This article from Science News Daily uses the lovely phrase “sleep fragility” to describe the unlovely phenomenon of sleep that is vulnerable to disruption. Researchers examined subtle changes in the brain’s alpha rhythm and found that these changes are a good indicator of times when sleep is more likely to be interrupted by noises or other stimuli from the outside world.
Alpha waves appear in electroencephalograms (EEGs) or magnetoencephalograms (MEGs) and are typically associated with wakeful relaxation. However, they also occur during sleep, although they aren’t visible to the eye in an EEG but must be revealed by mathematical analysis. In the study described in Science News Daily, sleeping volunteers were exposed to typical background sounds that can interrupt sleep; the sounds were repeated at increasing volume until their sleep was disrupted, as indicated by their EEGs. When alpha wave activity was stronger, their sleep was disturbed by quieter sounds. In other words, the alpha wave activity was correlated with more fragile sleep.
Sometimes I’m apt to drift up to the surface of sleep; it feels just like that, like something in my mind is too light and restless to stay submerged, and I keep floating to the surface. It’s not a whole lot of fun, but I like knowing a little more about what electrical activity is likely to be going on in my brain when it happens. (I wish I knew why, though!) And the researchers who have done this work say that it could be the first step toward finding ways to apply sleeping medications or other treatments that would kick in only when sleep is most fragile, rather than knocking the brain out entirely for the whole night. (I like the word “sledgehammer” that one of the scientists uses to describe sleeping pills; that’s one reason I’m generally reluctant to use them, because I don’t like to sedate my brain to that degree.)
The research is reported in Covert Waking Brain Activity Reveals Instantaneous Sleep Depth, by Scott M. McKinney et al. PLOS One 6(3), e17351, 2011.
Thanks for sharing this. I am hesitant to use sleep-enhancing pills for the reason you mentioned and some others. And like I’ve mentioned before, my problem is more in the staying asleep realm than falling asleep so melatonin (for example) does not seem to help.
But thank god for the biomechanics mechanism that does wake me so I can deal with the side affects of benign prostatic hypertrophy. Or was it the bottle of wine with dinner?
I sometimes have the same experience, and I have no prostate, so for me I know it’s the wine. 🙂