The reason we dream is a mystery that has long baffled scientists. Some researchers believe that dreaming is part of the process of encoding memories; others think it is our way of tackling unresolved real-life issues. Then, of course, there’s Freud who famously interpreted dreams as symbols of our unconscious desires.
But while experts can’t agree on a definitive answer about why we dream, most would agree that certain themes are particularly prevalent.
“Some very common dream themes include falling, flying, arriving late to something, failing an exam and being chased – for example, by wild animals, a monster, or a threatening human figure,” says Dr Josie Malinowski, a Lecturer in Psychology at the University of East London who specialises in sleep and dreams.
“For some of these common themes, it’s obvious that they are related to our waking-life worries – arriving too late and failing exams probably reflect the fact that these are things we worry about in waking life. Everyone who has been to school has been subjected to taking exams so dreaming about failing an exam seems to simply reflect worrying about that in waking life,” she tells HuffPost Lifestyle.
And this could apply, even if the narrative in question relates to something from our distant past:
“It’s interesting, though, that people continue to dream about failing an exam many years after having taken their last one, sometimes decades later. It’s possible that this dream takes on symbolic meaning later in life; maybe we dream of failing an exam when we’re stressed out, because early in life we associated stress with taking exams, so the dream represents the feeling of being stressed. Dreams do often seem to picture concretely, but not necessarily literally, the way that we’re feeling at the moment in waking life.”
Open to interpretation
Common dreams that involve things we don’t generally do in waking life, like being chased, are open to numerous interpretations.
“Some researchers think we have dreams like being chased, full of threats and fear, because one function of dreaming is to rehearse our responses to threatening situations – so if we successfully respond to a threat in a dream, then we’ll be prepared to repeat this in waking life,” says Dr Malinowski.
“A different explanation is that perhaps when we’re being chased in our dreams, it represents more of a psychological threat than a real-world physical threat, and the thing chasing us in the dream is actually a part of ourselves that we don’t want to face or engage with,” she adds.
Same dream, different person
While some dreams are fairly self-explanatory, others may have more complex layers of meaning but a dream-decoding manual won’t be able to give you the answers because exactly what that meaning is depends on the dreamer.
“If we take a symbolic interpretation of dreams, being chased could mean any number of things – if dreams are indeed symbolic, the symbols in dreams are likely to be unique to each person, so it wouldn’t be possible to say being chased means one specific thing for everyone – it would depend on the person, the way they see the world, and what’s going on in their life,” says Dr Malinowski.
Why some dreams are more vivid than others
While we know that the dreams we’re most likely to remember are those experienced during REM sleep, another question that has puzzled sleep experts for many years is why some of us only remember vague fragments of our dreams, while others recall their night-time narratives in vivid detail.
One study found that the temporo-parietal junction, an area of the brain involved in information processing, is far more active in those who tend to remember their dreams more vividly.
The researchers believe this may allow the dreamer to focus more attention on external stimuli, promoting ‘intrasleep wakefulness’, which means dreams are better encoded into the sleeper’s memory.
But even those who rarely remember their dreams can have periods of greater dream intensity and recall. And this change in response can often reveal something telling about our physical health.
Sleep deprivation: Research suggests that when we miss REM sleep one night, our body compensates by increasing it the following night. This is called REM rebound. A 2005 study published in Sleep found that losing 30 minutes of REM one night can lead to a 35 per cent REM increase the next night.
The researchers also found that dream intensity increased with REM deprivation. Subjects who were only getting about 25 minutes of REM sleep rated the quality of their dreams between nine and eight on a nine-point scale (one being dull, nine being dynamite).
Pregnancy: If you start having bizarre dreams while you’re pregnant, you’re not alone – and you’re not going mad. From dreaming about giving birth to inanimate objects to dreaming that you’ve left your baby somewhere, the weird and wonderful dreams of pregnant women have been well documented – and it’s not that surprising when you think of all those surging hormones on top of the inevitable anxieties that come with a life event of this magnitude.
Sleep apnoea: Frequent nightmares have been widely reported among those who suffer from sleep apnoea. One study found that the nightmares disappeared for 91% of patients who had treatment for their condition.
Lead researcher Ahmed S BaHammam MD said: “Apnoeic episodes cause frequent sleep interruptions. When apnoea occurs during dreaming, frequent sleep interruptions enhance dream recall. The choking attacks and the drop of oxygen during apnoeic episodes may affect the contents of the dreams, giving rise to nightmares.”