Sleep School: What We Learned from Matthew Walker’s Masterclass

As well as being a professor of neuroscience and psychology at U.C. Berkeley, Matthew Walker is the founder and director of the Center for Human Sleep Science. He shares his expertise on all things sleep-related in his bestselling book Why We Sleep and his TED talk “Sleep Is Your Superpower.” 

In his online masterclass on the subject, Walker speaks with the enthusiasm of one who is genuinely fascinated with the information he’s conveying. He has a knack for explaining potentially dry scientific details in memorable ways (“You can think of natural killer cells almost like the secret service agents of your immune system; a little bit like James Bond”), and his discourses on the physical aspects of sleep leave the viewer with a strong appreciation of the body’s innate intelligence. 

Here are some of the most eye-opening things about shut-eye that we learned from Walker’s masterclass.

Your Clever Brain 

• As you sleep, your brain is solving problems and seeking unexpected patterns. “By doing so, it can come up with these completely novel answers to previously unknown questions,” Walker explains. 

• Non-REM sleep helps strengthen and consolidate information you’ve accumulated throughout the day. The brain compares new data with previously known information. New connections are made, resulting in a “system update” of sorts.   

• New memories are cemented during non-REM sleep. Walker describes this as the brain’s way of “hitting the save button.” Memories are moved from short-term storage areas of the brain to the cerebral cortex, where long-term memories are filed. The brain also seems to be deleting information that might be unnecessarily taking up storage space. 

• During REM sleep, your brain paralyzes your body. This keeps you from hurting yourself by acting out your dreams. 

• REM sleep helps take the sting out of emotional wounds so that you feel better about hurtful experiences the next day. 

Notable Facts 

• Being a morning person or a night owl isn’t a matter of personal choice. An individual’s chronotype—his or her natural inclination toward a particular circadian rhythm—is dictated by genetic imprint. 

• While you sleep, immune cells find and eliminate virally infected cells or tumor cells in your body. 

• Sleep-deprived people can’t accurately discern emotions through facial expressions. 

Tips for Better Sleep 

• Get as much exposure to light in the morning as possible. Even on cloudy days, the brightness outside is stronger than most light you’ll get indoors. 

• Dimming half of your lights in the last hour before bed sends your brain the signal that it’s time to start winding down. 

• The optimum room temperature for good sleep is about 67 degrees Fahrenheit. The core temperature of your body and brain need to drop by around two to three degrees for you to fall asleep and stay asleep through the night. Taking a warm bath or shower before bed will bring blood to the surface of your skin. This removes heat from the body so that your core body temperature falls. 

Read more: What is Your Body Doing While You Sleep? 

Read more: Can't Sleep? Get Some Sun.

Read more: The Dangers of Insufficient Sleep

Read more: How to Get Back in Sync with Your Circadian Rhythm