[light scratching noises]
There's something very unsettling about this.
Is it?
>> Yeah. What about this?
[wheezing laughter]
No?
My eyes!
We have goggles for a reason!
[Brian's voice echos in the distance] ♪ MODERN ROGUE! ♪
[robot voice] The modern rogue does some freaky stuff with hands.
Jason Murphy, the other day I said, "Come on."
"Tell me a little bit more about what we're doing, while I play piano."
Stop!
What?!
What's the big deal?
It's so... it's kind of creepy.
Look, in my heart, I know that you
want to tell me
what's going on.
We're doing the body transfer illusion.
Body transfer illusion, what's the body transfer illusion?
You're making it both creepy and ridiculous.
Huh? How about this?
[sparring noises]
Okay.
So, the body transfer illusion is where you make a participant
perceive that this is their real hand.
Yeah, and there are different schools of thoughts about this. But basically, for those who believe
that consciousness as we experience it, is an illusion that's created by different parts
of your brain, all of which are not agreeing with each other, and they manufacture this
kind of constant software representation of reality around you.
One way that you can see the Photoshop in your mind working constantly is,
you ever see those floaters go across your vision?
Yeah.
They're there all the time, but your brain is constantly photoshopping them out.
You also have a blind spot in the middle of your vision that you have to work very hard
in order to perceive, because again you're brain is just constantly like,
"That's not important, write that out."
"Fill it in with what we imagine is there."
Right, it's how your brain synthesizes all of the different inputs:
touch, and taste, and smell.
And in this case, the visual stimulus is overriding everything else, including the fact that you
know that this is not your real hand.
Yeah, and we should point out that this is being used in some therapies.
One of the things that happens to people who have arms amputated, is they have phantom
limb itching and pain.
That's where you can feel, like, your hand hurting even though you lost that hand years ago.
And there's nothing to do about it, there's no way to scratch that itch and it's psychologically,
it drives you crazy, right? >> That sounds nightmarish.
Yeah, well and so one of the ways that they'll do it, is that they'll put a mirror there
and you'll put your arm without a hand, but then they'll eventually train your brain to
perceive that this is your hand, and then finally you can scratch that itch.
You can get some kind of data into your brain that says, "Hey, uh stop saying it's itching,"
"because look, it's been scratched."
And the brain's like, "Oh, okay. Must be scratched."
You also see this effect prevalent in virtual reality.
Oh my gosh.
The perception of your body, and it's even better now with stuff like the Vive,
and the room-scale.
You've got a lot of experience with this.
Oh sure, sure.
I'm pretty sure that part of the reason that you teleport in most VR games is because,
I found it very disquieting to press forward and see my body moving forward and not perceive it.
It doesn't line up with what I'm feeling in my body.
So it wasn't necessarily technological limitations, it was a limitation of the human brain.
I'm imagining, and I'm sure that that'll change over time, but for now, I very much prefer
just teleporting spot to spot so it's just a flash and now I'm somewhere else and I feel
like I'm in that space.
As opposed to something where it's like, let me move forward and I'm like,
"Myeh, this doesn't feel right."
I'm moving through space, but I don't feel any of that.
So this is also called the "rubber hand illusion."
It was discovered in Pennsylvania by some psychologists who were trying to figure out
how all of these sensory inputs determined how you actually perceive your body, and the
separation between mind and body.
That's so interesting, because I wouldn't have thought that sight would matter so much,
but I guess we're about to find out how much sight feeds into your perception of who and
what you are, right?
Yeah, in fact, as we're going to learn, it kind of overrides everything else.
Really?! >> Yeah.
Okay, all right, so I assume it's not rocket science.
Walk me through it, what are we doing?
Okay, the goal is to trick yourself into believing that this is your real hand.
Okay.
Now one of us is going to put our actual hand in here, and then we're going to take this
jacket, kind of have the illusion...
Basically fill in the gaps.
Yeah.
The more of these trappings of it being my real arm,
will help to encourage me to believe that it is.
>> Exactly.
Do you want to do it first? >> Yeah, here I'll do it.
Okay, so—oh wait, don't do that.
A-ha! >> Yeah, keep your right arm out.
Here, let me—
>> Put your real hand in here.
Okay, all right, all right.
Might have to sit down.
Yeah, here we go.
I look good.
Okay, so I assume I want to position my hand pretty close to where it is right here.
>> Right.
And then the box will cut off my view of my actual hand, and so instead I assume you do
the same moves to both hands at the same time.
Yeah, and what we're going to do is I have two different little makeup brushes.
You can use paint brushes or anything like that—
Oh my god.
I've already just experienced it.
The moment I looked up at you, and this was in my peripheral vision, I perceived this
as my hand for a split second. >> As your hand!
So it's already working?
And you haven't even done anything yet. >> Yeah.
Well it's already like a weird speed bump that I keep stumbling across, like as long
as I'm looking at the cameras over here, and I see this in the corner, it just feels like
that should be my hand.
Now what I'm going to do is, I'm going to take these brushes, we're going to brush them
both simultaneously across your hand in the same direction at the same time.
And on the same spot.
And on the same spot, it's going to be as synchronized as possible.
So I am meant to be looking at this
the entire time it happens? >> Oh yeah.
Yeah, that's key.
That's probably the most important thing.
I would imagine a more realistic hand would make an even better illusion, but...
Probably so!
They don't call it the realistic hand illusion, they call it the—all right, ready.
So the coordination is not perfectly synchronized, but it's close enough.
Yeah, I feel like more variety of where you're touching would help.
Really?
Yeah.
I'll tell you, it works much better when I'm not looking right at it.
Okay.
When I see it in my peripheral vision, it really starts to feel real.
Okay, that's getting weird.
It does have a cumulative effect.
It does get more and more real over time.
Like, for example just then, when I saw the brush move, I fully expected and anticipated
the sensation of touch on a different part of my hand.
So it doesn't take long to take effect?
Yeah!
That's pretty good!
Oh, that was weird.
Like just then you touched it, and I didn't feel it and it was like, I felt numb.
Yeah.
Like, that is good.
Oh wow, it's happening!
It's happening!
Oh my god, it really feels like my hand now!
That variety matters a lot.
Uh okay, you've got to experience this.
You've got to experience this. >> Okay.
Okay, all right, here we go.
All right, you feeling it?
I'm going to lean forward.
Okay.
So that I can't really see what's going on.
So here, I'm going to be weirdly placed so that I can make this accurate.
Mmk.
Oh, yeah.
>> Is it starting to happen?
I think it's starting to happen, yeah.
[through laughter] Yeah!
On a scale of one to ten, how much of your own hand do you perceive that as?
Like seven.
>> JASON: Oh wow, yeah.
>> Is it getting better, or?
>> It is getting better, yeah.
>> All right, tell me when you get to like an eight or a nine.
>> Okay.
Everything that I read said it has to be in the same spot, and it has to be synchronized
and et cetera, but you moving it around to different parts on the hand, that really does make a difference.
Yeah, I'm...
I'm like at an eight or a nine, it's uh—
Okay, hold on to that.
Hold on to that perception. >> Okay.
[uproarious laughter]
It's like,
oh my god!
You wrecked the hand, too.
Did you know I was going to do that?
Uh, no.
Awesome, okay go for it.
What was it like?
There was that moment where those two competing instincts collided.
Logically I knew, this is not my hand,
but seeing you— >> But you felt the gut-punch.
Yes!
There was that moment of, and not just from the noise or anything,
there was that moment of, "My hand just got ruined."
>> Yeah!
And the only thing that saved me, that yanked me out of it,
was that there wasn't a sudden burst of pain.
Wow! >> Yeah.
[Brian laughs] I'm mean—cause I retracted out of there!
Thinking I was controlling this, but there was that moment when it hit,
those two things collided,
"This is not your hand," "this is totally your hand it's going to hurt really bad!"
Okay, so this is perfect, because I wanted to do this with you not knowing that I was
going to surprise you with it, and I want to compare it.
Should we try it again, and this time you know it's coming?
And you can tell me if that affects the scenario?
Uh, yeah.
Let's do it!
Now the hand is damaged, but—
Well we'll see if that even matters.
I don't know that it matters, because it's already clearly not my hand looking at it, right?
Yeah let's do it again.
Tell me, on a scale of one to ten,
Okay.
when the illusion takes hold.
Yeah, it's, for me it's pretty immediate.
Try looking over at the camera. >> Oh, right!
Tell me if it's stronger in your peripheral vision.
Oh, definitely.
Right?
Yeah, that works much more potently, much more quickly.
I'm, yeah, I'm at like an eight right now.
It's good.
Okay.
All right, are you holding it?
Is it staying there?
Uh, I think so.
[laughter]
>> All right, is it still, is it still?
I'm not looking directly at it, but yeah.
>> So it's still at an eight?
I think so.
>> Okay.
[whispering] I wanted to pull away.
>> Really? Yeah.
This feels weird.
All right, here we go.
[startled] Oh—my god!
[wheezing laughter]
>> What's it like?
I kept having to remind myself, "Don't pull away, don't pull—"
And so I was like, I was willing myself to stay in place.
Wow!
Yeah, because every time you brought it down I was like...
[deep inhale]
And at first I thought, maybe it was just the anticipation of the noise and the impact.
But no, I kept wanting to—
Your body was thinking, "My fingers are in jeopardy."
It's like hot stove.
>> Yeah.
Yeah, yeah.
Here, let me try.
It might not work the same for you, but it certainly was effective with me.
[nervous wailing] Whooo!
♪ Ner-vous about this expe-riment. ♪
[Jason laughing]
Now give it your peripheral, right?
Peripheral vision. >> Yeah. Okay, all right.
So I'm only kind of half-looking.
Yeah, it definitely helps to only see it in your peripheral vision.
So it's like an awareness of it is better than raw visual, direct input.
>> BRIAN: Yeah, and it really is like a brief period of self-hypnosis,
where it's like you're training yourself.
You're letting yourself believe it.
In fact, you remember, and forgive me for bringing this up again, when,
when you stabbed me
in the hand and it messed up my nerves in my hand, one of the bits of advice is they said,
take your hand and just run it around in a bag full of rice and just be really in-tune
with what you're seeing as you touch.
Because essentially your brain is re-wiring the perception so that it can create this
illusion of conscious existence.
It's really, I'm at like a seven or eight now.
Yeah? You ready to try it? >> Yeah.
Yeah I am.
Okay, so I'm at an eight.
>> Mm-hmm.
I perceive that as my hand.
Wh-is it this one, or is it this one?
You mother—you mm.
GAWD
DAHMM
MIIITT!
[laughter]
That was jacked up!
>> Yeah, right?
That is more powerful than I had originally thought it would be.
It kind of freaked me out seeing the finger get severed.
Oh my god, that was a living nightmare.
[both laughing]
We just gave you PTSD.
Yeah, right?
Okay, so I guess for everybody at home, it's astonishing how quickly it takes root,
and how little it takes.
Just uh, something to obscure your vision from your actual hand.
>> Yeah.
Something to complete the image of the rest of your body, you know we used a jacket, but
I would imagine it would work even better if you built a jacket such that you cut a
slice in there so your arm goes out >> Oh, sure.
and you see your shoulder, you see, you know fill it with...
I don't know, cotton or something in there, you know.
Yeah, yeah.
What if you had this loaded with blood?
Oh my god!
Yeah, that'd be messed up.
Like, that was legit panic for a hot moment.
I give this a ten out of ten.
Yeah.
That is a must-try experience.
It's so easy to do.
And if anyone says otherwise, give them one of these.
Give them the finger!
The middle—this is the middle finger. Huh?
[uncomfortable shudder]
Oh, no!
No, not a—
[Brian laughing]
Where did the other finger go?!
— CC BY BIZARRE MAGIC — [branding furnace hissing]
[static and wind]
[laughter]
>> BRIAN: That looks great!
>> JASON: Right?
>> JASON: The Hand of Brian kind of sounds like a bad '70s horror movie.
[laughter]