KZN#32

Health
How does poor sleep affect our
ability to learn? Study investigates
A
team of researchers
from the University of
Zurich (UZH) and the
Swiss Federal Institute of Technology
(ETH) in Zurich, both in
Switzerland, set out to examine
the effect of a disturbed deep
sleep phase on the brain's ability
to learn new things.
More specifically, the new
study - published in the journal
Nature Communications - looks
at the brain's ability to change
and adapt in response to the
stimuli that it receives from the
environment, or neuroplasticity,
in the motor cortex and how it is
affected by deep sleep.
The motor cortex is the brain
area responsible for developing
and controlling motor skills,
and the deep sleep phase - also
called slow-wave sleep - is key
for memory formation and processing,
as well as for helping
the brain to restore itself after a
day of activity.
Manipulating the motor cortex
during deep sleep
The study involved six
women and seven men who
were asked to perform motoric
tasks during the day following a
night of unperturbed sleep, and
after a night during which their
deep sleep had been disturbed.
The tasks involved learning
a series of finger movements,
and the researchers were able to
locate precisely the brain area
responsible for learning movement.
Using an electroencephalogram,
the researchers monitored
the brain activity of the participants
while they were sleeping.
On the first day of the experiment
- after the first movement
learning session - the participants
were able to sleep without
disturbance.
On the second night, however,
the researchers manipulated
the participants' sleep quality.
They were able to focus on
the motor cortex and disrupt
their deep sleep, thus investigating
the impact that poor
sleep has on the neuroplasticity
involved in practicing new
movements.
The participants did not know
that their deep sleep phase had
been tampered with. To them,
the quality of their sleep was
roughly the same on both occasions.
Poor sleep keeps synapses
excited, blocks the brain's ability
to learn
Next, the researchers evaluated
the participants' ability to
learn new movements. In the
morning, the subjects' learning
performance was at its highest,
as expected.
However, as the day progressed,
they continued to make
more and more mistakes. Again,
this was expected.
After a night of restorative
sleep, the participants' learning
efficiency spiked again. But
after their night of manipulated
sleep, their learning efficiency
did not improve as significantly.
In fact, the morning after a night
of manipulated sleep, the participants'
performance was as low
as on the evening of the previous
day.
Kzn Lifestyle Magazine • Issue 32
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