Why do we dream?
Unfortunately, after years of in-depth research, we still do not have a clear answer to the questions: ‘why do we dream?’ and ‘do dreams mean anything?’
What we do know is that during REM (when most dreams occur) the amygdala, the area of the brain responsible for processing emotions, and the hippocampus, the area of the brain relating to memory, are both active.
This could explain why REM dreams have a story-like quality and why they are often emotional.
We also know that when a person is woken up immediately before they enter REM, they often experience tension, anxiety, and depression.
The years of studying sleep and dreams have led to many theories about why we dream. Let’s start with the three most popular theories.
Psychoanalytic theory (Sigmund Freud)
Psychoanalyst Sigmund Freud was amongst the first psychologists to study dreams scientifically in the early 20th century. Freud theorized that people are driven by hidden impulses which represent unconscious wishes.
Consistent with this theory, he suggested that dreams represent unconscious desires, thoughts, and motivations, after analyzing the dreams of hundreds of his patients.
Freud describes two different components of dreams: manifest content and latent content. Manifest content describes the actual images and thoughts experienced in the dream while latent content describes the hidden psychological meaning.
Freud believed that even bad dreams represent our hidden wishes in some way, and using his theory he helped many of his patients to uncover hidden emotions which they had not dealt with. His work has contributed to the popularity of dream interpretation which is still popular today.
However, his theory was based on speculation and the experiences his patients recalled rather than scientific testing. Research has failed to demonstrate that the manifest content of a dream disguises the true psychological significance.
Activation-synthesis model (J. Allan Hobson and Robert McClarley)
Whilst Freud theorized that dreams are deeply meaningful, other psychologists have suggested the complete opposite: dreams are a completely random product of processes in the brain.
The activation-synthesis model of dreaming was proposed by J. Allen Hobson and Robert McClarley in 1977.
This theory suggests that during REM sleep circuits in the brain become active which activates the limbic system (including the hippocampus and the amygdala) which is involved in learning, memory, emotions, hunger, aggression, and sex.
This leads the brain to synthesize and attempt to make sense of these signals.
Therefore, according to this theory, dreaming is simply the result of the brain interpreting internally generated signals occurring during sleep.
However, Hobson does not believe that dreams are meaningless.
He suggests that dreams are creative and could provide us with new ideas, of which a few may even be useful.
The final of the three most used dream theories is an information-processing theory.
This theory suggests that dreams occur because as we sleep our brains are processing all of the information, we have collected the previous day.
As we process memories and information, our minds create images and stories to manage all of the activity occurring inside our brains.
Continual-activation theory (Jie Zhang)
Although the above are the three most used theories of dreaming, many other theories have been proposed.
For example, psychiatrist Jie Zhang suggested continual-activation theory which proposes that our brains are always transferring short-term memories to long-term memory whether we are awake or asleep.
When we are asleep, dreams are a temporary storage area between short-term and long-term memory. They flash through our minds for just a short period of time before we file them away in long-term memory.
According to reverse-learning theory, dreams are serving a function which is to de-clutter our minds by clearing useless thoughts which have built up during the day, allowing us to refresh and prepare for the next day.
Problem-solving (Deirdre Barrett)
Harvard medical researcher Deirdre Barrett suggested that dreams help us to solve problems. Her theory is that the dreaming mind can make connections more quickly than the waking mind does.
Therefore we are able to solve problems more effectively when we are dreaming compared to when we are awake. The theory is partially based on the experiments Barrett conducted in which participants were asked to solve problems whilst ‘sleeping on them.’
The problem-solving outcomes were better for those who had more dreams.
Dreams and mental health
Changes in dreaming patterns can often be linked to psychological disorders. For example, an increase in nightmares can often occur in those suffering from most mental illnesses including depression, post-traumatic stress disorder (PTSD), schizophrenia and personality disorder.
Depression is linked to an increase in dreams involving negative emotions whilst schizophrenia is related to more dreams involving aggression and strange characters rather than familiar ones.
Individuals suffering from personality disorder tend to experience more dreams relating to distress and wake up feeling more distressed than they were before they went to bed.
They also generally experience more nightmares than anybody else, and their dreams fluctuate between good and bad more rapidly.
Psychologically-diagnosed people experiencing suicidal thoughts usually have more dreams with death themes. If you are experiencing any of these changes to dream patterns, it is important not to ignore it as it may be linked to serious mental illness.
Should you be experiencing other symptoms of mental illness, it would be beneficial to seek professional help.
If you decide to do this, mention any noticeable dream patterns to your counselor as talking about them could help you, and any changes can help to monitor progress or decline. Even in the absence of other symptoms, it would be beneficial to seek professional help for disturbing dream patterns.
Dream anxiety disorder
Although nightmares are common, nightmare disorder (also known as dream anxiety disorder or parasomnia) is relatively rare.
Nightmare disorder is when nightmares become a problem for example when they often occur, cause distress to the individual, disrupt sleep, cause problems with daytime functioning or lead to fear of going to sleep.
This can result from another psychological disorder or from other triggers such as medication, substance abuse, sleep deprivation, stress or trauma.
The disorder often leads to sufferers avoiding sleep as the nightmares feel so real that they are too scared to fall asleep.
However avoiding sleep can lead to many other issues including daytime sleepiness affecting work and other commitments, or mood problems such as depression and anxiety.
In the worst cases, nightmare disorder can often lead to suicidal thoughts or even suicide attempts.
If you or somebody who you know may be suffering from dream anxiety disorder, professional help could save their life.
Furthermore, it may be the only way to recover. Speaking to a counselor is often more helpful than people realize.
Researchers have identified a pattern of brain activity that predicts anger experienced during dreaming, according to a new study of healthy adults published in Journal of Neuroscience.
The research could potentially inform efforts to understand the neural basis of the emotional content of nightmares, a feature of various mental and sleep disorders.
Although emotions are experienced during both waking and dreaming, few studies have investigated the brain mechanisms underlying the affective component of dreams.
Pilleriin Sikka and colleagues at University of Turku, University of Skövde, and University of Cambridge discovered a shared emotional mechanism between the two states of consciousness.
The researchers obtained electroencephalography recordings from participants during two separate nights in a sleep laboratory.
After five-minute bouts of rapid eye movement (REM) sleep, participants were woken and asked to describe their dream and rate the emotions they experienced in the dream.
Dream Anger and its relationship to frontal alpha asymmetry. (C) Partial correlation coefficients between dream Anger and log-transformed alpha power over individual electrode sites, while controlling for the average whole-head alpha power.
The image is credited to Sikka et al., JNeurosci (2019).
Individuals who displayed greater alpha-band brain activity in the right, as compared to the left, frontal cortex during evening wakefulness and during REM sleep experienced more anger in dreams.
This neural signature – called frontal alpha asymmetry (FAA) – has been linked to anger and self-regulation during wakefulness.
Together, these results suggest FAA may reflect a universal indicator of emotion regulation.A
David Barnstone – SfN
The image is credited to Sikka et al., JNeurosci (2019).
Original Research: Closed access
“EEG Frontal Alpha Asymmetry and Dream Affect: Alpha Oscillations Over the Right Frontal Cortex During REM Sleep and Pre-Sleep Wakefulness Predict Anger in REM Sleep Dreams”
Pilleriin Sikka, Antti Revonsuo, Valdas Noreika and Katja Valli. Journal of Neuroscience. Published online April 15, 2019 doi:10.1523/JNEUROSCI.2884-18.2019