Waking brain activity persists during slumber
Making waves isn’t conducive to staying asleep, at least when the waves are a type of brain signal associated with being awake.
A type of brain activity known as an alpha wave emanates from the back of the head when a person is awake but relaxing with eyes closed. Scientists used to think that the wave was subdued and disappeared as a person fell deeper and deeper into sleep.
But the alpha wave doesn’t disappear; it just goes undercover during sleep, researchers report online March 3 in PLoS One. The covert alpha wave may help determine how deeply people sleep and how much noise is needed to rouse a sleeper.
The finding “stresses that sleep is really a dynamic process,” says Mathias Basner, a sleep researcher at the University of Pennsylvania in Philadelphia who was not involved in the study. The study shows that sleep doesn’t happen just in discrete blocks, as most charts of sleep stages would indicate. Instead, brain act