Why do we dream?
Throughout history, people have wondered why we dream. Does dreaming serve a purpose, or is it just the random firing of neurons in our brains?
From a scientific perspective, dreaming is probably the least well-understood aspect of sleep. While researchers can study what happens in the brain and the body while a subject is dreaming, it’s difficult to determine exactly why we dream. The ancient Greeks believed dreams could predict the future, but current theories suggest that dreams help us manage our memories and emotions.
The science of dreams
Dreams can happen during any stage of sleep, but they are more intense and vivid during REM sleep (the rapid eye movement stage). Because REM cycles are shortest after we first fall asleep and get longer through the night, our dreams are also likely to be shorter at first and longest just before waking. On average, we dream for an average of two hours across eight hours of sleep – but by the time we wake up, most of our dreams are forgotten.
Dreaming is a normal part of healthy sleep, but dreams are often very strange. Familiar places and people might look completely different. Space and time behave differently, and bizarre scenarios and imagery often play out.
It’s possible that this is a side effect of the neurotransmitters, or brain chemicals, that are more or less active when we are asleep. Dopamine, which has been linked to hallucinations, is more prominent during sleep, and may be why dreams are often surreal. On the other hand, neurotransmitters that usually keep us awake – histamine, serotonin and norepinephrine – are suppressed during REM sleep. This is why we are less aware of our surroundings.
Another thing that happens during REM sleep is the paralysis of voluntary muscle movements. This is called REM atonia, and the paralysis prevents us from acting out our dreams. It is totally normal, but some people experience a related condition called sleep paralysis. In sleep paralysis, the muscles remain paralysed for up to 10 minutes after waking. It can be a frightening experience, but it is harmless.
Theories about why we dream
One of the first people to develop a scientific theory of why we dream was psychoanalyst Sigmund Freud. Freud believed that dreams represented our repressed desires, and could be interpreted by a trained therapist.
Scientists have since moved on from Freud’s theories, but there may be some truth to his ideas. Recent research shows that we are more likely to dream about things that we are trying to ignore.
Dreams and our memories
Another popular theory about why we dream is that dreaming helps us consolidate our memories. Research has shown that sleep helps us retain information. Dreams may play a role in helping that process.
Dreams and our emotions
It’s also possible that dreams help us process our emotions. While the scenarios that play out in our dreams are not real, the emotions attached to them are very much so. Severe REM sleep deprivation has been linked with mental illness, suggesting that dreams play an important role in helping us deal with difficult emotions.
Making sense of our daily lives
Every day, our brains deal with an onslaught of information and experiences. One theory suggests that dreams help us with ‘mental housekeeping’, sorting out what we need to remember and what information can be discarded. This may also account for the random nature of dream imagery.
Preparing us for battle
The amygdala, a part of the brain associated with the survival instinct, is highly active during dream states. Evolutionary psychologists theorise that dreams are a way for our brains to simulate threats so we can practice our fight-or-flight response.
What do our dreams mean?
Countless books have been written about dream interpretation, but the meaning of dreams is probably highly personal to the individual. In times of stress, our dreams are often more vivid and we are more likely to remember them. The themes and emotions often have obvious connections with our day-to-day worries.
Researchers studying dream themes have identified 55 themes that are common across people from all backgrounds. Some of the most common dream themes include:
Being chased or pursued
Flying or falling
Sexual encounters
School and studying, or failing an exam
Being naked or inappropriately dressed
Losing teeth
Being late for something important
Finding a new room at home
Trying to complete a task
Some of these themes may be connected to experiences in waking life. However, it’s also possible that dreams don’t mean anything at all. According to the ‘activation-synthesis hypothesis’, dreams are simply the result of electrical impulses in the brain and we assign meaning to them when we wake up.
How can we make sense of our dreams?
If you’re interested in interpreting your dreams, try dream journaling. Keep a blank notebook and a pen beside your bed and write down whatever you remember from your dreams as soon as you wake up. Dreams tend to fade quickly, but you may find that you get better at remembering them with practice. Once you have a number of dream entries in your journal you can start to look for patterns and connections. If you also keep a journal of your waking life, you might start to see how your dreams relate and what your brain is trying to process.
IF YOU’RE EXPERIENCING PERSISTENT DISRUPTIONS TO YOUR SLEEP, CONSULT WITH A PHARMACIST OR TRUSTED MEDICAL PROFESSIONAL TO DISCUSS POSSIBLE SOLUTIONS.
Any advice provided in this content is of a general nature and does not take into account your objectives, health or needs. The information in this post is not intended to substitute medical advice, diagnosis or treatment and should not be exclusively relied on to diagnose or manage a medical condition. You need to consider the appropriateness of any information or general advice we give you, having regard to your personal situation, before acting on our advice or purchasing any over-the-counter sleep product.