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Why do we sleep? | Russell Foster


Why do we sleep? | Russell Foster

Russell Foster is a circadian neuroscientist: He studies the sleep cycles of the brain. And he asks: What do we know about sleep? Not a lot, it turns out, for something we do with one-third of our lives. In this talk, Foster shares three popular theories about why we sleep, busts some myths about how much sleep we need at different ages -- and hints at some bold new uses of sleep as a predictor of mental health.

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TED talk summary: Russell Foster - Why do we sleep?

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The Science of Sleep: Melatonin to Neural Pathways

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Russell Foster, Debra Skene and Stafford Lightman discuss the science of sleep. Why do we need sleep and what are the physiological processes driving our circadian rhythm? When is our circadian clock disrupted and how does this affect our health? Cognitive neuroscientist Vincent Walsh chairs the debate.
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The science behind sleeplessness can help us understand our rhythms so we can live better and healthier lives. While hormones, such a melatonin, play a role in driving our circadian clock, the amount of sleep we get and our sleep cycles also affect our hormonal release patterns, with far-reaching implications on our health.
Cognitive neuroscientist Vincent Walsh chairs a discussion with a panel of experts who specialise in circadian rhythms. They explore how light detection plays a role in our sleep-wake cycles, how hormone release is regulated and the implications of changes to our circadian clock and sleeplessness over time.

This event was supported by British Psychological Society and Society for Endocrinology.

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Your brain hallucinates your conscious reality | Anil Seth

Right now, billions of neurons in your brain are working together to generate a conscious experience -- and not just any conscious experience, your experience of the world around you and of yourself within it. How does this happen? According to neuroscientist Anil Seth, we're all hallucinating all the time; when we agree about our hallucinations, we call it reality. Join Seth for a delightfully disorienting talk that may leave you questioning the very nature of your existence.

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The TED Talks channel features the best talks and performances from the TED Conference, where the world's leading thinkers and doers give the talk of their lives in 18 minutes (or less). Look for talks on Technology, Entertainment and Design -- plus science, business, global issues, the arts and more.

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Why Do We Sleep?

We take a look how we slept in the past, how animals sleep, and try to figure out the science behind why we spend a third of our lives asleep. Why do we sleep? How do sharks sleep? How do dolphins sleep? Do animals dream? How did sleep evolve? Do Animals dream? What does poop have to do with all this?

Special Thanks To:

Roger Ekirch
His book:

The Stanford Center for Sleep Sciences and Medicine
William C. Dement
Clete A. Kushida

Lincoln Park Zoo
Rachel Santymire
Dan Boehm

Shedd Aquarium
Lise Watson
Lisa Takaki

Sleep Playlist Videos:
How Science Changed Sleep Forever -
Why Do We Sleep? -
Why Do We Dream? -
How To Sleep Better! -

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Music By:

Rob Scallon

Kevin MacLeod

Jason Shaw

Jake Chudnow

Image and Video Credits:

Bed Painting by Toulouse-Lautrec - Henri de Toulouse-Lautrec [Public domain], via Wikimedia Commons

Sleep Woman - by Aweisenfels - Own work. Licensed under CC BY-SA 4.0 via Wikimedia Commons

Japanese men sleeping on train - By Tischbeinahe (Own work) [CC BY-SA 3.0], via Wikimedia Commons

A Child Sleeping - By Alessandro Zangrilli (Own work) [Public domain], via Wikimedia Commons

Black Rhino Footage courtesy of Lincoln Park Zoo

Two Alligators - By Mfield, Matthew Field - (Own work) [CC BY-SA 3.0 ( via Wikimedia Commons

Eastern mud snake - By Geoff Gallice from Gainesville, FL, USA [CC BY 2.0 ( via Wikimedia Commons

Stingray - By Steven G. Johnson (Own work) [CC BY-SA 3.0 ( via Wikimedia Commons

Mako Shark - By Patrick Doll (Own work) [CC BY-SA 3.0 ( via Wikimedia Commons

Spinner Dolphins - By Alexander Vasenin (Own work) [CC BY-SA 3.0 ( via Wikimedia Commons

Killer Whales - By Robert Pittman [Public domain], via Wikimedia Commons

Mallard Ducks - By Fcb981 (Own work) [CC-BY-SA-3.0 ( via Wikimedia Commons

Free Range Chickens - By woodley wonderworks ((semi) free range chickens) [CC BY 2.0 ( via Wikimedia Commons

Why Do We Sleep?

(Visit: Sonia Ancoli-Israel, Ph.D., recipient of the National Sleep Foundation’s 2007 Lifetime Achievement award, discusses why people need sleep. Sleep disorders are a major public health concern affecting millions of individuals, families, and communities on a daily basis. We are a chronically overtired country, which often has grave health repercussions. Watch the Whole Show here: Series: Excerpts [Show ID: 32400]

Russell Foster: Why We Need More Sleep

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Russell Foster on how sleep science explains eye disease and mental health | Health | WIRED

Russell Foster, professor of circadian neuroscience at the University of Oxford, wants to change your views, thoughts and ideas about sleep.
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Sleep is still in many regards a mystery for scientists. However, Professor Foster, who spoke at WIRED Health, is working in new areas of neuroscience that are finding links between our sleep cycles and the state of our mental health, which could drastically change the way we think about sleep.

WIRED Health is a one-day summit designed to introduce, explain and predict the coming trends facing the medical and personal healthcare industries. This ambitious inaugural event was held on Tuesday April 29, at the new home of the Royal College of General Practitioners, 30 Euston Square, London.

Check out the full WIRED Health playlist here:

WIRED Health will return in 2015. Look at for details.


WIRED brings you the future as it happens - the people, the trends, the big ideas that will change our lives. An award-winning printed monthly and online publication. WIRED is an agenda-setting magazine offering brain food on a wide range of topics, from science, technology and business to pop-culture and politics.

Russell Foster on how sleep science explains eye disease and mental health | Health | WIRED

Russell Foster on how sleep science explains eye disease and mental health Full WIRED He

Russell Foster, professor of circadian neuroscience at the University of Oxford, wants to change your views, thoughts and ideas about sleep. Subscribe to WIRED ▻▻

The full article is available here: Professor Russell Foster of Oxford University delivers The Physiological Societys.

What does sleep have to do with mental health? Everything! To see more seminars like this, visit: The focus of Neuroscience Research Australia, or NeuRA, has always been.

Sleep Disruption & Mental Illnesses - Russell Foster

Russell Foster, Professor at Oxford Sleep and Circadien Neuroscience Institute was speaking during the Dreem Sleep Conference on how and why sleep disruption occurs and its connection with mental illness.

Light, sleep and circadian interactions: Biology to new therapeutic targets - Russell Foster

Russell Foster, University of Oxford, UK, gives his talk 'Light, sleep and circadian interactions: Biology to new therapeutic targets' at The Physiological Society 'Sleep and Circadian Rhythms from Mechanisms to Function' conference, 5–6 December 2018, Barbican Centre, London.

The science of how much sleep you actually need

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Getting plenty of sleep each night is important to maintaining a healthy and productive life. But how much sleep do you actually need?

Joe Avella and Jessica Orwig tackle this question on the Facebook series Science the $#!* out of it.

For the average adult, the National Sleep Foundation recommends 7 to 9 hours of sleep a night.

Today, however, many Americans are sleep-deprived, which can have significant adverse effects on physical and cognitive functions.

The reason why some people don’t get enough sleep can be accredited to busy modern lifestyles. But there are other reasons too.

It turns out habits such as using electronic devices or drinking alcohol right before bedtime can be detrimental to getting a good night’s sleep.

Learn more on how to get better sleep on this episode of Science the $#!* out of it. Watch the whole series:

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Prof Russell Foster - Sleep and Young People

Prof Russell Foster, Professor of Circadian Neuroscience at the University of Oxford talks with Director of Voices from Oxford Dr Sung Hee Kim. He stresses the importance of maintaining a good sleep cycle to the mental and physical health of young people. Russell speaks of how many teenagers nap after school, and then go to bed too late after interacting with the bright screens used in modern technology, none of which is conducive to getting a good night's sleep which is vital to be able to be able to function properly the following day. Russell also offers his advice and tips on how to improve sleep patterns, and thus become healthier, happier and more productive.

Pillow Talk -- The Biology of Sleep (1/3) and VC introduction

On the occasion of the Vice-Chancellor's Hong Kong Alumni and Friends reception, Professor Russell Foster, chair of circadian neuroscience and Head of the Nuffield Laboratory of Ophthalmology, presents his latest Oxford research into sleep science to the city that never sleeps.

Prof Russell Foster - The Molecules behind Circadian Rhythm

Prof Russell Foster talks with Prof Denis Noble about the recent Nobel Prize in Medicine and Physiology awarded to Jeffrey C. Hall, Michael Rosbash and Michael W. Young for their discoveries of molecular mechanisms controlling the circadian rhythm. They discuss the science of what was discovered, and the importance of the work in leading to a better understanding of how the day-night cycles of all organisms are controlled and regulated by this mechanism. Russell also expresses his admiration for the Nobel winners, and his delight that what was once a small academic field with only a handful of scientists studying it should be honoured in such a way.

Light, clocks and sleep: keeping an eye on the time, by Prof Russell Foster

36% of our lives are spent sleeping. This means that if you live to be 90, then you'll have spent 32 years sleeping.

Research by Prof. Russell Foster and other highlights that a good night's rest isn't a luxury--it's critical for your brain and for your health

Talk abstract:

We and most organisms possess a 24h biological (circadian) clock which acts to ‘fine-tune’ physiology and behaviour to the varying demands of the day/night cycle. Such a clock is only useful if biological time remains synchronised to solar time, and the daily change in the gross amount of light (irradiance) at dawn or dusk provides the most reliable indicator of the time of day. In mammals the “master clock” is located within small paired nuclei at the base of the brain called the suprachiasmatic nuclei (SCN). The SCN receive direct retinal projections which adjust the clock to the light/dark cycle, and eye loss in mammals blocks this completely. But how does the eye detect this light to provide the re-setting signal? Surprisingly, we found that visually blind mice, with genetic defects in the rods and cones, could still use their eyes to regulate the circadian system. These, and a host of subsequent experiments including studies in humans with genetic defects of the eye, showed that the processing of light information by the circadian and classical visual systems is different and that the mammalian eye contains an additional non-rod, non-cone photoreceptor based upon a small number of photosensitive retinal ganglion cells (pRGCs). These remarkable, and recently discovered receptors use “melanopsin” as their photopigment, which is sensitive in the blue part of the spectrum around 480nm. This presentation will explore the discovery, biology and clinical importance of this third photoreceptor system of the eye.

About Prof. Russell Foster:

Russell Grant Foster, CBE, FRS FMedSci (born 1959) is a British professor of circadian neuroscience, currently based at Brasenose College at the University of Oxford. He and his group are credited with the discovery of the non-rod, non-cone, photosensitive ganglion cells in the mammalian retina which provide input to the circadian rhythm system. Foster was elected a fellow of the Royal Society in 2008 and a member of the Biotechnology and Biological Sciences Research Council council in 2011. (from Wikipedia)

Cheltenham Science Festival - sleep research - Evan Davis and Prof. Russell Foster

Join sleep-deprived presenter of Radio 4′s Today's programme, Evan Davis, and Oxford BRC researcher Professor Russell Foster on the subject of sleep. Filmed at the Cheltenham Science Festival.

Russell Foster: What is Sleep?

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Cheltenham Science Festival - rhythm of life - lecture by Prof. Russell Foster

Professor Russell Foster wowed the crowds at Cheltenham Science Festival with his talk on how or if the month of your birth plays any part in your predisposition towards certain chronic illnesses.

While it is clear that animals and birds live by the seasons, for a long time humans have been able to counteract the harsh changes in light and temperature using central heating, indoor lighting and a continuous food supply. And yet there are some months of the year with higher frequencies of births, onsent of disease and mental health episodes. Discover with Russell Foster how the social, biological and physical pressures of the seasons still affect us.

Professor Russell Foster

Professor Russell Foster CBE was awarded an honorary Doctor of Science in February 2015. We invited him back to address students during graduation in July 2016.

Professor Foster is a leading scientist whose research has transformed our understanding of how the eye detects light and redefined the clinical diagnosis of blindness. An expert in ‘circadian rhythms’ – the 24 hour rhythmically changing cycle of light and darkness – he’s been active in developing new approaches to understanding and treating the pervasive problem of sleep and circadian rhythm disruption in psychiatric illness.



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