The Cockroach Beatbox

905,515 views ・ 2012-03-12

TED-Ed


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(musikk)
00:13
When you think about the brain,
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når du tenker på hjernen,
00:15
it's difficult to understand,
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det er egentlig en ganske vanskelig ting å forstå,
00:17
because if I were to ask you right now, how does the heart work,
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fordi hvis
00:20
you would instantly tell me it's a pump.
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Du ville forrtalt meg at det var en pumpe. At den pumper blod.
00:23
It pumps blood.
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00:24
If I were to ask about your lungs,
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og hvis jeg skulle spurt deg hvordan lungene dine fungerer,
Hadde du sagt at den bytter oxygen for carbon dioxide. Det er ikke vanskelig.
00:26
you would say it exchanges oxygen for carbon dioxide.
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00:28
That's easy.
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00:29
If I were to ask you how the brain works, it's hard to understand
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00:32
because you can't just look at a brain and understand what it is.
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00:36
It's not a mechanical object, not a pump, not an airbag.
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00:38
It's just like, if you held it in your hand when it was dead,
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00:41
it's just a piece of fat.
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00:43
To understand how the brain works, you have to go inside a living brain.
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00:47
Because the brain's not mechanical, the brain is electrical and it's chemical.
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00:51
Your brain is made out of 100 billion cells, called neurons.
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00:53
And these neurons communicate with each other with electricity.
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00:57
And we're going to eavesdrop in on a conversation between two cells,
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01:01
and we're going to listen to something called a spike.
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01:03
But we're not going to record my brain or your brain or your teachers' brains,
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01:07
we're going to use our good friend the cockroach.
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01:10
Not just because I think they're cool,
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01:12
but because they have brains very similar to ours.
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01:14
So if you learn a little bit about how their brains work,
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01:17
we're going to learn a lot about how our brains work.
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01:19
I'm going to put them in some ice water here
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01:22
And then --
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01:24
Audience: Ew! Greg Gabe: Yeah ...
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01:26
Right now they're becoming anesthetized.
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01:28
Because they're cold blooded, they become the temperature of the water
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01:31
and they can't control it so they just basically "chillax," right?
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01:35
They're not going to feel anything,
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01:37
which may tell you a little about what we're going to do,
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01:39
a scientific experiment to understand the brain.
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01:42
So ...
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01:44
This is the leg of a cockroach.
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01:46
And a cockroach has all these beautiful hairs
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01:48
and pricklies all over it.
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01:50
Underneath each one of those is a cell,
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01:53
and this cell's a neuron that is going to send information
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01:56
about wind or vibration.
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01:57
If you ever try to catch a cockroach, it's hard because they can feel you coming
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02:01
before you're even there, they start running.
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02:03
These cells are zipping up this information up to the brain
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02:06
using those little axons with electronic messages in there.
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02:09
We're going to record by sticking a pin right in there.
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02:11
We need to take off the leg of a cockroach --
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02:14
don't worry, they'll grow back --
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then we're going to put two pins in there.
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02:18
These are metal pins.
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02:19
One will pick up this electronic message, this electric message is going by.
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02:23
So, we're now going to do the surgery, let's see if you guys can see this.
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02:28
Yeah, it's gross ...
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02:32
All right. So there we go.
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You guys can see his leg right there.
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02:37
Now I'm going to take this leg,
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I'm going to put it in this invention that we came up with
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02:41
called the Spikerbox --
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and this replaces lots of expensive equipment in a research lab,
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so you guys can do this in your own high schools,
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or in your own basements if it's me.
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02:53
(Audience: Laughter)
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02:55
So, there.
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02:59
Can you guys see that?
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03:01
Alright, so I'm going to go ahead and turn this on.
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03:06
I'm going to plug it in.
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03:08
(Tuning sound)
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03:09
To me, this is the most beautiful sound in the world.
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03:11
This is what your brain is doing right now.
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03:13
You have 100 billion cells making these raindrop-type noises.
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03:16
Let's take a look at what it looks like,
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let's pull it up on the iPad screen.
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I plugged my iPad into here as well.
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03:22
So remember we said the axon looks like a spike.
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03:24
So we're going to take a look
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at what one of them looks like in just a brief second.
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03:28
We're going to tap here,
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so we can sort of average this guy.
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03:31
So there we see it. That's an action potential.
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03:34
You've got 100 billion cells in your brain doing this right now,
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sending all this information back about what you're seeing, hearing.
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03:40
We also said this is a cell
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that's going to be taking up information about vibrations in the wind.
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03:45
So what if we do an experiment?
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We can actually blow on this and hear if we see a change.
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03:49
Are you guys going to be ready?
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If I blow on it you tell me if you hear anything.
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03:53
(Blowing)
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03:55
(Sound changes)
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03:57
Let me just touch this with a little pen here.
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03:59
(Noise)
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04:02
That was the neural firing rate.
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04:04
That actually took a while in neuroscience to understand this.
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04:07
This is called rate coding:
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04:08
the harder you press on something, the more spikes there are,
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04:11
and all that information is coming up to your brain.
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04:14
That's how you perceive things.
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04:15
So that's one way of doing an experiment with electricity.
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04:18
The other way is that your brain is not only taking in electrical impulses,
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04:22
you're also sending out.
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04:24
That's how you move your muscles around.
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04:26
Let's see what happens if I've plugged in something that's electric
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into the cockroach leg here.
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04:31
I'm going to take two pins, I'm going to plug them onto the cockroach.
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04:34
I'm going to take the other end, I'm going to plug in into my iPod.
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04:38
It's my iPhone actually.
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04:39
Do you guys know how your earbuds work in your ears?
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You have a battery in your phone, or iPod, right?
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It's sending electrical current into these magnets in your earbuds
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which shake back and forth and allow you to hear things.
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04:51
But that current's the same currency that our brain uses,
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04:54
so we can send that to our cockroach leg
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04:55
and hopefully if this works,
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we can actually see what happens when we play music into the cockroach.
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05:00
Let's take a look.
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05:03
(Music beat)
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05:05
Can we turn it up? There we go.
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05:07
(Audience reacts and gasps)
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05:10
GG: So what's happening?
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05:11
Audience: Wow!
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05:13
(Laughter)
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05:14
So you see what's moving. It's moving on the bass.
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05:17
All those audiophiles out there,
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if you have awesome, kicking car stereos,
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you know, the bass speakers are the biggest speakers.
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The biggest speakers have the longest waves,
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which have the most current,
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and the current is what's causing these things to move.
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So it's not just speakers that are causing electricity.
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05:33
Microphones also cause electricity.
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05:35
(Beat)
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So I'm going to go ahead and invite another person out on the stage here
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to help me out with this.
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So there we go.
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05:42
(Beatboxing)
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This is the first time this has ever happened in the history of mankind.
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05:50
Human beatbox to a cockroach leg.
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05:53
When you guys go back to your high school, think about neuroscience
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and how you guys can begin the neuro-revolution.
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05:59
Thank you very much. Bye bye.
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06:00
(Applause)
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Original video on YouTube.com
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