by Simon Evans
Copyright
© 2008 BrainFit For Life
http://www.BrainFitForLife.com
A
couple of new reports came out this week addressing sleep in our culture. Everyone
knows that they feel a little cranky when they don’t get enough sleep. It’s
therefore no surprise that sleep affects your mood. What may be surprising, though,
is that scientists know very little about why that’s true.
We
understand quite a bit about why sleep disrupts your immune function, your metabolism
and your ability to learn and remember things. I have discussed each of these
in past articles. But we don’t know much about how sleep regulates mood.
An interesting new study published in Current Biology by Michael Walker, sheds
some light on this subject.
A loss of reason
A
complex brain circuit that involves both higher thinking centers and reactive
centers controls your emotions. It’s the higher thinking centers that separate
us from other animals. We have the ability (although we don’t always use
it) to evaluate our responses thoughtfully, before just reacting impulsively.
In
the new study, volunteers were either deprived of a good night’s sleep or
allowed to sleep normally. Researchers then looked at both their higher thinking
and their reactive brain centers after presenting them with some emotionally negative
images to stir their reactions.
They found that specific
reactive centers of the brain acted the same whether or not the volunteers had
slept well the night before. But certain higher thinking centers responsible for
keeping those reaction centers under control, were much less active in the sleep
deprived group.
The interpretation of this is that our ‘gut
reactions’ are not really that affected by lack of sleep (at least in this
situation) but our ability to reason and monitor those reactions is weakened,
which can have all kinds of downstream consequences.
Is
a longer workday productive?
Why is this important? Other
studies show that we are getting far less sleep today than we did a century ago
and throughout history. The advent of artificial light has extended the length
of our daily ‘productivity’, but many argue that this is actually counter-productive.
By not getting optimal sleep, we are decreasing our ability to function efficiently
the next day, and actually getting less done.
In fact, another
study just released shows exactly that. In this one, researchers, Patricia Murphy
and Scott Campbell, showed that napping is actually productive. First of all,
midday napping did not cause people to sleep less well at night, as many believe.
Second, midday napping improved performance on math, decision-making and reaction-time
tests. This increased performance was true after the nap and lasted all the way
into the next day, following the nap.
Many of us are so
busy that we steal hours from our sleep to attempt to get more done. But science
argues that we are not getting more done this way. We are actually reducing our
ability to be creative, make decisions, work efficiently and cooperate with other
people. Perhaps a little more time invested in our rest could dramatically improve
our career and personal relationships.
