Did you get enough sleep last night? Probably not, says Matthew Walker, cognitive neuroscientist and neurophysiologist at the University of California, Berkeley. Statistics show, he says, that two-thirds of adults fail to obtain the recommended 8 hours of nightly sleep.
If that doesn’t seem like a big deal, Walker has some robust research to counter that assessment, about the widespread cognitive and health effects of cutting short a night’s sleep. He will be sharing this growing body of research as the keynote speaker at CNS 2019 this March in San Francisco. In his lecture, which will be free and open to the public, the one message he hopes attendees will come away with is simple: “Sleep is the single most effective thing that you can do to reset your brain and body health,” Walker says.
CNS spoke with Walker about his sleep research, how he became interested in the field, and some of the research he’ll be presenting in his keynote at CNS 2019.
CNS: How did you become personally interested in cognitive neuroscience?
Walker: I started off and did all my education in the United Kingdom, and there, you can actually start off medical school aged 18. So I was heading on a path of medicine, and I was always asking questions in lectures. At one point, one of the professors pulled me aside and said, “Look, it’s great that you’re fascinated and you’re asking questions, but doctors are interested in answers, not questions, and you’re interested in questions — perhaps less so answers. In other words, I think you’re a scientist, not a doctor.” That was transformative. At that moment, I had already developed a keen fascination of the brain. I saw the brain as this epic, pinnacle of a problem, and for someone who was more interested in questions than answers, I had to go after that. So I started to move down the path of neuroscience as an undergraduate and became very interested in what was essentially cognitive neuroscience, which at that stage wasn’t yet formed as a field.
Why do we sleep? Without hubris, honestly, I believed that I would go and solve this question within a two-year postdoctoral position… That was 22 years ago. And I am still answering the question of why we sleep.
CNS: When did the study of sleep come into the picture?
Walker: I did my Ph.D. in psychiatry at the Medical Research Council, where I focused on dementia. I was examining people with different forms of dementia, using different brainwave patterns, specifically EEG, to see if I could differentially diagnose individuals very early in the course of the disorder, and I was failing miserably. And I couldn’t get any data for the the first two years. Then one night, I was reading how these different diseases — things like Alzheimer’s disease or Parkinson’s disease or Lewy body dementia — all targeted different areas of the brain in terms of their attack. Some of them targeted sleep centers, others did not. At that moment, I realized I was measuring brainwave activity at the wrong moment; I was measuring my patients whilst they were awake. At that time, there wasn’t much sleep research going on in the United Kingdom. So I taught myself how to set up a sleep lab. And with a small grant, I started recording sleep and got fantastic results. That was my kind of gateway entry into the field of sleep.
I then started to think that if the sleep is so disrupted in my patients, is it contributing to their symptoms? And at that point, I realized no one could answer a simple question: Why do we sleep? Without hubris, honestly, I believed that I would go and solve this question within a two-year postdoctoral position and then come back and figure out what was happening in my patients. That was 22 years ago. And I am still answering the question of why we sleep, but we are much further along now as a field.
CNS: What will you focus on in the upcoming keynote address?
Walker: I’ll speak about a whole collection of different brain deficits, as well as some body and interrelated brain-and-body deficits, that were just making new discoveries and publishing on. There are two areas that are really fascinating and novel right now.
Firstly, it’s not just the relationship between sleep and memory, but the nature in which that relationship fails and declines as we get older. I will describe evidence that I think demonstrates now that sleep disruption is an underappreciated factor that is contributing to memory decline or what we call cognitive decline in aging and Alzheimer’s disease. The reason that’s exciting is because, unlike many of the other factors that are associated with aging and Alzheimer’s that we can’t treat right now, such as changes in the physical structure of the brain or the vasculature of the brain, we can do something about sleep. It is modifiable and thus a new treatment target. In the talk, I will describe that one of my moonshot goals at my sleep center, is to try to electrically boost the amount of deep sleep in adults, and in doing so, see if we can salvage aspects of their learning and memory function.
The second area that I’ll speak about is sleep and mental health. I will describe some new and existing evidence that sleep essentially provides a form of overnight therapy. It is a nocturnal soothing bomb, so we can think of sleep as emotional first aid And I will describe the links between sleep and emotional brain regulation and psychiatric disorders as well.
If you think about the three pillars of health, you’ve got diet, exercise, and sleep. If you don’t exercise for a day or you don’t eat for a day, the loss of empowerment in your brain or body is nothing close to that which we see if you go a day or, specifically, one single night without sleep.
CNS: What do you find that the people commonly don’t understand about sleep?
Walker: I think there are several things. Probably the most dramatic is that most people underappreciate the impact that a lack of sleep has on both the brain and the body. I think the simple statement that most people in the street do not know is this: the shorter your sleep, the shorter your life. Short sleep predicts or causes mortality.
The second thing that many people do not know is that every major disease that is killing us in the developed world now has significant and causal links to a lack of sleep. That list currently includes Alzheimer’s disease, depression, dementia, and suicide, as well as cancer, diabetes, obesity, cardiovascular disease, stroke in both brain and body, and also hypertension.
If you think about the three pillars of health, you’ve got diet, exercise, and sleep. If you don’t exercise for a day or you don’t eat for a day, the loss of empowerment in your brain or body is nothing close to that which we see if you go a day or, specifically, one single night without sleep. Now of course those two other things are important, but in terms of magnitude of impact, a lack of sleep will demonstrably implode both the brain and the body in terms of its function.
CNS: What new tools are changing our understanding of sleep?
Walker: Aspects of electrical brain augmentation, electrical brain stimulation, are a really exciting area that we’re going to be able to use now to modify sleep. We no longer need to look to at pharmacological sleeping tools; we now have these electrical tools, so we can speak in the language of the brain. By speaking in that currency of the brain, we can actually try to sing in time with these electrical brain oscillations of sleep and try to boost them. It would be an electroceutical for sleep!
CNS: What’s next for your research?
Walker: Gosh, we’re doing so much exciting stuff at the Center for Human Sleep Science. We’re looking at sleep across the entire lifespan, not just in aging. But we’re now starting to do a lot of work in sleep during development. There are remarkable changes in sleep, even more dramatic than those that we see in aging, during the developmental years. We’re doing work with adolescents right now, looking both at learning and memory, as well as psychiatric and emotional and mental health issues. Of course, that is the time of life when many of the mental health disorders start to present and emerge. It’s also the time of life when sleep becomes challenges perhaps most for a number of different reasons. So that’s very exciting.
The other thing that’s exciting is that we are no longer just focusing on the brain because the brain doesn’t operate in isolation. We are an embodied organism. The brain communicates with the body. The body communicates within the brain. You can’t separate one from the other if you want to understand the brain, and we’re now starting to look at an entire snapshot of the whole organism. We’re looking at a genomics, proteomics; we’re looking at the gut microbiome, which has got some fascinating relationships with sleep and diet; we’re looking at bloodwork; we’re looking at metabolic profiles; and then we’re mapping all of those interrelated with the brain, and seeing how the entire organism is affected by sleep when you get it or impaired when you don’t get enough.
CNS: Anything else you’d like to add?
Walker: Looking forward to CNS 2018 and hope you sleep well, haha!
-Lisa M.P. Munoz