Twitter user @Foone decided to freak everyone out on Tuesday by posting a lesser known science fact about the ways in which our brains and eyes work together to lie to us all.
@Foone walked us all step-by-step (*or more accurately, tweet-by-tweet) through the whole freaky sordid truth about saccades and in doing so, revealed a sort of conspiracy of two, against us all.
Take a look at all the madness @foone exposed—IF. YOU. DARE...
You want to know something about how bullshit insane our brains are?— foone (@Foone) July 3, 2018
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
You've got some obvious solutions you could do.— foone (@Foone) July 3, 2018
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
first, it basically puts your visual system on "pause". You're not seeing blackness or even nothing, you're just not seeing period.— foone (@Foone) July 3, 2018
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.
you can see this effect happen if you watch an analog clock with a second hand.— foone (@Foone) July 3, 2018
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.
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) July 3, 2018
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?"— foone (@Foone) July 3, 2018
and the answer is simple! your brain has EVEN MORE UGLY HACKS on top of this to avoid you seeing that
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) July 3, 2018
And just like that, minds were blown:
Anyone watching me as I read this would've noticed me wiggling my eyes about trying to make my vision go blurry...— CyanideAppleGames (@DJCreeperGuy) July 4, 2018
If you do ketamine, the saccadic pause no longer functions and you physically see everything on the way from moving your eyes from point A to point B and it's savage— JRM (@pjfoster1313) July 4, 2018
I feel like there are huge advances to be made in VR by reverse engineering the eyes and the brain's visual processing on a deeper level. Can probably get better, more realistic experience at less than 10% of current rendering cost.— Rich Felker (@RichFelker) July 4, 2018
Just one more brick in the perception versus reality debate:
This makes me think of how we hear ourselves differently on audio/video recordings than how we think we Sound— Kevin (@artistkla) July 4, 2018
People thought the discussions being had on this Twitter thread were awesome and thought provoking, moving well beyond the OP's original focus—but they are all worth a read. Lots to mine here. Some even wanted to translate it for people around the world to enjoy:
Wondering whether I would have read this if it was in a blog rather than a rainforest worth of tweets...however it was interesting. Thank you.— John Swinburn (@johnnytheswin) July 4, 2018
Hey! This was a great thread! Do you mind if I translate it to portuguese and link it to your original tweet?— copikachu (@filipekiss) July 4, 2018
@Foone had lots of other brain/eye deception revelations on the thread that day—which you should definitely check out.
But Foone also left us all with this little time bomb of a tidbit:
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) July 3, 2018