.

------
kyberias
WAIT! Is this the reason why the 48 fps Hobbit movie looked so weird with
jumping frames and whatnot?

~~~
rzzzt
High frame rates are associated with TV shows and sitcoms:
[https://en.wikipedia.org/wiki/Motion_interpolation#Soap_oper...](https://en.wikipedia.org/wiki/Motion_interpolation#Soap_opera_effect)

Also, those 48 frames need to be converted to 60 frames and as a result, some
frames will be shown for a disproportionate amount of time and/or created by
mixing two adjacent frames. The article is about interlaced modes, but I think
it also applies to progressive scan: [https://en.wikipedia.org/wiki/Three-
two_pull_down](https://en.wikipedia.org/wiki/Three-two_pull_down)

~~~
kyberias
No I mean it looked weird in CINEMA where the frame rate was exactly 48 fps.
And by weird I specifically mean the jumpiness observed occasionally in
certain scenes. As if the frames were suddenly being played by much more that
48 fps. I doubt that this was a technical glitch but rather something
happening in my brain.

------
xvilka
We should fix it by adapting cephalopods' eyes[1] and throwing out our own
garbage.

[1]
[https://en.m.wikipedia.org/wiki/Cephalopod_eye](https://en.m.wikipedia.org/wiki/Cephalopod_eye)

------
jancsika
Isn't this exactly what requestAnimationFrame does?

------
YeGoblynQueenne
This is just so hard to read. I can't concentrate on what the author is trying
to say because I'm constantly distracted by the way they're trying to say it,
meaning all the irrelevant exclamations with which the author is peppering
their tweets.

I have to wonder: what is gained by mixing up so much noise with an
interesting message? Isn't there enough useful information in the subject of
saccades, without the tone (which I suppose appeals to some)?

It's like when you're trying to hold a conversation with someone that
disagrees with you on the internets and they constantly try to troll you,
starting their comments with sentences like "no, this is wrong, you're an
idiot and you don't know what you're talking about" before telling you why
they disagree, or what they mean etc.

------
Abimelex
whats this thing with shredding a blogpost into countless tweets?

------
Invictus0
I think batshit would be the proper type of shit for the title.

~~~
Ozzie_osman
I like the word "bullshit" for this, even though batshit is the more standard
expression. Because in a sense, this is about our brain bullshitting us.

------
Engineering-MD
I don’t seem to have the same experience of saccades as described here, I see
blur but mostly ignore it. When I look to the right and left of my screen, I
can see the light blur, and when looking across a projector beam I (and my
friends) can note the red blue and green colours as separate, but only during
the saccades. Anyone else have a similar experience?

------
tboyd47
> the answer is simple! your brain has EVEN MORE UGLY HACKS on top of this to
> avoid you seeing that.

Only computer programmers tend to describe biological systems in deprecating
terms like this, calling them ugly hacks, klugy, etc. As if we know best
what's elegant and what's klugy. I wonder if perhaps we do this because we
would never have the practical intelligence come up with a solution like that.
It's not a great look for us.

------
rewoi
I dont buy that. Vision developed for different purpose than to provide full
HD sharp vision across entire FOV. It has great pattern recognition and
peripheral motion detection. It heals itself. It has low power consumption. It
does not overheat and can work in many environments, even under water.

Modern competition like Go PRO require too much baby sitting, and can hardly
work for 2 hours without maintenance.

~~~
just-ok
> low power consumption

Hmm, well the visual cortex makes up almost a third of our entire brain, and
the brain uses ~20% of our daily energy. I’d hardly call that “low power”!
Though granted I don’t imagine you can break a sweat just from thinking.

~~~
aasasd
> _I don’t imagine you can break a sweat just from thinking_

I heard that people who were asked to do sorting tasks, i.e. just separate big
oranges from small ones, got tired as heck, comparably to physical workers.
Then again, dunno about sweat.

~~~
just-ok
Yep, mental exhaustion is undoubtedly a thing! I'd love to see how heart rates
change with something like test question difficulty. Since sweat is generally
a product of heat and occurs when your heart works harder during exercise, I
wonder if the heart _also_ works harder to pump the brain with more oxygen to
enable it to... think harder? Obviously just musing, am no physiology expert.

