Why do we dream?

An analysis of explanations for dreaming, why some of us are better at recalling our dreams, and how new technology, has meant that the ability to control our dreams could soon be in reach.

You may have studied ‘ultradian rhythms’ as part of your learning in Psychology and learned about the sleep cycle (a 90-minute cycle consisting of NREM (non-rapid eye movement) sleep and REM (rapid eye movement) sleep.

During REM, our brains are as active as they are when we awake, and it is during this stage that dreams are more likely to occur (although recent research suggests that we may have shorter, less detailed dreams in NREM sleep as well).

Dreaming itself has proved to be a source of fascination for hundreds of years, with Sigmund Freud once being quoted as saying that dream interpretation offers us a ‘royal road’ to the unconscious mind. Maybe you have dreamt of your teeth falling out, being unprepared for an event, or falling from a great height and found yourself wondering, what is the purpose of dreaming?

One theory of dreaming suggests that dreams function to interconnect and consolidate (make permanent) our memories. For example, by connecting what has happened to us recently with what was happened in the past. Alternatively, threat simulation theory states that we practice overcoming threats in our dreams (or nightmares) to better prepare us should we experience this in real life (researchers believe that this could reflect an evolutionary explanation of dreams that may aid our survival). On the other hand, an epiphenomenal view believes that we dream for no purpose at all and that dreaming is simply a series of passing images that we experience as we sleep.

Research suggests around a third of us can recall at least one dream per week, another third can recall at least one dream per month and a third of us can recall less than one dream per month. Psychologists believe that this difference stems from differences in brain activity. People who are frequent dream recallers have higher levels of activity in the region of the brain where the parietal and temporal lobes meet during the dream, and this leads to enhanced recall of the dream. Conversely, if a person has damage to this area dream recall stops completely.

More recent research has focused on ‘lucid dreaming’ this is when you are consciously aware that you are dreaming and may be able to influence what happens in the dream. Lucid dreams occur only in the REM stage of sleep and are relatively rare, with only 50% of people having had a lucid dream once in their lifetime and around 20% of people experiencing it once per month. New technology aims to enable people to have the ability to experience lucid dreams. Recent inventions include a mask that you wear when you are asleep which detects when your eyes are moving (during REM sleep) and flashes red lights at you. These lights cause the dream to change, for example, some objects may appear to be red, and this enables the person to realise they are dreaming, and the dream then becomes a lucid dream that the person can control.

The area of dream psychology is vast and new research is emerging all of the time. Whilst we know that almost everyone dreams every time they sleep, we still do not know definitively why we dream.

Questions you might want to consider following this blog:

• Which technique of studying the brain would be most useful in assessing which areas of the brain are active when we dream?
• Sleep stages are studied in a sleep laboratory, what implications might this have for the external validity of the findings of research into this area?
• As well as dreams, psychologists are interested in nightmares, to study nightmares, psychologists study people who have undergone a traumatic experience (e.g. an earthquake) and the nightmares they have and compare them to people who have not undergone such an experience. Which experimental method is this? Why might this type of method be more appropriate than an alternative in this area of study?

Listen: Speaking of Psychology (APA podcast) The science of dreaming, with Deirdre Barrett, PhD (apa.org)