Why do we dream?
Why do we dream?
Melbourne: Scientists may have finally uncovered why we dream – it could be
a crucial tool for sorting and filing information and discarding mental
trash, says an Australian researcher.
“One theory is that it’s a way of allowing your brain to recover and
consolidate all the memories and activities of the previous day, like filing
time,” The Daily Telegraph quoted Prof Drew Dawson from the Centre For Sleep
Research at the University of South Australia, as saying.
He added: “If we give someone a complex new task to learn and we let them
sleep but don’t let them dream, they’re almost as bad the next day as if
they didn’t sleep at all.”
Many people mistakenly believe “dream sleep”, or rapid eye movement (REM)
sleep, is the deepest stage of sleep.
According to Prof Dawson, humans were more deeply asleep prior to dreams.
The average sleeper went through several sleep cycles a night, each lasting
about two hours and finishing with REM.
Prof Dawson said: “Your brainwaves while you’re dreaming actually look very
similar to your brainwaves when you are awake.”
This has led some scientists to theorise that dreaming is an evolutionary
survival mechanism, which helps keep our brain alert.
Prof Dawson said: “It might prevent you getting so deeply asleep that you
would be vulnerable if you needed to wake up quickly.”
Brainwave tests on animals demonstrate all mammals dream, however, whether
dogs and cats and other species actually have visual dreams is impossible to
know.
Prof Dawson said: “It’s reasonable to think they probably do, but we don’t
know for sure.”
Sleep and fatigue expert Dr Stuart Baulk believes humans were essentially
paralysed when they entered dream sleep, with muscle tone changing to
prevent the body moving around.
Occasionally, some people experienced “sleep paralysis”, where they woke and
were fully conscious but still paralysed and seeing dreamlike images.
Dr Baulk said: “Although you see the room around you like normal, you might
still get the images from a dream.”
