Name: 「目の錯覚」について質問ある？ | Tech Support | WIRED Japan
Uploaded: 2025-02-15T08:50:17.000Z
Duration: 21 min 53 s
Description: Thousands of YouTube videos with English-Chinese subtitles! Now you can learn to understand native speakers, expand your vocabulary, and improve your pronunciation...

My name is Pascal Wallisch, a professor of psychology and data science at NYU.

I'm here to answer your questions from Twitter.

And O'Malley, oh, nice username, Anomaly, asks, have you seen the optical illusion where you stare at a spiral, then look away and things appear to be crawling?

If you look at the dot in the center, it's 10 seconds or so, and then look away.

The hand will appear like it is crawling.

There's been thousands of studies on this over the decades.

We know the neurons in your brain that are underlying the perception of motion.

Once they get active for a while, they get tired.

They fire at a lower rate than they did before.

You can measure this with voltages in the brain and we have.

Bernian asks, I was staring at the spinning dance illusion thing and she started spinning backwards.

This goes viral on social media every so often.

Every time this does go viral, people say, oh, if you see it spinning clockwise or counterclockwise, this will tell you whether you're like a left brain or a right brain person.

And I'm here to tell you, no, that has nothing to do with that.

The reason you can tell that it's not true is that if you look at this video, you might notice that midway looking at it, the dancer changes the direction of motion.

So if it was clockwise before, now it goes counterclockwise and vice versa.

Obviously nothing has changed in the stimulus.

If you watch this again, you will have a different experience, maybe.

The image itself is devoid of critical information.

So it's unclear if this hand is in front or this hand is in front.

So whether the dancer will spin this way or that way will depend on your assumption.

If you see the front hand or the back hand, yes.

And the way you can switch this, if you deliberately force yourself to presume that one arm is the front and one is the back.

One, your perception of the world is an interpretation of the world.

And that interpretation depends on the assumptions that you make about the world if there's not enough information about the world.

Spiros Lankos asks, what is motion-induced blindness?

Motion-induced blindness is a great example of like how important motion is.

So what you see in the video is if you focus on the dot in the middle and there's three yellow dots that are always there.

If you keep focusing on the middle, those dots in the periphery start to disappear.

Now I'm claiming that they're always there.

You can confirm that and you can rewind the video by just by keep looking at that.

This is another example of how your perception is a best guess of the world.

One is that there's three dots and they're always there.

And one is a rotating plane that's kind of occluding those dots.

And when in doubt, your brain will go with the motion.

And I'm actually now gonna ruin magic for you, I guess, because most magic tricks rely on this.

The idea is if I create some distraction by making a lot of motion here, I can do literally anything else in plain sight and you will not see it.

Sass the Seabass asks, can someone please explain the difference between the five phenomenon and beta motion to me?

If you're seeing this on a device and this is a video of me talking, there is no motion.

So you see I'm moving right now, but there's no motion.

You see still images, something like 30 or 60 or whatever the frame rate of your monitor is, a second.

Your brain is inferring the motion between that.

First one is obviously here and then obviously is here.

The brain is filling in that something is moving.

If something is here and then disappears, and then something is here, the brain concludes, infers as an unconscious inference, conclusion, it's a guess.

It didn't just, it was here and then it disappeared and then it was here.

And if you make this fast enough, 20 Hertz or 30 Hertz, it will appear like smooth motion.

What phi is, is you have the objects static, sometimes in a ring, and you have then some shadowy thing occluding it.

It will appear like a object is moving around them.

Kolyan asks, how do mirages happen so weird?

That is a example of a genuine optical illusion.

Most things that are called optical illusions are not optical illusions.

So a mirage is an example of an actual optical illusion.

In contrast, most of the other things we'll see today are not optical illusions.

The difference is those are not in the light.

It usually happens if there is air that's being heated by a surface, like for instance, a road, and that is then hitting a layer of air above it that's colder.

And at that transition between the cold air, which is denser, and the hot air, which is less dense, light will bend.

Does it feel like the dark parts are pushing brightness onto the center and the white is pushing out?

First of all, this is called the Asahi illusion by Kitaoka.

What I find is most striking about this is that the center part here, right, does to me, and probably to you, although it depends on your screen, look brighter than the background white in the background, right?

It's the exact same whiteness in the center than in the periphery, right?

So what is going on here is that the gradients of luminance that are pushing into the center, as the poster asks, make you assume that you're looking at something like the sun.

It dilates and constricts, depends on how much light is coming in.

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「目の錯覚」について質問ある？ | Tech Support | WIRED Japan

perspective

perceive

perception

context