What Does Your Brain Do While You Sleep?

Now we know, thanks to a Boston University sleep research study published in the journal Science. The results underline how vital sleep is for keeping our brains healthy, actually clearing toxins from our brains while we sleep. This new research may help provide new avenues for treating (and preventing) neurodegenerative brain diseases like Alzheimer’s.

What the study focused on:

  • When we sleep, our brains go through several unique phases, from a light slumber to a deep REM (rapid eye movement) sleep.
  • The Boston University study focused on non-REM sleep, that deep phase which happens earlier in the night and has been associated with memory retention.
  • Scientists knew from a 2013 study on mice that toxins like beta amyloid, which can contribute to Alzheimer’s disease, were swept away during this sleep stage.
  • Boston University researchers were curious how those toxins were cleared out and why that process only happened during sleep.
  • Researchers suspected that cerebrospinal fluid, a clear, water-like liquid that flows around the brain, might be involved, but didn’t understand why sleep was required to make the detox happen.

How the study worked:

There were several hurdles to navigate past. Study participants had to be able to fall asleep inside an MRI machine – no small task! Then, in order to get realistic sleep cycles, researchers had to run the tests at midnight, asking that subjects stay up late the night before so they would be sleepy enough to drift off once the test began.

  • Participants were outfitted with an EEG cap so researchers could look at naturally occurring electrical currents flowing through their brains during sleep. These currents showed which stage of sleep the person was in while the MRI measured blood oxygen levels in their brains and how much cerebrospinal fluid was flowing.
  • What researchers discovered was that during non-REM sleep, large, slow waves of cerebrospinal fluid were washing over the brain. The EEG readings showed that during non-REM sleep, neurons start to synchronize, turning on and off at the same time. Because the neurons stopped firing in unison, they didn’t need as much oxygen, which meant less blood would flow to the brain. The team then observed that cerebrospinal fluid would then rush in, filling in the (blood flow) space left behind.

Maiken Nedergaard, the neuroscientist at the University of Rochester who led the 2013 study that described how sleep can clear out brain toxins in mice said, “I don’t think anybody in their wildest fantasy has really shown that the brain’s electrical activity is moving fluid. So (this new study) is really exciting.”

“We know that the function of sleep is not just to relax,” says Leanne O’Neil of INDY Neurofeedback, “but is actually a very important brain health function. Since our neurons don’t all turn off at the same time when we’re awake, sleep is the only time brain blood levels allow waves of cerebrospinal fluid to circulate around the brain and clear out any metabolic byproducts that accumulate, like beta amyloid.”

What does this mean for treating Alzheimer’s?

Instead of targeting medications that act on one particular molecule (like beta amyloid) in the brain, new treatments might focus on increasing the amount of cerebrospinal fluid that washes over the brain. After all, brain aging is not just about just one type of toxin, but many.

The brain is endlessly fascinating, says O’Neil, and there is much to learn and put to good use in maximizing brain efficiency, dexterity, and high functioning. That’s why we are excited about our anti-aging protocol and all we do here at INDY Neurofeedback.

Daily Digital Life and Brain Health: Finding a Healthy Balance

Digital devices, television screens, computer screens, tablets, laptops, cell phones, LED screens… Most of us spend more time staring at a digital screen than we realize. In fact, studies suggest that 60% of people spend more than 6 hours a day staring at some kind of digital device.

“It’s not actually the device that is the problem,” explains Leanne O’Neil, Owner of INDY Neurofeedback, “it’s the artificial blue light coming from the device.” Blue light is one of the shortest, highest-energy wavelengths (the shorter the wavelength; the higher the energy.) Because they are shorter, these blue or High Energy Visible (HEV) wavelengths flicker more easily than longer, weaker wavelengths. This kind of flickering creates a glare that can reduce visual contrast and affect sharpness and clarity.

This flickering and glaring may be one reason for the eyestrain, headaches, physical and mental fatigue caused by many hours sitting in front of a computer screen or other electronic device.

Studies suggest that, over time, exposure to the higher energy of blue light may cause serious long-term damage to your eyes — and your brain.

Harmful effects include:

  • Disruptions of the natural circadian rhythm and sleep
  • Blurry vision, difficulty focusing, dry and irritated eyes, headaches, and age-related macular degeneration
  • Greater risk of certain cancers
  • Increased risk of depression

There’s growing medical evidence that blue light exposure may cause permanent eye damage, contribute to the destruction of the cells in the center of the retina, and play a role in causing age-related macular degeneration, which can lead to vision loss. It also negatively affects the brain.

What happens to your brain on blue light? Researchers have suggested that there is a specific neural pathway from the eyes to the brain—separate from how vision is transmitted—that ultimately causes blue light wavelengths to worsen headache pain and other symptoms. Overexposure to blue light can lead to intense headaches, a greater perception of pain and throbbing and even enhanced spreading of headache pain across the brain. Intense headaches can also include aura symptoms, photophobia and light sensitivity, dizziness/nausea, and more.

What can you do to protect yourself? Here are some ways that you can minimize the damaging effects of blue light:

  • Try “blue blocker” (blue-light) filtering glasses.
  • Warm the light settings on your devices by switching to “night mode” to make it easier on your eyes.
  • Turn your phone or computer off at least 2-3 hours before you go to bed.
  • Change your light bulbs to warmer tones and colors. Opt for more natural light if possible and avoid/remove fluorescents, if appropriate.
  • Give your eyes a break.Look away from your screen at least once every 20 minutes to let your eyes reset.

At INDY Neurofeedback, we know that keeping your brain in peak condition requires attention to diet, exercise, sleep, and yes – even what your eyes do during your waking hours. Here’s to your overall health!

What your brain does while you sleep

Scientists and our INDY Neurofeedback team know that our brains do an amazing amount of important work while we sleep. We also know that sleeping is an integral part of our life.

However, a thorough understanding of sleep as it pertains to our overall health is still not entirely known, largely because its functions are incredibly complex.

Here’s what we do know about the function of sleep, according to Scientific American magazine:

  • Sleep reenergizes the body’s cells
  • Clears waste from the brain
  • Supports learning and memory
  • Regulates mood, appetite and even the libido

As we fall asleep, our brains don’t shut down. Instead, they prepare to generate sleep in two distinct stages. The first phase, SWS, is slow-wave sleep.

“Most of our sleep is SWS,” says Leanne O’Neil of INDY Neurofeedback. “SWS shows up on our brain scans as large, slow brain waves. This makes sense, as a sleeping body is relaxed. Breathing is slow and rhythmic. This probably helps our brain and body to recover after all we process during our busy days.”

After the SWS stage, the brain activates REM (rapid eye movement) sleep. The purpose of REM sleep remains a puzzle, despite our growing understanding of its biochemistry and neurobiology.

“Through brain scans,” continues O’Neil, “we know that a dreamer’s brain is highly active, while in contrast, our body’s muscles are paralyzed. (This is why we feel we cannot move away from perceived danger when we have a nightmare.) Our body’s breathing and heart rate are often erratic, too.”

Scientists and neurofeedback specialists now know that a small group of cells in the brain stem controls REM sleep. Interestingly, when these cells become injured or diseased, dreamers often don’t experience REM muscle paralysis, which can lead to a serious REM sleep behavior disorder where individuals sleepwalk or act out their dreams, often violently.

Understanding the complex relationship between sleep and the brain is fascinating, especially to us at INDY Neurofeedback. That’s precisely why we do the work we do – helping our clients optimize their brain function to improve their overall health.


– the INDY Neurofeedback team