Here’s some health news that could lead to a potentially big health breakthrough: light sleepers may be at the mercy of a specific brain rhythm called the “alpha rhythm.”
A team at Massachusetts General Hospital found that a brain rhythm long associated with wakefulness persists in a hidden form during sleep. And this alpha rhythm can become more intense at times, affecting someone’s ability to sleep through noise or other disturbances.
To make their discovery, a team of researchers used computerized electroencephalography (EEG) rhythms in 13 volunteers who slept for three nights in the MGH Sleep Lab. Throughout each night, the volunteers were exposed to 10 seconds of typical background noises, such as traffic or a ringing telephone. The sounds were repeated at increasingly louder levels until the EEG showed that sleep had been disrupted.
The researchers then analyzed the EEG measurements, and found that the intensity of the alpha signal predicted how easily volunteers could be disturbed at the moment the measurement was taken, with a stronger alpha signal linked to more fragile sleep.
The researchers concluded that the alpha rhythm is not just a marker of the transition between sleep and wakefulness, but also carries some valuable information about sleep stability. It could be that sleep — rather than happening in stages — actually moves along a continuum of depth. This finding paves the way toward sleep treatments in which medication or other therapies are delivered moment-to-moment, only when needed. This could protect sleep when the brain is most vulnerable, but otherwise let natural brain rhythms continue on their course.
In the future, the researchers hope to understand the factors that maintain a sound sleep in the face of noise and other nuisances.
In the meantime, if you’re one of those sleepers who wake up at the slightest noise because you potentially have an overactive alpha rhythm in your brain, give earplugs a try. It won’t be as easy for your sleep to be disrupted if you can’t hear anything that will trigger those alpha rhythms.