A dream is not reality.
But who’s to say which is which?
Disney’s Alice Through the Looking Glass (2016)
The world of dreams has both captivated and mystified humanity since time immemorial. But whilst the private nature of dreams makes objective analysis difficult, there has been no shortage of scientific study into their origin and purpose. Modern-day neuroscientific research suggests that understanding the science of dreaming could provide major insights into the study of human consciousness.
So, what are dreams? Why do we dream? These are difficult questions to answer. Many think that dreaming only happens during REM sleep (a state distinguished by rapid eye movement and full body paralysis), but studies have shown that dreaming also occurs during nREM (non rapid-eye-movement) sleep and that the nature of our dreams varies according to the sleep stage in which they occur. Dreams during nREM sleep are typically thought-like, fragmented and relate to current daily concerns -- unlike the vivid and hallucinatory content of REM dreams, which follow loose and bizarre narratives and are characterised by high vividness and emotional load.
"...the study of dream content...has the potential to improve our understanding of psychiatric disorders."
It is well-known that REM sleep plays a pivotal role in the processing of emotional waking-life experiences, but whilst it is widely accepted that dreams serve an important function, there are many different theories as to what this function is.
One theory – the threat simulation hypothesis – suggests that dreams create a virtual reality-like simulation which allows us to rehearse threatening simulations and practice our responses. This may provide an evolutionary advantage, preparing us for potential future dangers.
Alternatively, there is evidence that dreams could help to regulate long term mood: one theory considers that the function of dreams is to help us solve daily concerns and recover after trauma exposure. The bizarre and emotional narratives of our REM sleep, laden with symbolism, may allow us to overcome trauma or everyday psychological stressors within the safety of our subconscious. A recent study seems to support this theory: divorced women who dreamed about their ex-husbands more often were better adapted to the divorce, suggesting that perhaps that it isn’t time that heals all wounds, but dreaming.
Curiously, dreams also may have the ability to influence our physiological state, with one study showing that individuals who dreamt of drinking water felt less thirsty after they woke up.
Whilst research into why we dream is important, understanding the content of our dreams, looking at what we actually dream about, could have even greater promise for neuroscientific research: the potential to reveal things about our subconscious. Freud once said that “it is only after seeing man at his unconscious, revealed by his dreams, (he) presents him(self) to us (so) that we shall understand him fully.”
"Dreaming can show us first-hand how the notion of a sense of self arises in our brains, and how vulnerable this notion is to disruption."
As dreams are created entirely and exclusively from within the brain, dreaming is said to reveal consciousness in a ‘very special, pure and isolated form’. Although online dream dictionaries are generally considered a pseudoscience, neuroscientific research shows that the study of dream content is not only invaluable in understanding human consciousness but also has the potential to improve our understanding of psychiatric disorders.
Fascinatingly, there is a multitude of evidence that dreaming during REM sleep is an experience similar to the psychotic symptoms of schizophrenia e.g. vivid imagery that is generated within our own minds and a diminished capacity to recognise the internal origin of these experiences. During psychosis, this inability to recognise the internal origin persists no matter how bizarre the hallucinations may seem to an outsider. A similar thing happens when we dream: we uncritically accept the random twists and turns of our dreams without doubting the nature of our experiences. Interestingly, psychotic patients are less likely to describe their dreams as being bizarre because their dream bizarreness largely overlaps with their hallucinatory experiences whilst awake.
Dreaming can show us first-hand how the notion of a sense of self arises in our brains, and how vulnerable this notion is to disruption. Some people are able to lucid dream, which is a rare ability to self-reflect within a dream, realise you are dreaming and subsequently control the events of your dream.
"Research suggests that if...whilst lucid dreaming,...[we].. insert bizarre items into the narrative of those events, it may defuse the emotion of the traumatic memories."
The premise behind Christopher Nolan's 2020 release, 'INCEPTION', took lucid dreaming to imaginative lengths. Photo: Warner Bros.
Some may think of lucid dreaming as a convenient way to have dinner with their favourite celebrity, but scientific research shows it to have great potential in helping us to understand those patients who can't recognise their own delusion. Lucid dreaming is the antithesis of psychosis; if psychosis can be considered being in a dream-state whilst awake, lucid dreaming is being awake whilst in a dream. This means that determining what happens in the brain during the period of ‘self-reflection’ that occurs whilst lucid dreaming could have huge potential in understanding individuals with psychosis, by shedding light on the mechanisms that underlie the lack of self-reflection into their own delusional state
The benefits of lucid dreaming do not end there. It is thought that psychotherapies focusing on inducing lucid dreams could be an effective way of treating patients with recurrent nightmares, such as those with Post-Traumatic Stress Disorder (PTSD), a disorder characterised by the involuntary re-experiencing of traumatic memories in flashbacks and recurrent nightmares. Research suggests that if we re-experience traumatic memories whilst lucid dreaming, and insert bizarre items into the narrative of those events, it may defuse the emotion of the traumatic memories. Imagery rehearsal treatment (IRT) – a cognitive-behavioural technique where nightmare sufferers are trained to repeat their nightmares and create a less frightening ending – has shown to be effective in reducing chronic nightmares within 6–12 weeks of treatment.
Dreams are essential for our cognitive health, whatever their exact function. When dreaming is disrupted, as happens with certain sleep disorders, our neurological health can suffer. Research presented at the Canadian Association for Neuroscience in 201714 suggested that REM sleep disorders may predict the development of neurological diseases such as dementia and Parkinson’s disease as far as 15 years in advance.
The study of dreaming is crucial in order to fully understand human consciousness. However, despite a recent upsurge in scientific interest, many fundamental questions on how and why we dream remain unanswered. For the most part, the world of dreaming still remains a mystery. What we know for certain is that dreaming is essential for both our mental health and physical health.
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