In The Sandman, the long-awaited Netflix adaption of Neil Gaiman’s dark and cerebral comic book series, dreams and nightmares are the designs of Morpheus, the king of dreams, who rules over a realm that we spend a third of our lives in – the Dreaming. In reality, however, there is no clear explanation for why you wake up in the middle of night, drenched in sweat, after having to take yet another exam you’ve not studied for and – oh no! – where are your pants?! Instead, the nature and purposes of dreams are the topics of fierce debate.
“We know the mechanics of dreaming,” says Mark Blagrove, professor of psychology at Swansea University, who specialises in the study of sleep and dreams. “We know that you’re more likely to have a dream in REM [rapid eye movement] sleep than in non-REM sleep. We know that there’s evidence for a ‘hot zone’ near the back of the brain, which turns dreaming on and off. But despite knowing all this, we’re not clear on why it actually happens.”
One theory, says Blagrove, is that dreaming has no function. Instead, it could be epiphenomenal, the incidental by-product of the brain’s natural processes while we’re asleep. But there are many other theories that would disagree.
For example, “One theory for why we have nightmares,” explains Blagrove, “is threat simulation theory, which suggests that we simulate threats such as, say, running away from wild animals to get practice at overcoming danger.” Another is social simulation theory, which means you simulate your social world while asleep. “That is plausible,” says Blagrove, “because dreams usually have at least one more character than the dreamer themselves. There’s also often emotion in the dream, along with intentions and plots.”
The most prominent theory however is related to the evidence that during sleep, we consolidate memories, transforming recent memories into long-term ones. Blagrove cites a recent study that he conducted in which participants were taught a story. “They were then given a choice between spending the next two hours asleep or awake,” he says. “And the people who had a period of sleep had a better memory of the stories than the people who had a period of wakefulness.”
The idea, continues Blagrove, is that during sleep, dreams come from the experience of the brain consolidating memories. “So we’re dreaming of what the brain is doing,” he says. “Now, that presents two options: either the dreams are merely a by-product of the memory consolidation process, or the dreams are a necessary part of that consolidation.”
And yet, while it has not yet been proven whether dreams have an intended function, that’s not to say that they don’t provide insight into the dreamers themselves. In The Sandman, Morpheus sculpts a myriad of strange creations – such as a man with teeth for eyes – that populate the land of the Dreaming. But in our minds, says Blagrove, the array of strange images and scenarios created from dreams are not the product of a mini David Lynch, directing in our skulls, but our natural inclination to think of life through story and metaphor.
“We think metaphorically all the time,” says Blagrove. “So for example, if you’re in a relationship with somebody and you may use phrases like ‘we’re going through a bumpy patch’. Similarly, we tend to think of love in terms of being a journey. And so the idea is that we go to sleep and then these metaphors that are in the background of our waking lives, they become environments that are visible. You actually live in the metaphor and experience it. So turning over a new leaf may see you physically turning over a new leaf.”
Blagrove gives the example of the children’s author Michael Rosen, who he once interviewed about the dreams he experienced after COVID-19 led to him spending 40 days in an induced coma. “In one of the dreams he goes over a wall at Land’s End and then he realises how dangerous it is so he gets pushed back,” explains Blagrove. “He then goes through this hole to get through this wall. He’s stuck in the hole and his wife is pushing him through and these two men on the other side are pulling him.”
The dream confused Rosen, until one of Blagrove’s colleagues came up with a convincing theory. “She realised ‘ah, he’s being pulled through’’, Blagrove says. “The dream is of him pulling through from COVID.”
About our expert, Prof Mark Blagrove
Prof Mark Blagrove is a psychologist at the University of Swansea, where he researches the possible functions of sleep and of dreaming.
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