0:00:05 > 0:00:07Who's in control of what you do?
0:00:10 > 0:00:14This sounds like a simple question, but the facts might surprise you.
0:00:15 > 0:00:18Almost every action that you take...
0:00:18 > 0:00:20PROTESTERS SHOUT
0:00:20 > 0:00:22..and every decision that you make...
0:00:23 > 0:00:25..and every belief that you hold...
0:00:26 > 0:00:30..these are driven by parts of your brain that you have no access to.
0:00:32 > 0:00:36We call this hidden world "the unconscious".
0:00:38 > 0:00:41And it runs much more of your life than you would ever imagine.
0:00:45 > 0:00:48In this film, I'm going to investigate the weird ways
0:00:48 > 0:00:52our brain secretly controls everything that we do.
0:00:59 > 0:01:01God, that was amazing!
0:01:03 > 0:01:04How, without our awareness,
0:01:04 > 0:01:08the brain controls the complex machinery of the body.
0:01:11 > 0:01:14And makes decisions without our awareness.
0:01:17 > 0:01:21This is the story of everything the brain does
0:01:21 > 0:01:23that remains hidden from us.
0:01:24 > 0:01:28It is the story of who's really in control.
0:02:09 > 0:02:10It's first thing in the morning
0:02:10 > 0:02:14and the streets here are almost completely silent.
0:02:14 > 0:02:15But all around me,
0:02:15 > 0:02:19one of the most remarkable events in the universe is taking place.
0:02:20 > 0:02:24In all of these houses, one by one,
0:02:24 > 0:02:27human consciousness is flickering to life.
0:02:28 > 0:02:32One of the most complex objects in the known universe
0:02:32 > 0:02:35is becoming aware that it exists.
0:02:42 > 0:02:44ALARM BLEEPS
0:02:44 > 0:02:47FAINT ALARM BLEEPS
0:02:48 > 0:02:50ALARM GROWS LOUDER
0:02:52 > 0:02:55RUSH OF TRAFFIC, SIREN BLARES
0:02:55 > 0:03:01This is the birth of YOU and this little miracle happens every day.
0:03:02 > 0:03:06Waking up is the moment when our conscious brains come online.
0:03:07 > 0:03:10But it's also the beginning of a great deception.
0:03:15 > 0:03:19It feels like YOU are in charge of all the decisions
0:03:19 > 0:03:21you're about to make.
0:03:26 > 0:03:28Like YOU are running the show.
0:03:31 > 0:03:34But it's not quite that simple.
0:03:37 > 0:03:40Take a moment to think about what it is to be conscious.
0:03:42 > 0:03:45To be aware of the world around you.
0:03:48 > 0:03:51Thinking about what you're going to have for breakfast...
0:03:51 > 0:03:54or what you're going to do next.
0:03:56 > 0:03:58When you're consciously aware,
0:03:58 > 0:04:02it feels like that's all that's really going on inside your head.
0:04:03 > 0:04:05But here's the surprise...
0:04:05 > 0:04:07All of that conscious you
0:04:07 > 0:04:11makes up the smallest bit of the activity in your brain.
0:04:14 > 0:04:18The conscious you thinks it's the captain of the ship...
0:04:19 > 0:04:23..but in truth it's nothing more than a stowaway.
0:04:29 > 0:04:33So, what is all this hidden activity inside our heads?
0:04:34 > 0:04:36A large part of it is dedicated to something
0:04:36 > 0:04:38that most of us take for granted.
0:04:40 > 0:04:42Operating the body.
0:04:44 > 0:04:47Most of the actions we make, even those that seem intentional,
0:04:47 > 0:04:50are automatic and unconscious.
0:04:50 > 0:04:52CROWD YELLS
0:04:52 > 0:04:55We can see this very clearly in a situation
0:04:55 > 0:04:57that demands a fast response.
0:04:59 > 0:05:03I'm about to face a fastball from Matt over there on the mound.
0:05:03 > 0:05:04In order for me to hit the ball,
0:05:04 > 0:05:07there's a very complex series of processes
0:05:07 > 0:05:08that has to happen in my brain.
0:05:08 > 0:05:10He pitches at 92mph,
0:05:10 > 0:05:14so that doesn't give me very much time to hit the ball.
0:05:15 > 0:05:16OK, ready!
0:05:19 > 0:05:23HEAVY WARPING TONE AS TIME SLOWS
0:05:28 > 0:05:30AMPLIFIED WING BEATS
0:05:34 > 0:05:38The ball leaves the mound and starts on its way to the home plate.
0:05:42 > 0:05:46This journey of 60 feet, six inches
0:05:46 > 0:05:49will take place in around four tenths of a second.
0:05:57 > 0:06:00And in that time, there's a huge amount for my brain to do.
0:06:02 > 0:06:06The light from the baseball needs to hit my eye...
0:06:07 > 0:06:11..work through the many miles of circuitry in my brain...
0:06:11 > 0:06:13ELECTRIC PULSING
0:06:15 > 0:06:19..and send signals to my muscles to swing the bat.
0:06:20 > 0:06:25This entire sequence unfolds in just a fraction of a second.
0:06:25 > 0:06:27BOOM!
0:06:28 > 0:06:30But here's the surprise.
0:06:30 > 0:06:33My conscious awareness hasn't yet had time
0:06:33 > 0:06:35to register what's going on.
0:06:38 > 0:06:41I strike the ball without thinking
0:06:41 > 0:06:45and only become aware of what's happened after the event.
0:06:54 > 0:06:57By the time the conscious mind gets the information,
0:06:57 > 0:06:59it's already old news,
0:06:59 > 0:07:02and this is because the ball simply travels too fast for me
0:07:02 > 0:07:05to be consciously aware of its position.
0:07:05 > 0:07:07And this is not just true of baseball,
0:07:07 > 0:07:09but in all areas of our life.
0:07:10 > 0:07:12NEON LIGHT BUZZES
0:07:13 > 0:07:17Every day, behind the scenes, the unconscious parts of our brain
0:07:17 > 0:07:19are hard at work helping us to accomplish
0:07:19 > 0:07:22even the most basic of tasks.
0:07:22 > 0:07:25Take drinking a coffee.
0:07:25 > 0:07:27It seems incredibly simple
0:07:27 > 0:07:31but, under the hood, our brains must unconsciously coordinate
0:07:31 > 0:07:35and make sense of trillions of electrical impulses.
0:07:35 > 0:07:38ELECTRIC PULSING
0:07:42 > 0:07:44As I touch the cup,
0:07:44 > 0:07:48my nerves transmit reams of information to the brain
0:07:48 > 0:07:50and that helps me to estimate its weight...
0:07:52 > 0:07:53..its position in space...
0:07:54 > 0:07:56..its temperature.
0:07:57 > 0:08:01My ability to control the cup relies on electrical impulses
0:08:01 > 0:08:06going back and forth from my hands and muscles to my brain
0:08:06 > 0:08:07and back again.
0:08:12 > 0:08:17Many of these signals will be sorted and processed in the cerebellum.
0:08:19 > 0:08:24Here, specialised neurons with up to 200,000 connections each
0:08:24 > 0:08:28help calculate the millions of micro-adjustments needed
0:08:28 > 0:08:31to achieve the smooth movement of the body.
0:08:31 > 0:08:34RAPID ELECTRONIC BLEEPING
0:08:38 > 0:08:42And yet, all of this remains completely hidden from me.
0:08:43 > 0:08:46I simply enjoy the experience of drinking my coffee.
0:08:49 > 0:08:52Every day as we move, hidden from view,
0:08:52 > 0:08:54our brains unconsciously process
0:08:54 > 0:08:57trillions upon trillions of calculations.
0:09:01 > 0:09:04This unconscious processing is what allows us
0:09:04 > 0:09:07to move with effortless grace through the world.
0:09:09 > 0:09:11It's a feat so remarkable
0:09:11 > 0:09:13that we have yet to build a machine
0:09:13 > 0:09:15that comes anywhere close to it.
0:09:21 > 0:09:24In fact, we've only just begun to discover
0:09:24 > 0:09:29the techniques that the brain uses to make its many calculations.
0:09:32 > 0:09:36There's so much that our brain does that's hidden from us,
0:09:36 > 0:09:40we often take for granted what's going on up there.
0:09:40 > 0:09:44But what would it be like if some of these unconscious skills
0:09:44 > 0:09:46were taken away from us?
0:09:48 > 0:09:52What amazes me, you know, you sit on a bench somewhere,
0:09:52 > 0:09:53just watch people walking by
0:09:53 > 0:09:55and you're sort of thinking,
0:09:55 > 0:09:57"You're doing that so fluidly
0:09:57 > 0:10:02"and so seamlessly, totally unaware of this amazing system
0:10:02 > 0:10:04"that's managing that process for you."
0:10:05 > 0:10:07At the age of 19,
0:10:07 > 0:10:11Ian Waterman suffered a rare type of nerve damage.
0:10:11 > 0:10:17Now every tiny detail of movement requires intense conscious effort.
0:10:19 > 0:10:23I lost the ability to manage my body automatically.
0:10:24 > 0:10:28That system that works in here somewhere,
0:10:28 > 0:10:33that we develop as we stand and tumble and fall as a baby
0:10:33 > 0:10:37and we develop as we grow - gone.
0:10:39 > 0:10:40For most people,
0:10:40 > 0:10:45this condition prevents any kind of coordinated movement,
0:10:45 > 0:10:48but over time Ian has learned to treat his body
0:10:48 > 0:10:50like a complex puppet.
0:10:54 > 0:10:59Ian has spent years analysing movement and working out
0:10:59 > 0:11:04how to perform each tiny flex and bend that the human body can make.
0:11:06 > 0:11:09Mustering an incredible mental focus,
0:11:09 > 0:11:14Ian is now able to put these all together to make himself walk.
0:11:19 > 0:11:26For Ian, walking is a monumental triumph of skill, dedication
0:11:26 > 0:11:28and concentration.
0:11:31 > 0:11:36It's an amazing loss and it's a significant cognitive effort
0:11:36 > 0:11:39to replace what comes automatically within us.
0:11:39 > 0:11:44It's an astounding facility that the body has to manage itself.
0:11:44 > 0:11:48You just don't know what it is until it goes.
0:11:56 > 0:12:01Next time you see a person moving, take a moment to marvel.
0:12:01 > 0:12:04Not just at the beauty of the human body,
0:12:04 > 0:12:08but at the power of the unconscious brain that's orchestrating it.
0:12:13 > 0:12:19Our unconscious brain is capable of some truly remarkable feats.
0:12:21 > 0:12:26But why is so much of what we do buried out of reach?
0:12:33 > 0:12:36To answer this question,
0:12:36 > 0:12:39we can take a peek into the mind of a champion.
0:12:44 > 0:12:50This is Austin Naber. He has set world records for cup stacking.
0:12:51 > 0:12:54Nothing you are about to see has been sped up in any way.
0:13:13 > 0:13:17Austin, that was terrific. How long have you been practising this?
0:13:17 > 0:13:19Um, two years and ten months.
0:13:19 > 0:13:21- And do you practise every day?- Yep.
0:13:21 > 0:13:23How many hours?
0:13:23 > 0:13:24Um, at least three or four.
0:13:24 > 0:13:27And when you first started this, how fast could you do it?
0:13:27 > 0:13:29Um, two minutes, two and a half minutes.
0:13:29 > 0:13:33- To do the same routine you were just doing?- Yeah, the cycle.
0:13:33 > 0:13:35OK, and how quickly can you do it now?
0:13:35 > 0:13:39- Five seconds.- Five seconds? Wow, that's quite an improvement.
0:13:39 > 0:13:42So, when you're doing that, are you thinking about what you're doing?
0:13:42 > 0:13:44- Not really.- You're just letting your hands do the work?
0:13:44 > 0:13:45Mm-hm.
0:13:46 > 0:13:48Watching Austin stack cups,
0:13:48 > 0:13:53you might expect that his brain is working overtime.
0:13:53 > 0:13:57Having to coordinate these complex actions so quickly,
0:13:57 > 0:14:01it seems like his brain must be burning a lot of extra energy.
0:14:01 > 0:14:03HE LAUGHS God, that was amazing!
0:14:03 > 0:14:06'But the real story's not quite that simple.
0:14:08 > 0:14:10'To gain a better insight into what's happening here,
0:14:10 > 0:14:12'we have to peek inside the brain.'
0:14:13 > 0:14:17- Austin, how does the cap feel on you?- Good.
0:14:17 > 0:14:21'The skullcaps we're being fitted with are devices for measuring
0:14:21 > 0:14:24'electroencephalography, or EEG.
0:14:24 > 0:14:29'They read electrical signals from the scalp to reveal clues
0:14:29 > 0:14:31'about the activity going on inside the brain.'
0:14:33 > 0:14:36'Conductive gel is injected at various points
0:14:36 > 0:14:38'to help boost the signal.'
0:14:38 > 0:14:41So, all the lights on your head are turning green, which is good.
0:14:41 > 0:14:43There's a good connection there.
0:14:43 > 0:14:45'With both of us rigged up,
0:14:45 > 0:14:49'we now have a window into the electrical world within our brains.'
0:14:49 > 0:14:51So, now we're going to race.
0:14:51 > 0:14:56'And we can see how much effort it takes our brains to cup stack.'
0:14:56 > 0:14:58- You ready?- Mm-hm.
0:14:58 > 0:15:00Set, go!
0:15:05 > 0:15:09Looking at the EEG, you can see that my brain is working full tilt.
0:15:10 > 0:15:13My conscious mind is actively searching for ways
0:15:13 > 0:15:16to best perform this task,
0:15:16 > 0:15:18and figuring out what to do next.
0:15:20 > 0:15:23It means there's a lot of electrical activity happening in my brain,
0:15:23 > 0:15:26and a lot of energy being expended.
0:15:28 > 0:15:32In contrast, Austin's brain is serene.
0:15:32 > 0:15:35Despite the speed and complexity of what he's doing,
0:15:35 > 0:15:38his brain is in an almost rest-like state.
0:15:42 > 0:15:43HE LAUGHS
0:15:43 > 0:15:46I'm...right there behind you!
0:15:46 > 0:15:47'So, how is he able to do this?'
0:15:52 > 0:15:56Austin's talent is a result of physical changes in his brain.
0:15:57 > 0:15:59During his years of practice,
0:15:59 > 0:16:02a specialised set of connections has been formed.
0:16:04 > 0:16:07He's carved the skill of cup stacking into the structure
0:16:07 > 0:16:09of his neurons.
0:16:11 > 0:16:14This allows Austin's brain to perform this task rapidly
0:16:14 > 0:16:16and efficiently.
0:16:26 > 0:16:31As we learn new skills, they change the structure of our brains.
0:16:31 > 0:16:35They move from software to become part of the hardware of the mind.
0:16:37 > 0:16:40It means Austin can even do this...
0:16:40 > 0:16:41blindfolded.
0:16:46 > 0:16:50When we practise new skills, we physically hard-wire them.
0:16:50 > 0:16:53Some people talk about this as "muscle memory".
0:16:53 > 0:16:55But it doesn't have anything to do with our muscles.
0:16:55 > 0:17:00All the changes are orchestrated across the vast seas of our brain.
0:17:03 > 0:17:05It's not just about cup stacking.
0:17:05 > 0:17:07As we develop from childhood,
0:17:07 > 0:17:10we all begin to acquire these burnt-in circuits.
0:17:11 > 0:17:13Everything from walking...
0:17:13 > 0:17:15to tying laces.
0:17:17 > 0:17:18Typing...
0:17:20 > 0:17:22..to riding a bike.
0:17:22 > 0:17:25All of these are skills that get hard-wired into the structure
0:17:25 > 0:17:27of our brains,
0:17:27 > 0:17:30making them automatic and energy-efficient.
0:17:33 > 0:17:37Despite the vast amount of information it processes,
0:17:37 > 0:17:40the human brain requires only as much energy
0:17:40 > 0:17:42as a 60-watt light bulb.
0:17:48 > 0:17:50But there's a consequence to hard-wiring.
0:17:51 > 0:17:53These skills become hidden from us.
0:17:55 > 0:17:56They become unconscious.
0:17:58 > 0:18:00I don't know how I'm riding this bike.
0:18:00 > 0:18:03The small corrections of the handlebars,
0:18:03 > 0:18:07the micro-corrections of my balance.
0:18:07 > 0:18:10And this is the same with all new skills that we learn,
0:18:10 > 0:18:13whether it's cycling, or reading, or typing,
0:18:13 > 0:18:16or driving a car, or playing the piano.
0:18:16 > 0:18:20We lose access to the sophisticated programmes that we're running.
0:18:24 > 0:18:28'And this can cause some odd effects for our conscious mind.'
0:18:32 > 0:18:33HORN BLARES
0:18:33 > 0:18:36Take the feeling commonly referred to as "autopilot".
0:18:38 > 0:18:41Most of us will have experienced it while driving.
0:18:43 > 0:18:45You're cruising along,
0:18:45 > 0:18:46and suddenly you're halfway home,
0:18:46 > 0:18:49with no memory of how you got there.
0:18:51 > 0:18:55This sensation happens because the driving is being performed
0:18:55 > 0:18:57unconsciously and automatically.
0:19:01 > 0:19:05Brains can be trained to perform almost any skill automatically.
0:19:09 > 0:19:13And some of them can seem almost superhuman.
0:19:20 > 0:19:24Through intense practice, the brain's ability to run on autopilot
0:19:24 > 0:19:28can be harnessed to achieve some extreme feats.
0:19:36 > 0:19:41Free solo climbing is climbing without anything but your body.
0:19:41 > 0:19:44There's no ropes, there's nothing holding you onto the rock
0:19:44 > 0:19:46but your hands and your feet.
0:19:52 > 0:19:54This is Dean Potter.
0:19:54 > 0:19:58From the age of 12, he's dedicated his life to climbing.
0:19:58 > 0:20:02These years of practice have hard-wired this incredible skill
0:20:02 > 0:20:04into the structure of his brain.
0:20:06 > 0:20:10But Dean's real challenge is to let these hard-wired skills
0:20:10 > 0:20:12run without conscious interference.
0:20:13 > 0:20:18A moment's hesitation, or stray thought, could spell disaster.
0:20:20 > 0:20:22To stay alive,
0:20:22 > 0:20:26Dean has to give over complete control to his unconscious.
0:20:30 > 0:20:32HE GRUNTS
0:20:32 > 0:20:37My most pinnacle moments are when I completely go away,
0:20:37 > 0:20:41consciously, and I find myself at the top of the rock.
0:20:41 > 0:20:42It's kind of like blackout.
0:20:42 > 0:20:46I'm... Don't know what happened.
0:20:46 > 0:20:48Um...
0:20:48 > 0:20:49But I'm on the top of the rock.
0:20:50 > 0:20:54As Dean climbs, he enters what's known as a "flow state".
0:20:56 > 0:20:59It's a form of brain activity experienced by different
0:20:59 > 0:21:03kinds of people, from meditation experts, to elite athletes,
0:21:03 > 0:21:05to professional musicians.
0:21:08 > 0:21:11It's sometimes referred to as "the zone",
0:21:11 > 0:21:14and it arises during total immersion in a task.
0:21:17 > 0:21:21In flow states, the neural circuits are able to run
0:21:21 > 0:21:24without the conscious mind interfering.
0:21:28 > 0:21:33When Dean enters a flow state, he operates without distraction
0:21:33 > 0:21:34and without fear.
0:21:35 > 0:21:39My perception is heightened.
0:21:39 > 0:21:42What I'm seeing is much clearer.
0:21:42 > 0:21:46The particles of dust in the air in front of me.
0:21:46 > 0:21:48Very subtle noises,
0:21:48 > 0:21:51or things that happen very fast become slowed down.
0:21:54 > 0:21:56I'm no longer in my rational thought.
0:21:56 > 0:21:58I'm in my...um...
0:21:58 > 0:22:02unconscious thought, where I'm just moving on the rock.
0:22:05 > 0:22:08I stop thinking about what I'm doing and I just do.
0:22:10 > 0:22:15We all have chatter when we're thinking of all the things in life.
0:22:15 > 0:22:18We all walk around with all this weight on us.
0:22:18 > 0:22:21Things we're worried about, or things we're hopeful for.
0:22:21 > 0:22:23Things that aren't...
0:22:23 > 0:22:28Like, really, they don't have to do with where we're at.
0:22:28 > 0:22:32And, for me, danger eliminates all that.
0:22:36 > 0:22:39The reason I'm doing all these things isn't to climb the rock.
0:22:39 > 0:22:43The reason I'm doing it is to enter the heightened state.
0:22:43 > 0:22:46So, it doesn't matter what I'm doing.
0:22:46 > 0:22:49If I can enter that heightened state, I'm happy.
0:23:05 > 0:23:07Months after this interview,
0:23:07 > 0:23:13Dean lost his life in a wingsuit accident in Yosemite National Park,
0:23:13 > 0:23:14doing what he loved.
0:23:25 > 0:23:26PULSE THROBS
0:23:29 > 0:23:33The hidden parts of the brain can take total control over our bodies.
0:23:38 > 0:23:42But it's also capable of shaping our lives in more profound ways.
0:23:53 > 0:23:56The man who would begin to uncover this
0:23:56 > 0:23:59revolutionised the way we think about who we are.
0:24:03 > 0:24:06His name was Sigmund Freud.
0:24:12 > 0:24:16In 1938, Sigmund Freud was fleeing from the Nazis in Austria.
0:24:16 > 0:24:20And he moved here, to this house in London.
0:24:20 > 0:24:23Freud was one of the 20th century's most influential thinkers,
0:24:23 > 0:24:27and that's because he ushered in a new way of thinking about
0:24:27 > 0:24:29why people behave the way they do.
0:24:33 > 0:24:36Freud's fascination with the brain had begun at medical school
0:24:36 > 0:24:40in Vienna, where he specialised in neurology.
0:24:40 > 0:24:44After graduation, he set up a private practice,
0:24:44 > 0:24:47treating patients with psychological disorders.
0:24:47 > 0:24:49Fascinated by what he saw,
0:24:49 > 0:24:53Freud soon began formulating radically new ideas
0:24:53 > 0:24:55about the unconscious mind.
0:24:58 > 0:25:03ARCHIVE RECORDING:
0:25:15 > 0:25:18Freud would become the founder of psychoanalysis -
0:25:18 > 0:25:21an approach that put the focus on understanding
0:25:21 > 0:25:24what's beneath conscious awareness.
0:25:26 > 0:25:30Ruth McCall is a psychoanalyst with a special interest in Freud's work.
0:25:32 > 0:25:35Before Freud, there was very little help.
0:25:35 > 0:25:39Freud pioneered a method of getting people just to talk.
0:25:39 > 0:25:43To try and get people to expose themselves through words.
0:25:43 > 0:25:47He would get people to lie on what he called a couch,
0:25:47 > 0:25:49and he sat behind them.
0:25:49 > 0:25:52Because when you break the linkage of eye-to-eye contact,
0:25:52 > 0:25:55people stop speaking to another person
0:25:55 > 0:25:59and they begin to speak a bit more to themselves.
0:25:59 > 0:26:00And that, we feel,
0:26:00 > 0:26:04leads to threads that have their end point in our unconscious.
0:26:07 > 0:26:12In an era before brain scans or powerful computer simulations,
0:26:12 > 0:26:16Freud's couch was his window into the world of the unconscious.
0:26:19 > 0:26:22Freud paid close attention to the information that was contained
0:26:22 > 0:26:24in slips of the tongue,
0:26:24 > 0:26:26and he hypothesised that all of this
0:26:26 > 0:26:29results from unconscious motivations.
0:26:29 > 0:26:33So, by paying attention to what was poking above the surface,
0:26:33 > 0:26:37Freud felt that he could get a good sense of what was lurking below.
0:26:38 > 0:26:42Freud had seen that beneath the surface of each of us
0:26:42 > 0:26:46lies a swirling sea of hidden motivations,
0:26:46 > 0:26:48and drives, and desires.
0:26:55 > 0:26:58The way we think, and feel, and act
0:26:58 > 0:27:01is profoundly influenced by this unconscious.
0:27:05 > 0:27:10Freud would be just one of many explorers of this brave new world.
0:27:13 > 0:27:15As the 20th century progressed,
0:27:15 > 0:27:19many other scientists began designing experiments
0:27:19 > 0:27:22to shed light on the mysterious workings of the mind.
0:27:26 > 0:27:29They were trying to uncover how much control
0:27:29 > 0:27:32our consciousness really has.
0:27:32 > 0:27:36But what they were to discover would be far stranger
0:27:36 > 0:27:37than anyone imagined.
0:27:43 > 0:27:46Take an experiment run in the mid-1960s by Eckhard Hess.
0:27:52 > 0:27:54It was a simple experiment.
0:27:54 > 0:27:57He asked men to look at photographs of women's faces
0:27:57 > 0:28:00and make judgements about them.
0:28:04 > 0:28:06How kind does she look?
0:28:09 > 0:28:12How selfish or unselfish?
0:28:14 > 0:28:16How friendly or unfriendly?
0:28:17 > 0:28:19And how attractive?
0:28:23 > 0:28:25It seems like a straightforward enough task,
0:28:25 > 0:28:30but as is often the case with psychological experiments,
0:28:30 > 0:28:32there was a catch.
0:28:32 > 0:28:36Unbeknownst to the subject, the experiment had been manipulated.
0:28:36 > 0:28:38In half of the photographs,
0:28:38 > 0:28:40the women's eyes had been artificially dilated,
0:28:40 > 0:28:44so it was the same woman, but with different-sized pupils.
0:28:47 > 0:28:50Dilated eyes are, among other things,
0:28:50 > 0:28:54a biological sign of sexual arousal.
0:28:54 > 0:28:57This was to drastically influence the choices that the men made.
0:28:59 > 0:29:01But without them being aware of it.
0:29:02 > 0:29:06It turns out that the men found the women with dilated eyes
0:29:06 > 0:29:09to be more attractive. Now, here's the important part -
0:29:09 > 0:29:12none of the men explicitly noticed that there was a difference
0:29:12 > 0:29:17in the size of the pupils and, critically, none of the men knew
0:29:17 > 0:29:22that dilated eyes is a biological sign of sexual readiness.
0:29:22 > 0:29:26But their brains knew and what they were doing was
0:29:26 > 0:29:29running deeply-carved evolutionary programmes
0:29:29 > 0:29:33steering their decision-making towards the right sort of mate.
0:29:34 > 0:29:37The subject's brains were recognising and analysing
0:29:37 > 0:29:40tiny details in the pictures
0:29:40 > 0:29:42and acting on them.
0:29:48 > 0:29:53All of this was happening without a flicker of conscious awareness.
0:29:57 > 0:29:59This kind of experiment reveals something
0:29:59 > 0:30:02fundamental about how brains operate.
0:30:02 > 0:30:06The job of this organ is to gather information from the world
0:30:06 > 0:30:08and steer your behaviour appropriately.
0:30:08 > 0:30:11And it just doesn't matter whether your conscious awareness
0:30:11 > 0:30:13is involved in that or not.
0:30:13 > 0:30:15And most of the time, it's not.
0:30:15 > 0:30:18Most of the time, you're not aware of the decisions
0:30:18 > 0:30:21that are being made on your behalf.
0:30:24 > 0:30:27Hess's experiment is just the tip of the iceberg.
0:30:27 > 0:30:29LAUGHTER AND CHATTER
0:30:31 > 0:30:35'Today, researchers have uncovered a whole range of scenarios
0:30:35 > 0:30:38'in which our unconscious brains make decisions
0:30:38 > 0:30:42'or change our behaviour without us realising what's happening.'
0:30:42 > 0:30:44- Here you go.- Thanks.
0:30:44 > 0:30:47'Here are just a few of the stranger ones.'
0:30:49 > 0:30:52If you're holding a warm cup of coffee,
0:30:52 > 0:30:56you'll describe your relationship with your mother as closer
0:30:56 > 0:30:58than if you're holding an iced coffee.
0:31:01 > 0:31:03When you're in a foul-smelling environment,
0:31:03 > 0:31:05you make harsher moral decisions.
0:31:09 > 0:31:12If you happen to find yourself
0:31:12 > 0:31:16sitting next to some hand sanitiser, that shifts your political opinions
0:31:16 > 0:31:19a little bit more towards the conservative side,
0:31:19 > 0:31:23presumably because it reminds your brain about outside threats.
0:31:26 > 0:31:29Every day, we're influenced in countless ways
0:31:29 > 0:31:32by the world around us and most of this flies
0:31:32 > 0:31:35completely under the radar of our conscious awareness.
0:31:38 > 0:31:42'Totally hidden from us, the unconscious brain is continually
0:31:42 > 0:31:47'reacting to the outside world and making decisions on our behalf.'
0:31:50 > 0:31:52So, all this might leave you wondering -
0:31:52 > 0:31:55why aren't we just unconscious beings?
0:31:55 > 0:31:59What exactly is the point of consciousness?
0:32:00 > 0:32:04Well, we can gather the first clue by looking at what happens
0:32:04 > 0:32:07when we encounter something unexpected.
0:32:17 > 0:32:20Although most of the time, your brain can run on autopilot,
0:32:20 > 0:32:23when you come across something you weren't expecting...
0:32:28 > 0:32:31..your conscious mind is called into action.
0:32:32 > 0:32:37It works to figure out if this new thing is a threat or an opportunity.
0:32:41 > 0:32:43This is one of the jobs of consciousness -
0:32:43 > 0:32:48to assess what's going on, to make sense of the situation.
0:33:02 > 0:33:04When your expectations are violated,
0:33:04 > 0:33:09consciousness is summoned up to work out the appropriate reaction.
0:33:11 > 0:33:12BUZZING
0:33:12 > 0:33:15But that's only part of the story.
0:33:15 > 0:33:16Consciousness isn't just about
0:33:16 > 0:33:19reacting to unexpected events in the outside world.
0:33:21 > 0:33:26It also plays a vital role in resolving internal conflict
0:33:26 > 0:33:30among the brain's many automatic subsystems.
0:33:35 > 0:33:37To understand the role consciousness plays,
0:33:37 > 0:33:42I'd like to imagine the brain as a vast sprawling organisation.
0:33:45 > 0:33:49One with many thousands of divisions and subdivisions.
0:33:50 > 0:33:54All collaborating and interacting and competing.
0:34:01 > 0:34:06I think of consciousness like the CEO of a large corporation.
0:34:06 > 0:34:09When a company is small, it doesn't need a CEO.
0:34:09 > 0:34:14But once an organisation reaches sufficient size and complexity,
0:34:14 > 0:34:18then it needs someone to rise above the daily details
0:34:18 > 0:34:20and take the long view.
0:34:24 > 0:34:29Within the brain, there are thousands of automated departments,
0:34:29 > 0:34:32each working on its own task.
0:34:37 > 0:34:40Some departments can overlap and collaborate,
0:34:40 > 0:34:43but what happens if there's a conflict between them?
0:34:45 > 0:34:47Say you're hungry, but you're on a diet?
0:34:50 > 0:34:53Or you feel sleepy, but you have an important deadline?
0:34:55 > 0:34:59When this happens, it's time for the boss to get a call.
0:34:59 > 0:35:01TELEPHONE RINGS
0:35:07 > 0:35:12In the event of an internal conflict, your conscious mind
0:35:12 > 0:35:16tries to work out what's best and make an executive decision.
0:35:19 > 0:35:21Consciousness is the arbiter
0:35:21 > 0:35:24of conflicting motivations in the brain.
0:35:28 > 0:35:31It has a unique vantage point,
0:35:31 > 0:35:33one that no other part of the brain has access to.
0:35:37 > 0:35:42Think of consciousness as a way for trillions of cells
0:35:42 > 0:35:45to see themselves as a unified whole.
0:35:45 > 0:35:51It's a way for a complex system to hold up a mirror to itself.
0:36:04 > 0:36:10Consciousness is one of evolution's greatest creations.
0:36:10 > 0:36:14It allows the brain to arbitrate the vast workings of the unconscious.
0:36:15 > 0:36:19It allows the brain to react to unexpected events.
0:36:21 > 0:36:24And it allows the brain to see itself.
0:36:28 > 0:36:33In acting as a long-term planner, consciousness has led us to become
0:36:33 > 0:36:36the most successful species on the planet.
0:36:42 > 0:36:46But what happens if consciousness goes off-line?
0:36:46 > 0:36:49If the unconscious parts of our brain
0:36:49 > 0:36:52are given complete control of our actions?
0:36:56 > 0:37:03In Toronto, in 1987, a 23-year-old man named Ken Parks would find out.
0:37:06 > 0:37:10The incident began when he fell asleep in front of his television.
0:37:11 > 0:37:13He went to sleep
0:37:13 > 0:37:17and he woke up maybe, perhaps an hour later.
0:37:17 > 0:37:19No, I shouldn't say he woke up.
0:37:19 > 0:37:22Er, he got up - big, big difference.
0:37:25 > 0:37:28He, er, left the house with his keys,
0:37:28 > 0:37:31did not lock the door, which he normally does...
0:37:31 > 0:37:34- ENGINE STARTS - ..got into his car.
0:37:34 > 0:37:37He drove 23 or 24km...
0:37:39 > 0:37:40BRAKES SCREECH
0:37:42 > 0:37:44- ..made four right-hand turns... - INDICATOR CLICKS
0:37:50 > 0:37:53..ended up in his in-laws's driveway,
0:37:53 > 0:37:56entered through the basement, where they slept...
0:37:57 > 0:38:00..strangled his father-in-law, not to the point of death,
0:38:00 > 0:38:03but strangled him to the point where he was immobile.
0:38:03 > 0:38:08He then went to the kitchen, er, found a long knife,
0:38:08 > 0:38:13and stabbed his mother-in-law, er, five or six times,
0:38:13 > 0:38:17and beat her with something, to the point where she fractured her skull.
0:38:20 > 0:38:25Ken then left their house and drove about a block away
0:38:25 > 0:38:28to the police station...
0:38:28 > 0:38:33walked in, hands bleeding, and he went over to someone
0:38:33 > 0:38:38who came to his assistance and said, "I think I've just killed somebody."
0:38:39 > 0:38:42To most people, Ken's guilt seemed obvious.
0:38:42 > 0:38:47But he appeared to have no memory of what had happened, or how.
0:38:49 > 0:38:52Ken was lying in a bed, er,
0:38:52 > 0:38:54with his hands completely bandaged,
0:38:54 > 0:39:00um, and...was bewildered.
0:39:00 > 0:39:06That's the way to describe him. Completely bewildered.
0:39:06 > 0:39:14Lost. Unable to understand what had happened, why it had happened,
0:39:14 > 0:39:18and some part of him wanted to ask the question, "Who did it?"
0:39:19 > 0:39:22Ken had a good relationship with his in-laws
0:39:22 > 0:39:26and everyone agreed he had no motive for the crime.
0:39:26 > 0:39:30Marlys began to suspect that something must have gone wrong in
0:39:30 > 0:39:35Ken's brain and she assembled a team of experts to help figure out what.
0:39:35 > 0:39:37They soon began to suspect
0:39:37 > 0:39:40the events might be connected to Ken's sleep.
0:39:44 > 0:39:50In prison, Ken was visited by sleep expert Dr Roger Broughton.
0:39:51 > 0:39:56His findings were to prove a revelation.
0:39:56 > 0:39:57They wired him up...
0:40:00 > 0:40:04..and they watched his sleep pattern for the first night.
0:40:04 > 0:40:07And then, the second night, they woke him up occasionally
0:40:07 > 0:40:09to see how fast he would go back to sleep.
0:40:15 > 0:40:22And then, they determined that the profile of the sleep pattern
0:40:22 > 0:40:26was consistent with that of a sleepwalker
0:40:26 > 0:40:33that could, er, move involuntarily and do specific kinds of actions.
0:40:37 > 0:40:39As the team began investigating,
0:40:39 > 0:40:42they found sleep disorders of all kinds
0:40:42 > 0:40:44throughout Ken's extended family.
0:40:47 > 0:40:50With no motive, no way to fake his sleep results,
0:40:50 > 0:40:54and such extensive family history of sleep problems,
0:40:54 > 0:40:57Ken was acquitted of the murder charge.
0:40:59 > 0:41:02The verdict was stunning.
0:41:02 > 0:41:05It was a moral vindication for Ken.
0:41:05 > 0:41:08It wasn't that he didn't do it,
0:41:08 > 0:41:12but there was no fault associated with it.
0:41:12 > 0:41:15He didn't wish it to happen, he didn't will it to happen,
0:41:15 > 0:41:17there was nothing he could do to stop it,
0:41:17 > 0:41:19it was completely outside of his control.
0:41:19 > 0:41:24The judge leaned down and said, "Mr Parks, you're free to go."
0:41:24 > 0:41:27He opened the door and walked out with me.
0:41:32 > 0:41:36After the trial, Ken was prescribed medication for his sleep disorder
0:41:36 > 0:41:41and it was decided that he no longer posed a risk to those around him.
0:41:42 > 0:41:46The case illustrates that people can carry out
0:41:46 > 0:41:51extreme and sophisticated behaviours with no conscious awareness.
0:42:11 > 0:42:15Our unconscious brains steer our behaviour.
0:42:15 > 0:42:18But how do our brains come to be the way they are?
0:42:20 > 0:42:22Why are there differences between us,
0:42:22 > 0:42:26making you and me behave differently when faced with the same choices?
0:42:28 > 0:42:31To answer this, we need to look one level deeper,
0:42:31 > 0:42:34to how our brains get built,
0:42:34 > 0:42:37and that begins with our genes.
0:42:40 > 0:42:42The genes you come to the table with
0:42:42 > 0:42:45can have an enormous influence on your behaviour.
0:42:45 > 0:42:48Consider this - about half of the population
0:42:48 > 0:42:50carries a particular set of genes,
0:42:50 > 0:42:55and if you have these, your chances of committing a violent crime
0:42:55 > 0:42:58go up by 882%.
0:42:58 > 0:43:02The overwhelming majority of prisoners carry these genes,
0:43:02 > 0:43:05as does almost everyone on death row.
0:43:05 > 0:43:09So we can't presume that everyone is coming to the table
0:43:09 > 0:43:12equally equipped in terms of drives and behaviours.
0:43:13 > 0:43:18By the way, we summarise this set of genes as the Y chromosome.
0:43:18 > 0:43:20If you're a carrier, we call you a male.
0:43:23 > 0:43:27Obviously, your gender is determined by your genes.
0:43:27 > 0:43:31But from there, how your DNA relates to your behaviour
0:43:31 > 0:43:34becomes a little more complex,
0:43:34 > 0:43:38because although you come to the table with a fixed pattern of DNA,
0:43:38 > 0:43:43not every one of your genes will get the chance to play a part.
0:43:44 > 0:43:48Genetics is only part of the story of who you become,
0:43:48 > 0:43:52because which of your genes express and when,
0:43:52 > 0:43:56this is influenced by the details of your environment.
0:43:56 > 0:43:59So the family that you are born into and the neighbourhood,
0:43:59 > 0:44:04and the culture you find yourself in, all of these interact with your
0:44:04 > 0:44:09genetics and this sends brains off on very different life trajectories.
0:44:09 > 0:44:11LOUD CRACK AND RUMBLING
0:44:11 > 0:44:13The activity of our billions of neurons
0:44:13 > 0:44:17is shaped by the internal and external world.
0:44:19 > 0:44:23Both our genetics and our environment collaborate
0:44:23 > 0:44:26to build our brains and thereby steer our behaviour.
0:44:29 > 0:44:34Put the same infant brain in a different time or place,
0:44:34 > 0:44:36and it will mould to fit that setting.
0:44:38 > 0:44:39Culture.
0:44:42 > 0:44:44Ideas.
0:44:47 > 0:44:49Belief systems.
0:44:49 > 0:44:53All these variables in our environment interact
0:44:53 > 0:44:57with our genes to physically change the structure of our brains.
0:44:59 > 0:45:04And this, in turn, defines who we have the chance to become.
0:45:08 > 0:45:13Our freedom is constrained by the world we happened to drop into.
0:45:17 > 0:45:19When you look at the brain this way,
0:45:19 > 0:45:24it seems clear that we are not the ones steering our own lives.
0:45:24 > 0:45:27At least, not nearly as much as we would like to believe.
0:45:34 > 0:45:36All this might leave you wondering
0:45:36 > 0:45:40whether the conscious mind is ever truly in control.
0:45:41 > 0:45:45Are there any decisions that can be made independently of your history?
0:45:49 > 0:45:52Do you have free will of any kind?
0:46:02 > 0:46:06It's a question philosophers and scientists have grappled with
0:46:06 > 0:46:10for centuries, but in the last few years, a small number
0:46:10 > 0:46:14of neuroscience studies have begun making inroads into the problem.
0:46:18 > 0:46:22We generally think that when
0:46:22 > 0:46:24we choose to do something,
0:46:24 > 0:46:27that there must be some activity in the brain that has to do with
0:46:27 > 0:46:29that thing of choosing.
0:46:29 > 0:46:34But it appears that nothing in what we can record in brain activity
0:46:34 > 0:46:38clearly points to something in the brain
0:46:38 > 0:46:41ascribed to this thing of choice, of free will.
0:46:43 > 0:46:47The mystery of free will has intrigued many neuroscientists,
0:46:47 > 0:46:50but Alvaro and his team will be the first to explore it
0:46:50 > 0:46:54using a technique known as transcranial magnetic stimulation,
0:46:54 > 0:46:56or TMS.
0:47:06 > 0:47:12TMS, it is really a way to induce current in a specific target
0:47:12 > 0:47:14of the cortex of the brain,
0:47:14 > 0:47:16without having to do surgery,
0:47:16 > 0:47:19without having to open up the skull or the skin.
0:47:20 > 0:47:23TMS can be used to initiate involuntary movement.
0:47:25 > 0:47:29This would lead Alvaro to design a simple experiment
0:47:29 > 0:47:31to explore free will.
0:47:32 > 0:47:35What we want you to do is look at that computer screen...
0:47:39 > 0:47:43When participants saw a red light on screen, they had to decide
0:47:43 > 0:47:48which hand they were going to move, but not actually make the movement.
0:47:48 > 0:47:51When the light turned yellow, they were given a burst of TMS.
0:47:54 > 0:47:55When the light went green,
0:47:55 > 0:47:58they simply had to move the hand that they had chosen.
0:48:00 > 0:48:03Alvaro found that by targeting certain areas of the brain
0:48:03 > 0:48:08with TMS, he could make participants change their mind.
0:48:15 > 0:48:17So what happened there?
0:48:17 > 0:48:21I seem to have planned to move my right but then at the last second,
0:48:21 > 0:48:23I changed my mind. I'm not sure why.
0:48:23 > 0:48:26This is the TMS response.
0:48:26 > 0:48:27You see a little pause
0:48:27 > 0:48:30and then this squiggly line is the voluntary movement.
0:48:30 > 0:48:35It was clear that TMS was causing the participant's movements,
0:48:35 > 0:48:39and yet many people remained convinced that they had made
0:48:39 > 0:48:42choices with their own free will.
0:48:42 > 0:48:44More often than not, a subject would say,
0:48:44 > 0:48:46"I did that."
0:48:47 > 0:48:51We would look at the recordings and say, "No, you didn't."
0:48:51 > 0:48:55And they would say, "Oh, sure, sure, I did, I did."
0:48:55 > 0:48:58So that was striking because it turned out subjects interpret
0:48:58 > 0:49:03anything that moved as their own choice, even though it wasn't.
0:49:03 > 0:49:08Alvaro's experiment reveals how good the conscious mind is
0:49:08 > 0:49:11at telling itself that a free choice has been made,
0:49:11 > 0:49:13even when it hasn't.
0:49:14 > 0:49:18Demonstrations like these are tantalising, but the truth is,
0:49:18 > 0:49:22science has yet to devise a conclusive experiment
0:49:22 > 0:49:25that proves or disproves the existence of free will.
0:49:27 > 0:49:31It may be that our science is just too young to know how to look for it
0:49:31 > 0:49:35or it might turn out that free will IS simply an illusion.
0:49:37 > 0:49:40But if we really don't have it at all,
0:49:40 > 0:49:42what would that mean for our lives?
0:49:44 > 0:49:46What if there is no free will?
0:49:46 > 0:49:49What if we are just systems that move from one state to the next
0:49:49 > 0:49:52in a completely predictable manner?
0:49:52 > 0:49:55A life that is totally predictable like that wouldn't really be
0:49:55 > 0:49:57worth living out, would it?
0:49:57 > 0:50:00But the good news is this - in practice,
0:50:00 > 0:50:02predictability is impossible.
0:50:02 > 0:50:06Let me show you what I mean with a simple ping-pong ball.
0:50:09 > 0:50:11As the ball enters the box,
0:50:11 > 0:50:14it is possible to predict very accurately
0:50:14 > 0:50:15where it is going to land.
0:50:18 > 0:50:20But as it begins to trigger other balls,
0:50:20 > 0:50:24things start to become more complex.
0:50:24 > 0:50:27MUSIC: Blue Danube Waltz by Johann Strauss II
0:50:29 > 0:50:32Any error in the initial prediction,
0:50:32 > 0:50:36no matter how small, becomes magnified as balls collide
0:50:36 > 0:50:39and bounce off the sides and trigger other balls.
0:50:44 > 0:50:46Soon, it becomes completely impossible
0:50:46 > 0:50:50to make any kind of prediction about how the balls will end up.
0:50:54 > 0:50:57The balls have no choice in the direction they move.
0:50:57 > 0:51:00They have no freedom to do it differently.
0:51:01 > 0:51:05And yet, the system is completely impossible to predict.
0:51:18 > 0:51:21MUSIC FADES
0:51:21 > 0:51:25Your thoughts and your feelings and your decisions,
0:51:25 > 0:51:30all of these emerge from the innumerable, ongoing interactions
0:51:30 > 0:51:31in your brain.
0:51:31 > 0:51:35This box has 150 ping-pong balls in it, but your brain
0:51:35 > 0:51:40has billions of times more interactions than that every second,
0:51:40 > 0:51:42and for your whole life, it never stops.
0:51:44 > 0:51:45What's more,
0:51:45 > 0:51:50each individual brain is embedded in a world of other people's brains.
0:51:52 > 0:51:56The neurons of every human on the planet fire and interact
0:51:56 > 0:52:02and influence each other, creating a system of unimaginable complexity.
0:52:04 > 0:52:09This means that even though brains follow predictable rules,
0:52:09 > 0:52:14in practice, it will always be impossible to know exactly
0:52:14 > 0:52:15where any of us are going.
0:52:21 > 0:52:25Our conscious minds play a much smaller role in our lives
0:52:25 > 0:52:27than we once imagined.
0:52:29 > 0:52:32Everything - from what we do,
0:52:32 > 0:52:34to who we are -
0:52:34 > 0:52:37is orchestrated by the unconscious brain.
0:52:44 > 0:52:46The cosmos turned out to be larger
0:52:46 > 0:52:50than we had ever imagined from gazing at the night sky.
0:52:51 > 0:52:53And in the same way,
0:52:53 > 0:52:56the universe inside our head
0:52:56 > 0:52:59extends far beyond our conscious experience.
0:53:11 > 0:53:14Today, we are getting the first glimpses
0:53:14 > 0:53:17of the vastness of this inner space.
0:53:36 > 0:53:40The human brain is nature's perplexing masterpiece.
0:53:54 > 0:53:58It's the most wondrous thing we've discovered in the universe,
0:53:58 > 0:53:59and it's us.
0:54:15 > 0:54:19Next time on The Brain - I'm going to investigate the weird ways
0:54:19 > 0:54:23our brains are constantly making decisions.
0:54:23 > 0:54:25Some we are aware of,
0:54:25 > 0:54:28most we are not.
0:54:28 > 0:54:29OK.
0:54:30 > 0:54:33Can you tell me what you're seeing? So this is very simple.
0:54:33 > 0:54:36'Without him knowing it, his brain will decide
0:54:36 > 0:54:38'whether this is a rabbit or an ostrich.'
0:54:38 > 0:54:40STATIC BEEPING
0:54:40 > 0:54:43This is the sound of a decision getting made.
0:54:43 > 0:54:46We are eavesdropping on single neurons working in concert
0:54:46 > 0:54:49with billions of other neurons to land on a choice.
0:54:50 > 0:54:53And this is what every decision in the history
0:54:53 > 0:54:55of the human species looks like.
0:54:55 > 0:54:59Traditionally, we assume that humans are rational decision-makers.
0:54:59 > 0:55:03They take in information, process it and come up with the best answer.
0:55:03 > 0:55:05I'm wondering whether to eat this yoghurt at all,
0:55:05 > 0:55:08because part of me wants it but part of me knows that it's fattening.
0:55:10 > 0:55:13Deciphering what we hear or see or smell -
0:55:13 > 0:55:15these are decisions.
0:55:15 > 0:55:17Falling in love,
0:55:17 > 0:55:20giving in, resisting.
0:55:20 > 0:55:24Decision-making is what allows us to navigate a course through life.
0:55:26 > 0:55:28And your lifetime of choices
0:55:28 > 0:55:30has sculpted you into the person you are
0:55:30 > 0:55:32right now.