Sleep Tracking and the Pleasure of REM

Both as a neurobiologist and human, I love REM sleep.

REM sleep is a special stage of sleep. When we are asleep, our bodies and brains cycle through different kinds of sleep every couple of hours. In the beginning, the cycles contain more deep sleep and slow-wave sleep, both of which help reset the body and mind. Healing happens best in deep sleep, and both get the brain to calm down, clear itself, and make room for new memories and experiences the next day. These stages can be very refreshing, especially after a hard day’s work, but they’re not what I’d call fun.

In REM, the many different brain bits rehearse whatever they thought was the most salient part of the day, and nothing says all the bits have to agree. For example, when I enter REM, one part might focus on a moment I stumbled, another part might go over an experiment I need to plan, and yet another could be thinking about the tasty lunch place I found. I won’t be aware of what each region is doing, but the part of my brain that stitches together all my senses during my waking hours is still trying to make a coherent reality. And the awareness that arises from that mishmash has given rise to religions and prophecies, and less grandly for myself, nightly entertainment. This is the non-reality in dreams; mine are vivid.



The dreams of a neurobiologist. Much like anybody else's.

I know, as a sleep scientist, that everybody experiences sleep differently. I do not know how universal my experience is, but I share it here in the hopes that it might inspire those who are not yet REM enthusiasts. I experience all of my senses and get a robust emotional ride. I have experienced terror and exuberance and even fallen in love in my dreams. When I was little, I used to have nightmares of being chased and would wake up afraid to go back to sleep. It took me into my teen years to wake up one night, angry at being chased more than scared. I remember thinking “this is my dream. I get to win.” I went back to sleep, beat up the monster chasing me, and have felt more aware of my dreams since. I wonder how that works, and how common that is.

That is why I track my sleep. I’m my own guinea pig for many projects, only because getting good sleep data is too expensive and too invasive at present for me to do it at a large scale. My colleagues and I use a mixture of sensors, hormone assessments, and careful logging to build models of sleep that allow us – more and more with each experiment – to predict biological changes from sleep stages gathered by wearable devices.

The current state of sleep tracking.

Right now, most sleep trackers seem a little gimmicky, and that’s because they are. But it’s not their fault. The spring bloom of sleep trackers and wearable devices we are currently seeing is our society realizing that sleep is an important part of health, and trying to find a way to start learning about what sleep actually looks like. Since no one knows what the right approach for getting those data will be, there are a lot of experiments going on. Some are done by publicly-funded scientists like me. Some are done by companies hoping their device will be the one. And some are done by citizen scientists. But all of us together are feeling our way into sleep, and each experiment brings the subsequent ones closer to being really helpful. Sleep is in part a response of the body and brain to what is happening to it in waking life, so eventually, we might be able to learn all kinds of sleep patterns with predictive medical applications.

I have used multiple sleep tracking devices over the years for my research, including more than one model of EEG – a mesh of electrodes recording electrical brain activity from my scalp. I have learned that my REM decreases in the days before I get sick, and that when I’m healthy I get about 40% of my night in REM, as compared to 10-20% for most people. Maybe that gives me room for a lot of big dreams.

I think that one day, sleep will be a vital part of how we track our health and take care of our loved ones as they grow and then age. In the meantime, learning about sleep gets me out of bed each day, and getting REM is enough fun to bring me back each night. I encourage you to try and share some of my sleep joy. Track your sleep or journal your dreams. Or share your sleep experiences with friends and learn about theirs. We all spend a lot of time sleeping. We ought to make use of it, and to enjoy it!

Dr. Benjamin Smarr studies the temporal structures that biological systems make as they move through time. An NIH research fellow at UC Berkeley, his work focuses on understanding how physiological dynamics like sleep, circadian rhythms, and ovulatory cycles are shaped by the brain, and how disturbances to those cycles give rise to disease. Dr. Smarr is also an advocate for scientific outreach, and routinely gives public lectures and visits K-12 classrooms to help promote the idea that by understanding the biology that guides us, we can live more empowered lives.