Matt Walker

Walker was born in Liverpool, England. He began studying medicine in Nottingham, switched to neuroscience and, during a PhD in neurophysiology supported by the Medical Research Council, studied brainwaves in people with dementia, which led him by accident into sleep research.⁠[1]

He received a B.Sc. in neuroscience from Nottingham University in 1996 and a PhD in neurophysiology from the Medical Research Council in 1999.⁠[2]

He was a lecturer in Harvard UniversityHarvard UniversityHarvard University is a private research university in Massachusetts, established by the Massachusetts Bay Colony legislature in 1636 and named in 1639 for early benefactor John Harvard. Its principal campuses are in Cambridge and the Allston and Longwood neighborhoods of Boston. It includes Harvard College, graduate and professional schools, and the Radcliffe Institute for Advanced Study. Two governing boards share oversight. Alan M. Garber was president as of October 2026, and the endowment stood at $56.9 billion at the end of fiscal 2025.Open the full entry’s Department of Psychology in 2001–2002 and from 2002 to 2007 an instructor in psychiatry and then assistant professor of psychology at Harvard Medical School, becoming a National Academy of Sciences Kavli Fellow in 2006.⁠[2]

In October 2007, as director of UC Berkeley’s Sleep and Neuroimaging Laboratory, he was senior author of a Current Biology study finding that the amygdala of participants kept awake for 35 hours was more than 60 percent more reactive to negative images; he said sleep deprivation makes healthy brains mimic certain psychiatric patterns.⁠[3]

In June 2015 he was senior author of a Nature Neuroscience study finding that the more beta-amyloid older adults had in certain brain regions, the less deep sleep they got and the worse their memory, while less deep sleep made clearing the protein less effective; he called it a vicious cycle and said poor sleep is potentially treatable through exercise, behavioral therapy and electrical brain stimulation.⁠[4]

He spent four and a half years writing Why We Sleep, published in the UK by Allen Lane in September 2017, which sets out links between sleep loss and diseases such as Alzheimer’s, cancer and diabetes.⁠[1]

In October 2017 he was interviewed by Terry Gross on Fresh Air about his new book Why We Sleep, discussing how insufficient sleep affects concentration, memory, the immune system, blood sugar and appetite, and his research on a possible link between inadequate sleep and Alzheimer’s disease.⁠[5]

On June 19, 2018, Scribner released a 368-page paperback of Why We Sleep, promoting it as a New York Times bestseller and quoting Bill GatesBill GatesBill Gates is an American entrepreneur, investor and philanthropist who cofounded Microsoft with Paul Allen in 1975 and served as its chief executive and chairman. He later shifted his focus toward global health, education and climate, chairs the Gates Foundation, and manages investments through arrangements including Cascade.Open the full entry’s recommendation of the book.⁠[6]

In May 2019 TED posted his 19-minute talk Sleep is your superpower; he later hosted the TED original series Sleeping with Science.⁠[7]

On November 15, 2019, Alexey Guzey published a long essay on his website alleging that the first chapter of Why We Sleep contains numerous scientific and factual errors, including an unsupported claim that sleeping less than six or seven hours doubles cancer risk and the attribution of a declared sleep loss epidemic to the World Health Organization, and alleging that Walker had edited out data contradicting his argument from a graph.⁠[8]

A post on the statistics blog Statistical Modeling, Causal Inference, and Social Science called Guzey’s critique careful and in many ways bulletproof, with the author saying he found the arguments persuasive.⁠[9]

On December 19, 2019, Walker published a post responding to readers’ questions about the book, welcoming corrections and saying a full set of corrections had been made and published in a second edition; he acknowledged that the book had misattributed to the World Health Organization the CDC’s statement that insufficient sleep is a public health epidemic, and listed studies supporting other points such as cancer risk.⁠[10]

On July 26, 2021, he released the trailer for The Matt Walker Podcast, a show about sleep, the brain and the body, whose description calls him an “awkward British nerd” who adores the communication of science to the public.⁠[11]

He appeared on episode 210 of the Lex FridmanLex FridmanLex Fridman is a Soviet-born, US-raised computer scientist and podcast host who works as an MIT research scientist on human-AI interaction and autonomous driving. His Lex Fridman Podcast is known for hours-long conversations with guests including heads of state and technology leaders.Open the full entry Podcast, whose description calls him a Berkeley sleep scientist and the author of Why We Sleep; topics included why we sleep, caffeine, chronotypes, overcoming insomnia, diet and sleep, where dreams come from and how sleep affects emotions.⁠[12]

In September 2025 Center for BrainHealth and UT Dallas announced that Walker would join on January 1, 2026, as inaugural director of the new Sleep Innovation Laboratories and professor of neuroscience and bioengineering in UT Dallas’s schools of behavioral and brain sciences and engineering; the announcement noted his 2020 Carl Sagan Prize for Science Achievements and that the appointment was made possible by private philanthropy.⁠[13]

In January 2026 the Sleep Innovation Laboratories launched at Center for BrainHealth, with sleep scientist Eti Ben Simon as associate director; in December 2025 the two had been accepted into the Boston Museum of Science’s inaugural Science Communication Fellowship.⁠[14]

On his website he says Why We Sleep has been translated into more than 40 languages and sold over 4 million copies; he co-founded the sleep-technology company Somnee, teaches a MasterClass course on sleep, and serves as a scientific adviser to Estée Lauder, Eight Sleep and Equinox Hotels.⁠[15]

Personal website: Public link: https://www.sleepdiplomat.com/ (opens in a new window)⁠[12]

X: Public account: https://x.com/sleepdiplomat (opens in a new window)⁠[12]

LinkedInLinkedInLinkedIn is a social networking platform for professionals. It was founded in 2002 by Reid Hoffman and others, launched in 2003, and listed on the New York Stock Exchange in 2011; after Microsoft acquired it for approximately $26.2 billion in 2016, it became a wholly owned Microsoft subsidiary. Its revenue comes from membership subscriptions, advertising, and recruitment solutions.Open the full entry: Public profile: https://www.linkedin.com/in/sleepdiplomat (opens in a new window)⁠[15]

Harvard Medical School: Official website: https://hms.harvard.edu/ (opens in a new window)⁠[7]

University of California, Berkeley: Official website: https://www.berkeley.edu/ (opens in a new window)⁠[16]

The University of Texas at Dallas: Official website: https://www.utdallas.edu/ (opens in a new window)⁠[14]