Living Well 60+ September – October 2015 | Page 26

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SEPTEMBER/OCTOBER 2015

What Are the Benefits of
Sleep?
Memory, learning and more are
impacted by sleep
by Dr. Tom Miller, Staff Writer

Sleep is an essential part of life for
both humans and animals. Did you
know giraffes can go without sleep
for weeks, while brown bats sleep
for nearly the entire day? From the
tiny tree shrew to the most physically imposing of mammals, animals
have varying sleep patterns and
habits. Mice, canines and rats have
similar sleep patterns to humans’.
Most sleep specialists agree the
common denominator for both
animals and humans is the existence
of rapid eye movement (REM)
sleep, the sleep state associated
with dreaming. Humans and all
other mammals display the same
level of brain activity and increased
heart rate variability during REM
sleep. For example, dogs often bark
or twitch their legs during REM
sleep; platypuses make movements
imitating the process where they kill
crustacean prey before eating it; and
humans talk in their sleep.

Even without fully grasping what
sleep does, we know going without
sleep for too long makes us feel
abnormal, and getting a good night’s
sleep can make us feel ready to take
on the world. Scientists have explored the question of why we sleep
from several perspectives. They have
examined what happens when humans or other animals are deprived
of sleep. They have looked at sleep
patterns in a variety of organisms
to see if similarities or differences
among species might reveal something about sleep’s function. Despite
decades of research and many
discoveries about other aspects of
sleep, the question of why we sleep
has been difficult to answer.
Scientists have developed several
promising theories to explain why
we sleep. One of the most recent
and compelling explanations is
based on findings that sleep is correlated to changes in the structure
and organization of the brain. This
phenomenon, known as brain

plasticity, is not entirely understood,
but its connection to sleep has
several critical implications. It is
becoming clearer that sleep plays a
crucial role in brain development in
infants and young children. Human
infants spend about 13 to 14 hours
a day sleeping; about half of that
time is spent in REM sleep. A link
between sleep and brain plasticity is
becoming clearer in adults as w