Scientists Discover Why Some Sleep Well & Others Don't

Don't we all love our sleep?  It's so utterly cleansing... if we are lucky.  But some of us don't sleep well or not long enough for sleep to "knit up the ravell'd sleeve of care.*"  Sleep researchers at five institutions looked to brain activity in this study of the secrets of a good night's sleep.

Specifically, what they studied was the relationship of noise sensitivity to sleep. During sleep, sensory input is modulated through spontaneous signals from our brain's thalamus to the cortex. 


The Brain: Image from TheBrain.mcgill.caThe Brain: Image from


These signals can be measured by EEG (electroencephalogram) readings and they show up as bursts of brain activity called spindles.

Studying the sleep patterns of 12 healthy adults during one full night of sleep, the team of researchers representing Harvard Medical School, Massachusetts General Hospital, University of Liege (Belgiium), Brigham and Women's Hospital, and the Cambridge Health Alliance established the rate per minute of spindle activity for each volunteer during stages 2 and 3 of Non-REM sleep.  During this first night of observation, quiet was maintained in the sleep labs.

During the following two nights, the researchers introduced noises that commonly occur during sleep, like air and road traffic and ringing telephones.  In response to these noises, those who had higher spindle rates under quiet conditions, were less likely to be aroused from sleep by the intermittent noises. Those with normally lower spindle rates, were more likely to have their sleep interrupted when noises were introduced.


 Spontaneous spindle detection: © Current BiologySpontaneous spindle detection: © Current Biology


While the researchers involved in this study, Spontaneous brain rhythms predict sleep stability in the face of noise, published in Current Biology, learned that the frequency of spindle activity was significant to a good night's sleep, no one seems to know how to increase that activity with intervention.

Perhaps, though, the spindle findings will lead to behavioural or pharmaceutical interventions that can help more of us just experience a good night's sleep!

*Macbeth, Act 2, Scene 2
Current Biology
via Business Week




Jan 4, 2011
by Anonymous


Since when is the British spelling of Behavioral used in America? Since spell check corrects it that way? If so it is a bastardization of American English and needs to be abolished. What ever happened to proof reading? What in the hell is this world coming to?

Jan 29, 2011
by Anonymous

Only 12 subjects? This is not a valid study.

To run a proper study, more subjects are needed (usually a minimum of 30, but more is always better). Although this research is interesting and the conclusion that a quieter sleep environment is more beneficial is likely correct, all they can really do is build a good case for additional study.

Feb 17, 2011
by Anonymous


This is so easily solved. Earplugs.

I've been using them for years now and I've slept well ever since.

Feb 18, 2011
by Anonymous

sounds easy

find out the history of the subjects.
do they live in noisy areas or noisy homes? Do they have to force their brain to accept outside input because they know it's the only way to get a good night's sleep? I bet people with higher spindle rates are accustomed to noise when they lay down to go to sleep. People with lower spindle rates probably have more control, maybe turn off appliances, live alone, or in a quiet neighborhood... think about it.