Dreams occur almost exclusively
during very deep sleep or REM sleep. Scientists can still only guess why we
dream. What’s clear however is we all spend about two hours a night dreaming
even though we may remember only five per cent of our dreams.
A dream’s journey through the
brain begins in the midbrain – specifically the pons – and ends in the
cerebrum, the part of the brain where learning, organisation, memory and
thought processes occur.
Read: 5 types of nightmares
This route has caused scientists
to speculate that dreams are important for the healthy functioning of these
processes. It would also explain why REM sleep is essential for the development
of the brain in children, and why babies need so much of this type of sleep.
There are several explanations
for the intimate connection between dreams and memory, and especially the
question of why we find it so difficult to remember our dreams. Some biologists
say dreams are the brain’s way of sorting and deleting unimportant information
so it doesn’t become overwhelmed and stop working.
Dr Hugo emphasises research into
the reasons for REM sleep and dreams hasn’t yet delivered any hard scientific
facts. ‘‘We do know REM sleep and dreams are essential for memory. Without REM
sleep the electrical currents in the brain that make up our memory literally
collapse. During dreams in REM sleep the memory currents are reactivated and
more firmly fixed.’’
During dreams, Dr Hugo explains,
memory networks contact other networks, starting a chain reaction. This could
explain why, during the same dream, different themes occur that are apparently
completely unrelated. Dream events also last as long as real-life ones and are
experienced in colour.
Whether you remember your dreams
depends on which sleep phase you’re in when you wake up, he adds. If you wake
up during REM sleep you’ll remember your dream.
The fascinating world of dreams
Hypnosis may improve deep sleep
High dream recallers show more brain activity
Image: Young girl sleeping in her bed from Shutterstock
Compiled by Mari Hudson
and Elise-Marie Tancred (Reviewed January 2012)