Why is it that when you’re binge watching your favorite new series on Netflix, you can stay up for hours past your normal bedtime – even if you were tired before you started watching? On the other hand, if you weren’t being entertained or captivated by a game or puzzle, you’d be much more likely to be lulled to sleep at that time. Indeed, sleep and goal-directed behaviors are mutually exclusive: you can’t do both at the same time. While this relationship is intuitively clear, for the first time, scientists at Stanford have clarified the circuitry between the brain’s reward and arousal systems. In the latest episode of humanOS Radio, I speak with Luis de Lecea, Professor of Psychiatry and Behavioral Sciences at Stanford University School of Medicine. Recently, he and his colleagues published a study in the prestigious journal Nature demonstrating that dopamine neuron activity (in the ventral tegmental area of the brain) is necessary in order to be awake. Furthermore, when they inhibited these neurons, there were able to promote what seemed like natural, healthy sleep.
In Professor Jamie Zietzer’s recent research on light and the timing of biological rhythms, he noticed something curious: brief flashes of light have a greater ability to adjust body clock timing than continuous light exposure.
For instance, let’s say you wanted to adjust your body clock to wake up earlier than you typically do in the coming days (a common scenario for those who travel across time zones). In order to make this adjustment, on the morning before you leave, you could wake up at 4:00am, turn on the room light and go back to sleep. This technique can adjust your clock by about 35 minutes, which means that if you typically awake at 7:30am, you could naturally wake up tomorrow around 6:55am (and the timing of all your other body processes would shift accordingly, too).
On the other hand, if you were to get 2 millisecond flash of light every 10 seconds starting at 4:00am (instead of laying in a room with the light on) – something Jamie’s research has demonstrated you can sleep through – you could advance your clock by about 120 minutes – over 3x more than continuous light.
What does this mean? Well, one thing it means is that it would be a heck of a lot easier to be up and ready before your typical natural wake time in those moments when you have an early start to your day (e.g., early plane flight). The ability to affect your body timing in this manner is more than a mere luxury; it’s also about personal safety and performance. None of us want to be on the road with sleepy drivers, and likewise, no one wants to have to perform at a time when you’re too sleepy to keep your eyes open. This is pretty exciting technology!
We typically associate the hormone melatonin with sleep. However, melatonin is actually involved in the timing and synchronization of a number of different physiological functions throughout the body. One of these functions is the regulation of blood sugar.
Recent research has found that a relatively large proportion of the human population is genetically predisposed to be more sensitive to the impact of this hormone on blood sugar control. This can lead to higher blood glucose levels, and ultimately greater risk of developing type 2 diabetes.
Here’s how it works, and what you can do about it.
Brainy Beds? Professor David Samson on Sleeping Platforms, Sleep Quality, and Thinking Speed, plus News!
Did our brains evolve as they have due to how we slept? In part, likely yes. In this episode of the humanOS Radio podcast, I speak with Professor David Samson about his research looking at primate sleeping platforms and their potential role to increase the cognitive abilities of certain great apes beyond the capacities of other primates. How does this connection work? The primates who create more comfortable beds for themselves appear to achieve substantial amounts of deep and REM sleep over the night. This is turn may have lead to the expansion of cognitive abilities over time. Can you benefit from the information shared in this discussion to improve your own sleep?
When the system in our body that controls the timing of our physiology becomes uncoordinated or misaligned, bad things happen. This can happen in several ways.
The most well-understood way is due to big fluctuations in the timing light exposure from day to day. This is why Apple recently introduce night shift to help limit the impact cell phones can contribute to this issue. But big fluctuations in the timing of light exposure is not the only way to misalign our rhythms. The type and timing of dietary fat also impact’s this system.
We do not enter into the world with infinite knowledge of ourselves and our surroundings. We don’t have knowledge or skill to survive, to dance, or to do martial arts with grace and efficiency. We don’t know enough about ourselves or know how to interact best with different types of people we encounter. We don’t know how to accelerate our ability to get better at something. We are born, however, with the capacity to learn and to remember, and by virtue of this skill, we have an incredible potential to do great things.
Professor Marcos FrankToday, important stuff happened to you. Tonight, when you sleep, your brain will extend the process of turning that stimulation – the sites, sounds, thoughts, emotions, facts, etc. – into memories that you can access at a moments notice in the future. It’s amazing when you think about it: experiences, facts, skills, and even thought patterns become a part of who we are. How much do you know now that you didn’t know 1o to 15 years ago, or even last week, last month, or yesterday? The process of accumulating information, and accessing when needed, is so routine it’s easy to forget that something is going to make it possible. As it turns out, sleep plays a vital role in the formation of certain types of memories. In this interview, I speak with someone who has made, and continues to make, significant contributions to help the world better understand how all this magic works. My guest is Marcos Frank, Ph.D., who is the Interim Chair of the Department of Biomedical Sciences in the Elson S. Floyd College of Medicine at Washington State University. I hope you enjoy this discussion as much as I did.
Around this time of year, much of the world is advancing their clocks by one hour to make efficient use of seasonal daylight. Americans switched to Daylight Savings Time last week, and this week Europeans will revert to Summer Time.
When this happens, we all “lose” an hour of sleep, because we have to get up and get things done an hour earlier than we have been. This is in relation not just to the light and dark cycles of the day, but also to our body clocks.
One hour sounds like a small change, but it can make a big difference in how we function, at least in the short term. For example, data from the past two decades shows that there is a statistically significant spike in the number of car wrecks on the Monday immediately following the shift to Daylight Savings Time in the US.
As we all adjust to the time change, it’s worthwhile to consider how other aspects of our lives can sway our circadian rhythms. Circadian clocks govern the rhythms of sleep and activity in virtually all animals and are responsive to a variety of stimuli like light and stress. Research is starting to suggest that our eating patterns – specifically when we eat – can also have a pervasive impact.
I am very happy to announce our new podcast, humanOS Radio. The aim is interview three categories of people: 1) Researchers whose work informs us about some aspect of how we live, 2) Entrepreneurs who are translating science into solutions, and 3) Investors making bets to predict (and support) the major future influencers on health. The format will be flexible, but most shows will around 30 minutes or less. I think the best way to get a sense of what humanOS will deliver is to listen to an episode or two. Without further ado, please find my conversation with Matt Buman, PhD., who is an Assistant Professor in the School of Nutrition and Health Promotion at Arizona State University.
Recently, research by Marie-Pierre St-Onge and colleagues evaluated whether sleep is modified in response to changes in dietary intake across the day. The study kept healthy participants in an inpatient unit, so there was a high degree of control to record what the participants ate and how they slept. During the first 4 days, the researchers gave the participants a controlled diet and monitored their sleep in response to what they ate. On day fifth day, however, the participants were allowed to choose their own food, and on that night, sleep changed: it took longer for the participants to fall asleep, they had less deep sleep and more arousals across the night.
We’re getting much less sleep than we used to! Well, at least that’s been the story, but this story has largely been based on self-reported sleep times. If we are getting less sleep than we should, we need to know. One approach to understanding this subject better is to investigate what “natural” sleep looks like. Luckily, we now have more information on this due to a ground-breaking study recently published by Professor Jerry Siegel at UCLA, and colleagues in the journal Current Biology. In his study, he evaluated three societies living in natural conditions (e.g., modern day hunter-gatherers) to examine their sleep behaviors and physiology. He also analyzed external factors like natural light, ambient temperature and the season in which the data was collected. And by doing so, Dr. Siegel appeared to turn the wide-spread belief that we are chronically sleep deprived on its head. At least that seemed to be the emphasis of most news reports that came out describing the study. But to really understand what this data means, we need to discuss the study and interpret the findings with an emphasis to explain the difference between sleep period and sleep time. Along with an article investigating this subject, you can listen to my interview with Dr. Siegel where we discuss the study and his findings.