Most people dream every night, but many do not remember their dreams when they wake up. There are several potential reasons that a person may forget their dreams.
Some people may recall brief, obscure fragments of a dream, while others have absolutely no recollection of them.
A dream is a series of images, thoughts, and sensations that occur in the mind during sleep. The act of dreaming is a universal but poorly understood experience.
Dreams have fascinated philosophers and researchers for ages. Although the scientific community has established a solid understanding of the physiology of sleep, they have made significantly less progress in understanding dreams and their functions.
This article will attempt to answer the question of why some people forget their dreams.
Everyone dreams, but many people do not remember their dreams upon waking. However, it is difficult to say exactly why one person can remember their dreams and another person cannot.
Dreams may arise when the brain sorts information into short- and long-term memory. A person may not remember the events of their dreams because they cannot access that information once they are awake.
In a 2016 article in the journal Behavioral and Brain Sciences, researchers posit that people forget their dreams due to changing levels of acetylcholine and norepinephrine during sleep.
In one 2018 study, researchers attempted to establish if a person’s brain structure influences how well they recall their dreams.
In this study, the researchers examined the associations between dream recall frequency and the density of white or gray matter in brain regions associated with dreaming, such as:
- the amygdala
- the hippocampus
- the medial prefrontal cortex (MPFC)
- the temporoparietal junction (TPJ)
The study involved 92 participants. The researchers categorized them into two groups based on their dream recall frequency.
The brain matter density of the amygdala and hippocampus did not significantly differ between the high and low dream recall groups. However, the participants who reported high dream recall had higher white matter density in their MPFCs than the low dream recall group.
The authors of a 2014 study found that people who had high dream recall also showed increased blood flow in the TPJ and MPFC regions of their brains.
Based on these findings, the study authors conclude that increased activity in the TPJ might promote the transition of dream experiences into memory.
The nature and function of dreams remain a mystery. Although researchers can observe, record, and analyze brain activity during sleep, they cannot identify exactly when a person is dreaming or determine the contents of a person’s dreams.
Currently, dream research relies on anecdotal evidence and people’s ability to recall and then explain their dreams in an interview.
Several factors can influence a person’s ability to remember their dreams. These include lifestyle factors, sleep hygiene practices, and differences in brain physiology.
The question “Why do we dream?” is easy to ask and has likely crossed many people’s minds at one point in their life.
However, answering it is quite difficult, as the medical community still does not fully understand the functions or mechanisms behind sleep and dreams.
Understanding more about sleep may help reveal why we dream. The sections below will look at this in more detail.
Why we sleep
Sleep is a vital part of our lives. In fact, most people spend about one-third of their lives sleeping.
Sleep serves several important roles in our physical and mental well-being. For example, researchers believe that sleep supports physical health by:
- reducing blood pressure, heart rate, and breathing
- regulating hormone levels
- controlling hunger and regulating the metabolism
- promoting immune system activity
- supporting physical growth and development
Sleep also supports brain functioning and emotional well-being. During sleep, the brain enters a state of active rest wherein it can repair and form new neural pathways.
Chronic sleep deficiency can increase the risk of obesity, heart disease, kidney disease, and diabetes.
Stages of sleep
It is important to note that sleep is not a passive state.
There are two types of sleep: rapid eye movement (REM) sleep and non-REM sleep, which is further divided into three stages. The brain cycles through non-REM and REM sleep around four to six times per night.
Stage 1 is the lightest sleep stage. It occurs during the transition from wakefulness to sleep.
Stage 2 begins about 25 minutes after sleep onset. During this stage, heart rate, blood pressure, and breathing decrease. Body temperature drops, and the eyes stop moving.
Stage 3 is the deepest sleep stage. During this phase, the brain produces slow delta waves. The muscles become completely relaxed, and heart rate and breathing reach their lowest levels.
REM sleep occurs about 90 minutes after sleep onset. REM sleep is characterized by rapid side-to-side eye movements, increased heart rate and blood pressure, and shallow, irregular breathing.
During this sleep stage, the brain gives off mixed frequencies that closely resemble those of brain activity during wakefulness.
Why we might dream
Dreaming usually occurs during REM sleep. People who wake up during REM sleep often report having dream experiences. That being said, people can have dreams or dream-like experiences during non-REM sleep.
Although sleep researchers, neurologists, and psychologists have posited numerous theories about the function (or functions) of sleep, the scientific community has yet to establish a consolidated interpretation of dreams.
Some potential reasons why we dream include:
- consolidating learning and memory tasks that occur during consciousness
- experiencing mental stimulation akin to daydreaming
- reflecting on and processing emotional stimuli experienced during consciousness
- reflecting on and processing emotional trauma that is too difficult to confront during consciousness
Some scientific evidence suggests that the brain regions that process emotions during consciousness are also active during REM sleep.
However, there is no conclusive evidence that suggests that dreaming or REM sleep directly affects a person’s emotional state. In fact, a lack of REM sleep for as long as 2 weeks has little to no effect on behavior.
Although we may not remember every dream in vivid detail, some dream experiences are so vivid that people remember them several years later.
Overactive or vivid dreams can result from:
- sleep deprivation, especially a lack of REM sleep
- alcohol use
- substance use
- frequent or chronic emotional stress
- hormonal fluctuations, especially those that occur during pregnancy
- mental health conditions, such as anxiety, depression, and schizophrenia
- sleep disorders, such as narcolepsy and REM sleep behavior disorder
The reasons that we dream and the function (or functions) of dreams remain unclear. However, we do know that everyone dreams and that most people can recall at least some dream elements.
Various factors contribute to a person’s ability to remember their dreams.
Vivid or disturbing dreams may be easier to recall than dreams that mimic the events of everyday life.
Using alcohol or other substances, experiencing stress, and experiencing sleep deprivation can all lead to overactive or vivid dreams in some people.