Eyes Wide Open

The transcript below may be for an earlier version of this episode. Our transcripts are provided by various partners and may contain errors or deviate slightly from the audio.

Shankar Vedantam: This is HIDDEN BRAIN. I'm Shankar Vedantam.

(SOUNDBITE OF CRICKETS)

Shankar Vedantam: In the early hours of the morning, when the air was heavy and the ticking clock ran slow, Randy Gardner would step out into his yard. He would stand beside the cactuses he'd planted and listen to the cars that whizzed by on Highway 54, which runs behind his home in San Diego. Standing in the moonlit shadows, he would call out in agony.

Randy Gardner: I would go out in the backyard at 3 in the morning and scream my head off like a wild animal.

Shankar Vedantam: Many people are familiar with the suffering Randy experienced - insomnia. There's a lonely communion that binds those who plead with the gods at 3 o'clock in the morning.

Randy Gardner: No one can help you. No one can make you feel better. No one can do anything. It's like you're going insane.

Shankar Vedantam: But Randy also knew he was different from everyone else. Many years ago, as a teenager, he tempted those very same gods. His punishment, he understood, was payback.

I was in San Diego recently for a conference. I had some downtime, so I decided to visit someone I'd been wanting to meet for a long time.

Shankar Vedantam: Are you Randy?

Randy Gardner: Yeah, I'm Randy.

Shankar Vedantam: Randy, Shankar. It's so nice to meet you.

Randy Gardner: Shankar, nice to meet you.

Shankar Vedantam: How are you?

Randy Gardner: I'm good.

Shankar Vedantam: Randy Gardner greets me in the driveway of his home. He gives me a warm handshake and a smile. He's wearing a lemon-colored shirt and sky-blue shorts that set off his deep tan. He exudes Southern California charm. Randy lives in a small green-and-white house, surrounded by sandy-brown stucco homes. The backyard is next to a noisy freeway. Randy and his wife Ilona.

ILONA GARDNER: I have a family nickname of Nona.

Shankar Vedantam: ...Share their place with a 13-year-old Bengal cat George.

(SOUNDBITE OF MEOW)

Shankar Vedantam: Sorry, what I meant was Prince George (ph).

Ilona Gardner: We did not spoil him. He came that way (laughter).

Shankar Vedantam: Randy and Ilona are now retired, which means lots of time to focus on George and their hobbies.

Randy Gardner: These are photographs that I took.

Shankar Vedantam: The walls are covered with some of his favorite shots.

Randy Gardner: The Golden Gate in San Francisco...

Shankar Vedantam: And stacked on the shelves are knickknacks and toys.

Randy Gardner: At one point, in the crawl space, I had over 500 puzzles.

Shankar Vedantam: Oh, my God..

Shankar Vedantam: Our story really begins in 1963 when Randy moved to San Diego. He was 17. It was the last in a long line of childhood moves.

Randy Gardner: I'm the oldest of four siblings in a military family. And my father traveled around, so we were in different places - every two years, we lived somewhere else.

Shankar Vedantam: In every town they lived in, Randy entered the science fair.

Randy Gardner: I was kind of a science nerd when I was young. When we came to this town, San Diego, I thought, boy, this is a big city.

Shankar Vedantam: If he wanted to win in San Diego...

Randy Gardner: ...Because I always got a first prize.

Shankar Vedantam: He'd have to pull out all the stops.

Shankar Vedantam: To understand the project he came up with, it's important to know something about the time. Rock 'n' roll was changing radio, and it wasn't just the songs that were gaining notice. It was the DJs playing them.

(SOUNDBITE OF RADIO SHOW, "YOUR HITS OF THE WEEK")

TRIPP: The fabulous 40 of 1959, your hits of the year - I'm Peter Tripp.

Shankar Vedantam: One of them was Peter Tripp, a New York City DJ who hosted "Your Hits Of The Week" on WMGM.

(SOUNDBITE OF RADIO JINGLE)

UNIDENTIFIED SINGERS: (Singing) It's the right spot. It's WMGM New York.

Shankar Vedantam: Peter plays an important part in our story. He wanted to stand out in the disc jockey world. And so in 1959, he came up with a stunt. He announced he was going to do a wake-a-thon to raise money for charity. He'd go eight days without sleep and be on display the entire time.

On January 20, 1959, Peter began broadcasting from a small glass studio in the middle of Times Square. Scientists were there to watch. For the next eight days, he hosted his show while fighting off sleep - preening at first, then yawning, eventually hallucinating. One thing he didn't do - sleep.

(SOUNDBITE OF RADIO SHOW, "YOUR HITS OF THE WEEK")

TRIPP: ...Because it was at 7:14 pm on January 28 of 1959 and we played this record after having stayed awake for 200 hours. Here are The Bell Notes and "I've Had It."

Shankar Vedantam: Peter's stunt invited others. A few months later, a DJ in Honolulu, Tom Rounds, raised the stakes by going 260 hours - more than 10 days without sleep. Intentional sleep deprivation was apparently like the ice bucket challenge for DJs in the 1960s.

Shankar Vedantam: Seventeen-year-old Randy Gardner, looking to make his mark on the science fair in a new city, wasn't impressed by these feats. Eight days without sleep, 10 days without sleep - big deal, he thought.

Randy Gardner: You don't need a lot of sleep. You don't need sleep. It was - that was the thinking back in the '60s. And that's the thinking that I had.

Shankar Vedantam: Randy decided to show up the showmen. He decided he was going to go without sleep for 264 hours - exactly 11 days.

Randy Gardner: And when I said, well, let's go 11 days, I wasn't even thinking about any negative things. I was thinking, this really isn't that big of a deal. You know, when it's over, you catch up, you get your sleep and you go right on by.

Shankar Vedantam: Even as a teenager, Randy knew that he had a special skill that made him different.

Randy Gardner: I'm a very determined person, and when I get things under my craw, I can't let it go until there's some kind of a solution.

Shankar Vedantam: He recruited two of his friends...

Randy Gardner: Bruce McAllister and Joe Marciano.

Shankar Vedantam: ...To help him stay awake.

Randy Gardner: If you're on your own, you're going to succumb. You're going to fall asleep.

Shankar Vedantam: Christmas break was coming up and Randy and his friends decided it was the perfect time to break the world record for going without sleep. The first two days were easy. He stayed away from beds and tried to stand as much as he could. But on day three...

Randy Gardner: I noticed that in the morning, I was really nauseous. And this went on for just about the entire rest of the experiment. And that's when I stumbled on eating citrus. For some reason, tangerines or oranges seemed to take the nausea away.

Shankar Vedantam: So your friends, of course, were keeping tabs on you, but they weren't actually accompanying you on the experiment. So what happened? Was one of them - did you have a rotation system where one of them was always up with you?

Randy Gardner: Exactly. It was a rotation system where one would be with me and the other would be sleeping. Or if it was in the daytime, they'd both be with me, obviously.

Shankar Vedantam: Soon, the stunt was attracting television reporters.

Randy Gardner: And that was a good thing because that kept me awake. You know, you're dealing with these people and their cameras and their questions.

(LAUGHTER)

Shankar Vedantam: Did you start to feel like your mental faculties were slipping, that it was harder to answer questions, it was harder to remember something, to formulate a phrase or a sentence?

Randy Gardner: That happened pretty soon. That started maybe day four or five, and it just kept going downhill. I mean, it was crazy where you couldn't remember things. It was almost like an early Alzheimer's thing brought on by lack of sleep.

Shankar Vedantam: The early hours of the morning were hardest. Everything was closed, everyone was asleep. Randy remembers visiting the local jail. Why did you go to the jail?

Randy Gardner: I don't know. Maybe because it was open at 3:00 in the morning (laughter). They never close.

Shankar Vedantam: A few days into the wake-a-thon, a sleep researcher from Stanford University showed up. His name, and this may feel like a pun to some of you, was William Dement.

Randy Gardner: And he rented a car, a convertible, and we drove around in that. So we had a really good time when Dr. Dement came down. That really helped me because that was like a fresh of something different and new to keep me going.

Shankar Vedantam: I understand that Dr. Dement also played a lot of games with you. He, besides sort of doing sort of psychological tests, he was actually - he actually played various sort of sports with you. Is that right?

Randy Gardner: We did a lot of pinball.

Shankar Vedantam: How did you do?

Randy Gardner: I did good. I think I beat him most of the time.

Shankar Vedantam: Actually, Randy won all the time.

Randy Gardner: Physically, I didn't have any problems - not walking or throwing the basketball around or playing the pinball games. But the mental part is what went downhill. The longer I stayed awake, the more irritable I got. I had a very short fuse on day 11. I remember snapping at reporters. They were asking me these questions over and over and over. And I was just - I was a brat.

Shankar Vedantam: On January 8, 1964, Randy broke the world record for going without sleep. He'd gone 11 days, 264 hours, without drifting off. There was only one way to celebrate. He was whisked off to a naval hospital where researchers kept an eye on him, and he went to sleep. How long did you sleep?

Randy Gardner: I slept just over 14 hours. I remember when I woke up, I was groggy but not any groggier than a normal person.

Shankar Vedantam: And did you find that over the next several days or weeks, you needed extra sleep?

Randy Gardner: No, not at all. I went right back to the regular mode. Everything was fine. Strange, isn't it?

Shankar Vedantam: Randy's sleep project earned him and his friends first place in the 10th Annual Greater San Diego Science Fair. It also ushered in a lifetime of fame.

(SOUNDBITE OF TV SHOW, "TO TELL THE TRUTH")

Shankar Vedantam: This is sound from the popular 1960s TV game show "To Tell The Truth." The show brings together four celebrity panelists… The panelists face three people who all claim to be the same person. The panelists have to guess which one is the real Randy. On the show, the real Randy Gardner is number two. He looks like Clark Kent. He wears dark, horn-rimmed glasses, his hair swoops to the left, he's soft-spoken and direct when answering questions. Most of the panelists figured out that this Randy was the real Randy. Over the next decades, Randy Gardner's life took different turns. He worked in horticulture, took a stab at photography and finished up his career working as a stock trader. But whatever he did, his teenage accomplishment stayed with him.

Randy Gardner: I'm some kind of a Bruce Springsteen in the sleep world. It's a very strange feeling.

Shankar Vedantam: Plenty of people have tried to do what Randy Gardner did - go days on end without sleeping. You can find clips of all their adventures on YouTube.

(SOUNDBITE OF YOUTUBE VIDEO, "DOCUMENTARY: NO SLEEP FOR A WEEK")

PAT: It's Sunday afternoon right now. And tonight's day one of going without sleep for the next week.

(SOUNDBITE OF YOUTUBE VIDEO, "NO SLEEP FOR 72 HOURS! CHALLENGE")

JEVON MULDROW: I'm about to stay up for three days.

(SOUNDBITE OF YOUTUBE VIDEO, "NO SLEEP FOR 72 HOURS CHALLENGE (3 DAYS WITHOUT SLEEP)")

JRIZZY JEREMY: This is going to be the hardest challenge I've ever done.

Shankar Vedantam: But if you're looking to set a new record for going without sleep… You're out of luck. The Guinness Book of World Records has eliminated the category, citing the health dangers of severe sleep loss.

Matthew Walker: That's right.

Shankar Vedantam: This is UC Berkeley neuroscientist Matthew Walker.

Matthew Walker: And I think it's important to keep in mind, by the way, that Guinness does seem to deem it acceptable for a man - I believe it was Felix Baumgartner - to ascend to the very outer reaches of Earth's atmosphere in a capsule, in a spacesuit, get out of that capsule and then free fall back down to Earth, breaking the sound barrier with his body, traveling at well over 1,000 kilometers per hour. That's deemed as OK to do. Sleep deprivation because of its deathly consequences - no longer. So I hope that frames the disease-related risk that Guinness rightfully recognizes regarding insufficient sleep.

Shankar Vedantam: Matthew Walker calls himself a sleep diplomat. He's spent more than 20 years studying the topic, and he's written a book titled "Why We Sleep." If your idea of being sleep deprived is days on end without enough rest, Matthew says, think again.

Matthew Walker: Even just the smallest amount of insufficient sleep, we see health consequences. And I think, perhaps, you know, one of the best examples of that small perturbation is one of the largest sleep experiments ever done. It's been performed on 1.6 billion people. It happens twice a year, and it continues to happen. It's called daylight savings time. And in the spring, when we lose an hour of sleep, we see a subsequent 24 percent increase in heart attacks. In the fall, when we gain an hour of sleep opportunity, there is a 21 percent decrease in heart attacks. So that's how fragile our brain and bodies can be to even just the smallest fluctuations of sleep. So we don't have to go to the Randy Gardner extreme of 11 days. Just one hour of sleep is all that it takes to show these types of demonstrable consequences in terms of ill health.

Shankar Vedantam: If you do the math - 11 days times eight recommended hours of sleep a night - that's 88 hours of sleep that Randy missed. When he finally went to bed, he slept only 14 hours.

Matthew Walker: The human brain is not capable of getting back all of the sleep that it has lost. So sleep, in this regard, is not like the bank. You can't accumulate a debt and then pay it off at some later point in time. There isn't a credit system in the brain or the body. And we can ask, by the way, why? Why isn't there something like that? Wouldn't that be wonderful? And there is precedent there - fat cells. So there were times in evolution when we would have feast, and there were times when there was famine. And we designed a system to come up and store that caloric credit and so that we could spend it when there was a debt.

Shankar Vedantam: There may be a reason our bodies don't do this. The right analogy to sleep might not be eating but breathing. You can't say, I'll skip today and catch up on my breathing tomorrow.

(SOUNDBITE OF MUSIC)

Shankar Vedantam: For a long time, Randy simply basked in the celebrity that his stunt had brought him. He'd found a way to cheat sleep. Life was good for him and his wife, Ilona.

Ilona Gardner: The focus of our life is pretty much George.

Shankar Vedantam: George, the cat, their teenage Bengal - Randy and Ilona love George. I don't know much about cats, but apparently, Bengals have the personality of a dog.

Randy Gardner: They fetch and...

Shankar Vedantam: They fetch?

Randy Gardner: Yeah, they fetch, yeah, yeah.

Shankar Vedantam: A cat that fetches - are you serious?

Ilona Gardner: Yep.

Randy Gardner: He doesn't do it much anymore.

Shankar Vedantam: Listening to Randy and Ilona ooze with affection for George is very sweet. When I came to visit, Ilona was getting ready to take George to the vet. They're very meticulous about his health. That's partly because a decade ago there was another cat in Randy and Ilona's life. She died...

Randy Gardner: ...Of tongue cancer. And I was so upset that the vets didn't catch it, that they never looked in her mouth to find this tumor, that they blamed every other thing. And then she died, and I was so wracked with guilt, which is stupid. You know, I would never do that now. You have to move forward. You can't go back. But I didn't then. And I think that's what triggered it.

Shankar Vedantam: The it Randy's referring to...

Randy Gardner: ...Is that I would go out in the backyard at 3 in the morning and scream my head off like a wild animal.

Shankar Vedantam: ...Is insomnia.

Randy Gardner: About 10 years ago, I stopped sleeping. I could not sleep. I would lay in bed for five, six hours, sleep maybe 15 minutes and wake up again. I kept thinking, well, this'll go - this will change because it seems to me that eventually, if you don't get enough sleep, your body will just say, we're going to sleep. But it never happened.

Shankar Vedantam: The man who conquered sleep was now begging for a full night's rest.

Randy Gardner: That's why I keep calling this some karmic payback for - you know, my body going, OK, buddy, yeah, OK, 11 days without sleep when you know damn well you need sleep - well, let's try this out for size.

Shankar Vedantam: Randy says going without sleep changed him.

Randy Gardner: And everybody thought I was some kind of ass. There's all kinds of ways to go to sleep, they say. You know, watch television, read a book. And I'm thinking, you know, if you can't sleep in the first place, reading a book isn't going to put you to sleep. I got news for you. I don't know where they came up with that one. Read a book. Watch TV. No, no, no, no, uh-uh. If you have that kind of a serious problem, you're done

Shankar Vedantam: Day in and day out, for years on end, Randy began to feel the way he'd felt at the end of his sleep stunt, except this time, there were no TV cameras, no reporters, no prizes.

Randy Gardner: I was awful to be around. Everything upset me. It was like a continuation of what I did 50 years ago.

Shankar Vedantam: We don't know what triggered Randy's insomnia. But there's some anecdotal evidence that prolonged sleeplessness can really mess up the brain. Remember Peter Tripp?

(SOUNDBITE OF RADIO SHOW, "YOUR HITS OF THE WEEK")

TRIPP: With your hits of the year, I'm Peter Tripp.

Shankar Vedantam: ...The radio DJ who inspired Randy with his wake-a-thon? Here's psychiatrist Floyd Cornelison, who monitored Peter, speaking on the television series "Secrets Of Sleep."

(SOUNDBITE OF TV SHOW, "THE SECRETS OF SLEEP")

FLOYD CORNELISON: The man I saw the first morning that he began this - when he was waving at everybody through the glass windows and smiling and laughing and joking with us - after the 200 hours had became a changed individual.

TV ANNOUNCER: In the months that followed, Tripp seemed unable to recover his center of gravity. He fought with his boss and lost his job. He ended up as a salesman, drifting from town to town across America. Those that knew him well were convinced that those eight days without sleep had left him permanently damaged.

Shankar Vedantam: So some of that might have been hyperbole. Still, Randy thinks what happened to Peter was real, and his age might have been a factor.

Randy Gardner: That's why I don't think you can do this kind of thing unless you're 17 or in that age group. I know I couldn't do it now. And I wouldn't do it, because I have more sense.

(SOUNDBITE OF MUSIC)

Shankar Vedantam: After a decade of insomnia in his 60s, Randy finally made an uneasy peace with sleep. He's regained the ability to drift off but only for about six hours a night. And it's required sacrifice.

Randy Gardner: I love drinking tea. And to this day, I can't drink tea because I'm afraid I won't be able to sleep at night. You have to have sleep. It's as important as - it's the big - I call it the big three - water, food, sleep. You got to have them - all of them.

Shankar Vedantam: Randy Gardner, the man who conquered sleep, is now terrified of going a night without it. After the break, we're going to dive deeper into the science of sleep with neuroscientist Matthew Walker.

Matthew Walker: If we didn't need eight hours of sleep, and we could survive on six, Mother Nature would have done away with 25 percent of our sleep time millions of years ago because when you think about it, sleep is an idiotic thing to do.

SHANKAR Shankar Vedantam: This is HIDDEN BRAIN, I’m Shankar Vedantam. Matthew Walker is a professor of neuroscience and psychology at the University of California at Berkeley. He studies sleep, and he's the author of the book "Why We Sleep." I started our conversation by asking him to tell me a story he describes in his book. It's about a pianist who relied on sleep for his creative process.

Matthew Walker: Yeah, I was giving a public lecture on sleep. And this wonderful sort of distinguished-looking gentleman with a fantastic kindly face walked to me. He was dressed in this great sort of tweed suit. And he said, I'm a pianist. And I was fascinated by what you were saying about sleep and how active a brain state it is. And I wanted to tell you that there are times when I will be trying to learn a new piece, and I just can't get it. And I get frustrated, I make the same mistake at the same place each and every time. And I'll sometimes play late into the evening. And I will walk away continuing to be frustrated, have a night of sleep and then when I come back and I sit down the next morning, I can just play perfectly. And what he was suggesting, perhaps, was that it wasn't practice that made perfect, it was practice with a night of sleep that made perfect.

Shankar Vedantam: I want to run two other examples by you, both of which seem to suggest that remarkable things happened to us while we're sleeping. I understand that guitarist Keith Richards from Rolling Stones kept his instrument and a recorder by his bed, and he did it in case inspiration struck while he was asleep. Did it ever happen?

Matthew Walker: It did. He would have this tape recorder and he would have his guitar and who knows what else around in the bedroom at the time. And one morning, he woke up and the tape had recorded all the way to the end. And he didn't remember anything about that night.

So he rewound the tape and he played it. And he says - and this is in his autobiography - there was almost this sort of ghostly vision of him strumming the chords to "Satisfaction." Arguably the most popular Rolling Stones song ever. And he said he created that classic guitar riff from his sleep.

(SOUNDBITE OF SONG, "(I CAN'T GET NO) SATISFACTION")

THE ROLLING STONES: (Singing) I can't get no satisfaction.

Matthew Walker: It was a dream-inspired musical piece of creativity followed by about 42 minutes of snoring. Lots of scientific discoveries though too have been birthed by way of dream-sleep-inspired creativity.

Shankar Vedantam: Speaking of scientific discoveries, I understand there's a connection between sleep and the discovery of the periodic table.

Matthew Walker: Dmitri Mendeleev was trying to understand how all of the known elements in the universe fit together. And it was his obsession for years. And he struggled and he couldn't figure it out. He would create playing cards with all of the different elements and he would deal them to see if he could find some equation by way of which they all fit together. And apparently so the story goes, February 17, 1869, he fell asleep exhausted, frustrated - couldn't figure it out. And there, in his sleeping brain, emerged the solution that his waking brain could not divine. He started to realize how all of these swirling elemental ingredients could actually snap together in this sort of what he described as a divine grid. And he woke up and he penned down this remarkable table, the table that we now call the Periodic Table of Elements. And he noted that he made just perhaps one or two changes.

Shankar Vedantam: Matthew says there are two types of sleep. Rapid eye movement sleep, also known as REM - this is when we dream. Then there's non-rapid eye movement sleep or non-REM.

Matthew Walker: And those two types of sleep actually play out in this wonderful battle for brain domination throughout the night. And that cerebral war is won and lost every 90 minutes and then replayed every 90 minutes to produce what we call a sleep cycle. And you go down into non-REM sleep first and then you go up into REM sleep and then you repeat the cycle.

Shankar Vedantam: You say that non-REM sleep might be implicated or involved in cementing memories and that there's a popular song that might get at this idea.

(SOUNDBITE OF SONG, "THE SOUND OF SILENCE")

SIMON AND GARFUNKEL: Hello, darkness, my old friend. I've come to talk with you again because a vision softly creeping left its seeds while I was sleeping and the vision that was planted in my brain still remains…..

Shankar Vedantam: So Matthew, what do Simon and Garfunkel get right about non-REM sleep?

Matthew Walker: It is prophetic wisdom of the most remarkable kind. We imprint information during the day. We sort of - that seed is planted there within the brain during the day. In other words, we learn information. But we also know that that vision that was planted in the brain still remains in the sound of silence, in this - in the dark of night. And it's there that specifically deep non-REM sleep goes to perform its memory functions. Deep non-REM sleep almost hits the save button on those recently acquired informational pieces so that when you wake up the next morning, you have remembering rather than forgetting.

Shankar Vedantam: Non-REM is all about helping us retain information. And as we saw from the music of The Rolling Stones and the creation of the periodic table, REM sleep, dream sleep, spurs creativity. But Matthew says dreams also have another function.

Matthew Walker: That function seems to be about emotional therapy or what I would describe as overnight therapy. Dream sleep provides a fascinating neurochemical soothing balm. It is during dream sleep and only during dream sleep when our brain shuts off a stress-related neurochemical called noradrenalin.

Now, its sister chemical everyone will be familiar with in the body. That's called adrenaline. And it's during dream sleep that that chemical is actually shut off. But what we also know is that the emotional and memory centers of the brain during dream sleep light up in terms of their activity. And so we've proposed that dream sleep provides this perfect opportunity where we can start to reactivate and replay painful, difficult emotional experiences. But we do so in a neurochemically, quote, unquote, "safe" environment. And we now understand that dream sleep actually helps separate and strip away that painful emotional sting from those informational experiences so that you wake up feeling better about it. You wake up with a memory of an emotional event but it's no longer emotional itself. It's that form of nocturnal therapy.

Shankar Vedantam: But what about bad dreams?

GRETA PITTENGER: Hi, I'm Greta Pittenger.

Shankar Vedantam: Greta is a researcher at NPR. And about eight or nine years ago, her relationship with sleep changed. I'll let her tell you the story.

PITTENGER: I had been dating a guy who is now my husband. But at the time, we were just dating. He rode a motorcycle, and that was his only form of transportation. So whenever I'd go out with him or he'd drive me to work or something, I would ride on the back and had my own helmet and stuff. Late one night, we were coming home from a party and we were in downtown Seattle.

Streets were pretty empty, but we were going pretty slow coming out of a stoplight and a large white SUV ran a red light and crashed into us from the left side. The next thing I remember is waking up on my back in, like, an elevated planter kind of off on the side of the sidewalk. You know, there's, like, the street on one side and then the other side has, like, a little kind of retaining wall with, like, plants and ferns. And so I was kind of halfway into that. It was about - I'd fallen off the bike and hit my right thigh on that concrete planter and broke it - broke the femur, like, right in half. And when I woke up, I was on my back with my legs kind of dangling and there was flames around me. And then, like, that's when I think I saw my then boyfriend Joey on the sidewalk. And it was, like, he was also injured separately but didn't have much time to think about any of those things 'cause luckily the police station was two blocks away. And so then police were the first people there and they came and dragged us out.

(SOUNDBITE OF AMBULANCE SIREN)

PITTENGER: The actual crash of the car had punctured the motorcycle. And then there were - the first sound I really remember was an explosion of the motorcycle tank blowing up, which was - yeah. I don't trust my memories of how intense it was, but it was very, very scary. Joey actually broke the other femur. He broke his left femur from the impact of the car. I broke my right femur from hitting that wall. He also broke a few other bones, so I stayed in the hospital for maybe four days after surgery. And he stayed for I want to say at least a full week, maybe 10 days 'cause he had a couple surgeries. I didn't sleep pretty much at all, partially because of the painkillers. But I think also that's when, like, bad dreams were starting. And I couldn't stop reliving that moment of the crash. I'm not sure if I had these exact dreams in the hospital. But for a couple years after all of this, I would just keep having dreams about things crashing into me or things running over me and then specifically that moment also when that car hit us.

I would keep going back to that. And I remember waking up, like, with a start - you know, like, when you wake up suddenly and sometimes you can't remember why but you know you feel like you fell. Like, you feel like you just fell into bed, that feeling. I like to write, and I've kept a journal since I was in fourth grade. I had written about it right after it happened at my mom's insistence. I was staying with her and my dad at the time and just, like, I'd wake up from my nap just bawling. She'd said, like, you know, maybe you should just write it down and let it go, kind of hoping that might help. And I think it did for a little bit, but then it kept coming back. And I tried to avoid it.

Shankar Vedantam: When we were talking about dreams some time ago, Matthew, you said that one of the potential virtues of dreams is that they might allow us to relive or experience things that happened to us or things that might happen to us in a relatively safe space. And as we do this, we process what happened and then potentially learn from it. What about nightmares, though?

Nightmares are not pleasant. They can be disruptive. They can actually be acutely painful and certainly in Greta's case, they were disruptive to her life. Why would the brain be designed to have nightmares?

Matthew Walker: It's not clear whether the brain actually is designed to have nightmares or whether this is actually the process going awry. And we think it may be the latter because when we look at patients, for example, who have post-traumatic stress disorder or PTSD, repetitive nightmares are actually so reliable in those patients that they actually form part of the diagnostic criteria for that disorder itself. What we think is happening in the case of PTSD is that that chemical that we spoke about that normally is shut off during dream sleep, the chemical noradrenalin, remains too high. And it may be that when that chemical is too high in its concentration, we can't gift ourselves that normal therapeutic benefit that REM sleep provides so that the dreams themselves become particularly emotionally strong and difficult. And you don't get that resolution the next day. And so the process steps and repeats. And it happens time and time again. And it is perhaps only when there is some degree of contextualization, be it by way of medication that is now given to certain PTSD war veterans. For example, drugs out there that seem to help lower that chemical, that stress-related chemical, give them normal dream sleep. And it gives them back that ability to process those events. That's one way to help. Another is that perhaps by journaling it and going through that process of shifting the context or reformulating it in one's mind, it becomes less stressful.

Shankar Vedantam: In fact, this is exactly what Greta discovered herself, too.

PITTENGER: So about two or three years after the crash, I was finally seeing a psychiatrist about the kind of lasting trauma and trying to get over that and trying to sleep - I mean, I was trying to help my insomnia as well. And we talked about those dreams. And he suggested - he knew I liked to write. And so he suggested in my journal just rewriting that dream because it doesn't - it's a dream. It's not reality. And so it doesn't need to mimic reality. So just change it. The way I changed that dream was that instead of a car coming and hitting the motorcycle, the motorcycle transformed into a winged horse and flew away - away from the car, away from all that crash, and then just landed safely back at our apartment, dropped us off. And so writing about it again years later, but in a totally different way, not trying to be accurate, not trying to remember was much different. It definitely got me to stop having those vivid dreams. I've had flying dreams in the past, but I started to have more types of those dreams of the kind of being lifted away from gravity and from the weight of these emotions. You know, like, when you wake up from a dream, and it doesn't really leave a mark on you? That was a good feeling to kind of be like, oh, yeah, I guess I did have that dream. Oh, yeah. That was nice. Just, like, this past month, Joey and I bought mopeds, which is, like, something he used to do before he even had a motorcycle, and I have never ridden before. And I'm, like, I feel like such a badass on this, like, little, like - it's such a dorky little thing. It's, like, half bike with a tiny engine on it, and it sounds like super high-pitched and has the dorkiest horn, but it's, like, yeah, look how cool I am. I have to wear a full-face helmet. (Laughter).

Shankar Vedantam: When we come back, we look at the amazing range of things a good night's sleep can accomplish.

Matthew Walker: You know, sleep is the Swiss Army knife of health.

Shankar Vedantam: Welcome back. So let's talk just for a bit about the amount of sleep that people need. You and many other experts say people should strive to get eight hours of sleep every night. To tell you the truth, I got about six hours last night, and I feel fine.

Matthew Walker: Tell me where you live. I am coming round tonight. We will have a sleep salon, a sleep - I will inflict change no matter what.

Shankar Vedantam: Well, here's my question, Matthew. If I can get away with sleeping 25 percent less than the recommended amount one night, why can't I do it every night? And just think of the upside, you know? I can spend two hours every day reading wonderful books like yours, building a better podcast, being more productive. Surely, it's a good thing.

Matthew Walker: If we didn't need eight hours of sleep and we could survive on six, Mother Nature would have done away with 25 percent of our sleep time millions of years ago. Because when you think about it sleep is an idiotic thing to do. You're not finding a mate, you're not reproducing, you're not finding food, you're not caring for your young. Worse still, you're vulnerable.. So as it has been said before, if sleep does not provide a remarkable set of benefits then it's the biggest mistake the evolutionary process has ever made. And it didn't make a spectacular blunder in putting in place through 3.6 million years of evolution this thing called an eight-hour sleep need.

Shankar Vedantam: You know, I remember once going to a talk that showed the level of light pollution on the planet, the parts of the planet where there were the highest levels of artificial light. And then the researcher took that, you know, the image off the screen and replaced it with an image showing the distribution of prostate cancer around the world. And there was a remarkable correlation between the areas of the world which have light pollution, where presumably people are staying up later and later at night and presumably getting less sleep than they need, and the incidence of prostate cancer. Now, of course this is a correlation. We don't know if one is connected to the other. But you said there has been some evidence at least that sleep might be implicated in the development of cancer.

Matthew Walker: There is. And it's fast becoming, I think, strong evidence and causal as well. We know, for example, that one single night of short sleep - and these are laboratory studies where you perhaps are limited to just four hours of sleep for one single night - the next day that will drop critical anti-cancer fighting cells, called natural killer cells, by 70 percent, seven zero. That is an alarming state of immune deficiency, and it happens quickly after essentially just one bad night of sleep. We also know from the associational evidence that insufficient sleep is linked to cancer of the bowel, cancer of the prostate and cancer of the breast. And the link between a lack of sleep and cancer has since become so strong that the World Health Organization has now classified any form of nighttime shiftwork as a probable carcinogen. In other words, jobs that may induce cancer because of a disruption of your sleep-wake rhythms.

Denmark, based on the strength of the evidence that we were just discussing, became the first country to actually pay worker compensation to women who had developed breast cancer after years of nighttime shift-working government sponsored jobs. So I think automation is going to help, I think, with this revolution of technology where we can start to limit that type of shift work whenever possible. We should absolutely do that and start to scale it back. We can also architect professions better, I think. We know that people are genetically predisposed to being nighttime people or morning people. Why don't we think about asking those questions and seeing if we can help people sort of fit what we call their chronotype, which is their morning-ness or evening-ness propensity, fit that into the job flexibility in those work hours and see if there's some overlap?

Shankar Vedantam: When you were a kid, your family took a vacation to Greece. And then when you visited Greece again as an adult, you noticed a very big change. What was it?

Matthew Walker: Back in the 1980s when I went on holiday there, were signs in the shop store windows that would give the opening hours. And they would open from between sort of 10 to 2 and then it said closed between 2 to 4 or 2 to 5 p.m., and then open from 5 through until 10:00 or 11:00 in the evening. And it was so different to the way in which sort of shops back in England would operate. You know, maybe there was a one-hour lunch break or a half-hour lunch break, but for the most part it was 9 to 5 hours, classic. And of course what it was describing was this classic siesta-like behavior.

Now, back in the mid 1990s, the Greek culture actually started to abandon the siesta-like practice. And fortunately, or, unfortunately, a group of scientists from Harvard University School of Public Health decided to quantify the health consequences of this radical change in sleep practice. And with many Greek tragedies, as was the case here, the results were heartbreaking, but in the most literal sense. What they actually observed was a 37 percent increase risk for death from heart attacks across that six-year period as a consequence of doing away with that siesta behavior. It was actually particularly strong in working males, almost a 60 percent increased risk of death from heart attacks.

So I think that that again suggests not only how important sleep is, and when sleep is taken away we see this type of danger to our cardiovascular health. It raises actually a different question, which is, how should we be sleeping? And are we sleeping currently - the way in which we do, through modernity in industrialized nations - in the way that we were designed? The answer may actually be no because the way that we currently try to sleep is what's called monophasic sleep where we sleep one single bout throughout the night. We aim for how ever much we can. But if you look at some cultures who are untouched by electricity, sort of hunter-gatherer tribes for example, they actually tend to sleep bi-phasically. They tend to sleep for sort of six, seven hours at night then they'll have a siesta-like nap in the afternoon. And it turns out that we all have this in us. It is genetically hardwired that we all have a preprogramed drop in our alertness some time after lunch.

Now, many of us think it has to do with the lunch that we have. It's actually not. You can stop the lunch and you still get it.Which actually does argue from an evolutionary perspective that we should be sleeping bi-phasically rather than monophasically - two bouts of sleep rather than one, perhaps.

Shankar Vedantam: I have to say, Matthew, that in some ways when it comes to sleep, there's almost a sense of people bragging about not getting enough sleep, right? I mean, it's certainly, in the United States it's seen as a, you know, badge of honor to say, you know, I get very little sleep because I'm so productive and I work so hard and I achieve so much.

Matthew Walker: You're so right. Because what we've done is actually stigmatized sleep. We label people who get sufficient sleep - and I choose that word very carefully - with being lazy, with being slothful. And that is a terrible disservice to society. And we don't always have that opinion, by the way. You know, no one looks at an infant sleeping during the day and says, what a lazy baby.

Shankar Vedantam: (Laughter).

Matthew Walker: And we don't. You know, and we laugh, but we don't because we know that sleep at that time of life is non-negotiable. It's absolutely necessary. But now even into early childhood, not only do we abandon the notion that sleep is important and should be celebrated, we chastise people for getting sufficient sleep and give them this label.

Shankar Vedantam: Tell me about your own sleep habits, and tell me what you do to ensure you get a good night's rest.

Matthew Walker: I'm going to sound like a desperate prude, and I'm so sorry. And it sounds hokey, as well, but I actually give myself a non-negotiable eight-hour sleep opportunity every night.

Shankar Vedantam: Do you try and stick to very rigid hours - sleeping at the same time, waking up at the same time? Do you use an alarm clock? Do you avoid technology before you go to sleep?

Matthew Walker: I do. So I stop checking my email at a certain time. I have software installed on my computers that does away with the harmful blue light, and I shut them off at least an hour and a half before bed. But you mentioned perhaps the single most important sleep prescription that I could give everyone which is regularity. Just go to bed at the same time, wake up at the same time, no matter what. Whether it's the weekday or the weekend, if you've had a good night of sleep or a bad night of sleep, stay as regular as you can. That's the best piece of advice I can give you for getting good sleep at night.

Shankar Vedantam: Matthew Walker is a professor of neuroscience and psychology at the University of California at Berkeley. He studies sleep, and he's the author of the book "Why We Sleep." Matthew, thank you for joining me today on Hidden Brain.

Matthew Walker: You're very welcome. Thank you very much, and I do hope you sleep well tonight.

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Hidden Brain is produced by Hidden Brain Media. Our production team includes Brigid McCarthy, Autumn Barnes, Laura Kwerel, Kristin Wong, Ryan Katz and Andrew Chadwick. Tara Boyle is our EP. I'm Hidden Brain's EE.

I’m Shankar Vedantam, see you next week.