All human beings sleep – but it’s not always simply a case of nodding off, having a dream and then waking up.
In fact, research has shown that many of us have experienced some kind of unusual ‘dream phenomena’.
While some of these can make our dreams seem comforting or even exciting, others are downright terrifying.
From sleep paralysis, false awakenings and lucid dreams, one sleep expert has helped patients overcome and control many of them.
Jane Teresa Anderson, a dream analyst and neurobiologist based in Tasmania, Australia, says dreams ‘reflect common life themes’.
‘Dreams reflect waking life but take us deeper, revealing the unconscious side of our daytime experiences,’ she said.
‘They tend to feature a problem or challenge that is not overcome.’
It comes shortly after scientists revealed the grisly truth about what happens if you die in a dream.
Sleep paralysis is when you cannot move or speak as you are waking up, often combined with distressing hallucinations of a terrifying figure holding you down
SLEEP PARALYSIS
Perhaps the most famous – and terrifying – of sleep phenomena is sleep paralysis, which affects just 7.6 per cent of people.
Sleep paralysis is when you cannot move or speak as you are waking up, often combined with distressing hallucinations of a terrifying figure holding you down.
It occurs at a specific stage in the sleep cycle called REM – where the eyes move rapidly while closed and the body shuts down muscle control.
‘As you enter sleep, your brain switches on a mechanism that inhibits your motor muscles from moving much apart from the odd twitch, preventing you from getting up and acting out your dreams,’ Anderson explains.
‘When you wake up suddenly, usually from a scary dream, or a noise in the room, or your alarm going off while you are deeply asleep, there can sometimes be a lag between your mind waking up and your body shaking off the sleep paralysis.
‘So, you can find yourself partially alert but unable to move your body and, naturally, this can feel terrifying if you don’t understand what’s happening.’
Sufferers often report the accompanying sense of pressure on the chest and a vision of someone holding them down – perhaps a person, a ghost or demon.
‘The Nightmare’ by Swiss artist Henry Fuseli (1781) is thought to be a depiction of sleep paralysis in a young woman perceived as a demonic visitation
In humans, sleep is generally separated into ‘non rapid eye movement’ or NREM sleep and rapid eye movement or REM sleep. A typical night’s sleep goes back and forth between the stages
Aside from great emotional stress, the body can then enter ‘a state of physiological fear’, according to Anderson.
‘Given your likely interpretation that there’s an evil intruder in the room, or that you’re trapped, panic can ensue and breathing can become laboured,’ she said.
Sleep paralysis has been linked with insomnia, jetlag, PTSD and narcolepsy – a long-term condition that causes a person to suddenly fall asleep.
HYPNAGOGIC VISIONS
Hypnagogic visions are the freaky hallucinations that flit through the brain during the transition from wakefulness and sleep.
Anderson says hypnagogic hallucinations are ‘not quite dreams’ because they occur when we’re still awake, albeit just about to fall asleep.
Often taking the form of images, patterns and even bright lights or perceived sounds, hypnagogic hallucinations usually the first sign that we’re nodding off.
When we’ve been trying to doze off for hours, the arrival of hypnagogic visions can be a huge relief because it shows sleep is finally coming.
Hypnagogic hallucinations are ‘not quite dreams’ because they occur when we’re still awake but nearing sleep. Artists have used this psychedelic ‘twilight zone’ as inspiration
Artists have used this psychedelic ‘twilight zone’ as inspiration, including Paul McCartney who took the concept of a yellow submarine from the hypnagogic state.
McCartney said in 1994: ‘I remember lying in bed one night, in that moment before you’re falling asleep – that little twilight moment when a silly idea comes into your head – and thinking of ‘yellow Submarine, we all live in a yellow submarine’.
Researchers aren’t sure what causes hypnagogic hallucinations but say they are neurologically similar to both daytime hallucinations and dreams.
HYPNOPOMPIC VISIONS
Similarly, hypnopompic visions are the illusions we experience when we have opened our eyes but are still to properly wake up.
Our brain is not quite engaged with the waking world and a result we often conclude that we’re seeing ghosts or spirits in the room, according to Anderson.
‘We wake up or open our eyes while still dreaming and “see” (experience) our dream images projected onto our bedroom or wherever we are sleeping,’ she said.
Younger children are often terrified and scream and cry with these episodes, which can be mistaken and misdiagnosed as night terrors, nightmares, or panic attacks.
Hypnopompic visions are the illusions we experience when we are waking up. Even though our eyes are open, our brain is not quite engaged with the waking world
Hypnopompic visions (while waking with eyes open) are said to be less common than hypnagogic visions (falling asleep with eyes closed).
LUCID DREAMS
For most of us, when we are dreaming our brain perceives it as reality, just as it does with the real world when we are awake.
But about one fifth of people are gifted with lucid dreams – the experience of knowing that we are dreaming.
This state of ‘heightened awareness’ lets lucid dreamers control what happens within the dream and willingly go on exciting trips in impossible worlds.
The difference between normal dreaming and lucid dreaming is like the contrast between watching a film at the cinema and living the scenario for real.
Depicted in films such as ‘Inception’, lucid dreaming could provide a useful link between the real world and the dream world.
Anderson said she has had lucid dreams, once of which involved ‘fearless flying acrobatics, soaking up the sensations of superb ease and weightlessness’.
‘When I do I usually have a stronger sense of being in two realities at the same time, in the dream, and also in my bed,’ she said.
In Christopher Nolan’s classic action film Inception, characters consciously navigate through impossible dream worlds (pictured)
Lucid dreams let more have more enjoyable ‘trips’ or psychedelic adventures when they go to sleep (depicted here by an AI)
‘Lucid dreaming, in whatever form, at heart, helps us to become more consciously aware of the illusory nature of whatever seems to be our reality.’
PARASOMNIAS
Parasomnias refer to the physical displays that our body performs while our brain is still asleep – sleepwalking being the most famous.
They tend to occur during the deeper stages of non-REM sleep when we are not paralysed and hence we’re able to move about.
Some of the most bizarre parasomnias include talking, moving hands, laughing or crying, and aggressive movements like hitting and kicking.
But according to recent research, there’s also eating, driving and ‘sexsomnia’ – unintentionally initiating sex during sleep – which is said to mostly affect men.
Often, those who experience the disorder wake up during sexual intercourse and feel confusion about how it started.
It can also throw up issues regarding consent, which can land people in criminal courts.
Unintentionally having sex during sleep, (sexsomnia, a type of parasomnia) may be related to external factors such as stress and alcohol
FALSE AWAKENINGS
False awakenings, which also usually occur during the REM stage, are when we think that we have woken up but are actually just dreaming it.
Following the false awakening, we can even dream that we’re performing our daily morning routines such as showering, cleaning, eating and using the toilet.
It’s almost the opposite of sleepwalking, where our brain is still in sleep mode but our body is out of bed and active.
Although they’re not thought to be dangerous, false awakenings can cause confusion when we eventually do wake up in real life.
SHARED DREAMING
Shared or ‘twin’ dreaming is when two people share similar or even identical dreams in the same night, even at approximately the same time.
In their dream, Person A may experience an event in a certain setting while also witnessing a friend or family member there (person B).
In turn, person B may have the same dream setting with person A there too – similar to the shared scenarios portrayed in ‘Inception’, directed by Christopher Nolan.
While still a very mysterious and little-understood dream phenomena, shared dreaming is thought to stem from shared experiences in real life.
But it’s also said that identical or non-identical twins may be especially prone to shared dreams, due to their biological closeness.
According to Anderson, shared dreaming ‘adds a touch of spookiness’ but there’s usually a rational explanation.
‘Before looking for spookier explanations for your shared dreams, think about which waking life experiences you both shared,’ she said.
‘Explore how your slightly differently detailed dreams might reflect your slightly different perspectives on the situation.’
