Why Do Some of Us Sleep More Soundly?

It’s a mystery you may have never thought about: Why does it seem like some people can sleep through just about anything, while others wake up when a feather drops on the floor next to them?  A new article this week from Healthday talks about research that’s trying to answer that question.

Dr. Jeffrey Ellenbogen, chief of the division of sleep medicine at Massachusetts General Hospital and assistant professor of neurology at Harvard Medical School, is leading the study.  He says the reason has something to do with the differences in people’s brain rhythms.

From the Healthday article:

Reporting in the Aug. 10 issue of Current Biology, Ellenbogen and his colleagues studied how sensitivity to noise during sleep is associated with a type of brain activity called sleep “spindles” — bursts of fast brain rhythms that punctuate the otherwise slow-wave patterns characteristic of sleep.

To see if spindles might shield the brain from sound in the environment, the researchers first measured spindle production in the brains of 12 healthy adult volunteers during a quiet night of sleep. On the next two nights, they evaluated the volunteers’ sleep behavior in the presence of noises like road and air traffic or a ringing telephone.

The researchers found that people with higher rates of spindle rhythms were consistently less likely to awake in response to these noises.

Read more of the Healthday article at the Businessweek website.