0:00:12 > 0:00:14Are you ready for our Ouch Snips? Snip!Ouch!Exactly.
0:00:24 > 0:00:25Is it...?
0:00:30 > 0:00:32Especially if you're in maths class.
0:00:32 > 0:00:35Believe it or not, the answer is B!
0:00:35 > 0:00:36Your brain really does perform
0:00:36 > 0:00:3810 quadrillion calculations
0:00:38 > 0:00:40a second.
0:00:40 > 0:00:44Which means your brain's the most complicated computer on the planet!
0:00:44 > 0:00:46So, why is it so wrinkly?
0:00:46 > 0:00:48This is a case for Investigation Ouch.
0:00:50 > 0:00:53I'm here at the Brain Cut Room at University College - London.
0:00:53 > 0:00:57And I'm about to get very close to a real human brain.
0:00:57 > 0:01:00This is not for the squeamish.
0:01:00 > 0:01:03We've got exclusive access to this human brain to show you
0:01:03 > 0:01:06all its inner workings.
0:01:06 > 0:01:08This organ controls every single thing you do.
0:01:08 > 0:01:11Even now, your brain is busy sending messages all over your body.
0:01:13 > 0:01:17No, this brain feels rubbery because it's been preserved.
0:01:17 > 0:01:20But the brain inside your head right now is soft and squishy.
0:01:22 > 0:01:25That's because our brains are actually made up of 75% water
0:01:25 > 0:01:27and the rest is mostly fat.
0:01:27 > 0:01:30And the average adult brain weighs 1.5 kilos.
0:01:30 > 0:01:33That's as much as three tins of baked beans.
0:01:33 > 0:01:37Try picking them up and you will see how much weight a neck has to carry.
0:01:37 > 0:01:39And if you look closely at the brain, you can
0:01:39 > 0:01:41see that it's actually all folded up.
0:01:41 > 0:01:44If we unfolded all this, it would be enormous
0:01:44 > 0:01:46and we would need a head the size of a surfboard.
0:01:46 > 0:01:48But there's more to find out than that.
0:01:48 > 0:01:53This big, wrinkly structure is controlling your body 24/7.
0:01:53 > 0:01:55Yes, even when you are asleep.
0:01:55 > 0:01:58So, although the brain is full of fat and water,
0:01:58 > 0:02:01it's actually one of the most amazing computers on earth.
0:02:02 > 0:02:05Not bad for something that looks like a sponge.
0:02:05 > 0:02:08But how does your brain control the rest of your body?
0:02:08 > 0:02:10Well, it's all done by sending electrical messages
0:02:10 > 0:02:12through your nerves to your muscles.
0:02:12 > 0:02:15Whether you're walking, blinking or picking your nose,
0:02:15 > 0:02:18it's these messages from the brain that control movement.
0:02:18 > 0:02:21But we have a clever way to interfere with these signals.
0:02:21 > 0:02:23Time to head to the lab.
0:02:23 > 0:02:26And in order to do that, we are going to use this multipulse
0:02:26 > 0:02:28transcranial magnetic stimulator!
0:02:30 > 0:02:32It's a big magnet.
0:02:32 > 0:02:34But it's a cool, big magnet.
0:02:34 > 0:02:36It sends electric magnetic pulses to the brain,
0:02:36 > 0:02:40which interfere with the brain's own electrical signals and that
0:02:40 > 0:02:43means we can use it to work out which bit of the brain does what.
0:02:45 > 0:02:47Let's give this brain scrambler a whirl.
0:02:47 > 0:02:49Now, Chris, what I want you to do first of all,
0:02:49 > 0:02:52is reach up with your left hand and pick your nose. All right?
0:02:52 > 0:02:54Perfect. You did it perfectly, that's lovely.
0:02:54 > 0:02:56Now, I'm going to get you to do the same thing again,
0:02:56 > 0:03:00but this time, I'm going to try and interfere with the brain scrambler.
0:03:00 > 0:03:03So, Chris, when you are ready, pick your nose.
0:03:03 > 0:03:04CLICKING
0:03:04 > 0:03:07Every time Chris's finger wiggles,
0:03:07 > 0:03:09that's the magnet or brain scrambler,
0:03:09 > 0:03:11interfering with his brain's signals,
0:03:11 > 0:03:13which means he can't pick his nose properly.
0:03:13 > 0:03:15Did you miss?
0:03:16 > 0:03:19But the magnetic brain scrambler is also showing us
0:03:19 > 0:03:22which part of Chris's brain controls his left hand.
0:03:22 > 0:03:24I'm on the right side of Chris's body,
0:03:24 > 0:03:26but it's his left hand that is twitching.
0:03:26 > 0:03:29Now that's because your brain is wired back to front.
0:03:29 > 0:03:32So, the right side of his brain controls the left side of his body,
0:03:32 > 0:03:36and vice versa. So, let's now try it on the other side.
0:03:36 > 0:03:37And you are ready, go.
0:03:37 > 0:03:40So, now I'm interfering with the left side of Chris's brain
0:03:40 > 0:03:42and look, his right hand is all over the place.
0:03:42 > 0:03:44I feel like a cup of tea.
0:03:44 > 0:03:45That sounds lovely.
0:03:48 > 0:03:51Actually, it's me that's drinking the tea and it's cold tea,
0:03:51 > 0:03:53but you'll see why.
0:03:53 > 0:03:56I reckon we could have a bit of fun with this brain scrambler.
0:03:56 > 0:03:58CLICKING
0:03:56 > 0:03:58Whoop, there it goes.
0:03:58 > 0:03:59HE COUGHS
0:03:59 > 0:04:03The brain scrambler is interfering with our brain's normal signals
0:04:03 > 0:04:05and it's creating a right mess.
0:04:05 > 0:04:07HE LAUGHS
0:04:08 > 0:04:11So, we've shown you what a real human brain looks like.
0:04:11 > 0:04:15And that the brain is an amazing organ that controls
0:04:15 > 0:04:18everything you do with superfast electrical signals.
0:04:18 > 0:04:21See you next time!BOTH:Bye.
0:04:21 > 0:04:23Bye.Bye.Bye!Bye.
0:04:23 > 0:04:25Byeee!
0:04:25 > 0:04:27MOUTHS: Bye. MOUTHS:Bye.