Virtually everybody dreams. Researchers estimate people dream for approximately two hours every night, even if they forget most of those dreams.

There are still many mysteries surrounding the purpose of dreams and why the brain creates stories during sleep. It is difficult to study something that takes place while asleep and relies on people remembering what they experienced upon waking. However, new research has advanced the scientific understanding of dreaming.

What Are Dreams?

Dreams are the mental thoughts, feelings, imagery, and sensations people experience during sleep. They primarily arise as a result of brain activity in the cerebral cortex, the outer layer of the brain that is responsible for higher-order thought processes.

Dreams can encompass a variety of themes and emotions, and they range from bizarre and intricate stories to sensations without specific content. Further, during dreams the body can experience sensations or activities it normally cannot during waking life. For example, people who have paraplegia have reported being able to walk during their dreams, and phantom limb pain can disappear during dreaming for people with this condition.

Dreams are not under the conscious control of the sleeper but they can feel lifelike, even if the events are impossible. During sleep, the brain creates a conscious-like experience by itself, with dreams often containing experiences, people, or subjects from waking life.

While dreams can occur in any stage of sleep, they primarily take place during rapid eye movement (REM) sleep, the sleep stage when brain activity most closely resembles waking. REM dreams also tend to be more vivid, emotional, and story-like than those that take place in other stages of sleep.

What Are Nightmares?

Nightmares are a type of dream associated with frightening or other strong negative emotions. Researchers generally define nightmares as bad dreams that are so severe they wake the sleeper up. Among other factors, nightmares can be brought on by worries, stress, traumatic events, or mental health disorders.

What Is a Lucid Dream?

A lucid dream is a dream in which the dreamer knows they are dreaming and may be able to exert some control over what is happening in the dream. Researchers estimate approximately 50% of people have had a lucid dream at least once. A lucid dream may occur randomly, when the dreamer spontaneously realizes they are dreaming. People may also use special techniques to try to induce lucid dreaming.

Why Do We Dream?

More research is needed to know exactly why people dream, but studies have uncovered some possible theories:

  • Learning and Emotional Regulation: Dreams are heavily influenced by real-life memories, and some scientists believe they may contribute to memory consolidation and emotional regulation. Recent research has found that people with damage in areas of the brain that control memory and imagination experience less detailed dreams, suggesting that dreams might be a continuation of thought processes that are similar to waking life.
  • Creativity: REM sleep is associated with creativity, which may explain the often bizarre, fantastic nature of dream imagery. Anecdotally, many people claim that dreams have inspired creative works and helped with problem-solving.
  • Wish Fulfillment: Sigmund Freud, the neurologist famed for founding psychoanalysis, believed dreams were a form of wish fulfillment, and studies have found that suppressed thoughts can bubble back up to the surface in dreams. However, many current-day researchers consider psychoanalytic dream interpretation to be a pseudoscience.
  • Default Mode Network: Researchers are currently exploring how dreams might arise from a system known as the default mode network. Often associated with daydreaming, the default mode network incorporates multiple brain areas and kicks in when a person is not concentrating on anything in particular. Some experts believe that bizarre dreaming in REM sleep occurs when part of the default mode network becomes disconnected from areas that ground thoughts in reality.
  • Synaptic Regulation: Along the same lines, other researchers propose that dreaming might be the byproduct of mental housekeeping, when the brain is busy sorting through memories to decide which to keep and which to prune away.

What Do Dreams Look Like?

People may dream in color or in black and white. Individuals with blindness are more likely to experience other senses during their dreams, such as touch, taste, smell, or hearing.

While dreams occur in the mind, the body may react in relation to what is happening in the dream. Although most muscles are paralyzed during REM sleep, eye movements, muscle twitches, breathing, and heart rate may all correspond with dream experiences. Also, emerging research shows that external stimuli such as spraying water on the skin or playing certain types of sounds may influence dream content.

Interpreting Dreams

Dreams can be influenced by what happens in daily life. They often include familiar people, objects, settings, or experiences, but these may be mixed together in unique ways. One study found that over 80% of dreams reported by the participants contained memories related to a sense of self or personal history.

For example, pregnant people often experience dreams about pregnancy, childbirth, or being a mother, and bereaved people may dream about their deceased loved ones.

When dreams represent situations that are preoccupying you in your waking life, they may help you find a solution to a problem. In one study, participants were told to think for 15 minutes about a problem that had been bothering them before falling asleep. About half of the people said they dreamed about the problem, and one in three reported finding a solution.

Tips to Remember Your Dreams

It is normal to forget dreams. Researchers believe this may be because memory processes shut down during sleep, so dreams can only be remembered if the sleeper wakes up shortly afterward. However, for those who would like to remember more of their dreams, there are some techniques that may help:

  • Be Open to Experience: Take an active interest in remembering your dreams, and keep an open mind regarding new experiences.
  • Keep a Dream Diary: Keep a notebook on your bedside table. Write down as much as you remember about your dreams whenever you wake up.
  • Sleep Longer: Periods of REM sleep become longer the more you are asleep, and people are generally more alert after waking from REM sleep as opposed to non-REM sleep. Being alert when waking is linked to better dream recall, so by extending your sleep period, you may be more likely to remember your vivid REM dreams.


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