By Cesca Anderson

A dream can sometimes feel incredibly real – as if the sensations experienced are actually happening – but when we wake up to everyday reality, we cannot make sense of anything and wonder what it all meant.

Most dream analysts believe that dreams are not meaningless, but littered with messages from our unconscious. They are inner communications that if heeded, have the potential to set us on the road to a richer, more fulfilling path in life. Sadly many of us forget our dreams upon waking and this is a great loss. According to the Talmud: ‘A dream which is not interpreted is like a letter which is not read.’

Dreams tantalize us with their mystery. What are they? Why do we have them? Where do they come from? What do they mean? Are they a preview of things to come, or a glimpse of the past? Are they a vital link to our inner world: a gift from our intuition? Can dreams lead us to important insights into our waking life, and help us decide which action to take and which path to follow?

The hows, whys and whats of sleep and dreams

Sleep is absolutely crucial for our physical, mental and emotional health and wellbeing. It is during sleep that we abandon conscious control of our physical body and the unconscious mind is allowed to roam free, giving rise to dreams.

Although we now know a lot more about dreams, their real purpose isn’t yet fully understood. It wasn’t until we approached the middle of the twentieth century, with the first electronic monitoring of the brain, that we began to get a clearer idea of the nocturnal adventures of the mind. For centuries it was thought that the purpose of sleep was to rest the body and the mind, but this reasoning was disproved when it was shown that both the body and the mind are active during sleep. If sleep doesn’t rest the body or mind, then what is it for?
Sleep researchers may not yet have discovered the real reason for sleep or dreams, but they have discovered some fascinating things. For example, it seems that when we are asleep, our brains are a bit like computers that are offline. This means that they are not idle, but are filing and updating the day’s activities. They take stock of your body and release growth hormone to repair damaged tissues and stimulate growth, while the immune system gets to work on attacking any viral or bacterial infections that may be present. Some experts believe that the brain jettisons trivial information during sleep to prevent it becoming overburdened with unimportant information, but this explanation is perhaps too simplistic, as no memory can be totally eradicated.
The advent of space travel gave scientists the opportunity to prove that resting the body was not the main function of sleep. What they found instead was that prolonged periods of isolation decreased the need for sleep. In other words, the fewer stimuli received from other people or external contacts during the day, the less sleep was required. It seems we have a sleep control centre at the base of our brain linked with activity and wakefulness. When that gets overloaded we get tired, but if there has not been enough stimuli from the outside world, the sleep mechanism isn’t triggered. It seems therefore that boredom and lack of stimuli may account for many cases of insomnia. (Paradoxically, over stimulation also produces insomnia.)

The four stages of sleep

Perhaps the best way to understand sleep and dreams is to understand the brain. At the very start of the twentieth century it was found that the brain gives off electrical impulses, and by the 1920’s scientists could measure brain waves, to obtain these readings, electrodes were attached to various parts of the head, and then the impulses being transformed onto electroencephalograms (EEC’s) on computer screens.
It seems that once you settle down to bed, your brain and body undergo radical changes from their waking state. The difference between being asleep and being awake is the loss of conscious awareness, and once you start to doze, dream researchers believe that you progress through four stages of sleep. These form the basis of a cycle that repeats four to five times every eight hours of sleep.

During the first stage, your body and mind become relaxed. Heart and breathing rate slow down, blood pressure lowers, body temperature drops slightly and the eyes roll from side to side. You are neither fully conscious, nor fully unconscious, and could easily awake if disturbed. This stage of gradually falling asleep is called the hypnagogic state (the hypnopompic state is a similar state when you are just waking up) and you may experience hallucinations that float before your eyes.

In stage two, breathing and heart rate become even slower, eyes begin to roll and you become more and more unaware of the noises of the outside world. It isn’t until the third stage of sleep however that you are sleeping soundly and it would be difficult to wake you. Finally you enter a deep sleep state known as non-rapid eye movement (NREM) when you brain is released from the demands of the conscious mind. It will now be quite hard to wake you and, although you may sleep walk or have night terrors, you will rarely be able to remember them. This slow-wave sleep cycle lasts about ninety minutes. At the end of stage four, you move back through stages three, two and one, at which point you enter a phase known as rapid eye movement, or REM sleep.

REM Sleep

REM sleep is recognised by tiny twitches of facial muscles and slight movements of the hands. Blood pressure rises, breathing and heartbeat become faster, eyes dart rapidly around the under closed eyelids as if looking at a moving object. Researchers have discovered that when sleepers are awakened during REM sleep they typically say that they have been dreaming.

Most of the dreams you remember occur during the REM stage when the brain is fully active. After about ten minutes of REM you enter stages two, three and four again, and keep moving backwards and forwards through the sleep cycle. As the cycle continues however, the REM phase gets longer and longer with the longest phase being around thirty to forty five minutes. Of all your dreams during all the stages of REM and NREM (as it has recently been discovered that we dream then too), the final REM stages are the ones you are most likely to remember.

Research on sleep deprived animals shows that sleep is necessary for survival. For example, whilst rats normally live for two to three years, those deprived of REM sleep survive only about five weeks on average, and rats deprived of all sleep stages live only about three weeks. Other studies have shown that subjects repeatedly awoken during REM – which means they were deprived of dreams – become anxious, bad tempered and irritable. This suggests that sleep is vital for physical rest and repair, and REM sleep, when we are most likely to dream, is essential for our emotional wellbeing. Therefore while we still aren’t’ sure about the why’s, what’s and how's of sleep and dreams, it is possible to conclude that the reason we sleep is to dream.

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