Have you ever woken up from a weird dream or nightmare wondering why it was so bizarre? Or wondered why some people dream often and very vividly? Why others say they never remember their dreams or don’t feel they dream at all? And perhaps the most basic question: Does dreaming actually serve any healthy or functional purpose?
The SleepCare.com Dream Series will attempt to answer these questions from a variety of perspectives of dreaming. Similar to how your description of an elephant may change depending on whether you’re looking at it from the front, back, side, or top, each of the perspectives provide clues and answers to the question of what exactly dreaming is–and how it can impact our lives.
The Psychological Perspective of Dreaming
A good starting point for understanding psychological perspectives on dreaming is the work of Sigmund Freud and his contemporary, Carl Jung. Both were psychoanalysts who focused on the unconscious as a way of understanding why people dream.
Freud viewed sleep as a way for the body and brain to temporarily “disconnect” from the constant stream of stimuli coming from the environment. For example, he noted that when people sleep, they typically turn off the lights, make the room a comfortable temperature, and cover up with a blanket if cold. All this is done to reduce potential external stimuli that could wake people from sleep.
The brain also needs to contend with internal stimuli, however. Freud described these as base, uncontrolled urges and desires that people have, such as sex. In order to prevent these urges from disrupting sleep, the brain creates dreams as ways to fulfill these “wishes” which would be socially or morally unacceptable for people to act on if they were awake.
While Freud focused primarily on the individual, Jung took a broader approach when explaining dreams. He felt that while dreams did reflect the subconscious, they were also opportunities for individuals to tap into the “collective unconsciousness”, which Jung explained as a universal wisdom or pool of knowledge that would show up in different cultures or people groups in the form of archetypes. Archetypes typically are myths, tales, or legends about characters. According to Jung, accessing these archetypes and the collective unconsciousness during dreams can help resolve conflicts that are currently being faced by individuals.
Jung also broke dreams down into a specific format. He noted dreams often consist of four parts. First, the setting and environment for the dream is established. Second the plot for the dream plays out, including some element of essential change to the storyline. The finale occurs next, where the conflict of the plot is resolved and critical developments are ultimately made. Finally, the dream is brought to some sort of closure or ending before waking up from sleep. According to Jung, people cannot consciously affect the endings of their dreams.
The Contemporary Theory of Dreaming
Over the course of analyzing the content of hundreds of dreams, psychologist and psychoanalyst Ernest Hartmann noticed that most dreams have a central image and a corresponding emotional intensity attached to it. When researching the effect of the September 11th, 2001 terrorist attacks on dreams, he found that while the content of dreams did not change much from before to after the attacks, the emotional intensity and vividness of dreams did—specifically, emotions became more pronounced after the attacks compared to before.
To explain how emotion could affect people’s dreams, Hartmann developed the Neural Net Theory. According to this theory, the brain consists of neural networks that function together in a very rigid, highly organized manner during waking consciousness because there are specific goals that guide their activities. During dreaming, however, these networks are free to function in much more loosely connected, “auto-associative” manner, so they are able to form connections that they would not be capable of making during waking consciousness.
Hartmann theorizes that people’s emotions are what guide the connection making processes of the brain’s neural networks in dream sleep. He uses the analogy of a calm sea surface to describe how the brain functions normally during dreaming. A strong storm that causes large swells and waves to the sea surface is the equivalent of whatever emotions people are experiencing at that particular time. The function of dreaming then becomes to “resolve the storm”—in other words, to resolve the strong emotions by integrating them with long-term memories that can be accessed during the loosely-connective, auto-associative state the brain is in dreaming. Hartmann calls this The Contemporary Theory of Dreaming.
The Neurological Perscpective of Dreaming
The human brain is the most complex and mysterious part of the human anatomy. Many of the unanswered questions surround the act of dreaming. SleepCare.com has devoted a four-part series to explaining the various functions and theories of dreaming. In this part we discuss the neurological perspective of dreaming, where dreams are thought to exist to as a biological function that serves a specific purpose(s).
The neurobiological approach to dreaming focuses on how the actual, physical brain functions when a person is dreaming. Because of this perspective, dreams are viewed entirely as physiological events that do not have any deeper meaning that can be deconstructed and analyzed, as in the psychological view. The content of dreams is taken to be nothing more than a result of the processes that occur in the brain during dream sleep, which typically happens during Rapid Eye Movement (REM) periods throughout the night (although not exclusively).
The Activation-Synthesis Theory
Prior to the late 1970s, most of the research on dreams and dreaming focused on the content of dreams and psychological interpretations of them. In 1977, however, Harvard University psychiatrists John Allan Hobson and Robert McCarley suggested a new approach, which was called the Activation-Synthesis Theory.
In EEG studies of the brain during sleep, they noted that an area of the brain called the pons generates brief, random signals that were called PGO (ponto-geniculo-occipital) spikes. Hobson and McCarley said that another section of the brain that is active during REM sleep—the forebrain—responds to all these random signals by generating various images. These images form the content of dreams and correspond to the quick eye movements and phasic bursts of muscle activity that are characteristic of REM sleep. Because the initial PGO spikes are random, as are the forebrain’s attempts to “interpret” them with dream imagery, Hobson and McCarley suggested the content of dreams becomes bizarre when compared with waking consciousness. Another explanation for the bizarreness of dreams comes from the brain’s neurochemistry during dream sleep: in particular, the levels of the neurotransmitters serotonin and norepinephrine are lower, and levels of acetylcholine are higher. These result in the distortions, unusual juxtapositions, sudden scene changes, and illogical reasoning that are characteristic of bizarreness in dreams.
Revising the Activation-Synthesis Theory
Twenty years later, neuropsychologist and psychoanalyst Mark Solms would revise the Activation-Synthesis theory based on his research involving the dreams of 361 patients suffering from a variety of brain lesions and injuries. Upon examination, 29 of the patients did not have any actual damage and were designated as a control group. Of the 332 patients remaining, 220 of them had no changes to their dreaming despite their brain injuries. This meant that of the original group, 132 patients did experience a change in their dreaming. Solms determined that 112 of these patients had forebrain lesions, but no damage to the brainstem (where the pons is located). This suggested that the forebrain was just as important, if not more so, than the pons for dreaming to occur.
While it was not possible to deliberately remove patient’s forebrains to investigate the effects of such operations, Solms did the
next best thing: he looked at scientific literature between 1940 and 1975, when frontal lobotomies were done as a treatment for schizophrenia. The findings were fairly significant: between 70-90% of lobotomized schizophrenics suffered a complete loss of dreaming.
Dreaming Not Limited to Just REM Sleep
As early as the mid-1960s, researchers investigating the nature of dreaming reported findings that indicated dreaming occurred not just in REM sleep, but in NREM sleep as well (although the dreams were significantly less frequent and shorter in length). Because neurobiological theories used eye movements and phasic muscle events of REM as a key part of their explanation for dreaming, there wasn’t really a good answer for how dreaming could occur during NREM sleep from this perspective. The research Mark Solms did, indicating the importance of the forebrain network to dreaming (as opposed to primarily the pons, as in the Activation-Synthesis theory), bridged this gap. It did so by explaining that REM sleep provided the ideal conditions to trigger the forebrain network, although it was also possible in rare instances during NREM, particularly during sleep onset.
The Develpmental Perspective of Dreaming
It’s easy to think back to when we were young and remember how things were different: what we thought of parents and adults, trips to a doctor’s or dentist’s office, first day of school. Do dreams fall into this category as well? Are the dreams we have as children significantly different from those we have as adults? We continue the Dream Series to look at the developmental perspective of dreams throughout the different stages of life. Is dreaming an ability that people are born with, or does it develop as they grow through childhood and adolescence? Psychologist David Foulkes has spent most of his life conducting research to answer these question.
Dreaming in Children and Adolescents
Foulkes set up a longitudinal study with participants which allowed him to see how dreaming occurred at various ages through childhood and adolescence. His initial group included seven boys and seven girls ages two through four that he followed for a span of five years, looking at dreaming between the ages of three and nine. He also studied a second group of participants—eight boys and eight girls ages nine and ten—for five years to examine dreaming during the ages of nine to fifteen.
In the first, third, and fifth years of the studies, Foulkes had the participants come into the lab to sleep for a total of nine nights. While in the lab, they were awakened three times—from either NREM or REM sleep—and were asked about any dreams that they had or were having at those moments. To ensure experimenter consistency, Foulkes conducted all 2,711 awakenings himself.
Analyzing the data he collected, Foulkes found that for children under five years of age, dreaming primarily consisted of static or bland images. By ages five to eight, dreams had a sequence of events to them but lacked a well-developed narrative. Compared with adults, dreams of young children showed lower levels of aggression, misfortunes, and negative emotions. Gender differences in dream content showed up in late childhood but really didn’t become significantly prevalent until adolescence.
Another significant development occurred at the nine to eleven age range: the recall rate of dreams for children approached those of adults. Compared to adults, dreams of young children showed lower levels of aggression, misfortunes, and negative emotions. Other studies investigating children’s dreams found they have a higher number of animal characters than those of adults, particularly wild or frightening animals such as snakes, spiders, or insects. Interestingly, there were less domesticated animals (dog, cat, horse) present for children than adults.
The Dreams of Adults
Given their greater cognitive and verbal abilities, it is reasonable to think that collecting dream reports from adults in a lab setting would be significantly easier than doing so with children. In practice, however, this is not always the case. Being awakened from sleep and asked to give a report (while likely a little groggy) of what was just being dreamt about is difficult for adults just as it can be for kids. Additionally, adults can be motivated to tell the researchers something (as opposed to admitting they can’t recall anything) if they’re being compensated in some manner for their time and participation. Adults may also be less likely to confess embarrassing or troubling elements in their dreams, as compared to children—who are notorious for their lack of inhibitions and blunt descriptions.
Despite these challenges, much information has been gained about the dreams of adults. The biggest finding is that the vast majority of dreams are rather mundane and typically involve everyday tasks. Adult dreamers are rarely alone in their dreams—about half of the time family members or friends and acquaintances are involved, with strangers or unknown persons present the rest of the time. Compared to the other senses, auditory (sound) cues are present most frequently, and may show up in a large variety of ways: conversations, doors opening or closing, dogs barking, traffic sounds, etc. Negative emotions—particularly when they can be explicitly recalled—outnumber positive emotions in dreams by a 2:1 ratio. This may help explain why, while bizarre dreams are a minority compared to mundane ones, they often stand out so readily and are usually thought of quickly when adults are asked to recall a dream from their past.
Dreaming as Part of the Developmental Process
In evaluating different developmental tasks as predictors for dream reporting, Foulkes found that the development of visuospatial skills was the only reliable predictor in children ages five to nine. This suggested that having a visual imagination may be a requirement before dreaming (as we think of it as adults) can really occur. Foulkes also noted that once children had the ability to dream, their linguistic and descriptive skills started to correlate with the length and narrative complexity of their dream reports.
The results of these studies led Foulkes to develop a new discipline called “psychoneirics”, which is the cognitive psychological study of the processes of dreaming. Noting that dreaming develops alongside various mental skills needed for waking consciousness, Foulkes determined that REM dreaming is a skilled cognitive act where memories and knowledge are reprocessed, leading to the generation of consciously understood and organized dream narratives. Because of their developmental similarity, the dreaming process can be modeled after the system people use to produce language. First, an input is selected—in other words, what do we want to dream? Next, the structure and elements of the dream are filled in—for example, what are the scenes? Who are the characters? What happens? Once these are put together, all the elements are stored as a complete dream, then sent to the areas of the brain that will produce the content as an actual dream that we are capable of recalling and narrating when we’re awake.
The Evolutionary Perspective of Dreaming
Have humans always been able to dream? While it may seem an unusual question to consider, from an evolutionary perspective, we haven’t. Finnish neuroscientist Antti Revonsuo notes that when we dream, the brain builds a very realistic model of the world where some elements occur less frequently than they do in everyday life, and others appear more often. Additionally, the content of dreams is consistently and significantly changed by certain types of experiences when we’re awake. Using these observations, and evidence gathered from a variety of other sources, Revonsuo developed the Threat Simulation Hypothesis of dreaming.
The Threat Simulation Hypopthesis of Dreaming
Unlike the emotional functions of dreaming from a psychological perspective, the Threat Simulation Hypothesis assigns a biological purpose to dreaming: the realistic rehearsal of threats that may be faced while awake, which improves the odds of survival and producing children to continue the species.
Although the body’s muscles are typically paralyzed while dreaming, the brain’s activity level is comparable to when a person is awake—meaning that how the brain responds to events in a dream is similar to how it will respond when the person confronts the situation while awake. This principle is often used by athletes who mentally rehearse successfully competing over and over again (during both waking and dreaming states) to further train their bodies for competition. In a similar manner, those human ancestors who developed a capacity for dreaming would have a survival advantage over those who did not because they’d be rehearsing survival techniques and solving problems while asleep.
Evidence From Several Different Areas
Support for an evolutionary approach to dreaming comes from a variety of sources, according to Revonsuo. All the senses—sight, hearing, touch, etc.—are present in dreaming at approximately the same frequencies they’re used during waking consciousness. Threatening events and negative emotions tend to be occur more often in dreams than they do naturally during the day, suggesting frequent unpleasant content (such as the threats that one must navigate for survival). Children’s dreams show a much larger number of animal characters than adult dreams, and they are more likely to be perceived as wild or threatening in young children—which makes sense if our ancestors’ dreams trained them for how to deal with the untamed animals of that era. Among adults, the most common type of recurring dream is one in which the individual is being pursued or chased, a common dilemma for primitive humans.
What Does This Mean For People Today?
Of course, the environment today is much different than that face by our human ancestors. Does this mean that dreaming doesn’t have much of a purpose for modern people? Not necessarily. While dreaming may not directly enhance one’s chances for survival as it did for our ancestors, the idea that it serves as a “rehearsal” for situations faced during waking consciousness can have useful applications. One of these might be athletes training for a competition, as mentioned earlier—or anyone who wants to build their confidence for performing a task by “practicing” it mentally while dreaming. It might also be helpful for soldiers or those who may undergo potentially traumatic events in the course of their jobs, such as firefighters or police officers. Research investigating nightmares of those suffering from post-traumatic stress disorder has found one key aspect to how frequently they occur is the degree to which the danger in the dream is perceived as being targeted to the dreamer or to someone significant to them. This makes sense when viewed from the Evolutionary Perspective on dreaming. Treatment for these individuals can effectively use image rehearsal therapy as a way to rewrite the storyline for the dream and enable the dreamer to survive.