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What if you could make[br]your sleep more efficient?

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As a sleep scientist,

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this is the question[br]that has captivated me

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for the past 10 years.

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Because while the lightbulb[br]and technology have brought about a world

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of 24-hour work and productivity,

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it has come at the cost

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of our naturally occurring[br]circadian rhythm

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and our body's need for sleep.

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The circadian rhythm dictates[br]our energy level throughout the day,

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and only recently we've been conducting[br]a global experiment on this rhythm,

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which is putting our sleep health

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and ultimately[br]our life quality in jeopardy.

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Because of this,

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we aren't getting the sleep we need,

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with the average American[br]sleeping a whole hour less

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than they did in the 1940s.

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For some reason,

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we decided to wear it as a badge of honor

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that we can get by on not enough sleep.

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This all adds up to a real health crisis.

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Most of us know that poor sleep[br]is linked to diseases

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like Alzheimer's, cardiovascular disease,

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stroke and diabetes.

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And if you go untreated[br]with a sleep disorder like sleep apnea,

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you're more likely[br]to get many of these illnesses.

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But did you know about sleep's impact[br]on your mental states?

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Poor sleep makes us[br]make risky, rash decisions

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and is a drain[br]on our capacity for empathy.

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When sleep deprivation literally makes us[br]more sensitive to our own pain,

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it's not so surprising that we have[br]a hard time relating to others

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and just generally[br]being a good and healthy person

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when we're sleep-deprived.

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Scientists are now starting to understand

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how not only the quantity

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but also the quality of sleep[br]impacts our health and well-being.

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My research focuses

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on what many scientists believe[br]is the most regenerative stage of sleep:

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deep sleep.

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We now know that generally speaking,

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there are three stages of sleep:

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light sleep,

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rapid eye movement or REM

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and deep sleep.

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We measure these stages by connecting[br]electrodes to the scalp, chin and chest.

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In light sleep and REM,

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our brain waves are very similar[br]to our brain waves in waking life.

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But our brain waves in deep sleep[br]have these long-burst brain waves

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that are very different[br]from our waking life brain waves.

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These long-burst brain waves[br]are called delta waves.

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When we don't get the deep sleep we need,

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it inhibits our ability to learn

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and for our cells and bodies to recover.

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Deep sleep is how we convert[br]all those interactions

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that we make during the day

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into our long-term memory[br]and personalities.

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As we get older,

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we're more likely to lose[br]these regenerative delta waves.

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So in way, deep sleep and delta waves

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are actually a marker[br]for biological youth.

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So naturally, I wanted to get[br]more deep sleep for myself

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and I literally tried almost every gadget,[br]gizmo, device and hack out there --

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consumer-grade, clinical-grade,

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what have you.

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I learned a lot, and I found[br]I really do need, like most people,

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eight hours of sleep.

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I even shifted my circadian component

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by changing my meals,[br]exercise and light exposure,

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but I still couldn't find a way[br]to get a deeper night of sleep ...

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that is until I met[br]Dr. Dmitry Gerashchenko

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from Harvard Medical School.

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Dmitry told me about[br]a new finding in the literature,

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where a lab out of Germany showed[br]that if you could play certain sounds

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at the right time in people's sleep,

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you could actually make sleep[br]deeper and more efficient.

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And what's more, is that this lab showed

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that you actually could improve[br]next-day memory performance

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with this sound.

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Dmitry and I teamed up,

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and we began working on a way[br]to build this technology.

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With our research lab[br]collaborators at Penn State,

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we designed experiments[br]in order to validate our system.

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And we've since received grant funding[br]from the National Science Foundation

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and the National Institute of Health

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to develop this deep-sleep[br]stimulating technology.

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Here's how it works.

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People came into the lab

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and we hooked them up[br]to a number of devices,

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two of which I have on right here --

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not a fashion statement.

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(Laughter)

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When we detected[br]that people were in deep sleep,

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we played the deep-sleep[br]stimulating sounds

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that were shown[br]to make them have deeper sleep.

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I'm going to demo this sound[br]for you right now.

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(Repeating sound waves)

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Pretty weird, right?

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(Laughter)

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So that sound is actually at the same[br]burst frequency as your brain waves

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when your brain is in deep sleep.

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That sound pattern[br]actually primes your mind

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to have more of these[br]regenerative delta waves.

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When we asked participants[br]the next day about the sounds,

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they were completely unaware[br]that we played the sounds,

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yet their brains responded[br]with more of these delta waves.

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Here's an image of someone's brain waves[br]from the study that we conducted.

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See the bottom panel?

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This shows the sound being played[br]at that burst frequency.

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Now look at the brain waves[br]in the upper part of the graph.

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You can see from the graph

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that the sound is actually producing[br]more of these regenerative delta waves.

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We learned that we could[br]accurately track sleep

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without hooking people up to electrodes

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and make people sleep deeper.

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We're continuing to develop

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the right sound environment[br]and sleep habitat

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to improve people's sleep health.

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Our sleep isn't[br]as regenerative as it could be,

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but maybe one day soon,

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we could wear a small device

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and get more out of our sleep.

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Thank you.

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(Applause)