Question: why do we dream?

Nina Rzechorzek answered on 18 Jun 2019: last edited 18 Jun 2019 8:50 pm

Excellent question – this remains quite controversial and there are multiple theories that try to explain the function of dreaming. One line of thinking is that dreams are simply a by-product of rapid eye movement (REM) sleep and serve no real purpose at all. However, more recent evidence has pointed towards some key functions of dreams:
(1) To nurture our emotional and mental health. During REM sleep dreaming, key emotion and memory-related regions of the brain are reactivated, whilst a key stress chemical (noradrenaline) is shut down within our brain. This allows us to almost ‘re-live’ and therefore learn from important life events without being crippled by the emotional baggage that came with them the first time. In this way, REM sleep dreaming acts as a kind of therapy to ‘heal’ emotional wounds. This disconnection of useful information from extreme emotion fails in post-dramatic stress disorder (PTSD) where the levels of noradrenaline apparently remain abnormally high.
(2) Decoding our waking experiences – particularly to help us interpret the facial expressions of others and ‘read’ our social world – this function becomes really active as we transition into adolescence (and have to start making decisions for ourselves about how other people are feeling)
(3) To enhance our problem solving capabilities and creativity through intelligent information processing. Mendeleev’s formulation of the periodic table of elements, Mary Shelley’s vision for ‘Frankenstein’, and some of the greatest hits of The Beatles were all apparently dream-inspired! Lucid dreamers try to harness this power by controlling their dreams – but only about 20% of people can lucid dream, and the jury is out on whether this is beneficial or detrimental in the long-term.
You can find out more about the science behind sleep and dreaming in the book ‘Why We Sleep’ by Matthew Walker