Interrupted sleep. At least, that’s what
one recent study shows. We’ve long known
that sleep deprivation makes people bad-
tempered and miserable, and that insomnia
is linked to depression, but exactly why is
less certain. When volunteers slept in a lab
and reported their mood every day, some
were made to go to bed later than usual while
others had their sleep interrupted several
times. Both groups had the same total
amount of sleep but the interrupted sleepers
reported worse changes in mood.
The researchers concluded that a lack of
slow-wave sleep, which is the deepest type
of sleep, was to blame. But don’t jump to
conclusions. These interruptions may be like
being woken by a crying baby or a snoring
partner. They break into your sleep cycle
unpredictably at random times, therefore
disrupting the normal sleep pattern. But if you
regularly wake up yourself in the night you
are probably waking at the end of each cycle
and this would not have the same detrimental
effect on your slow-wave sleep. SBWhat is worse for your mood – interrupted sleep
or shortened sleep?
We’d also argue that being
hooked up to lab equipment is not
conducive to a good night’s restA branch of the trigeminal nerve
extends around the eye and down to the
nose. An ordinary sneeze is triggered
by sensory signals sent from the nose
along the trigeminal nerve. But the pain of
plucking can cause a fake sneeze signal in
nearby nerve endings. LVWhy does plucking
your eyebrows make
you sneeze?
Tears and sweat both have
approximately the same salinity, but sweat
contains oils and hormones that could irritate
the eyes. The sweat that runs into your eyes
has also run over your hair and forehead first,
so it has had plenty of opportunity to pick up
dust and grime along the way. LVWhy do sweat sting
your eyes, but tears
do not?
PHOTO: ALAMY, GETTY X2