How A PhD Who Specializes In Overthinking Gets Better Sleep
I don’t know about you, but there are times when I dread going to bed. I hate lying quietly in the dark with my thoughts. I spiral about sickness, finances, my family members dying, some stupid thing I said that day…it’s endless.
And it feels impossible to turn off. Then there’s the 2 a.m. wake-up during which my anxieties, insecurities, and fears give me a Broadway performance.
We all want peaceful, restorative sleep. So what is our mind doing, and how can we shut it down?
The science of sleep
As a quick overview, we have two thought networks: the central executive network (CEN), and the default mode network (DMN). The CEN runs when we focus our attention on something. It is task-oriented and purposeful. The DMN runs whenever the CEN goes offline. It is the mental chatter we hear all day long. Our stream of consciousness.
Unfortunately for us, the DMN is negatively biased, meaning it loves to point out the worst. It brings up embarrassing or painful memories, and terrifying possibilities.
Night is when the CEN is tired. Right when we need to turn the DMN off, it becomes harder to focus and do exactly that.
If we’re uptight or don’t feel safe (hello, life in 2025), the DMN also resists turning off. Researchers at Brown University and Georgia Institute of Technology watched people fall asleep in a brain scanner to better understand why people have a hard time falling asleep in hotels1.
They discovered that during the first night, the left hemisphere of the DMN remained more active than the rest of the brain. It woke up other brain areas when something unexpected happened (e.g., a voice in the hall, a hotel door closing), making sleep restless or nonexistent.
The more alert the DMN was to the outside world, the longer it took for people to fall asleep. The DMN was the one keeping them awake and alert when they didn’t want to be.
So what can we do?
How to train your DMN for better sleep
Now that we know the reason behind our nighttime anxiety sessions, we can seek to override the DMN using several techniques.
Try them and see which works well for you:
- Take a hot bath. In the hours leading up to sleep, our bodies naturally drop between 2 and 3 degrees Fahrenheit. When you take a hot bath or shower, you simulate that process, improving sleep duration and quality. In fact, a hot bath or shower can help people fall asleep almost as fast as Ambien2. If you worry that you will wake everyone else up, try using a heating pad to warm your hands and feet. This produces an attenuated version of the same cooling process.
- Breathe. When your DMN gets wrapped up in its insecurities and worries, it stresses the body out. Your muscles clench, and your breathing becomes shallow. When my DMN is on fire, the first thing I notice is that I am clenching my jaw. Honestly, I get nightmares where I shatter my teeth and they feel like shards in my mouth. Tense, much? So to help your DMN calm down, try soothing the body. Unclench your jaw. Take several deep breaths. Actively relax your muscles. The more you can take yourself out of a stress response, the more likely you will be able to turn off the DMN.
- Read or watch something boring. When your DMN won’t shut up, find something neutral and boring to read, watch, or listen to. Reading is wonderful, but sometimes it is too far a leap to go from a major life anxiety spiral to a book, in which case, cut yourself some slack and watch a show. Personally, I turn to National Geographic documentaries in these moments. There’s something about a geologist standing on a hilltop passionately talking about how rocks solve the mysteries of the universe that soothes me.
- Force your mind to recall something. The scariest part of the going-to-sleep process, whether it’s in the beginning or middle of the night, is when you’re just lying there wanting to fall asleep. When you actively ask your mind to do something, you prevent the DMN from taking center stage. After I’ve watched my geology shows, I try to remember what I learned in the program. Or, try recalling the plot line of the book you’re reading, or one of your favorite movies, as if it is playing in your head. Giving yourself a neutral cognitive task while falling asleep stops the DMN from stealing the show.
The takeaway
We all struggle with getting quality sleep. Yes, the next day will feel like a waste, and you will count down the minutes until you can be home and cozy (and if you have dependents, they are asleep). That’s all of us.
The most important thing we can do is not take our nighttime musings too seriously. Not believing these thoughts and letting them go will get you far in achieving solid sleep the next night.