Go Back   EcoModder Forum > Off-Topic > The Lounge
Register Now
 Register Now
 


Reply  Post New Thread
 
Submit Tools LinkBack Thread Tools
Old 07-04-2018, 06:54 AM   #1 (permalink)
Not Doug
 
Xist's Avatar
 
Join Date: Jun 2012
Location: Show Low, AZ
Posts: 9,991

Chorizo - '00 Honda Civic HX, baby! :D
90 day: 35.35 mpg (US)

Mid-Life Crisis Fighter - '99 Honda Accord LX
90 day: 32.86 mpg (US)
Thanks: 6,668
Thanked 1,908 Times in 1,450 Posts
The brain is pretty cool

Someone calling himself "Foone" posted some stuff about how human vision works with dozens of twitter posts, which was shared with dozens of screen shots on Imgur. Crustysmegma asked "can someone put this into a format that isn't Twitter?"

Here goes:

Quote:
You want to know something about how absolutely insane our brains are? OK, so there's a physical problem with our eyes: We move them in short fast bursts called "saccades," right? Very quick and synchronized movements.

The only problem is: They go all blurry and useless during this. Having your vision turn into a blurry mess every time you move your eyes is obviously not a good idea, so our brains hide it from us. Now imagine you're an engineer and you have this problem. You've got some obvious solutions you could do.

1. Make the vision go black during movement. Some VR games do this!
2. Just keep showing the last thing we saw prior to movement.

Both are good options with different downsides, but oh no! This is assuming everything makes sense and is chronological and (regular) logical. Your brain does neither of these options, really. First, it basically puts your visual system on pause. You're not seeing blackness or even nothing, you're just not seeing period. Then when you finish your saccade, it shows you what you now see at the new position and then it pretends it can time travel.

It seriously shows you the image at the new point, but time-shifts it backward so that it seems like you were seeing it the whole time your eyes were moving, and because your brain is not a computer with a consistent clock, this works.

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. That's because your freaking visual system just lied to you about how long time is in order to cover up the physical limitations of those chemical camera orbs you have on the front of your face.

We've known about this effect for over 100 years, it's called "Saccadic masking," and more specifically Chronostasis. Your visual system lies to you about when things happen by up to half a second(!) just to avoid saccades blurring everything.

So, while I firmly believe we're basically just overgrown biological computers, we're apparently computers programmed by completely insane drunkards in Visual Basic 5 and you might think "Hey wait, wouldn't my vision pausing for half a second have all kinds of weird effects on moving objects? Why don't they appear to stutter when moving?" The answer is simple! Your brain has even more ugly hacks on top of this to avoid you seeing that. If you've got a clock where the second hand doesn't tick, but instead smoothly rotates you won't see this because your brain recognizes it's moving and adjusts what you see to make sure it sees the right thing. It's only really obvious with periodically moving things like a clock hand because it's not moving (so not triggering the movement-during-chronostasis hack), but it moves at a set rate, so you can notice that rate appearing to change.

It's tempting to think of your eyes and visual system as a camera just dumping a video feed into your conscious brain, but that's absolutely not the case. What you think you see and what your eyes actually see are two exceptionally different things.

The big obvious one is the blind spot. Vertebrate eyes are wired backward so we've got a blind spot in each eye where the nerves enter into the eye. About 6 degrees of your vision in each eye is just not there as there are no light sensitive cells there. Do you see a blind spot right now?

No, you probably don't. Close one eye! There's now no way for the other eye to fill in the gaps. Still, no blind spot. Your visual system is lying and making up content it thinks is there. You literally cannot see what you think you see.

Here's another one: You can see in color, right? (Well, some of you can't.
Sorry, eh) You can see in color all throughout your vision, it's color everywhere?

Well, most of your cone cells (which are sensitive to color) are in the fovea, a little spot in the center of your vision.


So, outside of that center-of-vision spot you have very little color perception. There's some, but it's very limited compared to your main color vision. Your vision system is lying. It's remembering what colors things are and guessing and filling in the gaps. It's basically doing a Ted Turner colorization process on your non-central vision.

There are even weird effects like what's called "Action-specific perception." If you get a bunch of white balls of various sizes and toss them at people, then ask them to estimate the size of the balls thrown at them, they'll have a certain size estimate, right? Now repeat the experiment, but ask them to try to hit the balls back with a bat and suddenly the all the estimates shift larger. They actually see the ball as bigger because they need to hit it. Their vision is exaggerating to make it easier to see!

Which just goes to show, like I wrote, your vision is not a camera. Perfect accuracy is not one of its goals. It does not care about objective reality. That's not important. What's important to the evolution of the visual system is any trick that helps you survive, no matter how dumb or weird it is. So if you want an accurate visual representation of what things look like use a camera, not your eyes.

In any case the original point was that while you might know this about your eyes being poor cameras that lie to you, you might still think that at least they're consistent time-wise. They don't mess with your sense of time passing just to make up for visual defects. Nope!

If you can't get it done in time, turn back the clock, and pretend you did. That's a perfectly good solution when you're the visual system.

BTW, Hierarchon reminded me of a neat trick with saccadic masking: Go look in a hand mirror. No matter how close you bring it to your eyes and how much you look around, you will never see your eyes move. You're blind during these moments, but you still think you are seeing. She additionally pointed out that your phone's selfie mode is not a mirror and it has a slight delay, so you can see your eyes moving. For fun, here's a Wikipedia example of the blind spot. Stare at the L with only your left eye, adjust the distance, and the R will disappear. You don't see nothing or black, see the background because you expect to.

This is why laser damage to your retina can be so insidious. Your visual system already hides holes in your vision. What is one more? So, you damage a small spot of your retina and your visual system covers it up, but since you didn't think "Well that was terrible, I better take better care of my eyes!" and stop messing with lasers, you keep doing it, and eventually you accumulate so much damage that your visual system simply cannot manage hiding it all and your vision rapidly degrades.

The other reason lasers are so dangerous is that they don't necessarily trigger the same responses as regular incoherent light. Your pupil reflex is only triggered by some special cells in the center of your eye, so an off-center laser might not cause your iris to contract and infrared laser light is just as dangerous as visible laser light, but can't trigger your blink reflex. Your eyes automatically close when exposed to bright light, but they can't detect infrared light. Despite not seeing it, it still causes damage.

Anyway, back to how amazing and crazy your vision is: 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. Their vision system started flipping the image. It only took them a couple of hours to get back to normal after taking off these glasses, though.

The last really fun part about this flipping experiment: Your eyes already do it. Based on how our vision is wired, we should be seeing everything upside-down. We don't, but only because our visual system has had our whole life to adapt to this.

BTW, since a few people have brought it up: There's a great sci-fi novel by Peter Watts called "Blindsight." In it humans encounter an alien race they call Scramblers who can move very fast and precisely and they exploit saccades [...].

Check it out if you're into hard SF stories of first contact. It's got some fascinating ideas about human vision, very unique aliens, the nature of consciousness, the future of humanity in the face of perfect VR, and vampires. (Really, it has vampires, while still being hard SF)

Attached Thumbnails
Click image for larger version

Name:	2000px-Schematic_diagram_of_the_human_eye_en.svg.jpg
Views:	218
Size:	65.2 KB
ID:	24519   Click image for larger version

Name:	eye trivia 2.png
Views:	210
Size:	272.4 KB
ID:	24520   Click image for larger version

Name:	eye trivia 3.png
Views:	215
Size:	16.0 KB
ID:	24521  
  Reply With Quote
The Following 5 Users Say Thank You to Xist For This Useful Post:
Gasoline Fumes (07-05-2018), MetroMPG (07-04-2018), mort (07-05-2018), niky (07-05-2018), redpoint5 (07-04-2018)
Alt Today
Popular topics

Other popular topics in this forum...

   
Old 07-04-2018, 06:58 AM   #2 (permalink)
Not Doug
 
Xist's Avatar
 
Join Date: Jun 2012
Location: Show Low, AZ
Posts: 9,991

Chorizo - '00 Honda Civic HX, baby! :D
90 day: 35.35 mpg (US)

Mid-Life Crisis Fighter - '99 Honda Accord LX
90 day: 32.86 mpg (US)
Thanks: 6,668
Thanked 1,908 Times in 1,450 Posts
I know that we are not supposed to quote anything in its entirety, but I wanted to present someone else's material in a more professional format without changing it drastically. I did replace a part at the end with a [...]. I was tired of writing and that part seemed redundant, but if it will really make you happy, you can thank Qussow: "TL;DR Your brain is a lazy chump 'cause reality is predictable 99.99% of the time and now that we know that, we can mess up stuff hard."

Edit! I forgot the source! Push-ups for me!
https://imgur.com/gallery/3GBsZLE

Last edited by Xist; 07-07-2018 at 05:07 PM..
  Reply With Quote
Old 07-04-2018, 01:48 PM   #3 (permalink)
Batman Junior
 
MetroMPG's Avatar
 
Join Date: Nov 2007
Location: 1000 Islands, Ontario, Canada
Posts: 21,761

Blackfly - '98 Geo Metro
Team Metro
Last 3: 70.09 mpg (US)

MPGiata - '90 Mazda Miata
90 day: 53.56 mpg (US)

Winter beater Metro - '00 Chevrolet Metro
90 day: 61.98 mpg (US)

Fancy Metro - '14 Mitsubishi Mirage top spec
90 day: 58.72 mpg (US)

Even Fancier Metro - '14 Mitsubishi Mirage top spec
90 day: 66.29 mpg (US)
Thanks: 3,473
Thanked 6,281 Times in 3,250 Posts
Neat, neat, neat!


My favourite university course was the very last one I took (I saved an elective). The course was Intro to Neuropsychology, and was full of stuff like this. If I'd taken it earlier, I probably would have taken a lot more. Maybe even switched departments.
__________________
Latest mods: 3-cylinder Mitsubishi Mirage. EcoMods now in progress...
Ecodriving test:
Manual vs. automatic transmission MPG showdown



EcoModder
has launched a forum for the efficient new Mitsubishi Mirage
www.MetroMPG.com - fuel efficiency info for Geo Metro owners
www.ForkenSwift.com - electric car conversion on a beer budget
  Reply With Quote
Old 07-05-2018, 12:04 AM   #4 (permalink)
Master EcoModder
 
Join Date: Aug 2010
Location: Philippines
Posts: 2,173
Thanks: 1,739
Thanked 587 Times in 401 Posts
Saccadic masking is precisely why drivers hit motorcyclists.

Narrow objects directly at the center of our focus are sometimes masked by our vision.

Which is why you MUST shift focus from time to time, because peripheral vision is more adept at detecting riders.

And why, as a rider, it's sometimes advisable to make yourself bigger than you are. Move around a bit in lane so you're not stuck in a driver's blind spot.

-

Also, AWESOME share, Xist!
  Reply With Quote
Old 07-05-2018, 09:38 AM   #5 (permalink)
Batman Junior
 
MetroMPG's Avatar
 
Join Date: Nov 2007
Location: 1000 Islands, Ontario, Canada
Posts: 21,761

Blackfly - '98 Geo Metro
Team Metro
Last 3: 70.09 mpg (US)

MPGiata - '90 Mazda Miata
90 day: 53.56 mpg (US)

Winter beater Metro - '00 Chevrolet Metro
90 day: 61.98 mpg (US)

Fancy Metro - '14 Mitsubishi Mirage top spec
90 day: 58.72 mpg (US)

Even Fancier Metro - '14 Mitsubishi Mirage top spec
90 day: 66.29 mpg (US)
Thanks: 3,473
Thanked 6,281 Times in 3,250 Posts
Quote:
Originally Posted by niky View Post
And why, as a rider, it's sometimes advisable to make yourself bigger than you are. Move around a bit in lane so you're not stuck in a driver's blind spot.

Yup! That was probably the single most interesting thing I learned in the motorcycle safety course: "slalom" in your lane when coming into certain higher risk situations, like a car signalling to turn left across your path, or waiting to pull out from a side street or driveway.


I swear I once saw a driver start to turn across my path and suddenly stop (with a startled look on her face) when I started weaving around in my lane.
__________________
Latest mods: 3-cylinder Mitsubishi Mirage. EcoMods now in progress...
Ecodriving test:
Manual vs. automatic transmission MPG showdown



EcoModder
has launched a forum for the efficient new Mitsubishi Mirage
www.MetroMPG.com - fuel efficiency info for Geo Metro owners
www.ForkenSwift.com - electric car conversion on a beer budget
  Reply With Quote
The Following User Says Thank You to MetroMPG For This Useful Post:
niky (07-06-2018)
Old 07-06-2018, 06:04 AM   #6 (permalink)
Master EcoModder
 
Join Date: Aug 2010
Location: Philippines
Posts: 2,173
Thanks: 1,739
Thanked 587 Times in 401 Posts
Quote:
Originally Posted by MetroMPG View Post
Yup! That was probably the single most interesting thing I learned in the motorcycle safety course: "slalom" in your lane when coming into certain higher risk situations, like a car signalling to turn left across your path, or waiting to pull out from a side street or driveway.


I swear I once saw a driver start to turn across my path and suddenly stop (with a startled look on her face) when I started weaving around in my lane.
It also helps when driving tiny cars... Just letting people know you're there by being a bit more active makes them less likely to accidentally cut you off.

Unless they're total jerks and will cut you off either way.
  Reply With Quote
The Following User Says Thank You to niky For This Useful Post:
MetroMPG (07-06-2018)
Old 07-06-2018, 01:55 PM   #7 (permalink)
EcoModding Newb
 
redpoint5's Avatar
 
Join Date: Aug 2010
Location: Oregon
Posts: 8,389

Acura TSX - '06 Acura TSX
90 day: 29.14 mpg (US)

Lafawnda - '01 Honda CBR600 F4i
90 day: 47.32 mpg (US)

Big Yeller - '98 Dodge Ram 2500 base
90 day: 21.82 mpg (US)

Prius Plug-in - '12 Toyota Prius Plug-in
90 day: 57.64 mpg (US)

Mazda CX-5 - '17 Mazda CX-5 Touring
90 day: 28.5 mpg (US)
Thanks: 2,829
Thanked 3,227 Times in 2,405 Posts
Nobody cuts me off when I drive the DOT yellow (Big Yeller) truck. I've had people wait 1/8th of a mile down the road for me to pass at 30 MPH rather than pull ahead of me. Meanwhile, everyone is eager to get out ahead of my Prius.

Perhaps that is another reason people like pickups; they are given more respect on the road.
__________________
Gas and Electric Vehicle Cost of Ownership Calculator







Give me absolute safety, or give me death!
  Reply With Quote
Old 07-06-2018, 04:22 PM   #8 (permalink)
Not Doug
 
Xist's Avatar
 
Join Date: Jun 2012
Location: Show Low, AZ
Posts: 9,991

Chorizo - '00 Honda Civic HX, baby! :D
90 day: 35.35 mpg (US)

Mid-Life Crisis Fighter - '99 Honda Accord LX
90 day: 32.86 mpg (US)
Thanks: 6,668
Thanked 1,908 Times in 1,450 Posts
People cut off my school bus all of the time.

They assumed I was driving slowly? I only drove slowly after hitting my brakes to avoid hitting someone that cut me off.

I maintained the speed limit wherever possible.

I do not have any idea if anyone tailgated me.

What is the worst that could happen?

Attached Thumbnails
Click image for larger version

Name:	ej0nxp0ubvto50jpk0i3hzmup9foeox.jpeg
Views:	124
Size:	68.0 KB
ID:	24528  
  Reply With Quote
Old 07-06-2018, 05:19 PM   #9 (permalink)
EcoModding Newb
 
redpoint5's Avatar
 
Join Date: Aug 2010
Location: Oregon
Posts: 8,389

Acura TSX - '06 Acura TSX
90 day: 29.14 mpg (US)

Lafawnda - '01 Honda CBR600 F4i
90 day: 47.32 mpg (US)

Big Yeller - '98 Dodge Ram 2500 base
90 day: 21.82 mpg (US)

Prius Plug-in - '12 Toyota Prius Plug-in
90 day: 57.64 mpg (US)

Mazda CX-5 - '17 Mazda CX-5 Touring
90 day: 28.5 mpg (US)
Thanks: 2,829
Thanked 3,227 Times in 2,405 Posts
Quote:
Originally Posted by Xist View Post
People cut off my school bus all of the time.
I had a school bus pull out in front of me when I was traveling at 65 MPH in a van. It was so bad that I had to swerve onto the gravel shoulder and pass the bus on the right. The gravel was too soft to apply the brakes and steer, so I just concentrated on maintaining control and gently crept back onto the pavement ahead of the bus.

Speaking of people pulling out and leaving no time to brake; on that same road, just a quarter mile away from where the bus had pulled out in front of me, a car did the same thing. That incident was so severe that I had to steer left as violently as traction would allow, and that sent me off the left side of the road, off a 2ft drop into a farmers field. I always wondered if the guy noticed what he had caused as I whizzed past him and out into the field. He didn't stop.

I had to drive about a half mile through the field to find a slope onto the raised road. Man that Subie was an incredible machine.
__________________
Gas and Electric Vehicle Cost of Ownership Calculator







Give me absolute safety, or give me death!
  Reply With Quote
Old 07-07-2018, 04:34 PM   #10 (permalink)
Master EcoModder
 
freebeard's Avatar
 
Join Date: Aug 2012
Location: northwest of normal
Posts: 17,485
Thanks: 4,713
Thanked 5,828 Times in 4,649 Posts
That's a pretty exhaustive First Post, but neglects the mystery of the color Magenta completely.

I read Eye and Brain after it came out in 1966. TLDR; the eyes are specialized portions of the brain that extend out on stalks called the optic nerve. Preprocessors if you will.

It's turtles all the way down.

__________________
.


Shower thoughts: Honey is the tastiest of all the insect vomits we have tried so far.

_________________
  Reply With Quote
Reply  Post New Thread


Thread Tools




Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2020, vBulletin Solutions Inc.
Content Relevant URLs by vBSEO 3.5.2
All content copyright EcoModder.com