Transcription
[Music] I wake to sleep and take my waking slow. I feel my fate in what I cannot fear. I learn by going where I have to go. We think by feeling what is there to know. I hear my being dance from ear to ear. I wake to sleep and take my waking slow. I learn by going where I have to [Music] go.
The adult brain, crowned by the cerebral cortex, a wrinkled mass of tissue just a fraction of a CM thick. Within its furrows lie our powers to reason, judge, understand. But buried beneath is an unconscious underworld, a cluster of structures that drives our appetites, moods, and emotions. For a long time, it was thought the brain was divided into two: emotion was one thing and thought was something else, and these were two things that were interfering with each other. But it's now clear that this division was wrong, just completely wrong. [Music]
There's a highly choreographed, hardwired relationship between the thinking areas of the brain and the feeling areas of the brain. One affects the other at all [Music] times. It is not possible to have a properly working reason system without having a properly working emotion system. What you think, what you create, the problems you solve, the way you reason, don't exist in a vacuum. There is always the backdrop of emotion and feeling. We are not thinking machines; we are feeling machines that think. [Music] [Music]
It's been 23 years since he suffered the stroke that was just horrible. I just felt like I had totally lost my best [Music] friend. I wanted to bring him back to the person that he was, but you know, in reality, I should have known I [Music] couldn't. The doctor said to me, the best thing to do is to actually have a funeral for Marvin, the one that you married, and accept the Marvin that you brought home as a totally different person, because because he'll never be the [Music] same. At 56, Marvin Baitman is a shadow of the young husband and father he once was. A stroke has left him paralyzed on one side of his body, but its most devastating impact is less visible: he has been cut off from his emotions. "I want to see my mom," please. No, I [Music] want to put the lotion in the [Applause] [Music] [Applause] basket.
So how did that make you feel when we were watching it? Well, it's um, I don't know, it's it's well, it's hard. I'm trying to think; it's like I I know you're working for a word, but I can't think of one right now. It's okay. At the University of Iowa, researchers are trying to understand why Marvin cannot feel a simple emotion like [Music] fear. A scan shows the stark region where Marvin's brain has [Music] died. The core of the damage is in areas that have to do with creating a feeling. It's not that he has lost the ability to produce an emotion; the losses have more to do with the ability to feel. "Can you remember like from this picture to that picture, a long time?" "Well, no, see, I was we still live in WI there." "Yeah, I know, and then this is after I got moved and I had that stupid stroke." "Yeah, yeah."
Emotion: you can see it on Marvin's face—a smile, a laugh, a scowl of frustration. But what he does not experience is the awareness of emotion. Emotions are generated by structures hidden deep in the brain. The tiny, almond-shaped amygdala is the first to respond to an emotional event, triggering a series of split-second reactions within the brain's emotional core. Waves of nerve impulses travel down the brain stem, setting off an instantaneous visceral response throughout the body. A lot of the time, the machinery that produces the emotion is operating without us noticing it at all, creating changes in posture and in facial expression, altering the way the organs inside the body are working, preparing the body for what's needed next, generating chemical responses that you will never know existed. And all of this is what constitutes the emotional state for most people. Awareness of a feeling follows just milliseconds after an emotion is created. The body sends signals back to the area of the brain responsible for conscious thought, making us aware of our feelings. It is in this region of emotional awareness that Marvin's stroke decimated hundreds of millions of brain cells. Marvin experiences emotion; his body responds, but when the physical response is communicated back to his thinking brain, the signal falls into a void. Marvin can only guess at what he or others may be feeling. "Differ when you're married, there's an emotional connection between two people. That connection is no longer there. It's like somebody cut that wire between the two of us. If I try and talk to him, you know, about something that's bothering me or um, well, I just need somebody to listen, he's just not there for me. There's no empathy or sympathy; he just can't get that feeling, and he knows it should come, but it just won't."
This is the Shell Valley in the French Alps. Avalanche paths are evident all around. In the past, before the stroke, Marvin was a successful salesman selling plumbing supplies throughout Iowa, but he hasn't been able to work in 23 years. "Valley, he was very ambitious, driven. No, he doesn't really want to make any decisions as far as anything important, you know. No, I couldn't make decisions like I thought I should, and I probably wouldn't, you know, make a decision about different things. I probably would have screwed myself up because I didn't. When wasn't for Arlene, we wouldn't be where we're at because I didn't make, you know, proper business decisions on the house and any any bills or anything like that because I just wasn't able to make decisions."
Marvin has trouble deciding because he has lost the emotional connection to his past. Memories and the emotions that go with them guide our every decision, but for Marvin, memories are bereft of feeling. "All the things that you go through in your life in terms of decisions are inevitably accompanied by some kind of emotion, positive or negative. Each decision has some kind of similarity with a decision of the past, and when you are in a position to decide once again, you will call up an emotional memory that will appear as a gut feeling and will lead you in one direction or another. So what you have is literally a navigational aid, something that helps you get to the right decision, and if that is broken down, then you're at the mercy of facts and logic, and that's just not good enough."
Marvin is rudderless as he navigates through daily [Music] life. "But um, I'm not an inv—I'm not uh—I'm not. Some days, probably people probably think I am, but I'm not, you know. I'm able to do a lot of things. I give everything up to have him back emotionally." "Okay, yeah, we care about each other, you know, and I always love him, but I just miss the old Marvin."
There's an old idea that emotion is not at all a good thing because it is difficult to control, but emotion is extremely useful. Emotion is not a luxury; emotion is part and parcel of the mechanisms that allow us to stay alive. Feelings seem intangible, intensely subjective, but now, using new imaging technologies, scientists have demonstrated that emotions have a physical place in the brain. Anger, happiness, sadness, fear—sometimes intense, often fleeting—each has a specific neural circuitry that has evolved over millions of years. [Music]
Why do we have these emotional states? What are they for? Well, they all serve a purpose; they're all adaptive. By having a feeling of emotion, you have a possibility of taking into account what happened and using that for the proper planning of future actions. If something caused happiness because it was something that was potentially good for you, having that feeling is going to help you organize your planning around the possibility of getting some more of that good thing that you [Music] had. Even emotions that are disturbing, like anger or fear, have their purpose. No one's life is free from stress, and when those stresses occur or problems arise, we have specific emotions that are part of our repertoire for a reason because they help us solve those important problems. Anger, for example, is a constellation, a package of brain responses that facilitates our ability to remove obstacles that are in the way of important goals. With fear, the essential thing is to place the organism out of danger. So, for instance, an animal can rapidly flee from the predator or freeze. And so the experience of certain kinds of negative emotions are absolutely necessary and appropriate. Where problems arise uh is when an emotion persists for a much longer duration of time uh than it normally would.
"It was 6:00 a.m. I was like every day, normal day, going to work. I was stopped in the red light in the intersection, and um, as soon as the light turned green, I I start going. I just heard a 'or,' and I take a look my right side, the car. It's all that I can remember. I thought it was over, but I'm still so scared."
It's 6 a.m. on January 24th. You are driving yourself to work; you're listening to the radio. You stop at the intersection of School Street and Highland Avenue. It's been a year since the accident that broke Johnny Cortez's arm and leg. His bones have healed, but he is still unable to free himself from tormenting memories and crippling [Music] fear. At the VA Research Center in Manchester, New Hampshire, scientists are monitoring Johnny's level of anxiety. He is suffering from post-traumatic stress disorder, PTSD. [Music]
One of the diagnostic signs of PTSD is that the reminders of the traumatic event produce a physical [Music] response. "We decided to use the patient's own memory of the traumatic event as a stimulus so we can measure bodily changes in the laboratory. As you're going through the traffic light, suddenly you see the light of a car coming on your right side, about to crash into you." What we saw while we were watching Mr. Cortez remembering that automobile accident that he went through was his heart rate going up much higher than it was prior to the memory. It started out around 90 and it wound up above 140. The beating of Johnny's heart and the sweat on his skin testified to Johnny's anguish and provide a window into his brain. "We think that what's going on in the mind of the person with PTSD is not a simple memory; it's a reexperiencing situation; it's a reliving. If they feel as if they're really back in their traumatic situation, then their hearts start to beat faster and their hands get sweatier because they're preparing to deal with a very frightening event."
The car crashes into you. Your chest is constricted, and you want to scream. You hear sirens and then a female voice asking you something, but you can't answer the question. The voices around you are like a dream. You're confused and feel the blood rushing to your head. In PTSD, something breaks; an event occurs, and the body body and the brain cannot accept that it's over. And so, instead of moving through it, people get stuck. "You're always afraid that it will come back. They think that it has come back when they hear certain sounds or feel certain things in their bodies and remind them of it, and it becomes like a cancer that sits there inside of your memory that dominates how you see the world and how you see yourself." "Most often, I can't sleep very well. The bad dreams, they are they are terrible, and uh, when I got bad dreams and nightmares, I don't know how, but I can't remember, but I just woke up when I realize I am on the floor crying and my wife trying to call me, say it's okay, Johnny, it's okay." [Music]
How has fear, a life-saving evolutionary response to danger, been transformed by a traumatic accident into PTSD? At Massachusetts General Hospital in Boston, scientists are examining the fear response, scanning the brains of people with and without post-traumatic stress disorder as a series of expressionless faces faces are flashed in front of [Music] them. Hidden among the faces is a single image that signifies threat: a face frozen in terror. In that instant, one part of the brain in every test subject is highly responsive: the amygdala. "The amygdala is a small structure which cares a lot about threat and fear. If there's something that may be potentially harmful to us, it is a brain area which gets activated very quickly and recruits other areas of the brain to try to deal with this unexpected circumstance. The uh amygdala sends outputs to the body so that your muscles begin to tense uh hormones are released, blood pressure goes up, and all of these are part of the protective response of the body uh designed by evolution to help you stay [Applause] alive."
Imagine you're walking down a path in the woods, and all of a sudden there's a curved object that looks like a snake on the ground, and you find yourself stopping with your leg resting above that object, and you look down and see that it's simply a stick. So why did your leg stop like that? In the normal brain, the the amygdala acts like an early warning system, alerting us to danger, but the amygdala does not act on its own. The frontal cortex, where we think and reason, plays a crucial role. There are two parallel routes of fear processing in the brain. One will go directly to the amygdala; it's a quick and dirty pathway and trigger a fear reaction unconsciously. But then, as the information slowly makes its way to the cortex, the cortex perceives the difference between the stick and the snake and says it's only a stick. Once the discerning cortex has determined that there is no call for panic, it sends a message to the amygdala, quieting the fear response. But in post-traumatic stress disorder, the cortex is held hostage by a amygdala. Thinking is hijacked by emotion. "People with PTSD are very sensitively tuned to pick up threat and respond to even very minor stimuli as if the life were in danger. All there is is your fear and your threat, and my life has come to an end. You're trapped. Any single noise let me jump; I me nervous; my heart starts beating fast. So I say, what's going on with me? An accident that happened to everybody to everyone. An accident can change the life for [Music] someone. Why I can't understand why."
Most people suffering from PTSD are like Johnny, at the mercy of an overly sensitive amygdala and the hormone that gives that extra burst of energy to help us fight or take flight in the face of danger: adrenaline. In a moment of terror, the amygdala sets off a cascade of reactions; a wave of nerving impulses travels down the brain stem and triggers the release of adrenaline in the body, sending a flood of stress hormones into the brain that help etch the memory of the danger more deeply into our neural circuitry so we can avoid it the next time. "An emotionally arousing experience releases hormones which will enable you to deal with that experience in the future because you'll have a stronger memory of that particular set of circumstances, and you can use that information information to make decisions about what you do in the future." But people with PTSD appear to have an overly sensitive amygdala; even a harmless sound can set it off again and again. The traumatic moment is involuntarily recalled and relived repeatedly, activating the amygdala and releasing adrenaline each time, searing the trauma deeper into the memory centers of the brain. Post-traumatic stress disorder is simply ordinary emotion and memory gone haywire. It's gone too far; it's using a very adaptive mechanism for a maladaptive [Music] purpose.
If PTSD begins with a jolt of adrenaline, can blocking the effect of adrenaline stop PTSD before it starts? [Music] In the emergency room at Massachusetts General Hospital, where Johnny was treated after his accident, scientists have been experimenting with a new treatment. If it works, it might spare traumatized patients a lifetime of nightmares and anxiety. "Why not see if giving a beta blocker, a drug which blocks the action of adrenaline, why not give that to subjects who have had a traumatic experience so that even if they relive the situation, even if they have these flashbacks, they won't have the adrenaline making too strong a memory?" In a carefully controlled study, traumatized accident victims were given the beta blocker drug as soon as they arrived in the emergency room and then four times a day for two weeks. The preliminary data suggests that by interfering with adrenaline's impact, beta blockers can stop the vicious cycle of post-traumatic stress disorder in its tracks. "If post-traumatic stress disorder can be weakened or blocked, then there is a way to prevent this disease, and until now there has not been one. So that's pretty big news. If it turns out to work out that way, there'll always be the memory there, but the hope is to prevent that from becoming so strong that it takes over the life of the individual and becomes not just a strong memory, but it becomes a very significant emotional disorder."
Just as fear has turned against Johnny Cortez, terrorizing him with its unrelenting persistence, other emotions too can go awry. Anger, desire, sadness are just as tangible as fear, and any one of them can spin out of control with devastating consequences. "Emotion tells us what's good about our world, what's bad about our world. Emotion forms self-concept, but our whole self-concept can get away from us. We can feel hopeless and worthless; we can feel that there's no future for [Music] us."
Lauren Slater first checked into a psychiatric hospital at the age of 14, suffering from severe depression. Ten years later, after having been in and out of the same hospital, she was still suffering. "When I was 24, 25 years old, my fifth hospitalization was fairly brief. They were at the end of the line with me. What could they do for this girl, now become young woman, who they'd seen year after year? And I was just discharged from the hospital, and I didn't have a place to go, so I went to this motel, and I fell asleep. I was in this half-state between sleep and wake, and I could see very very clearly where my life was going. I knew that I did not want to live the way I had been living. I saw myself clearly; I saw who I was and what I was and what I had become, and I knew I wanted out. And 'out' meant two things: one of two things; it meant somehow either getting better, changing, or it meant leaving, and those were both options for me."
It was at that moment in the hotel room that I made a choice: I wanted to try getting better. That's what I wanted to try. [Music] First, Lauren went on living with depression, grooved in her brain—not the passing blues we all can feel, but a chronic and confounding disease we are still struggling to understand. "What goes wrong in the brain to cause depression? Because depression can have profound symptoms; it can change lives; it can lead people to end their lives. And yet, when we look at the brain of a depressed person, we don't see any holes in it, any obvious lesions. I mean, it's far different from many other disorders. We don't know what causes it; we don't have a pathology of it like we do for Alzheimer's disease or Parkinson's disease. So all we have at the present time is we have a collection of clinical signs and symptoms." [Music]
"To feel depressed, to me, is to feel dead. It's to feel that all of the things in your life that gave you comfort and meaning, they're no longer even familiar. Deadness, terror, horror, distorted time—it's the ultimate isolation; it's the ultimate wordlessness, which is why it's so hard to talk about it." An image captures what words cannot: the depressed brain. No physical damage is apparent, but to scientists, its signature is clearly visible in patterns of brain activity. The prefrontal cortex, the part of the brain with which we understand and engage with our world, has grown dull and silent. The emotional core of the brain is sending the prefrontal cortex signals, flooding it with chemicals carrying emotional messages, but the prefrontal cortex can only make tentative attempts to respond. There should be a constant interplay between what we feel and what we think, but in the state of intense depression, the balance between emotion and feelings and thinking and reasoning becomes out of [Music] whack.
Anyone can become depressed, but chronic, unrelenting depression seems to run in families, passed through the genes generation to generation—a vulnerability that can be heightened by traumatic experiences early in life. "Looking at my family history, you can see that depression runs through the family tree. My father has definitely struggled with depression, and his mother and his father suffered as well, so I know that it's there, and it goes back. I also think, though, that the environment had a really significant role in how those genetic tendencies or inevitabilities were played out. There were episodes of violence, of pretty serious violence, um, where there would be punching, hitting, pulling by the hair, a lot of cruelty, a lot of humiliation, and it was like that day after day after day."
We know that there are critical periods in childhood when the brain is remarkably plastic, and one of the consequences of early trauma is very likely that the brain does not form the normal connections that it normally would, and it's going to have consequences in adulthood. Most people who experienced depression did not experience childhood abuse, but Charles Nerver believes that physical, sexual, even emotional abuse can make the brain abnormally sensitive to stress and later in life make some people more vulnerable to depression. Scientists have found that people with depression often produce too much of the stress hormone cortisol. "Many conceptualize depression as the stress response gone awry. Stress uh is is really an event that should be very time-limited. You're exposed to a stressor; your stress hormones should be released, and they should turn off very quickly. But in the brain of a depressed person, stress triggers too much cortisol for too long. Chronic exposure to this normally stress hormone can be toxic to the brain. You can think of it almost as leaving a scar, as changing the brain, as making the brain more vulnerable to subsequent [Music] depressions."
"After my experience in that motel room, I really worked hard to pull it together. I tried to live without symptoms; I tried to live without collapsing. It was boot camp for a year—absolute boot camp. I had charts, lists, this this and that, anything to just get myself on the right road. Huge amount of sweat equity went into that effort, and it didn't work. And when it didn't work, I was ready, really ready to throw in the towel. And I wasn't just a year; it was those 10 years preceding it. I was exhausted. So suicide, it was a welcoming thought to me."
People kill themselves when they are depressed as a way of trying to spare themselves from unremitting and unrelenting pain. Suicide is one viable cure for depression; that's how the depressed person sees it. But there's this tenacious part of not only me but all of us: we want to live. "So I called the psychiatrist that I had been seeing, and she said to me, 'There's this new drug on the market, and I think we should try it. It's called Prozac.' And my response to that was, 'Don't, don't. I don't want another drug.' And yet, when the psychiatrist offered me a possible way out, I immediately jumped for it, and so I tried it. You know, swallow a little biochemical missile, and boom, kaboom, you're changed." [Music]
The brain contains 100 billion cells, neurons, and they make 100 trillion connections, or synapses, and each of the neurons release chemical substances called neurotransmitters, and these neurotransmitters are the legal tender of the brain; that's how these cells communicate with each other. As the neurotransmitters flow through the brain like a river, sending a steady stream of information between the brain's emotional and thinking regions, just a few milligrams of an antidepressant like Prozac, Zoloft, or Paxil can quickly and radically affect one of them: the mood-influencing chemical serotonin. In the synaptic gap between the neurons where serotonin delivers messages from one cell to another sit a series of molecules that work like locks on a canal, regulating the flow of serotonin, determining its rise and fall. In the depressed brain, serotonin is often at low levels. An antidepressant can plug the entry to some of the molecular locks, forcing serotonin levels to rise in the open spaces between the cells—a change that occurs throughout the brain, but especially in the brain's prefrontal cortex. "And the fact that it occurs in the prefrontal cortex, I think, is very intriguing, since this is the very area that people would have um guessed would be a critical area in being able to regulate your mood."
For the brain to be able to get itself back on track, higher levels of serotonin stimulate a cascade of reactions that bring the brain back into balance. Within weeks, the symptoms of depression mysteriously lift. "What we really want to understand is that last step, that last bit, that change in the wiring, so that the 'I'm no good' changes to 'maybe things are not so bad,' and that is going to take an enormous amount of progress in neuroscience. But when we understand that, we're going to understand very very important things."
About what it means to be human, how things go wrong, and how things can go right. When I first went on Prozac, for the first like six months were like probably the best six months of my life. Suddenly, I could feel, um, I could feel pleasure; I could feel happiness; I could feel sadness. It was like this whole range of possibility. I was walking around stunned. My senses were very different; colors were different, uh, my taste buds were different, my tongue was different. This world was suddenly open to me that I had never really explored.
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Before there are no words to convey how unbelievable that experience was, um, how much happiness I had. It has been 12 years since Lauren first found relief from depression. Ever since, she has worked to rebuild her life. She received a doctorate in Psychology, married, oh, had a child. In my more reductive moments, I tend to think, alter serotonin transmission, alter the person; beginning and end of story. But the story, of course, always gets more complicated. You really are, you know, one of the miracle stories here for this treatment. I've been on this now for 12 years, you know, and I always feel like, you know, my big concern is that I'm on borrowed time with it, um, and I know that it's borrowed. A decade more than a decade now, a decade plus two years, which is good, but I, I have to say, I don't know that I'm a Prozac wonder story. I mean, because, you know, well, because I started on 10 milligrams and I'm now, you know, eight times that, which is why I'm suspicious of the drug. I am very suspicious of the drug, but Lauren here's, although I also, of course, I'm half in love with it, but I am suspicious of it. The fact that you've been on the stuff, it's been your mainstay, you've been free of symptoms most of the time; we've been able to get you freer of symptoms when you've become symptomatic, is both a nifty thing and one that's unfortunately a little rare in the treatment of chronic severe depression. One rarely sees a depression as severe as yours which remits as fully as yours.
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Has. I thought, now I have this drug and it's great; I thought I actually had it licked, but then it became a much more complicated relationship. It became, and, and I became an unreliable lover, um, one who had the capacity to, to, to save me and yet who could leave me at any moment utterly stranded. Lauren is not cured of depression; drugs only relieve the symptoms. And like an infection that resists an antibiotic, Lauren's brain periodically begins to resist the antidepressant; she relapses; dosages must be increased; different drugs must be found. Patients call it the Prozac poop.
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Out. My biggest fear with Prozac poop out now is that now that I have a child, it's no longer just me, and I'm afraid that I will not be able to function as a parent and that that will obviously have repercussions for my daughter. Lauren will always need medication to help her get on with her life, to simply go to work each day. But now she looks beyond her own suffering to helping others. Um, I, I think when I was young, I thought I was just lazy, and I think everyone else thought I was just lazy, but, um, it's like when you're at the dentist's office and you get like that lead cape put on you, when I'm depressed, I feel like I always have it on. Now what you're telling me, okay, is that, drawing on her own experience with depression, Lauren has become a practicing psychologist, counseling patients at a community clinic in Boston. Like Lauren, many of them take drugs to relieve their depression. You started off the therapy session saying that you have no resources outside of your doctors and your medication; you'd be a puddle of sugar should I and your psychopharmacologist, and, but I guess, and, and the pills themselves suddenly fly away. But when we look, I think that drug therapy probably gives a leg up, um, the ability to become symptom-free enough so that you can learn new ways of behaving. But I resist in myself and in other people being reduced simply to a series of biochemistry, so in some, or biochemical interaction, so in some ways I insist on some; there's got to be some kind of therapeutic process here that's not just talking about our synapses. You yourself told me that you've built a support network, you've come out of the closet with your depression, and that that really helps. And these are all of the coping mechanisms that you have. The fact is that you have resources inside of you. For many people, drugs alone are not enough to keep depression at bay. Research has demonstrated that the most, most effective way to treat depression is with a combination of drugs and talk therapy. Talk therapy works because it works on the brain. Anytime we learn something new, anytime we change our mind about something, anytime we remember something, we can do that only by changing the physical structure of our brain, by changing literally synaptic connections so that we're processing information differently. We can think of therapy as the brain learning a skill that's not unlike learning a complex motor skill, or, for example, um, um, becoming adept, uh, at a particular sport, uh, or becoming adept at a musical instrument, where there's systematic practice and that practice leads to a demonstrable change in behavior. You know, the anxiety of getting depression is almost worse than the depression, and the thing that you need to remember about that is that you have always gone through it, maybe with cuts and scrapes and various wounds, but you've always gotten through it. So the curiosities and energies that had always been rightfully mine were finally taking their place. And yet, for me, it was not that simple. My personality, yes, had always consisted of suppressed energies and curiosities, but also of depressions, echoing intensities, drivenness that tipped into pain. I missed these things, or parts of them anyway, for they were as familiar to me as dense fog and drizzle, which has its own sort of lonely beauty, as does a desert or the most mournful of music. Having lived with chronic depression, a high-pitched panic, and a host of other psychiatric symptoms since my earliest years, I had made for myself an illness identity, a story of self that had illness as its main motive, the explanatory model on which my being was based, and now gone. I had tipped over, stepped over the border into health. There was no more depression, which had felt like the stifling yet oddly comforting weight of a woolen blanket, or anxiety, which lent a certain fluorescence to things, or voices which had always been there, sometimes louder, sometimes softer, some North Star of sound in the night. In the 12 years since she has left the hospital that had become a second home, Lauren has tamed her depression and learned to live with it. At times it can be a precarious peace, but one that has allowed her to write and become a critically praised author. When I was in the hospital, there was a mental health worker who, who was so smart, and she said to me around maybe my fourth time in, "You're just going to come back here forever, aren't you?" And it looked that way; it looked like that was going to be my life. In some ways, I feel like I'm just so damn successful, but not for the reasons that you might think, um, but because I'm out and I've stayed out.
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The adult brain is capable of the whole panoply of human
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thought, but it's emotion that is at the very heart of our thinking lives. Our lives are governed by emotions and the interaction of emotions with our thought processes; that's, that's who we are. We are emotional people. There is no such thing as a, a non-emotional moment in
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life. We think by feeling. What is there to know? I hear my being dance from ear to ear; I wake to sleep and take my waking slow; I learn by going where I have to
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go. Next time on The Secret Life of the Brain: One weekend our daughter was here, and he walked into the kitchen and he said, "Who are you?" In its final decades, the brain is faced with a new set of challenges. Sixty-three years old and can't tie your own shoes; isn't that ridiculous? But it marshals surprising powers of renewal. What makes the engine go? Desire, desire, desire. Next time: The aging brain. Take a 3-D animated tour of the brain at PBS online; find brain teasers, take a cognitive test, and more at pbs.org.
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Major funding for The Secret Life of the Brain is provided by the National Science Foundation; America's investment in the future. Funding is also provided by Pfizer. We're spending nearly 5 billion looking for the cures of the future. We have 12,000 scientists and health experts who firmly believe the only thing incurable is our passion. Pfizer: Life is our life's work. The Medtronic Foundation, on behalf of Medtronic, providing lifelong solutions for people with chronic disease. Medtronic: When life depends on medical
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technology. The Park Foundation, dedicated to education and quality television. The Dana Foundation. The Corporation for Public Broadcasting, and by contributions to your PBS station from viewers like you. Thank you.
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