Perhaps no hairstyle is as iconic as Princess Leia’s twin tightly spiraled buns. It’s a mental image that most of us can conjure fairly easily (if you’re lost, a quick Google search for “Princess Leia’s hair buns” should enlighten you).
Now that unique hairstyle is used by neuroscientists to illustrate the pattern that brain waves make while we sleep. Beyond looking cool, these oscillating waves also have a critical function: they help organize and consolidate memories.
Discovered by Dr. Terry Sejnowski of the Salk Institute for Biological Sciences in La Jolla, California, Princess Leia brainwaves have transformed our understanding of sleep, memory, and brain function.
How “Sleep Spindles” Form
New Memories While You Sleep
We associate sleep with rest, but while our eyes are shut, our brains are hard at work. That’s because our brain needs to decide which events from the previous day should be moved from the short-term memory storage in the hippocampus to long-term memory storage in the neocortex. Known as memory consolidation, this process determines our ability to recall past events.
Specifically, Princess Leia brainwaves or “sleep spindles,” are the mechanism the brain uses to transfer memories into the neocortex.1 These unique waves occur during early stages of non-REM (rapid eye movement) sleep. If you’ve got a photographic memory, it’s because you’re generating an above average number of Princess Leia brainwaves while you’re asleep.
These Sleep Brainwaves Resemble
Carrie Fisher’s Twisty Hair Buns
Scientists had long suspected that sleep time brainwaves played an important role in memory, but their knowledge was limited. Using electrodes, scientists were only able to detect brainwaves in one area at a time. To solve this problem, a team at the Salk Institute led by Dr. Sejnowski used intracranial electrocorticograms (ECoGs) in order to measure activity throughout the entire brain.2
Here’s what they found: the brainwaves begin in the hippocampus, where all of your day’s memories are stored. They then activate in the thalamus, which is responsible for incorporating vital personal information, and finally peak in the neocortex.3 The brainwaves weren’t simultaneously firing throughout the brain as earlier researchers had hypothesized, but instead sweeping in circular patterns around the neocortex.
The team at Salk believes that because a memory is made up of many parts (like sights, sounds, and smells), it is actually divided into multiple components and stored in different regions of the brain.4 That’s the reason these waves move from one area to the next – they need to consolidate complete memories into long-term storage.
These sleep spindles lasted only about 70 milliseconds, but each they occurred between 200 and 500 times per night.5 The pattern they made reminded Dr. Sejnowski of the Star Wars princess’ twisty hair buns.
Sleep: The Force To Help You
Learn & Remember More
Princess Leia brainwaves are more than just a curiosity. They may also have important implications fighting a number of neurological disorders. “If we understand how memories are being linked up like this in the brain, we could potentially come up with methods for disrupting memories after trauma,” says Dr. Sejnowski.6 He even speculates that understanding sleep spindles could lead to breakthroughs in battling schizophrenia.
For the rest of us hoping to generate as many of these sleep spindles as possible, the key is a consistent and uninterrupted sleep schedule. That means going to bed and waking up at the same time every day, avoiding screens the hour before bed, and making your sleeping environment as dark as possible.
If you’re an insomniac, there are a number of natural sleep aids that might do the trick for you. Melatonin, magnesium, and valerian root are all over-the-counter herbal remedies for poor sleepers.7