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.
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.
Compiled by Mari Hudson and Elise-Marie Tancred