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Why Humans Can't Recall Dreams

By: Sai Srihaas Potu

Dreams are ways in which your subconscious mind communicates with you. To interpret it, you need to analyze the meaning of your dreams. One has dreams during the rapid eye movement sleep. Various theories on dream interpretations exist but the real purpose of dreams is still unknown. Dreams are closely associated with human psychology. Research shows that during an average lifespan, a human being spends about six years dreaming which is around two hours every night.

Several theories claim that dreaming is a random by-product of REM sleep physiology and that it does not serve any natural function. Phenomenal dream content, however, is not as disorganized as such views imply. The form and content of dreams are not random but organized and selective: during dreaming, the brain constructs a complex model of the world in which certain types of elements, when compared to waking life, are underrepresented whereas others are over-represented. Furthermore, dream content is consistently and powerfully modulated by certain types of waking experiences.

Today, many people see dreams as a connection to the unconscious mind. There are varying natures of dreams, such as exciting, frightening, melancholic, magical, and even adventurous; and our dreams seem to range from normal and ordinary right through to bizarre and completely surreal. With the exception of lucid dreaming, the events that occur in our dreams are normally outside the control of the dreamer. The dreamer is self-aware during lucid dreaming. Sometimes, dreams can implant a creative thought, thus giving the dreamer a sense of inspiration.

Why humans dream remains one of behavioral science's great unanswered questions. At the same time, research has shown that almost 95% of people don’t remember their dreams. The psychology behind dreams is a gray area for scientists as they continue to look for answers. To understand why a significant portion of the human population is not able to remember their dream, we will look at previously published research papers and their take on this topic.

Nearly everyone has had a dream at some point in life. The frequency of dream recall may vary or even fade at points in one’s life. Dreaming may occur as specific regions of the brain are activated through sequenced electrical patterns and chemical activity. It is normal to dream, but it is common to not recall the dreams that occur. The dreaming state can be identified by measurements made as part of a diagnostic polysomnogram, including the recording of the electroencephalogram (EEG), the electrooculogram (EOG), and the electromyogram (EMG). The tell-tale signs of REM sleep include an active brain, rapid eye movements, and a loss of muscle tone.

There are a few possible explanations for dreams that cannot be remembered. First, it is possible that REM sleep is not occurring, or at least not occurring as much as normal. Medications may suppress REM sleep. In particular, antidepressants seem to have a powerful influence by delaying the onset or reducing the amount of REM sleep. Alcohol may also act as a REM sleep suppressant, at least until it wears off. If REM sleep is occurring, the vivid dreams that are associated with it may not be recalled. If there is a transition from REM sleep to another state of sleep, before recovering consciousness, the dreams may be forgotten.

As a general rule, dreams fade quickly after waking. The electrical signals and chemical signatures that constitute the experience of the dream may disappear as wakefulness ensues, like a message written on a fogged mirror that vanishes as the steam evaporates. Elements of the dream can be recalled later in the day, perhaps triggered by an experience that reactivates the same area of the brain that created the dream overnight. Particularly memorable dreams may create an impression that persists for decades. Recounting the dream to another person may help to stabilize the memory. Dreams that are associated with intense emotions, including fear, may also stick in the mind. The amygdala is an area of the brain that may help to elicit these emotion-laden dreams.

Sleep disorders may impact dream recall. Untreated obstructive sleep apnea may also contribute to fragmented REM sleep as disturbed breathing occurs due to the relaxation of the airway muscles. For some, this may lead to increased dream recall. Sleep apnea may likewise lead to REM sleep deprivation and effective CPAP therapy may cause a profound rebound of REM sleep. People with narcolepsy also experience sudden sleep transitions that contribute to dream recall, sleep-related hallucinations, and sleep paralysis. Poor sleep habits, stress, and psychiatric conditions may also fragment sleep and increase dreaming and recall. With this in mind, the future of the “dream” research has the potential to enhance our understanding of the subconscious state and change the scope of sleep medicine.


1. Dement W, Kleitman N. The relation of eye movements during sleep to dream activity: an objective method for the study of dreaming. Journal of Experimental Psychology. 1957.

2. Fosse MJ, Fosse R, Hobson JA, Stickgold RJ. Dreaming and episodic memory: a functional dissociation? Journal of Cognitive Neuroscience. 2003.

3. Nielsen TA, Stenstrom P. What are the memory sources of dreaming? Nature. 2005.


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