How sleep affects your emotions Sleeping with Science a TED series
So exactly, how does a lack of sleep
impact our emotional brain?
Why does that lack of sleep make us
so emotionally irrational
and hyperreactive?
[Sleeping with Science]
Well, several years ago,
we conducted a brain imaging study.
And we took a group of healthy adults.
And we either gave them
a full night of sleep
or we sleep-deprived them.
And then the next day,
we placed them inside an MRI scanner,
and we looked at how
their emotional brain was reacting.
And we focused on one
structure in particular,
it’s called the amygdala.
And the amygdala is one
of the centerpiece regions
for the generation
of strong emotional reactions,
including negative emotional reactions.
Now when we looked at those people
who had had a full night of sleep,
what we saw was a nice,
appropriate moderate degree
of reactivity from the amygdala.
It wasn’t as though
there was no response at all,
but it was an appropriate response.
Yet in those people
who were sleep-deprived,
that deep emotional brain center
was in fact, hyperactive.
Indeed, the amygdala
was almost 60 percent more responsive
under conditions of a lack of sleep.
But why was that the case?
And what we went on to discover,
is that there’s another
brain region that’s involved.
This brain region is called
the prefrontal cortex,
and it sits directly above your eyes.
And you can think
of the prefrontal cortex
almost like the CEO of your brain.
It’s very good at making
high-level, executive, top-down
control decisions and reactions.
In fact, it’s one of the most
evolved regions of our brain.
And one of the parts
of the brain that it controls
is this deep emotional
center, the amygdala.
Now in those people
who had had a full night of sleep,
there was a nice, strong
communication and connection
between the prefrontal cortex,
regulating that deep
emotional brain center.
But in those people
who were sleep-deprived,
that communication, that connection
between the prefrontal cortex
and that deep amygdala
emotional brain center
had essentially been severed.
And as a consequence,
the amygdala was responding
far more reactively
due to a lack of sleep.
It’s almost as though without sleep
we become all emotional accelerator pedal,
and too little regulatory control brake.
And that seems to be the reason
that we become so unbuckled
in terms of our emotional integrity
when we haven’t been sleeping well.
So that’s the bad that can happen
if I take sleep away from you.
But it turns out
that there’s something good that happens
when you get your sleep back.
And sleep, particularly
rapid eye movement sleep,
actually offers a form
of emotional first aid.
Because it’s during sleep at night
that we take these difficult
emotional experiences
that we’ve been having during the day,
and that sleep acts almost
like a nocturnal soothing balm,
taking the sharp edges off
those difficult experiences.
And so perhaps it’s not time
that heals all wounds,
it’s time during sleep that provides
that form of emotional convalescence.
So that when we come back the next day,
we’re able to cope
with those emotional memories.