Dream Series: Part I – Dreams are stories and images that our minds create while we sleep. They can be entertaining, fun, romantic, disturbing, frightening, and sometimes bizarre.
They are an enduring source of mystery for scientists and psychological doctors. Why do dreams occur? What causes them? Can we control them? What do they mean?
- We may not remember dreaming, but everyone is thought to dream between three and six times per night.
- It is thought that each dream lasts between five to 20 minutes.
- Around 95 percent of dreams are forgotten by the time a person gets out of bed.
- Dreaming can help you learn and develop long-term memories.
- Blind people dream more with other sensory components compared with sighted people.
There are several theories about why we dream. Are dreams merely part of the sleep cycle, or do they serve some other purpose?
Possible explanations include:
- representing unconscious desires and wishes
- interpreting random signals from the brain and body during sleep
- consolidating and processing information gathered during the day
- working as a form of psychotherapy
From evidence and new research methodologies, researchers have speculated that dreaming serves the following functions:
- offline memory reprocessing, in which the brain consolidates learning and memory tasks and supports and records waking consciousness
- preparing for possible future threats
- cognitive simulation of real life experiences, as dreaming is a subsystem of the waking default network, the part of the mind active during daydreaming
- helping develop cognitive capabilities
- reflecting unconscious mental function in a psychoanalytic way
- a unique state of consciousness that incorporates experience of the present, processing of the past, and preparation for the future
- a psychological space where overwhelming, contradictory, or highly complex notions can be brought together by the dreaming ego, notions that would be unsettling while awake, serving the need for psychological balance and equilibrium
Much that remains unknown about dreams. They are by nature difficult to study in a laboratory, but technology and new research techniques may help improve our understanding of dreams.
There are five phases of sleep in a sleep cycle:
Stage 1: Light sleep, slow eye movement, and reduced muscle activity. This stage forms four to five percent of total sleep.
Stage 2: Eye movement stops and brain waves become slower, with occasional bursts of rapid waves called sleep spindles. This stage forms 45 to 55 percent of total sleep.
Stage 3: Extremely slow brain waves called delta waves begin to appear, interspersed with smaller, faster waves. This accounts for four to six percent of total sleep.
Stage 4: The brain produces delta waves almost exclusively. It is difficult to wake someone during Stages 3 and 4, which together are called “deep sleep.” There is no eye movement or muscle activity. People awakened while in deep sleep do not adjust immediately and often feel disoriented for several minutes after waking up. This forms 12 to 15 percent of total sleep.
Stage 5: This stage is known as rapid eye movement (REM). Breathing becomes more rapid, irregular, and shallow, eyes jerk rapidly in various directions, and limb muscles become temporarily paralyzed. Heart rate increases, blood pressure rises, and males develop penile erections. When people awaken during REM sleep, they often describe bizarre and illogical tales. These are dreams. This stage accounts for 20 to 25 percent of total sleep time.
Neuroscience offers explanations linked to the rapid eye movement (REM) phase of sleep as a likely candidate for the cause of dreaming.
Dreams are a universal human experience that can be described as a state of consciousness characterized by sensory, cognitive and emotional occurrences during sleep. The dreamer has reduced control over the content, visual images, and activation of the memory. There is no cognitive state that has been as extensively studied and yet as frequently misunderstood as dreaming.
There are significant differences between the neuroscientific and psychoanalytic approaches to dream analysis. Neuroscientists are interested in the structures involved in dream production, dream organization, and narratability. However, psychoanalysis concentrates on the meaning of dreams and placing them in the context of relationships in the history of the dreamer.
Reports of dreams tend to be full of emotional and vivid experiences that contain themes, concerns, dream figures, and objects that correspond closely to waking life. These elements create a novel “reality” out of seemingly nothing, producing an experience with a lifelike timeframe and connections.
Nightmares are distressing dreams that cause the dreamer to feel a number of disturbing emotions. Common reactions to a nightmare include fear and anxiety.
They can occur in both adults and children, and causes include:
- emotional difficulties
- use of certain medications or drugs
Lucid dreaming is the dreamer is aware that they are dreaming. They may have some control over their dream. This measure of control can vary between lucid dreams. They often occur in the middle of a regular dream when the sleeping person realizes suddenly that they are dreaming. Some people experience lucid dreaming at random, while others have reported being able to increase their capacity to control their dreams.
What goes through our minds just before we fall asleep could affect the content of our dreams. For example, during exam time, students may dream about course content. People in a relationship may dream of their partner. Web developers may see programming code. These circumstantial observations suggest that elements from the everyday re-emerge in dream-like imagery during the transition from wakefulness to sleep.
Studies have examined the “characters” that appear in dream reports and how they the dreamer identifies them.
A study of 320 adult dream reports found:
- Forty-eight percent of characters represented a named person known to the dreamer.
- Thirty-five percent of characters were identified by their social role (for example, policeman) or relationship to dreamer (such as a friend).
- Sixteen percent were not recognized.
Among named characters:
- Thirty-two percent were identified by appearance
- Twenty-one percent were identified by behavior
- Forty-five percent were identified by face
- Forty-four percent were identified by “just knowing”
Elements of bizarreness were reported in 14 percent of named and generic characters. Another study investigated the relationship between dream emotion and dream character identification. Affection and joy were commonly associated with known characters and were used to identify them even when these emotional attributes were inconsistent with those of the waking state.
The findings suggest that short-term memory is less active in the dreaming brain than during waking life.
The concept of ‘repression’ dates back to Freud. He maintained that undesirable memories could become suppressed in the mind. Dreams ease repression by allowing these memories to be reinstated. A study showed that sleep does not help people forget unwanted memories. Instead, REM sleep might even counteract the voluntary suppression of memories, making them more accessible for retrieval.
Two types of temporal effects characterize the incorporation of memories into dreams:
- the day-residue effect, involving immediate incorporations of events from the preceding day
- the dream-lag effect, involving incorporations delayed by about a week
The findings of one study suggest that:
- processing memories into dream incorporation takes a cycle of around seven days
- these processes help further the functions of socio-emotional adaptation and memory consolidation
Dream-lag is when the images, experiences, or people that emerge in dreams are images, experiences, or people you have seen recently, perhaps the previous day or a week before.
The idea is that certain types of experiences take a week to become encoded into long-term memory, and some of the images from the consolidation process will appear in a dream.
Events experienced while awake are said to feature in 1 to 2 percent of dream reports, although 65 percent of dream reports reflect aspects of recent waking life experiences.
The dream-lag effect has been reported in dreams that occur at the REM stage but not those that occur at stage 2.
MEMORY TYPES & DREAMING
Two types of memory can form the basis of a dream.
- Autobiographical memories, or long-lasting memories about the self
- Episodic memories, which are memories about specific episodes or events
A study exploring different types of memory within dream content among 32 participants found the following:
- One dream (0.5 percent) contained an episodic memory.
- Most dreams in the study (80 percent) contained low to moderate incorporations of autobiographical memory features.
Researchers suggest that memories of personal experiences are experienced fragmentarily and selectively during dreaming. The purpose may be to integrate these memories into the long-lasting autobiographical memory. A hypothesis stating that dreams reflect waking-life experiences is supported by studies investigating the dreams of psychiatric patients and patients with sleep disorders. In short, their daytime symptoms and problems are reflected in their dreams.
In 1900, Freud described a category of dreams known as “biographical dreams.” These reflect the historical experience of being an infant without the typical defensive function. Many authors agree that some traumatic dreams perform a function of recovery. One paper hypothesizes that the main aspect of traumatic dreams is to communicate an experience that the dreamer has in the dream but does not understand. This can help an individual reconstruct and come to terms with past trauma.
The themes of dreams can be linked to the suppression of unwanted thoughts and, as a result, an increased occurrence of that suppressed thought in dreams. Fifteen good sleepers were asked to suppress an unwanted thought five minutes prior to sleep.
The results demonstrate that there were increased dreams about the unwanted thought and a tendency to have more distressing dreams. They also imply that thought suppression may lead to significantly increased mental disorder symptoms.
Research has indicated that external stimuli presented during sleep can affect the emotional content of dreams. For example, the positively-toned stimulus of roses in one study yielded more positively themed dreams, whereas the negative stimulus of rotten eggs was followed by more negatively themed dreams.
Typical dreams are defined as dreams similar to those reported by a high percentage of dreamers. Up to now, the frequencies of typical dream themes have been studied with questionnaires. These have indicated that a rank order of 55 typical dream themes has been stable over different sample populations.
The 55 themes identified are:
- school, teachers, and studying
- being chased or pursued
- sexual experiences
- arriving too late
- a living person being dead
- a person now dead being alive
- flying or soaring through the air
- failing an examination
- being on the verge of falling
- being frozen with fright
- being physically attacked
- being nude
- eating delicious food
- being locked up
- insects or spiders
- being killed
- losing teeth
- being tied up, restrained, or unable to move
- being inappropriately dressed
- being a child again
- trying to complete a task successfully
- being unable to find toilet, or embarrassment about losing one
- discovering a new room at home
- having superior knowledge or mental ability
- losing control of a vehicle
- wild, violent beasts
- seeing a face very close to you
- having magical powers
- vividly sensing, but not necessarily seeing or hearing, a presence in the room
- finding money
- floods or tidal waves
- killing someone
- seeing yourself as dead
- being half-awake and paralyzed in bed
- people behaving in a menacing way
- seeing yourself in a mirror
- being a member of the opposite sex
- being smothered, unable to breathe
- encountering God in some form
- seeing a flying object crash
- seeing an angel
- part animal, part human creatures
- tornadoes or strong winds
- being at the movie
- seeing extra-terrestrials
- traveling to another planet
- being an animal
- seeing a UFO
- someone having an abortion
- being an object