Sleep often seems to be in short supply these days.
Long gone are the days when the old saw “early to bed, early to rise …” was
even close to being attainable. On the rare occasions when an early night is
possible, the novelty of the situation is such that we toss and turn until it
becomes later than usual that sleep arrives.
Sleep is not just sleep, of course. We may long for
a “deep dreamless sleep,” but that won’t regenerate us, no, dream on. The sort
of sleep when our eyes are moving rapidly under closed lids, (REM sleep), is
what we need in order to tame our amygdalae.
Just how important this is has been ably
demonstrated by van der Helm et al in a study published in the current issue of
the Journal of Current Biology (1,2). In their experiment, they showed nasty,
upsetting pictures, 150 of them, to 35 people at bedtime. Half of them were
allowed to sleep, and maybe have bad dreams, but the other half had to tough it
out without sleep.
The following day, they all had to face up to the
same set of nasty images whilst they had their heads in the big magnet of the
fMRI scanner to check out the intensity of activity of their
amygdala-hippocampus network.
The sleepers showed much less activity. Their
dreamy sleep had quieted their adrenergic neurotransmitters and got their amygdalae
back on track. (The adrenergic neurotransmitters are a large group of chemicals
like acetylcholine, dopamine and norepinephrine that play havoc with your
emotions.)
It seems that the old advice to sleep on it and
“that it’ll look better in the morning” holds true. Of course, even if it looks
better, it may not be better, but at least it’s a start.
- Van der Helm et al, J. Current Biology, doi:10.1016/j.cub.2011.10.052
- http://www.bbc.co.uk/news/health-15862384
