The mirror stage occurs when we are toddlers in the journey of self discovery. The hippocampus "is critical to the storage of memory," as Morgan Freeman puts it.
PKM zeta is a molecule that "jumps into action when we are forming new memories." ζ-inhibitory peptide (ZIP) inhibits protein kinase Mζ (PKM ζ).
Alain Brunet personally experienced the 1989 École Polytechnique massacre in Canada. Propranolol is a β blocker.
Steve Furber has designed SpiNNaker chips to model the activities of a simple brain.
Thanks for watching. Follow for more videos.
#csomosspacescience
#throughthewormhole
#season3
#episode4
#cosmology
#astronomy
#spacetime
#spacescience
#space
#nasa
#spacedocumentary
#morganfreeman
#whatmakeus?
#whoweare?
PKM zeta is a molecule that "jumps into action when we are forming new memories." ζ-inhibitory peptide (ZIP) inhibits protein kinase Mζ (PKM ζ).
Alain Brunet personally experienced the 1989 École Polytechnique massacre in Canada. Propranolol is a β blocker.
Steve Furber has designed SpiNNaker chips to model the activities of a simple brain.
Thanks for watching. Follow for more videos.
#csomosspacescience
#throughthewormhole
#season3
#episode4
#cosmology
#astronomy
#spacetime
#spacescience
#space
#nasa
#spacedocumentary
#morganfreeman
#whatmakeus?
#whoweare?
Category
📚
LearningTranscript
00:01We all spend our lives on a search for something so close, yet always just out of reach.
00:10Some call it the ego, others the soul.
00:18Now modern science is prying into our thoughts, our memories and our dreams
00:24and asking the profoundly puzzling question, what makes us who we are?
00:36Space, time, life itself.
00:43The secrets of the cosmos lie through the wormhole.
00:54Space, time, life itself.
01:00What is it that makes me, me?
01:05Or makes you, you?
01:08Is it the things we know?
01:11The people and places we've experienced?
01:14What makes me the same person now as when I was 40?
01:18Or when I was 10?
01:20What is it that gives each one of us our unique identity?
01:25Scientists are beginning to tackle this profound puzzle.
01:30To do so, they must probe one of the last great frontiers of our understanding.
01:36The brain.
01:39Every summer, I used to go camping with the Boy Scouts.
01:42Each item of clothing I took with me had to have my name sewn onto it.
01:48Morgan.
01:50It was a name I never really liked when I was a boy.
01:53I wondered how my life might be different if I had been called something normal, like Robert or John.
02:01Well, like it or not, the name I was given framed my identity.
02:06It helped make me who I am.
02:09Happy birthday.
02:12What's walking?
02:14Show your mom.
02:16Bye.
02:17Beautiful.
02:19Wish you were here.
02:24Alison Gopnik is on a search to discover how and when we first understand who we are.
02:31She's a child psychologist at the University of California at Berkeley.
02:35So the process of forging an identity, of figuring out who it is that we are, that's a process that really takes us our whole lifetime.
02:43But some of the most crucial parts of that seem to be things that we're learning in this very, very early period of our lives.
02:49As adults, it's easy to take our identities for granted.
02:54We accept that who we are now is the same as who we were a minute ago.
02:59But Alison has discovered that identity is not so solid for young children.
03:05They spend much of their time trying to figure out just who they are.
03:09So when kids are just doing the everyday things that kids do, when they're playing and exploring and pretending, what they're actually doing is being involved in this great existential philosophical research program.
03:24What it means to be a person.
03:25One of the first milestones in this program is called the mirror stage.
03:32It begins when a child is first able to recognize his or her own reflection.
03:38The thing about a mirror isn't just that you see a body and a face, which is fascinating, but you connect it to your own kinesthetic feeling of yourself, the way your own body feels.
03:47Alison uses a clever experiment on her toddlers to detect which of them have developed an awareness of their reflections.
03:56She places a smudge of blue ink on their noses and tells them to look in the mirror.
04:02There he is. There he is right there.
04:07Fifteen-month-old John is hardly fazed by the blue-nosed child staring back at him because he's not able to recognize that the child in the mirror is not able to recognize.
04:17They're interested in the fact that that baby in the mirror has a spot, but they don't seem to connect that to the fact that there's actually a spot on their own noses.
04:26When Alison tries the same test on Karen, who is just a few months older than John, she does something quite different.
04:34Look at that. There we go. Look. What is that?
04:40And now the babies seem to realize, oh yeah, that person in the mirror, that's the same person that I am.
04:44It is a big first step on a long journey of self-discovery.
04:50But Alison's work has shown that her subjects have a lot more philosophical research ahead of them.
04:58This is three-year-old Geneva.
05:01Alison tempts her with what looks like a box filled with cookies.
05:04But Geneva will soon find out that she can't judge a box by its cover.
05:11What do you think is inside this box?
05:17What do you think this is?
05:21Chocolate cookies.
05:22Chocolate cookies.
05:23Should we find out?
05:25Let's open the box.
05:27We'll find out what's inside.
05:30Markers.
05:32Markers. There's markers inside.
05:35Hmm.
05:37When I first showed you this box, all closed up like this.
05:42What did you think was inside it?
05:44Markers.
05:46Markers.
05:48Geneva cannot reconcile that she now knows the box is filled with markers when she once thought it was filled with cookies.
05:57The concept that there is a you who is the same person even if your thoughts have changed is not an understanding you're born with.
06:06It is something you come to learn.
06:09Alison tries the cookie box test with four-year-old Jim.
06:13I have a question for you.
06:15What?
06:17When you first saw this box, all closed up like this, what did you think was inside it?
06:23Cookies with chocolate chips.
06:26Uh-huh. And what's really inside it?
06:29Markers.
06:31Yeah! That's great!
06:33So a very important part of my identity is being able to say,
06:35well, when I was 16, I believed different things than I do now, but it was me who believed those different things.
06:43When children realize their identities can survive any change in their beliefs, they stop forgetting the things they don't believe anymore.
06:51And for the first time, they unlock the astonishing power of human memory.
06:56In this very hall I used to perform in the choir takes me back.
07:06In this very hall I used to perform in the choir.
07:10My own memories are so richly detailed and I spent many hours in this hall rehearsing, practicing, it just takes me back.
07:21Neuroscientist Donna Addis is head of the memory lab at the University of Auckland, where she investigates how memories shape us.
07:36She does this by tearing into a horseshoe-shaped area in the brain called the hippocampus.
07:42For the last 50 years, scientists have known that the hippocampus is critical to the storage of memory.
07:53We learned this thanks to one man known as Patient H.M.
08:00He had severe epilepsy and in 1953 received a radical new treatment.
08:06His hippocampus and part of his inner temporal lobes were cut out.
08:14After the surgery, H.M. never suffered a bout of epilepsy again.
08:21But he had completely lost the ability to form new memories.
08:27He said each day is like waking from a dream.
08:31He had lost his identity.
08:35His sense of who he was was frozen at age 27.
08:40As days turned into decades, he could no longer recognise the man staring back at him in the mirror.
08:48How much of who we are is built upon the memories we make each and every day?
08:53Traditionally, memory research has really focused on the past and in the last few years researchers such as myself have been looking at the ability to imagine the future and how memory might actually play a role in that.
09:10Donna and her team set up an experiment to determine just how the hippocampus and our memories help us perceive our future selves.
09:19So what we do is we have subjects come into the lab and we have them retrieve around 100 memories.
09:26I remember going to visit my cousin in Germany.
09:30We walked along the beach and at the end there was a cave.
09:34And I gave my grandmother a seashell for Christmas.
09:37And for each memory they identify a person, a place and an object that might be important.
09:42The Autobahn.
09:43The Autobahn.
09:44My mother.
09:45Two penguins.
09:46Boston.
09:47My boat bike.
09:48Aquan waterfront.
09:49My girlfriend, Sierra.
09:50The hospital.
09:51My brother Wayne.
09:52Eastern Beach.
09:53Amsterdam Airborne.
09:54The cave.
09:55A week later, Donna brings her subjects back, places them in an fMRI machine and shows them details from their recalled memories.
10:03But she deliberately jumbles the details.
10:06An object from one memory has been grouped with a place from another memory and a person from yet another.
10:13Donna then asks them to make a story out of these mixed up memories.
10:19To imagine something that has not happened yet, but potentially could.
10:23We ask them for each person, place, object that they're seeing now to imagine a future event that might happen to them within the next five years or so.
10:35While the participants are imagining their futures, Donna measures their brain responses.
10:42To her surprise, the part of the brain that is vital to storing memories of the past, the hippocampus, is blazing with activity.
10:50The hippocampus is playing a really important role, not only in remembering, but also allowing us to build these future simulations.
11:00Memory is important not only for the past, but also for the future.
11:05For building up that sense of who we are.
11:10Our memories are crucial to forming our identities.
11:13But one group of scientists had discovered that our memories can be manipulated without our even knowing it.
11:21Are we really who we think we are?
11:24Our ability to remember is truly remarkable.
11:29In the course of our lives, the average person will grasp the meaning of a hundred thousand words, get to know around seventeen hundred people, and read over a thousand books.
11:44From these vast metal stores of experience, we each build our own identity.
11:49A pattern of memories that is uniquely ours.
11:54But what if those memories could be rewritten?
11:58Could we change who we are?
12:01Can we change who we are?
12:06Any work with him in New Zealand?
12:08No, he won't.
12:09Neuroscientist Tali Sherot, from the University College London, and Micah Edelson, from the Weissman Institute of Science in Israel, love going to dinner parties.
12:20But they're not just having fun. They're doing it for the sake of science.
12:23They study how social pressures alter who we are.
12:28Well, imagine a situation that you're sitting in a dinner party.
12:33You have a pretty good memory of some situation that happened.
12:37And you actually remember it happening in a certain way.
12:40But all of your friends are telling you that you're actually wrong.
12:44They're saying that something else happened.
12:45Tali got the umbrella and she slipped the umbrella through the letterbox.
12:49No, no, no. I'm quite sure it wasn't me.
12:51No, it was definitely you. You were definitely holding the umbrella.
12:54No, it was definitely Steve.
12:56Yeah, I really think it was Tali.
12:58No, because we were really impressed that Steve managed to hook it around.
13:00And remember we had that big fanfare because we were out in the rain.
13:04When someone changes their memory so that it fits other people's opinion,
13:09do we actually change a signal in the brain that is representative of the memory?
13:14Or is it just that we try to please other people?
13:18Social pressures can make us change the way we tell stories.
13:22But can they also make us change the stories we tell ourselves?
13:27Our actual memories?
13:29Tali and Micah set up an experiment to find out.
13:32Not in a restaurant, but in a lab.
13:35They bring in a group of volunteers to watch a film together.
13:38Afterwards, the volunteers answer basic questions about the film to test what they remember.
13:47A few days later, the participants take the same questionnaire inside a brain scanner.
13:54Only this time, Micah and Tali apply a social pressure.
13:59This time they were exposed to fake answers that were supposedly given by their fellow group members.
14:08The group is led to believe that the others who took the test remembered the character in the film was not wearing a hat.
14:15And most people changed their answers to go along with the crowd.
14:22Almost 70% of the cases, the participants conformed and they gave a wrong answer, even though they were initially pretty confident about their correct answer.
14:29But were they just outwardly complying with the social norm?
14:34Or did their memories actually change?
14:38So we test them again a week after, once we've removed the social pressure.
14:45And we assume that if they're still making an error, that means that their memory was actually changed.
14:50Tali and Micah found that most test subjects stuck with the wrong answer even without peer pressure.
14:56The falsehood has taken root in their brains.
15:01It actually causes a long-lasting memory error.
15:06And using our brain data, we are able to actually identify when such a long-lasting memory error will occur.
15:14The brains of those people who changed their memories showed high activity, not just in the hippocampus, where memories are stored,
15:22but also in a part of the brain that is connected with emotional and social responses, the amygdala.
15:31A lot of what we know about the amygdala and its function comes from the animal world.
15:36So our reaction to anything that's emotional, if we suddenly hear a noise which is frightening, or processing emotional expressions on one's face, the amygdala is crucial for all of these functions.
15:51And it probably helps us increase memory, because in a fearful or emotional situation, the amygdala activation is heightened, and it also increases activation in related structures like the hippocampus.
16:05The amygdala is like a bouncer at a nightclub.
16:10It decides which memories get to play a part in shaping our life histories.
16:15The ones that carry emotional weight are allowed in.
16:18The ones that don't are not.
16:20The participants who changed their memories were emotionally affected by the pressure to conform, setting their amygdalas ablaze.
16:33And the false memory snuck in.
16:36So by looking at amygdala activation, we can actually predict which memories are going to be changed for a very long time and which are not.
16:43You have to realize that memories are not like a videotape.
16:48Because people can be extremely confident that things happened like they think they happened when they didn't.
16:55Our memories are not just a record of the events that took place in our lives.
17:00They are malleable and fallible.
17:04Our identities are created with constant input from our society.
17:09No man is an island.
17:11But could we go a step further and deliberately re-engineer someone's identity?
17:20To do that, you have to be able to peer into a person's innermost thoughts.
17:26And believe it or not, that technology is already here.
17:36We are all actors, to some extent.
17:39Who we appear to be can change depending on our mood or the company we keep.
17:47But there is one time when who we really are comes to the fore.
17:53When we dream.
17:55What if we could see our dreams and study them?
17:59Could we know each other in a more profound way than ever before?
18:07During an average lifespan, a human being spends about six years dreaming.
18:13That's more than 52,000 hours of imagery buzzing through our unconscious brains.
18:18Computational neuroscientist Yuki Kamitani believes one day it will be possible to watch and record what people are dreaming.
18:33When that happens, we will all get to know ourselves on a much deeper level.
18:40I believe that if we can reconstruct or decode the contents of a dream, the identity is revealed.
18:48If we remember our dreams, it is often as a series of emotionally charged images.
18:56In fact, scientists have found that the visual cortex of a dreaming brain is highly active.
19:03Patterns of electrical activity wash over it, which makes Yuki wonder, can we learn to read those patterns and convert them into images on a computer?
19:16Brain activity can be seen as a code or an encrypted message about what's going on in the visual world.
19:25The patterns of images we make in our brains are highly distorted, in the same way a pair of shattered glasses distorts our view of the world.
19:37But if we collected data on hundreds of images seen through those shattered lenses,
19:43we could find a correspondence between the distorted images and the real ones.
19:47It might take a while, but if we gave that job to a powerful computer, it could decode the scrambled images into recognizable ones.
19:57And this is how Yuki tried to crack the code that turns images into patterns of activity in the visual cortex.
20:05We measure the brain activity of human subjects, and we let the subject go into the scanner and scan their brain.
20:13And during that, we present some images to the subject, typically several hundreds or thousands of images in a single experiment.
20:23The images Yuki shows people are simple black and white shapes, a square, a cross, a line.
20:31Using a powerful computer array, he records the precise pattern of activity in the visual cortex.
20:37After multiple trials with the same person, the computer learns to distinguish the patterns triggered by each image.
20:46In other words, the computer can judge purely from the brain activity which of the shapes the subject is looking at.
20:53And then, Yuki does something remarkable.
20:56He shows the subject's brand new images, images the computer has never seen, and lets the computer try to draw a picture of what the subjects are seeing.
21:09These are the images the computer reads inside people's brains, and these are the images they are actually looking at.
21:17This is the first time anyone has been able to know what people are seeing purely by looking at their brains.
21:27Looking at the visual cortex, we have just succeeded in reconstructing seeing images.
21:34We are now trying to reconstruct imagined images, or images in your dreams.
21:41Yuki's method as yet only works on pixelated black and white images.
21:48But with a few more years of refinement, Yuki believes we will be able to record our dreams as full-color, high-definition movies.
21:57And that would truly be a window into our souls.
22:00Those, you know, unconscious aspects of our mind defines what we are, and what the identity is.
22:09So, I think if we can reveal some dream contents, uh, which someone is not aware of, then, that might reveal some deep, uh, property of that person.
22:23Our true identities could soon be laid bare for all to see, including the parts we don't want seen, like our deepest held secrets and fantasies.
22:38But you may not have to worry, because the power to edit the contents of our minds is close at hand.
22:47Our brains are filled with memories.
22:55Some of them bring us joy.
22:58Others make us wish we could forget.
23:01Whether we like it or not, our memories shape how we think and how we act.
23:06But now, one group of researchers thinks it has found a way to change memory.
23:15And perhaps, change who we are.
23:23Can we deliberately change our sense of identity?
23:27Neuroscientist Andre Fenton from the State University of New York doesn't see why not.
23:32To him, the brain and its pathways of connections between neurons are like the labyrinth of streets in New York City.
23:41A maze he navigates on his daily runs.
23:45And just like Manhattan traffic, conditions for the flow of electricity around the brain are not the same on every route.
23:53If you experience something, there's been an electrical activation somewhere in the brain that spreads through the brain.
24:02And that is your experience.
24:04As in a city, there are roads that connect one district to another district.
24:08And those roads can be very big boulevards and send a lot of traffic.
24:13Or they can be small alleys that send very specific information, but nonetheless not very rapidly or very easily.
24:19For years, scientists thought the pathways in our brains were set in stone after we matured from babies to adults.
24:28Alleys could not become wider. Highways could not become narrower.
24:33But now, it has become clear that the roads in our adult brains are under constant construction.
24:39Every time we store a new memory, electrical activity propagates through millions of neurons.
24:48Just as Andre is forced to find a new route if his pathway is blocked, our neural pathways adjust themselves to process and record new experiences.
24:57And so, what neuroscientists understand is that there's a sufficient amount of this plasticity throughout life and that it is affected and modulated and controlled by experience.
25:13Recently, scientists have identified a molecule in the brain that jumps into action when we are forming new memories.
25:20It is called PKM-zeta.
25:25PKM-zeta stands for protein kinase Mzeta. It's my favorite molecule.
25:31When PKM-zeta gets told to deploy in a neuron, it gets told to do that on the basis of a recent experience.
25:42And what it does is it mediates efficient or increased efficiency of neural transmission.
25:53When a memory needs to navigate its way through the traffic of our brains, PKM-zeta clears the way, making sure the memory safely reaches long-term storage.
26:03Those long-term memories, the ones that you form now and you will keep forever, that kind of information storage seems to be mediated by PKM-zeta.
26:17But Andre knew of a chemical that could neutralize PKM-zeta called Zeta Inhibitory Peptide, or Zip.
26:25And he wondered if he injected it into a living brain, could he prevent it from forming long-term memories.
26:33So the logic of the experiment we did is very straightforward.
26:38What you want to do is produce a memory.
26:42A rat is in a rotating carousel.
26:45And the key here is that whenever it enters that part of the floor, it becomes electrified.
26:50And so they very quickly and rapidly learn to stay away from that part of the room.
26:58In this computer-generated readout of Andre's experiment, the rat runs around the carousel, but consistently avoids the triangular-shaped shock zone.
27:09Thirty days later, Andre puts the rat back in the chamber and observes that it still remembers to stay away.
27:16It has stored a new long-term memory in its brain.
27:22But when Andre injects the rat's hippocampus with Zip, he sees something extraordinary.
27:28When the rat is put back in the carousel one more time, it runs right over the shock zone as though it had never been shocked before.
27:37You could see that the animal behaved more or less like a naive animal, so it was very exciting.
27:42Andre has erased a piece of the rat's memory.
27:48The ability to forget people we have met, places we have been, things we have done, is now a pharmaceutical possibility.
27:57But Andre can't see inside his rat's brain.
28:01And so he cannot be sure how many memories the Zip molecule erased.
28:05As we begin to work out the synaptic organization of memories, we'll then be in a position to understand whether it's possible to actually make selective manipulations of particular memories.
28:22We are always going to be confronted with the possibility of erasing all memories, which could never be a good idea.
28:29Using Zip to erase a specific memory is still a ways off.
28:39But in Montreal, one doctor has found another way.
28:44He's washing away painful memories that make his patients prisoners inside their own identities.
28:50Who we are depends on where we have been, who we have loved, who we have lost.
29:01For some of us, painful memories can linger like an open wound.
29:05They can hold us back from becoming who we want to become.
29:09Dr. Alain Brunet is a psychologist at McGill University in Montreal.
29:19He specializes in treating people with post-traumatic stress disorder.
29:24Alain himself has a deep understanding for the condition.
29:28In 1989 at the University of Montreal, a deranged man carried out the worst mass shooting in Canadian history.
29:36Alain was on campus, studying for his master's degree in psychology.
29:41He shot, he went through the corridors, he shot 12 women, and eventually there were 13 deaths.
29:48The crisis intervention that had been conducted after this event was very poorly done.
29:55And many of us were left with a bad taste in our mouth.
29:58And so it did have a profound effect on me and on what I decided to study.
30:08This horrific event started Alain on a path that he is still following today.
30:14He helps people who suffer from PTSD get back a part of themselves that seems to be lost.
30:21PTSD can be conceived as a disorder of memory.
30:31Because in a sense, it's really about things that you wish you'd forget.
30:35That memory has been burned into your brain and is way too powerful.
30:41And it's making you fearful in situations where you shouldn't.
30:44Memory is a little bit like writing with ink.
30:52So you can see that the ink is still wet.
30:56If I use my fingers and go over my writing, it will smear what I just wrote.
31:03And this is exactly like the workings of memory.
31:05But when a memory is emotionally powerful, proteins in the brain build connections between neurons and the memory is transferred to a separate long-term storage area.
31:19There, it leaves a lasting impression.
31:23Once the ink is dry, the memory is there for good.
31:27Of course, it might fade with time, but that memory will still be accessible.
31:32Many scientists believe that once the ink of a memory is dry, it is fixed and indelible.
31:43But Alain believes that every time we recall a memory, it is like we are creating a brand new memory all over again.
31:52When you recall a memory, it becomes active again, and it becomes buzzing with electrical activity.
31:59It's really a little bit like if you were rewriting the words again with fresh ink.
32:06The moment someone recalls a painful memory, Alain believes he has an opportunity to modify it.
32:15I've had a lot of traumatic events happen in my life, which I was able to, you know, work through and live through.
32:22But then the death of my daughter, it was too much. I couldn't function. I couldn't work any longer.
32:30I had absolutely lost who I was. There's no doubt about that.
32:34Lois Boucher, who has come to Alain for help, is in for an intense treatment.
32:43As a first step, he asked her to methodically recall her painful memory by reading aloud a personal account of the traumatic event.
32:53Okay. I heard the doorbell at 5 a.m. I went to the door in my nightgown, thinking it was my daughter.
33:02When I saw that it was the police, I excused myself to go get my house coat on.
33:06As I'm walking down the hallway to the bedroom, they ask if anybody is at home with me.
33:12While Lois reads, she's under the influence of a drug Alain administers called propranolol,
33:20a simple beta blocker that reduces high blood pressure and has a well-known side effect of slight memory loss.
33:28I know that something is terribly wrong.
33:31I get a knot in my stomach, my heart starts beating faster, and I can feel myself shaking inside.
33:41When I come back to the living room, he tells me Nicky has been hit by a truck on the 401, and my Nicky is dead.
33:48All of a sudden, I crouch down and start to sob uncontrollably.
33:55The pain is incredible. My chest hurts. I think, how can I make it through this?
34:05They did that once a week for six weeks, and then we tested them with a battery of tests, interviews,
34:12and psychophysiological measurement of their responding while they're listening to an account of their trauma.
34:20After six weeks of treatment, 70% of Alain's patients show hardly any signs of PTSD symptoms.
34:28They could talk about the pain without being forced to relive it.
34:32And that really blew our mind, because they had only received one small dose of a medication,
34:42and those people had been suffering from PTSD for decades.
34:46Alain's patients have written over their traumatic memories.
34:51They have a second chance to reclaim their lives and to reclaim a sense of self.
34:56As you carried on, it got easier. You never forgot the feelings. Like, I'm always going to be upset about it.
35:06My daughter died. That's never going to go away.
35:09But now I can think about what happened without feeling like I'm going to lose my mind.
35:13With trauma, there will always be a time before and a time after.
35:24But in my opinion, people gain back their own self.
35:30Alain seems to have found the fine-tuned tool that can target specific memories.
35:37But even if we can envisage a time when our identities can be transformed or restored,
35:45we still haven't grasped the most fundamental aspect about what makes us who we are.
35:51What is it that makes our brains able to question who we are in the first place?
35:57One man thinks he has the answer.
35:59He's trying to recreate the essence of what makes us us in pieces of silicon hardware.
36:10The core of who we are is something we carry with us everywhere we go.
36:16It lives somewhere in the web of billions of neurons in our brains.
36:21Now, some scientists are trying to discover if this biological network can be replicated in silicon hardware.
36:32Whether we can build a robot that will ask itself,
36:37Who am I?
36:44Computer engineer Steve Ferber from the University of Manchester
36:47is on a quest to find out if a human identity can be built.
36:53He is attempting to make the first replica of the brain that works in real time.
36:59If he succeeds, he could unlock the secret of what makes us who we are.
37:04I think the whole issue of understanding the brain is fascinating.
37:08It's so central to our existence.
37:10We're pretty sure that our understanding of the brain is missing some fundamental ideas,
37:14and one of these is how information is represented in the brain.
37:19Steve believes there is a neural code that runs our brains,
37:25that one code is responsible for controlling multiple jobs,
37:30seeing, hearing, learning language.
37:33It's just a matter of finding out what the code is.
37:35He suspects the best place to look is in the part of the brain that is far more evolved in humans than in other species.
37:44The thin, wrinkly outer layer called the neocortex.
37:49So the neocortex is a very interesting area of the brain,
37:53because it's pretty much the same at the back where it's doing low-level image processing,
37:57and at the front where it's doing high-level functions.
38:02So if you're born without sight, a lot of your visual cortex will be taken over processing sound.
38:09And it's quite common that people who don't have sight have much more acute hearing.
38:14So there must be something in common about the algorithms that are used there,
38:18if only we could see what that was.
38:19Computer engineers have been trying to replicate biological brains for decades,
38:25using standard computer technology.
38:27But Steve believes they've been going about it all wrong.
38:32In a conventional computer, data gets moved around in large chunks.
38:38That would be like a chef dumping an entire dinner and dessert into one pot
38:44and serving a pile to one unfortunate customer.
38:47But the brain is more like a cocktail party.
38:53Small bits of data are passed around and shared.
38:58Before you know it, connections are being made and a complex situation is underway.
39:08This highly interconnected way to arrange small packets of data
39:12is what Steve wants to replicate in a custom-designed silicon circuit.
39:18He has created a brand-new type of computer chip,
39:23specifically engineered to mimic the way neurons work in the brain.
39:28It is called the Spinnaker chip.
39:30Spinnaker is a compression of spiking neural network architecture.
39:36If you say it quickly enough, it comes out like Spinnaker.
39:39The Spinnaker chip is a massively parallel computer designed to run models of the brain in real time,
39:45which means that all model runs at the same speed as the biology inside your head.
39:49Each one of Steve's Spinnaker chips can be programmed to replicate the behavior of 16,000 neurons.
39:57That's only a tiny fraction of the 100 billion neurons we have in our brain,
40:02but it is a significant step beyond anything that has been done before.
40:06Steve and a team from the Technical University of Munich are now wiring these brain-like chips to robots.
40:15This might look like a remote-controlled toy, but it is not.
40:20It is controlling itself by sensing the world around it.
40:25So the robot is basically following the line entirely under neural control.
40:30It has a vision sensor on the front.
40:32The vision information is being sent into the Spinnaker card.
40:37The Spinnaker card is executing the real-time neural network,
40:40and then the outputs from the Spinnaker card are being sent back via the laptop to the robot
40:45and controlling its movement.
40:47The brain is over there and the body is over here.
40:49The robot's Spinnaker chip brain mimics the way a real biological brain works.
40:54Just like a child, it interacts with its environment
40:58and uses its physical body to understand the world around it.
41:03The more it experiences, the smarter it gets.
41:07Our current systems have four chips on.
41:10They can model about 50,000, 60,000 neurons.
41:13In a few months' time, we'll have boards about 10 times bigger than that,
41:17and they'll be getting up to the level of complexity of a honeybee, which has 850,000 neurons.
41:22And then beyond that, we'll build systems and get up to mammalian brain sizes.
41:30The human brain is a formidably complex system,
41:34and it would take millions more Spinnaker chips to build one.
41:38But Steve is confident it is possible.
41:40If you had a model of the mind running in a machine, I don't see why it shouldn't behave in exactly the same way.
41:48The question of whether machines modeling the brain may ultimately be capable of supporting imagination, dreams, and so on.
41:56It's a very hard question, but I don't see any fundamental reason why we shouldn't expect that.
42:00Steve believes that human brains run on simple algorithms, and what works for humans will also work for his machines.
42:13The journey to forming an identity begins when a body guided by networks of neurons struggles to navigate its way through the world.
42:22It learns, adapts, remembers, and eventually becomes self-aware.
42:35What makes us who we are?
42:38Our identities are built bit by bit from our memories, our dreams, and our imaginations.
42:44No one's sense of self is fixed.
42:48Life is a journey that makes us all unique.
42:52And discovering who we are is our greatest and longest adventure.
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