Here are the speakers who appeared in this session of TEDGlobal 2013. Click the speaker’s name for a full recap of their talk:

Molly Stevens studies and creates new biomaterials that could be used to detect disease and repair bones and human tissue.

Regenerative neuroscientist Siddharthan Chandran explores how to heal damage from degenerative disorders such as MS and motor neuron disease.

Grégoire Courtine and his interdisciplinary lab imagine new ways to recover after devastating, mobility-impairing injury to the spinal cord.

Biomedical engineer Mark Kendall aims to shake up how vaccines are delivered with the Nanopatch.

Photographer Fabian Oefner creates stunning visual representations of natural forces.

Drawing on threads stretching deeply into their musical ancestry, the brothers of oud group Le Trio Joubran spin passionate oud music for the 21st century.

Photo: James Duncan Davidson

For decades, scientists said that the human brain contains 100 billion neurons. However, when neuroscientist Suzana Herculano-Houzel hunted for the source of this often-quoted number, she couldn’t locate one. So she set out to count herself … by making brain soup.

She brings a vial of brain soup with her onto the TEDGlobal 2013 stage. This substance was made by dissolving donated brains, destroying the cell membranes but leaving the nuclei intact. This made a homogenous mixture that allowed her to count the neurons in a sample. As it turns out, the human brain really has 86 billion neurons.

Why does this difference of 14 billion neurons matter? It answers a vital question: What makes the human brain different, allowing us to get together for thought-fests like TEDGlobal 2013, while other animals don’t?

For a long time, scientists thought that all mammal brains were made of the same material. But if that were true, then mammals with larger brains would be the most cognitively able. That simply isn’t true. Plus, human brains reveal a few oddities. For instance, Herculano-Houzel says, we have a larger cerebral cortex than it seems like we should have, given the size of our bodies. Meanwhile, human brains use a tremendous amount of energy. While the brain is 2% of the body, it uses 25% of the calories we need to function each day. Why should the rules of evolution not apply to humans?

This brings us back to Herculano-Houzel’s finding that the human brain actually contains 86 billion neurons. The new baseline allowed her lab to do comparisons to other animal brains. And they found that human brains are proportional in terms of the number of neurons and energy use to other primate brains — they are just larger. “It’s a great reminder of our place in evolution,” says Herculano-Houzel.

Which still leaves the question: Why would we have a larger brain than a great ape that has a much larger body? The answer comes down to the extreme energy cost of the primate brain. There appears to be some kind of evolutionary trade-off between the size of the brain and the size of the body — there’s a metabolic limitation, and primates can only consume enough calories to support one or the other.

So the next logical question is: What allowed us to transcend this limitation and support this large brain? Herculano-Houzel points out that our cerebral cortex is especially dense, containing 16 billion neurons. It takes a lot of energy to support that.

Photo: James Duncan Davidson

The answer is so simple, it’s something you’ve probably never thought about. Herculano-Houzel states it in two words: We cook. Cooking is essentially the act of using fire to pre-digest food, and thus to get more energy out of the same amount of food. In fact, cooking food makes it yield about three times as many calories. This is what allowed our brains to get bigger in a relatively short period of time while remaining a primate brain. Cooking also allowed us to support this large cerebral cortex, which in turn supports complex thought.

Wrapping it all up, Herculano-Houzel concludes, “I take a look at my kitchen, and I bow down to it.”

She’ll just maybe skip the soup.

Photo: James Duncan Davidson

Talking as fast and fervently as a circus busker, TED Fellow Greg Gage introduces the world to RoboRoach — a kit that allows you create a cockroach cyborg and control its movements via an iPhone app and “the world’s first commercially available cyborg in the history of mankind.”

“I’m a neuroscientist,” says Gage, “and that means I had to go to grad school for five years just to ask questions about the brain.” This is because the equipment involved is so expensive and complex that it’s only available in university research labs, accessible to PhD candidates and researchers. But other branches of science don’t have this problem — “You don’t have to get a PhD in astronomy to get a telescope and study the sky.”

Yet one in five of us will be diagnosed with a neurological disorder — for which we have no cures. We need more people educated in neuroscience to investigate these diseases. That’s why Gage and his partners at Backyard Brains are developing affordable tools that allow educators to teach electrophysiology from university down to the fifth grade level.

Explaining the RoboRoach as it’s being set up for demonstration, Gage explains that the neurons inside the cockroach’s antennas allows it to navigate the world, sending information back to the brain. If the cockroach is touched by an object on the left it moves right, and vice versa. “What if we sent a little pulse of electricity?” asks Gage.

Photo: James Duncan Davidson

As he speaks, he and his partner, Tim Marzullo, release a large South American cockroach wearing an electronic backpack — which sends an electrical current directly into the cockroach’s antenna nerves — onto the table on stage. A line of green spikes appear, accompanied by a sound like rain on a tent or popcorn popping. “The common currency of the brain are the spikes in the neurons,” Gage explains. “These are the neurons that are inside of the antenna, but that’s also what your brain sounds like. Your thoughts, your hopes, your dreams, all encoded into these spikes. People, this is reality right here — the spikes are everything you know!” As Greg’s partner swipes his finger across his iPhone, the RoboRoach swerves left and right, sometimes erratically going in a full confused circle.

So why do this? “This is the exact same technology that’s used to treat Parkinson’s disease and make cochlear implants for deaf people. If we can get these tools into hands of kids, we can start the neurological revolution.”

After Gage’s talk, Chris Anderson asks about the ethics of using the cockroaches for these purposes. Gage explains that this is microstimulation, not a pain response — the evidence is that the roach adapts quickly to the stimulation. (In fact, some high school students have discovered that they can control the rate of adaptation in an unusual way — by playing music to the roaches over their iPods.) After the experiment, he says, the cockroaches are released to go back to do what cockroaches normally do. So don’t worry — no animals were irretrievably harmed in the making of this TED talk.

Photo: James Duncan Davidson

Standing on the TED stage looking stunning in a blue dress, neuroscientist and author Sandra Aamodt  reveals that three and a half years ago on New Year’s Eve, she made a decision: She gave worrying about her weight. Instead, she learned to eat mindfully — and lost 10 pounds. For Aamodt, who had been dieting unsuccessfully for 30 years, this was a major life change. She started her first diet at age 13, and found that the weight always came back.

As a neuroscientist, she wondered what made losing weight so hard. Turns out the brain is an incredibly efficient regulator of body weight. Isn’t weight loss about how much you eat versus how much energy you burn? Nope, it’s not that simple an equation: it turns out that hunger and energy use are controlled by the brain, mostly behind the scenes, and this unconscious force is stronger than mere willpower. The brain has its own sense of what your body should weigh — no matter what you believe — called the set point, which has a range of about 15 pounds. While lifestyle changes can shift your weight within this range, it’s much harder to move outside of it.

Like a thermostat, Aamodt says, chemical messengers from the hypothalamus gland help regulate hunger, activity and metabolism to keep your weight stable as conditions change. Think of it this way: You can try to change the temperature in your house by opening a window in winter, but your thermostat will kick up the heat to balance the difference in temperature. Our brains work the same way, managing to maintain our weight at what it considers normal. It’s a response to our evolutionary history: For most of human history, food was scarce, and our bodies worked hard to keep us from starvation.

Photo: James Duncan Davidson

This means that whether you start out fat or thin, when you try to override the system by dieting, the brain thinks you’re starving. You get hungrier, and your muscles burn less energy. Even after keeping weight off for seven years, your brain still wants to make you gain it back. This makes sense in evolutionary terms, increasing our chances of survival in time of famine, but as Aamodt wryly notes, it doesn’t work out so well in our time of drive-through burgers. (Changing the food environment, she suggests, might be the most effective solution to obesity.) Even worse news is that while set points can go up, they rarely go down.

So if we’re outgunned by our hardwiring, what hope is there? Aamodt says psychologists categorize eaters into two sets: intuitive eaters, who eat according to their bodies’ hunger signals, and controlled eaters, who try to control when they eat — like dieters. Intuitive eaters are less likely to be overweight, while the controlled eaters are vulnerable to binging. Children are particularly vulnerable, she says: Girls who diet in their early teens are more likely to gain weight five years later, no matter their starting weight, and the same factors lead to eating disorders. Something else that predictably leads to eating disorders: a family member who makes fun of them for their weight. ”So,” Aamodt says, “don’t do that.”

But surely we have to keep weight down for health reasons? That’s another myth. Aamodt says lifestyle choices are far more important to maintaining health than weight. She cites a study that measured the risk of death over a 14-year period based on four healthy habits: eating fruits and vegetables, getting exercise, not smoking, and drinking in moderation. For someone who is overweight and who practices no healthy habits, the risk of death is high, but adopting just one good habit brings that person back within normal range. (Note that this is true for overweight people, not obese people. For obese people, it takes all four habits to bring them back into a normal range.) And regardless of weight, for those who adopted the four healthy habits, weight makes very little difference to health. The message: if it’s really health you’re worried about, you can take control by adjusting your lifestyle.

And if that’s not convincing enough, Aamodt makes the counterintuitive assertion that dieting typically causes gain weight over time. Five years after a diet, most people have regained the weight — and 40% have gained even more than they lost. It would seem that dieting contributes to obesity rather than preventing it.

For her own part, Aamodt solved the conundrum by becoming an intuitive eater, shifting her attitude towards food. “My solution, in a word, is mindfulness,” she says. Not as in yoga or meditation, but giving yourself permission to eat whatever you want, slowly, and without distractions, paying attention to how your body feels when hungry or satisfied, and letting hunger determine when you’re done. “It took about a year to learn,” says Aamodt, “but it was worth it. I’m so much more relaxed about food than I ever have been in life. It’s like aliens have taken over my brain.”

She warns that intuitive eating may not make you lose much weight, but every diet tested has failed in the long run, and as willpower is a limited resource, any weight-loss strategy that relies on it is doomed to fail when it’s necessary to focus on something else. It also does a lot of collateral damage. In the United States, 80% of girls at age 10 have been on diet. Shocking. “Our daughters have learned to measure their worth by a wrong scale,” concludes Aamodt. “If they stopped dieting, most of them would be happier and healthier, and as adults most of them would probably be thinner. I wish someone had told me that when I was 13.”

Photo: James Duncan Davidson

Neuroscientist Russell Foster opens a session of TEDGlobal all about … us, asking the question: Why do we sleep? Thirty-six percent of our lives are spent asleep, which means, if you live to 90, you’ll have slept for 32 years. But we don’t appreciate sleep enough, says Foster. He quotes Thomas Edison — “Sleep is a criminal waste of time, inherited from our cave days” — and Margaret Thatcher — “Sleep is for wimps.” Simply put, says Foster, not only do we not appreciate sleep, but we treat it like an illness and an enemy.

Of course this simply shouldn’t be the case. In fact, some areas of the brain are more active during the sleep stage than while the body is awake. But the essential question that we — ahem — lose sleep over: Why do we sleep? There is no real consensus, but Foster gives three popular answers:

1. Sleep is for restoration, to replenish and repair metabolic processes. Indeed, a whole host of genes are “turned on” only during sleep — genes associated with restoration and metabolic pathways.
2. Sleep is for energy conservation, to save calories. This may seem an intuitive answer, says Foster, except that the difference between sleeping and quietly resting is about 110 calories a night, the equivalent of a hot dog bun. Not a very good upshot for such a complex process.
3. Finally, sleep is for brain processing and memory consolidation. This is the explanation Foster espouses. Studies show that if you prevent people from sleeping after a learning task, their ability to learn is basically smashed. And worse, our abilities to come up with novel solutions after a complex task are reduced after sleep deprivation.

The danger of sleep deprivation can’t be stressed enough. For one thing, sleep-deprived people fall asleep involuntarily, taking “microsleeps” they can’t control. Thirty-one percent of drivers, says Foster, will fall asleep while driving at least once in their lifetime. That is: 100,000 accidents a year happen because of tiredness.

Photo: James Duncan Davidson

For those who want to take control of their sleep habits, Foster has some tips:

1. Decrease your amount of light exposure at least half an hour before you go to bed.
2. Make your room a bedroom a haven for sleep by making it dark and cool.
3. Turn off your mobile phones, computers and anything that will excite the brain.
4. Don’t drink caffeine after lunch.
5. Increase light exposure when you wake up.

He also busts some myths:

1. Teenagers are lazy? Nope. Their biological clocks make them sleep and wake later.
2. You need 8 hours of sleep a day? Nope. That’s just an average.
3. Older people need less sleep? Nope. Sleep demands of the age don’t slow down.
4. Early to bed, early to rise makes a man healthy, wealthy and wise. Nope. Just wrong, on many levels. It just makes you more smug.

Good to know. But where Foster’s true expertise comes in is in new research he and his colleagues are conducting on the links between sleep and mental illness. According to Foster’s research, genes that have been shown to be important in the generation of sleep, when muted, predispose individuals to mental-health problems. Foster suggests that sleep levels could be used as an early warning signals for illnesses like schizophrenia. Research has found that schizophrenia patients stay awake during the night phase, asleep during day, suggesting that sleep and mental illness aren’t simply associated, they are physically linked. Which opens the door for sleep to be used as a new therapeutic target.

To conclude, Foster urges us to take sleep seriously. He gives a final quote on sleep, from the writer Jim Butcher: “Sleep is God. Go worship.”

Thomas Insel: Toward a new understanding of mental illness “These are just remarkable changes,” says Thomas Insel, Director of the National Institute of Mental Health, in today’s talk given at TEDxCaltech. “All of them boil down to understanding something about the disease that has allowed us to detect early and intervene early.”

Sadly though, Insel says, the news isn’t good across the board. The rate of suicide, he says, has not changed at all over the last three decades. About 90% of suicides are related to mental illness. And while 1 in 5 people will be affected by a psychiatric disorder, scientists still understand dangerously little about these diseases. In fact, says Insel, we don’t even know what to call them. The terms preferred at the moment – “mental disorders” and “behavioral disorders” — are misleading, because they point to symptoms rather than to the disease itself.

“Both of those terms which have been in play for a century or more are actually now impediments to progress,” says Insel. “What we need conceptually here is to rethink these disorders as ‘brain disorders.’”

In this talk, Insel reveals why he believes we are about to turn a corner in understanding the brain, which he calls an “organ of surreal complexity.” As scientists get a better understanding of its workings and development, they’ll start to understand the patterns of brain disorders. It’s possible that, as with heart disease, scientists will be able to identify risk factors. To hear how this could lead to early detection of brain disorders — and even interventions before a person so much as experiences or displays symptoms — watch this fascinating talk.

“The good news stories in medicine are early detection and early intervention,” explains Insel. “If we waited until the heart attack, we would be sacrificing 1.1 million lives every year in this country to heart disease. That’s precisely what we do when we decide that everyone with one of these brain disorders has a ‘behavioral disorder’ – we wait until the behavior becomes manifest.”

Insel’s talk reminds us of two powerful TED playlists.

First it reminds us of the list “All Kinds of Minds,” which features several TED Talks from people who’ve had the experience of living with a brain disorder. It begins with legal scholar Elyn Saks describing her own experience of schizophrenia, moves on to activist autism activist Temple Grandin describing how her mind works, and builds to Joshua Walters, who is bipolar, asking: What’s the balance between medicating craziness away and riding its creative edge?

Insel’s talk also reminds us of the playlist “How does my brain work?,” which brings together talks about incredible research that’s helping scientists better understand our minds. It begins with neuroscientist Daniel Wolport giving a fascinating theory on why the brain evolved, moves on to Allan Jones and his initiative to map of the brain, and ends with Michael Merzenich giving evidence of the brain’s plasticity.

Also very worth checking out: Thomas Insel’s blog, where he just last week wrote about CLARITY, the newest way scientists at Stanford University are looking at the brain »

How do we negotiate when to sell a stock, whether to rat out a partner in crime, how to play a poker hand, or what to ask for when negotiating a job offer? In each of these situations, the actions of others will greatly affect our outcomes — and yet, we have no idea what they are thinking. These are the kinds of situations that game theory has helped mathematicians and economists parse for decades.

In today’s talk, given at TEDxCalTech, behavioral economist Colin Camerer surveys new research that is taking game theory to the next level — by taking fMRI and EEG scans of people’s brains as they engage in bargaining games. The idea is to see what brain circuitry is used as people make decisions, and to map out what agreement and disagreement look like in the brains of humans … and in chimpanzees, who appear to be better at these negotiations than we are.

While the seeds of game theory were planted as early as Plato, the field gained prominence in the 1940s and 1950s, thanks to the work of John von Neumann (who wrote Theory of Games and Economic Behavior) and John Nash (of A Beautiful Mind fame). Since then, eight game theorists have won the Nobel Prize in Economics. To hear about new neuroscience approaches to this classic area of study, watch Camerer’s talk. And below, read some recent several articles about how game theory can apply to our everyday lives.

1. What makes a person decide to donate a kidney? As Stanford economist Alvin Roth has shown, it is largely a question of game theory and market economics. According to the October 2012 Reuters story, “Alvin Roth Transformed Kidney Donation System,” in 2004, Roth created the New England Program for Kidney Exchange, a method that used computers — and an algorithm designed by UCLA mathematician Lloyd Shapley — to pair groups of donors and create the types of kidney donation chains depicted on Grey’s Anatomy. Before this system, says Reuters, there were just 19 kidney transplants from live donors in the United States. In 2011, that number rose to 443. In total, about 2000 people have received kidneys through Roth’s system. And in October of 2012, both Roth and Shapley were awarded the Nobel Prize in Economics for their work in taking “stable allocations” from an abstract concept to a reality.
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2. Another real-life problem that Roth has tackled: in extremely large school systems, how can students be matched with the right school? In the Forbes magazine story, “What Al Roth Did to Win the Nobel Prize in Economics,” journalist Susan Adams takes a look at how Roth leveraged the tools of game theory to tame the high school matching system in New York City, where 80,000 8th graders must be dispersed to 700 schools every year. She writes, “Before Roth got involved, the matching system was so screwed up that a third of the city’s eighth graders didn’t even participate.”
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3. In their book, It’s Not You, It’s the Dishes, journalists Paula Szuchman and Jenny Anderson wonder if the daily negotiations of marriage are more like playing a game of poker than most people realize. In the article “Marriage and the Art of Game Theory,” which ran on the Daily Beast in July of 2012, Szuchman writes, “Game theory is the study of how we make decisions in strategic situations. Classic examples: the Cuban missile crisis, soccer penalty kicks, and the first scene of The Dark Knight. When you find yourself debating whether to wait for the bus another minute or give up and walk, you’re facing a game-theory dilemma … To cooperate or not to cooperate? To budge or stand your ground? To say ‘OK, fine’ or ‘not a chance’? These are questions married people find themselves asking with surprising frequency.”
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4. Could game theory explain why so much head-butting happens in the United States Congress, especially as they approached the fiscal cliff in late 2012? (Watch Adam Davidson’s talk explaining the fiscal cliff.) In The Atlantic op-ed “How Game Theory Explains Washington’s Horrible Gridlock,” Mohamed A. El-Erian applies the principles of game theory to Congress’ negotiation over the budget. He writes, “Here is the typical cycle: Responding to the ‘national call,’ the two parties’ initial narratives trend towards ‘grand bargains’ aimed at removing headwinds to growth, jobs, and prosperity. As differences prevail, this gets replaced by a ‘mini bargain,’ or one that would deliver some progress together with momentum for future success. As this also proves elusive, negotiations get quite acrimonious. If and when an 11th-hour compromise emerges, it lacks both content and momentum: The majority of meaningful decisions are postponed, and both Democrats and Republicans emerge from the experience more bitter — at each other, and also within their respective parties.” (Also see: “Game Theory Expert Analyzes Fiscal Cliff.”)
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5. Of course, the economic standoff of late 2012 wasn’t fully resolved — it was in large part delayed, leading to the more recent “sequester.” In the article “The Strange Game Theory of the Sequester,” Pacific Standard writer David Dayen wonders if Barack Obama is using game theory tactics in moving forward on sharp budget cuts. He writes, “Making clear the impact of forced austerity may offer the best hope for discrediting and reversing it. When faced with closures of national parks, shutdowns of government offices, delays in needed services like the disposition of federal benefits, and long lines at the airport due to a reduction in TSA personnel and air traffic controllers, the thinking goes, perhaps Congress will get moving on a less painful solution.”

David Anderson: Your brain is more than a bag of chemicalsWhile few hands shoot in the air, Anderson goes on to explain the connection — that research conducted by manipulating brain chemicals in fruit flies is giving us valuable insight into the brain circuitry of emotions and mental illness. And these neural underpinnings are more complex than many think.

“We tend to believe — and the popular press aids and abets this view — that [psychiatric disorders] are a chemical imbalance in the brain,” says Anderson. “As if the brain were some kind of bag of chemical soup full of dopamine, serotonin and norepinephrine.”

The brain circuitry of mental disorders are complex, and yet the medications we’ve used to treat them for the past two decades work from a simple model — they treat every part of the brain as if it were the same. This is one of the big reasons that current psychiatric medications don’t work well, says Anderson, and why they have many unpleasant side effects that lead many to avoid them.

Explains Anderson, ”Using them to treat a complex psychiatric disorder is like trying to use engine oil by opening up the can and pouring it all over the engine block—some of it will dribble into the right place, but a lot of it will do more harm than good … What we need to do is use our ingenuity and our scientific knowledge to try to design a new generation of treatments that are targeted to specific neurons and specific regions of the brain that are affected in particular psychiatric disorders.”

Anderson’s lab approaches this challenge in an interesting way — by asking questions like, “How long will a fruit fly stay angry if we inhibit its dopamine system?” To hear how this all works, watch this fascinating talk — a must-see for anyone who has or knows someone with a mental disorder.

Fruit flies, otherwise known as Drosophila, are the workhorse of brain research. Here, a playlist of TED Talks about research with these amazing insects.

Gero Miesenboeck reengineers a brain Gero Miesenboeck reengineers a brain Instead of mapping the brain by recording the activity of every neuron — a daunting task — Gero Miesenboeck works the other way around. At TEDGlobal 2010, he shares his reverse engineering approach, revealing how manipulating neurons leads to a clear understanding of what they do.

Michael Dickinson: How a fly flies Michael Dickinson: How a fly flies From an engineering standpoint, it is incredible that fruit flies are able to lift off, given the size of their bodies and the delicate structure of their wings. In this talk from TEDxCaltech, Michael Dickinson shares the marvel — and how it is made possible by the fly’s nimble brain.

Eva Vertes looks to the future of medicine Eva Vertes looks to the future of medicine At age 17, Eva Vertes discovered a compound that stopped the damage in a fruit fly’s nervous system, caused by heavy metals. Many think this could be a first step toward a treatment for Alzheimer’s. In this talk from TED2005, Vertes walks us through that research, and shares an exciting possibility — that cancer could potentially be used as a treatment.

Read Montague: What we're learning from 5,000 brains Read Montague: What we’re learning from 5,000 brains Fruit flies and mice have long been the organisms we use to study the brain. At TEDGlobal 2012, Read Montague shares the tool — fMRI — which is allowing his lab to study thousands of human brains as they interact with each other.

And some TEDx Talks to watch:

• Luke O’Neill at TEDxDublin: From fruit flies to cancer
• Hidehiko Inagaki and Ketaki Panse at TEDxCaltech: “Emotion” in the hungry fly brain

Photos: James Duncan Davidson

Daniel Reisel is here to talk about our brains. In particular, how we might change them–and how this kind of thinking might just change the tenor of society as a whole.

He introduces us to Joe, who’s 32, and a murderer. Reisel met Joe in Wormwood Scrubs, a high-security prison that houses England’s most dangerous prisoners. On a grant from the UK Department of Health, Reisel visited the jail to study inmates’ brains and try to find out what lay at the root of their behavior. “Was there a neurological cause for their condition?” he asks. “And if there was a neurological cause, could we find a cure?”

Initial research showed that psychopaths like Joe indeed had a different physiological response to emotions such as distress or sadness. “They failed to show the emotions required; they failed to show the physical response. It was as though they knew the words but not the music of empathy,” Reisel describes. MRI scans (yes, transporting psychopaths across London in rush hour to place them in a scanner, unadorned by metal objects such as, say, shackles, was a nightmare) showed an interesting phenomenon and a tentative answer: “Our population of inmates had a deficient amygdala, which likely led to their lack of empathy and their immoral behavior.”

Acquiring moral behavior is a part of growing up, like learning to speak. By 6 months, we can discriminate between animate and inanimate objects. By 10 months, we can imitate actions. By the time we’re 4, most of us are able to understand the intentions of others, a prerequisite for empathy. But that’s not to say that it’s not possible to learn such behaviors in later life.

Reisel wants to talk neurogenesis. This is the birth of new neurons in the adult brain, and Reisel is fascinated by its promise. He left his work with psychopaths to work on mice, whose brains he studied in very different environments. Some were kept in a shoebox devoid of entertainment (similar to, say, a prison cell); others lived in an “enriched environment.” Mice in the former condition lost their ability to bond with their fellow mouse; those in the latter showed the growth of new brain cells and connections. “They also perform better on a range of learning and memory tasks,” says Reisel. “Of course, these mice do not develop morality to the point of carrying the shopping bags of little old mice across the street. But their improved environment results in healthy, sociable behavior.”

Could this research influence the design of our prison systems? “When you think about it, it is ironic that our current solution for people with dysfunctional amygdalas is to place them in an environment that actually inhibits any chance of further growth,” he says. He’s not suggesting that we should pack up all our prisons. Instead, perhaps we might think of rehabilitation through programs such as Restorative Justice, which encourages perpetrators to take responsibility for their actions. “This stimulates the amygdala and may be a more effective rehabilitative practice than simple incarceration,” says Reisel. It’s a fascinating proposition. “Such programs won’t work for everyone. But for many, they could be a way to break the frozen sea within.”

It’s a charming, chilling, thought-provoking talk. Reisel leaves us with three lessons from his work over the past fifteen years. We need to change our mindset, he says. “The moment we speak about prisons, it’s like we’re back in Dickensian — if not medieval — times. For too long we’ve allowed ourselves to be persuaded of the false notion that human beings can’t change, and, as a society, it’s costing us dearly.” Next, we need to prompt and promote cross-disciplinary collaboration. “We need people from different disciplines, lab-based scientists, clinicians, social workers and policy makers, to work together.”

Finally, we need to use our own brains, our own amygdalas, and we need to rethink our view of prisoners such as Joe. After all, if we see psychopaths as irredeemable, how are they ever going to see themselves as any different? Wouldn’t it be better for Joe to spend his time in jail by training his amygdala and generating new brain cells? Reisel concludes: “Surely that would be in the interest of all of us.”

Mapping the human brain is an endeavor several TED speakers have already begun embarking on. Here, a look at talks about how this mapping can take place — and why it’s a scientific priority.

Erin Schuman: How neurons reach out to each other
If we’re going to understand how our brains create us, we will need to know how our brains build themselves at the smallest levels. It’s no easy feat: each neuron can have 100,000 synapses. But using some of the same methods you could use to count the number of fish in a pond, Erin Schuman shows how neurons distribute the assembly work in a decentralized way — and how understanding those decentralized systems could further our understanding of all kinds of successful networks.

Ralph Adolphs: The social brain
We humans can’t help but attribute our social qualities our non-human companions. Anyone who’s yelled at their computer can attest to that. Ralph Adolphs studies that kind of social behavior, both when it’s normal and when it’s not. In this fascinating talk, he shares how we know which regions of our brains are essential to social interactions and sheds light on the behavioral loop in which our actions and feelings affect our perceptions of social situations as much as the realities of those situations.

Andres Lozano: Turning dials in the brain
Sometimes, when you want to learn how something works, you need poke it with an electrode. Andres Lozano does that to living brains, albeit with far more precision and control than you may think is possible — and he’s alleviated symptoms of crippling neurological disorders, like dystonia and Parkinson’s, along the way. Telling uplifting success stories, he shows you how he does it and previews his promising next steps — attempting to “turn the lights back on” in Alzheimer’s patients.