During sleep, our brains are “cleaned.” Waves of fluid wash through the organ, collecting waste products from cells and sending them out via the circulatory system.
Scientists believe this cleaning may be central to sleep’s ability to renew our minds.
Now an Oregon-based startup has developed a headband that could enhance sleep and the cleaning that goes with it. Researchers plan to test the device on 90 people in a new $4.3 million project funded by the U.S. Department of Defense that was announced on Tuesday.
The project will also assess if the device has restorative effects on the brains of people who are awake.
The headband is the brainchild of Eugene, Ore.-based Brain Electrophysiology Laboratory (BEL) and its CEO and founder, Don Tucker, a professor emeritus of psychology at the University of Oregon. The headband can both measure electrical activity in the brain and induce it.
“We have impressive talent coordinating together,” for the project, Tucker told GeekWire, “scientists who love to study and argue about the brain.” The project includes neuroscientists at the University of Washington, Oregon Health & Science University, and other institutions.
If the project is successful, it will have implications for sleep-challenged service members and other people with sleep dysfunction, say the researchers.
Improving the brain’s cleaning function with a device “could improve the cognitive effects of acute sleep deprivation and chronic sleep restriction,” said Jeffrey Iliff, a UW professor of psychiatry and behavioral sciences and neurology, in a press release. The brain system was first observed eight years ago by Iliff and Maiken Nedergaard, at the University of Rochester in New York.
In 2013, the international journal Science called Iliff and Nedergaard’s findings one of the top 10 breakthroughs of the year. Iliff’s TED talk has been viewed more than 5 million times.
“Now we hope to see if we can use what we’ve learned to help people overcome poor or interrupted sleep and the brain dysfunction that follows,” said Iliff, who with Nedergaard dubbed the process “glymphatic clearance.”
The headband uses a process called transcranial electrical stimulation to generate slow wave activity in the brain. That’s the type of activity involved in deep sleep, when glymphatic clearance is most active.
The new study will assess if the headband improves glymphatic clearance in the brain in people who are sleeping and awake, and in people who are sleep deprived. The researchers will also measure slow wave activity and other sleep parameters and investigate the device’s effects on cognitive ability.
The use of the device during wakefulness is more “speculative,” Iliff told GeekWire in an email. That research is based on studies showing that electrical stimulation of the brain can induce glymphatic clearance in animals even when they are awake. By testing if the same effect occurs in people, the researchers will be “Essentially seeking to ‘replace’ one of the functions of sleep in people that don’t have the opportunity to sleep,” Iliff said in the email.
“The impact of enhancing clearance in the absence of sleep is potentially pretty big,” he added.
The data could also have implications for people with neurological conditions such as traumatic brain injury, Alzheimer’s disease and other dementias, said the researchers. Scientists have linked dysfunctions in the cleaning process to dementia, though research is ongoing.
Results are expected next spring from the project, which also involves researchers at Montana State University, the University of Montana, the University of North Carolina, Chapel Hill, and the University of Florida.
Tucker has been inventing devices to record and influence brain activity for decades. He previously founded the neurosciences company Electrical Geodesics, which was acquired by global company Philips in 2017 for a reported $36.7 million. Philips shut down the 60-person Eugene-based operation last year and sold its portfolio.
BEL has 30 employees and is funded privately through proceeds of the previous sale and through government grants, said Tucker. He highlighted some features of the headband for GeekWire:
- The device can assess stages of sleep using EEG recordings of brain activity. Sleep staging is done on a “nanocomputer,” and EEG data are uploaded to the BEL database in the cloud for further processing and classification. Physicians can also review the EEG data through the cloud services.
- Sleep staging enables the researchers to induce deep sleep at the right time in the sleep cycle (at the end of a stage called N2).
- Tucker and his colleagues recently published a study showing that the device induced longer periods of deep sleep in people during overnight sessions, compared to sham stimulation.
- Researchers induce deep sleep by turning on pulses of transcranial electrical stimulation that are in the wave form typical of the slow oscillations of deep sleep. “Amazingly, the brain synchronizes its activity with this externally applied current,” said Tucker, “As a result the slow oscillations are bigger – and they stay bigger and last longer even after we turn the current off.”
- The researchers are developing “brain age” assessments by classifying the person’s sleep stages. With age, people get less sleep, and that increases the risk for dementia.
- The prototype device is “very comfortable to sleep in,” said Tucker, adding, “The final product will of course be more elegant.”