The Why and How of Dreams

Dreaming is a normal mental activity that occurs while we sleep. Everybody dreams. In fact, we experience about three to six dreams every night and spend about 25% of our time asleep dreaming, although some researchers believe this percentage might be considerably higher!

But most people rarely remember their dreams and, even they do, the memory of the dream fades quickly  unless it is written down or otherwise recorded.

Still, dreams have always been a source of fascination and many questions about dreaming remain unanswered. However, considerable progress in better understanding the why and how of dreams has been made, thanks to rigorous studies.

A lot of clinical and scientific evidence shows that dreams often reflect our ongoing concerns and emotionally salient experiences. Sometimes these representations are metaphorical or associative in nature, which is one reason dreams have such a bizarre aspect to them. Since dreams can mirror our waking state of mind or our concerns as well as our personal perceptions of  ourselves, others and the world we live in, they are of great interest.

Even though we still don’t know exactly why and how we dream, many people find it useful to pay attention to their dreams, even sharing them with others. Without falling into pseudoscience through popular books on universal dream symbols, talking, writing, thinking or drawing about our dreams can be a good and enriching way to connect with our inner world and do self-exploration. It’s also not surprising that dream-related material is sometimes used as a therapeutic tool to increase self-awareness, insights, and creativity. It can also be part of a family sharing time to learn more about each other, and an opportunity for parents to address the importance of sleep quality and hygiene for our general well-being.

Why do we dream?

Probably the most frequently asked question about dreaming is: “Why do we dream?” Various theories and sleep studies help us better understand the diverse dream functions. Sleep recordings provide key information about how dreams could be part of memory function and emotional regulation. As you might expect, there is still no definitive answer, but the following are the theories that are keeping researchers “awake at night” for over the past 10 to 15 years.

  • Dreams have an evolutionary function. One way to think about the function of dreams is to ask what adaptive role dreams may have served in our ancestral environment. The most frequently cited model is called the Threat Simulation Theory (TST) of dreams. In essence, this theory is centered on the idea that dreaming evolved as a mechanism for simulating threatening events and rehearsing possible means of avoiding or surviving them. This would be one reason why, even today, some dreams contain psychologically or physically threatening material. The brain, according to this model, creates a convincing virtual world in which we can perceive various kinds of threats and practice adapted behaviours in response to these dangers. Another, more recent variant of this model suggests that dreams evolved as a way for us to engage in and explore social simulations. Dreaming, thus helped improve the survival and reproductive success of our ancestors by strengthening our social skills and interactions. In that sense, dreaming can be viewed as an automatic brain function in a way to practice adapted behaviours in a similar way we can voluntarily practice certain behaviours with daytime visualization techniques.
  • Dreams are involved in memory consolidation. It is now well established that sleep plays a vital role in memory and learning (see “Why sleep?”). Some sleep researchers believe that dreams play a role in these processes meaning that by having subjective experiences (dreams) tied to a moment in our life or something that has to be learned, dreaming could help us memorizing it.
  • Dreams help regulate our emotions. For some clinicians and researchers, dreams are a form of “nighttime therapy” that help us digest and integrate personal emotional experiences, particularly negative emotions, within the safe context of sleep. As such, dreams may be viewed a natural stress management and emotional regulation mechanism.
  • Dreams help us solve problems. The fact that some discoveries, inventions and works of art have dreams as their main source of inspiration leads some of us to believe that dreaming helps us find solutions to our problems. But while dreams can and do sometimes lead to wonderful insights, it remains that very few dreams have this problem-solving quality.
  • And if dreams have no biological function in and of themselves? Some dream and sleep researchers believe that while dreams can be of great interest and are likely meaningful products of the sleeping brain, they have no biological function beyond those accomplished by sleep itself (see “Why sleep?). Thus, sleep has an important biological function, whereas dreaming itself would only be a by-product of sleep, or what is known as an “epiphenomenon.”

It is important to keep in mind that whatever the function of dreams may be, the brain executes the function regardless of whether or not we remember our dreams. Thus, the biological function of dreams most probably does not depend on our capacity to remember our dreams. If it did, it would be a colossal waste of time since the vast majority of dreams are never remembered to begin with!

How and when do we dream?

Dreams occur at any sleep stage. As we fall asleep, we pass from lighter stages of sleep to deeper ones (like slow-wave sleep) and also when we experience what is known as rapid-eye movement sleep (REM sleep) (see “What is sleep?”). Dreams can take place in any of these sleep stages.

As we drift asleep, images and thoughts from the day may play in our minds. That’s a type of dreaming.

Dreams recalled from deeper, slow-wave sleep, are often described as thoughts, images or feelings more than complex stories.

REM sleep is the sleep stage most frequently associated with the recall of long, complex and often emotionally engaging and bizarre dreams, which includes most nightmares. Since we spend a larger amount of time in REM sleep towards the end of the night, that is when most vivid dreams take place. Chances are that morning awakening will happen after a REM sleep dreaming session, explaining why these long and bizarre dreams are more often remembered and reported.

Aside from the differences observed between the sleep stages, dream content-recording studies allowed dream researchers to classify dreams reported by sleepers in different types. Here are the most common types of dreams:

  • Typical dreams are those that a large proportion of the population will experience at least once in their lifetime. Even though dreaming is a personal experience and a large variety of dream content exists, there are universal themes. Examples include dreams of falling, flying, of losing one’s teeth, of sex, and of being chased. Researchers have established that typical dreams exist across cultures and have been part of the human dream experience for millennia. There appears to be some sex differences, however, with men being more likely than women to report dreams involving sexual experiences, physical aggression and natural catastrophes and women more likely to report themes related to interpersonal conflicts.
  • Nightmares are the dreams that trigger the most intense negative emotions, often so much so, that they cause the dreamer to wake up and have difficulty going back to sleep potentially affecting sleep duration and quality. As such, frequent nightmares can have a detrimental impact on daytime life.

    Nightmares occur more frequently during REM sleep in the latter part of a night’s sleep, close to awakening. Nightmares are often confused with night terror, which occur during the first part of the night, in slow-wave sleep (see Night terror, for more on how to differentiate one from the other and act accordingly).

    Although fear is the most frequently experienced emotion in nightmares, they can also feature other intense negative emotions including sadness, helplessness, confusion, guilt and disgust. Themes of death and physical or psychological threats are often part of the nightmare scenario.

    Most nightmares arise during childhood or can be related to a trauma, e.g. a car accident or war-related events.

    Although nightmares are present at all ages, they are predominantly observed during childhood with one to four percent of preschoolers reporting nightmares “often” or “always.” While most children will experience the occasional nightmare, in some cases particularly frequent or intense nightmares can be due to waking life insecurities, fears or stress.

    After adolescence, women tend to report more nightmares than men. About six percent of adults report having nightmares on a monthly basis, and one to two percent once a week or more. In adults, nightmares can also be stress-related, but also related to  anxiety, depression, or trauma. In addition, nightmares can result from a new medication or, conversely, from the withdrawal from various drugs, including alcohol.

  • Recurrent dreams are the ones that we have repeatedly over a period of months, years or even decades. These dreams can be either a distressing or a positive experience, but they share the characteristic of being similar in content even with repeats over time. One distressing dream, well known by most students, is the recurrent dream of being late or unprepared for an exam. Some recurrent dreams, however, are positive in nature, like flying or discovering a secret room in a house.

    Some clinicians believe that negatively-toned recurrent dreams tend to occur during times of stress or self-doubt. Nightmares can also be recurrent when associated with traumatic experiences and post-traumatic stress disorder; professional help is then recommended.

  • Lucid dreams are those in which the sleeper becomes aware that he or she is dreaming. Some lucid dreamers are able to take control of their dream content while asleep. This ability can be learned and practiced, and even used as a treatment for nightmares.

How to better remember your dreams?

Since dreams can be used for amusement, personal interest, as a source of creativity, or for self-exploration, some people try to remember their dreams as often as possible. Some will record their dreams in a sleep diary or by other means, so that the fragile memories of dreams don’t fade over time.

Dream recall can be improved by increasing interest in your dreams and by making a few adjustments to your sleep routine. Here are some tips for improving your dream recall:

  • Before going to bed, tell yourself that you will remember your dreams. Research has shown that autosuggestion, along with sufficient motivation, works for many.
  • When you wake up in the morning, give yourself a chance to remember what was going through your mind. In order to do so, try to relax and keep your eyes closed. Don’t think about the day that lies ahead but focus on any images or feelings that you may have experienced in your sleep.
  • Keep a pen and paper (dream diary) or a voice recorder (cell phone will do) by your bedside and start keeping a journal of the dreams you remember.
  • Some people also enjoy sharing their dreams with their bed partner or family during breakfast.

All of these simple things can significantly impact how frequently and vividly you remember your dreams.

What to do if bad dreams or nightmares are a problem to you?

Vivid, bad dreams and nightmares are not necessarily harmful unless they create a lot of distress. For some people, they may work as a natural adaptive mechanism, especially during periods of emotional stress. However, if nightmares are affecting your emotional well-being or other spheres of your daytime functioning, consulting a sleep or mental health professional is recommended.

Do not overlook repeatedly negative or chronic distressing dreams as they might reflect psychological or medically-related conditions. Over time, negative dream experiences such as nightmares can result in a fear associated with going to sleep and sleep loss. This is true of both children and adults.

For some, sharing bad dreams and nightmares with trustworthy individuals can help, while others will benefit from the simple exercise of writing down a modified version of the nightmare. It does not matter what in the nightmare is changed; it can be the beginning, or the end, or a small detail, or anything else that feels “right” to the dreamer. Children can do the same with the use of drawings. Practice this every time you have a bad dream or nightmare. This technique, known as the Imagery Rehearsal Therapy (IRT), has proven effective in adults and children alike.

In summary, while dreams can be disturbing to some, they are generally highly intriguing but also elusive creations of our sleeping brain. And while researchers still don’t agree on why we dream or what function dreams may serve, there is growing appreciation for their importance, not only for the individual, but also for clinicians and scientists alike.