TechTweets


	foone @Foone · Jul 03 You want to know something about how bullshit 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, synchronized movements. The only problem is: they go all blurry and useless during this
	foone @Foone · Jul 03 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.
	foone @Foone · Jul 03 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
	foone @Foone · Jul 03 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.
	foone @Foone · Jul 03 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.
	foone @Foone · Jul 03 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. And because your brain is not a computer with a consistent clock, this shit works.
	foone @Foone · Jul 03 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.
	foone @Foone · Jul 03 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.
	foone @Foone · Jul 03 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.
	foone @Foone · Jul 03 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.
	foone @Foone · Jul 03 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?" and the answer is simple! your brain has EVEN MORE UGLY HACKS on top of this to avoid you seeing that
	foone @Foone · Jul 03 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.
	foone @Foone · Jul 03 it's only really obvious with periodically moving things like a clock hand, because it's not moving (so not triggering the movement-during-chronostatis hack) but it moves at a set rate, so you can notice that rate appearing to change.
	foone @Foone · Jul 03 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 so very, very not the case. What you think you see and what your eyes can actually see are two exceptionally different things.

foone @Foone · Jul 03

You want to know something about how bullshit 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, synchronized movements.
The only problem is: they go all blurry and useless during this

foone @Foone · Jul 03

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.

foone @Foone · Jul 03

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

foone @Foone · Jul 03

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.

foone @Foone · Jul 03

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.

foone @Foone · Jul 03

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.
And because your brain is not a computer with a consistent clock, this shit works.

foone @Foone · Jul 03

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.

foone @Foone · Jul 03

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.

foone @Foone · Jul 03

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.

foone @Foone · Jul 03

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.

foone @Foone · Jul 03

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?"
and the answer is simple! your brain has EVEN MORE UGLY HACKS on top of this to avoid you seeing that

foone @Foone · Jul 03

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.

foone @Foone · Jul 03

it's only really obvious with periodically moving things like a clock hand, because it's not moving (so not triggering the movement-during-chronostatis hack) but it moves at a set rate, so you can notice that rate appearing to change.

foone @Foone · Jul 03

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 so very, very not the case. What you think you see and what your eyes can actually see are two exceptionally different things.