Dreams are defined as images, experiences and thoughts people experience while asleep. There have been many attempts at providing an explanation as to why we dream, theories have been proposed since the 18th century. Some of these potential explanations include: consolidating and processing information, a representation of unconcious desires and wishes, to aid memory, preparation for future threats and to process emotions.

 

How does sleep work?

To truly understand how dreams work you need to understand the cycle of sleep we all experience. Sleep is cyclical and occurs in four stages; NREM taking up the first 3 and REM being the fourth, taking up 20-25% of an adults sleep and occuring 90 minutes after first falling asleep. REM stands for rapid eye movement. During this stage of sleep voluntary muscles become immobilized, resulting in temporary paralysis, apart from the eye and respiratory muscles. REM is when the body processes information, creates memories and increases depleted chemicals; most importantly, it is when we dream. According to the National Sleep Foundation, each dream lasts from a few seconds to 30 minutes meaning adults dream for 2 hours of every 8 hours of sleep on average. The brain undergoes 4 to 6 cycles of sleep a night, resulting in 4-6 dreams. Dreams that occur in the last sleep cycle before you wake up are the ones you are most likely to remember.

All of this information, gathered by an EEG (electroencephalogram) recording brain activity, has been extremely useful for psychological development surrounding dreams. The knowledge of when we dream and what scientific processes occur during that time allows psychologists to stop simply theorising and instead, back up their hypotheses with physical evidence.

 

Theories developed over time

Sigmund Freud was the first psychologist to suggest that dreams may have a scientific purpose in the 18th century. Primarily believing they were to act out desires that the person was unable to fulfil in reality and then expanding his judgement to include the theory of dreams serving as a way to express guilt or conquer trauma. His overall theory of dreams was that they were manifestations of unconcious workings of the brain. Nowadays, following on from scientific developments which significantly aid the study of dreams, they have been found to be essential to your mental health. Helping us process emotions by constructing memories of them, even if the experience in your dreams aren’t real the emotion within it is. Without this processing of emotions, they all remain active and can result in increased stress and anxiety.

 

Antti Revonsuo‘s hypothesis of dreaming: Threat Simulation Theory (TST) of 2000

Found that during REM sleep the amygdala (flight or flight section of the brain) fires in similar ways as it does during a survival threat. He explains that ‘the primary function of negative dreams’ is ‘a rehearsal for similar real events’ to increase the speed of ‘threat recognition and avoidance’. To summarise, this more modern peace of evidence suggests that dreams are an evolutionary trait designed to help us practice being safe; another theory coming to light as technology improves.

 

There have also been studies investigating differences in dreams, resulting in evidence such as 80% of participants younger than 30 dream in colour in comparison to 20% of 60 year olds. There is also evidence to suggest that dream intensity and recollection decreases with age.

 

Types of dreams

During lucid dreams the dreamer has awareness of being in their dream and some control over it’s narrative as well. These dreams are often associated with metacognition, awareness and understanding of one’s own thought process. 50% of people recall having at least one lucid dream in their life and 10% report having them two or more times a month. Lucid dreaming was first recognised following a written record from Aristotle, the Greek philosopher, who described a state of awareness of his dreaming state. This then sparked more research, more recently using an EEG to record brain activity. Researchers have found that during lucid dreams the prefrontal cortex exhibits increased activity during lucid dreaming compared to standard REM sleep, the prefrontal cortex being associated with cognitive tasks such as desicion making. Lucid dreamers are often more creative and have a greater internal locus of control, meaning they are less likely to conform/obey.

Lucid dreaming can decrease nightmares as you have the ability to redirect the events of your dream towards something more pleasant and relaxing, lowering the anxiety and stress which follows the feeling of being out of control.

 

Vivid dreams are dreams that feel so real that you can recall it very clearly when you wake up. They often occur in the last cycle of sleep (before you wake up) as you are most likely to remember these dreams. Vivid dreams can be caused by many things:

• Medication (e.g. Anti-depressants)
• Sleep disorders: waking up and interrupting your sleep cycle means you’re more likely to remember your dreams (e.g. Insomnia)
• Anxiety and stress
• Pregnancy: increased hormones
• Mental health conditions
• Substance abuse

 

Nightmares are vivid disturbing dreams that often cause anxiety, they’re most common during stressful periods and after traumatic experiences. Recurring dreams are believed to be linked to unsatisfied psychological needs.

 

Conclusion

Dreams are still considered a phenomenon even though there have been many scientific explanations presented as to why we dream. Some may believe that dreams are completely meaningless and are simply disconnected thoughts and images. However, often dreams are shaped by the individual’s life and link to real emotions and experiences. There have been many theories, various options as to why we dream, taking cognitive and spiritual approaches; this article was written to help provide you with a deeper understanding of these approaches.

 

– Sarah Greenhalgh