Table 1

Suggested Influence of Dreaming Brain States on Dream Content

ACTIVE

RELATIVELY INACTIVE or BLOCKED INPUT/OUTPUT

The brain stem and limbic system appear to act as “activators” of the REM state of sleep we typically associate with dreaming.  They arouse us into the pseudo-consciousness of REM sleep and the amygdala appears to modulate the internally generated cortical input, thus activating the emotion-related processing that stimulates the dream.¹³  How the dream forms remains controversial. Hobson and McCarley take the position that the dream is a result of higher brain centers interpreting or try to make sense of the activity in the lower centers. Antrobus argues that higher brain centers, and some cognitive processes, are involved in the creation of dreams at the onset.^{cited in 67}  Citing data that similar dream characteristics occur in a percentage of both REM and NREM sleep, Solms contends that dreaming is a function of a “dream on” mechanism in the forebrain, considering REM activation independent from dream formation.^{cited in 67}

3.1.2  The Dual Brain

 The prior section discussed various centers in the brain that are active and inactive in the dream state, and how those combinations might be responsible for the content of the dream story.  Another view of brain processing during the dream state comes from a more generalized view of how the two hemispheres typically process information.

 The brain is structured as right and left hemispheres linked by several bundles of nerve fibers that establish a communications path between the two halves. The control of our body movements and our senses are divided between these two hemispheres in a cross-wise fashion.  That is, the right side of our body is controlled by the left hemisphere and the left side by the right hemisphere.  Also it is the left hemisphere that is connected to the right visual field in each eye, and the right hemisphere that is connected to the left visual field in each eye.  

 At a gross hemispheric level, differences in processing have been observed between right and left hemispheres.  Some of these differences were discussed in the prior section as associated with the right and left side of the frontal and parietal lobes.  The left hemisphere, or “left brain,” has been found to be more involved in understanding language, processing speech and reading, labeling things with words, and in linear logical thinking.  It is charged with creating a model or story that makes sense.  The right hemisphere, or “right brain,” is more involved in processing non-verbal information (music, art, pattern recognition), forming associations and understanding what an object represents (as opposed to its name) and in visual understanding.  It also detects and interprets anomalies of experience,³⁸ a process that is important in understanding the nature of dreams.

 These distinct differences between right and left processing, however, are not pure.  The more distinct differences lie with right-handed males.  It is found that with left-handed individuals and with females, there is more bilateral or reversed representation of function normally attributed to one hemisphere or the other i.e., they might have speech functions in the right hemisphere rather than the left, or right hemisphere functions represented in both hemispheres.  Regardless of individual variations with individual brain structure, it remains useful to understand the nature of the information processing differences, since they may hold a useful relationship to differences between waking and dreaming thought.  

 Some of the most widely cited characteristics^{9, 36, 38} attributed to the two hemispheres are illustrated in Table 2.  Note the strong similarity between the right brain processing characteristics, and the characteristics of the dream state.  Observe how unlike the dream state the left-brain processing is.  If there is a strong link between the right brain and the dream state, then perhaps viewing the dream from the standpoint of the thought processes attributed to the right brain provides a further key to understanding dreams.

Table 2 Functions Attributed to Brain Hemispheres

Research associated with hemisphere activity during dream sleep⁴⁵ resulted in a variety of theories; including Bakan's early (1977-78) theory⁴⁶ that dreaming is primarily a function of the right hemisphere.  Drawing on experimental evidence from studies of EEG, brain injury, epilepsy and sleep research, Bakan contended that, "marked similarities exist between dream experience and the kind of thinking which has been ascribed to the right hemisphere, e.g., perceptual, fantasy, affective, primary process.”  

 Much of the linking of dreaming with the right hemisphere originally came from observations of patients with damage to the right parietal region of the brain.  Patients reported that they no longer had dreams and lost the ability to visualize, despite previous abilities in these areas.^{10, 11, 45}  In 1972, researchers^45,47 found shifts in the ratio of right and left EEG amplitude during changes from REM to NREM sleep.  In a sleep laboratory study of right-handed males, they found the right hemisphere to be more active than the left during the dream state (REM).  This reversed during NREM (non-dreaming) sleep.

 More recent evidence with more specific measurement tools, as noted in table 1, shows that it is more than just the right brain involved in dreaming, but rather various sections of the brain activating and de-activating that make the dream state more like right brain activity and less like left brain activity.  This likely occurs because some of the more influential centers that are activated in the dream state, are specific to the right hemisphere, such as the right inferior parietal cortex.³⁹ This is the visuospatial processing center of the brain perhaps involved in image and dream space construction. Also centers that are deactivated (such as the left parietal cortex, and dorsolateral prefrontal cortex) are responsible for processing functions that are typically associated with left hemisphere.  Nofzinger found an increase in activation of the right hypothalamus and the right frontal cortex during REM sleep and a decrease in the left frontal cortex.³⁹  Marquet found an increase in the right parietal cortex and decrease in the left during REM.^{cited in 39}

3.2  Neurological Influence on Dream Content

If we consider the information in table 1 relating to the normal functioning of the centers of the brain that are active and inactive during dream, and table 2 relating to the nature of the processing taking place in the right hemisphere, a picture emerges of why dreams appear as they do.  The connections are theoretical assumptions but they do create a good picture of why dreams appear as they do and how they might relate to the waking life experiences and concerns of the dreamer.  

 3.2.1 The Dream Experience

 1) Dreams Originate from Within

 Since the sensory cortexes (sites D and E) are blocked, little to no external sensory information is stimulating the dream.  External stimuli is usually ignored or incorporated into the dream, rather than interrupting the dream storyline, and it is usually observed to modify the ongoing dream, rather than being the primary initiator of the dream.  Dreams therefore originate entirely from within.  Hobson¹⁴  and many other researchers conclude that that the forebrain and other associative regions of the brain that are active, responds to projections from the midbrain and limbic system, by surfacing associations in visionary or other sensory forms, which we experience as the dream.

 2)  You are Conscious in Dreams

 Dreams represent a sleeping state of consciousness.  Centers that arouse consciousness (sites 1 and 2) become active.  Also, the same centers in the brain that process and perceive much of our waking space are active as well (sites  5, 7, 8). Thus, in our dreams we perceive that we are awake. Foulkes ^{cited in 67} argues that dreams are little more than waking consciousness stripped of most sensory input and freed from the obligation of making coherent connections to the external world.  We are not in quite the same state of consciousness as when awake, but we are consciously viewing and moving around in a dream space, which we believe to be real.  

 3) Time and Linear Logic Have Little Meaning

 The Posterior Cingulate Gyrus is inactive, thus episodic and working memory is inhibited, resulting in a dream story that does not follow a strict time sequence. Thus dream sequences can suddenly switch on us, and we fail to even notice or reflect on what changed until we wake up.  This switch is perhaps a result of completing one synthesis of associations, and beginning another, as a new unresolved emotional stimulus enters the dream space.  Dreams are observed to occur in a series of short segments, often with a common theme, that tend to take off in many directions and end with divergent and multiple conclusions from sequence to sequence. This could be a result of the issue the dream is dealing with, by stimulating many associations and memories all at once. Perhaps the influence of right hemisphere, which perceives and processes issues in a simultaneous holistic fashion, is attempting to resolve the same issue from all its various aspects, sequence by sequence.  Dreams appear to synthesize all the emotional content and associations in a holistic manner, looking for a pattern that best accommodates it all.

 When working on a dream with one or more sudden scene changes, treat each scene as a separate, but related, dream. Trying to relate it as one dream, with a logical connection between scene changes, rarely works.  Also working with the entire dream as a series of related dream sequences is more revealing than working with a single segment.  

 4)  Your Will is Absent or Diminished

 This inactive logic center of our sleeping brain (site A) is also the seat of our will, plus decisions and actions based on will.  Therefore in our dreams we generally don’t think to control our actions or the storyline of the dream, even though the dream is all created within our own mind.  We tend to exist as just a character in the dream, which is reacting to, subject to, or following the plot of the dream.  The possible exception is lucid dreaming, in which control is possible, but is not always total, and generally lasts for only a short time according to LaBerge.^{cited in 39}  The knowledge that the dream is not subject to the will of the ego is beneficial to dreamworking.  The characters in the dream, which represent feelings, beliefs, disconnected fragments of our personality, threatening emotional memories etc., are free to express their nature in the dream outside the influence of our will.  

 3.2.2  Dream Communications – an Internal  “Language” ?

 There remains some controversy among researchers over whether the dream itself actually contains anything of meaning for the dreamer.  If we consider the dream in light of how it is typically used in therapy or self-help, however, meaningful experiences can indeed be attributed to dreams.  Whether the “meaning” actually comes from within the dream, or how we work with the dream narrative, emotions and personal associations, a constructive “language” seems to emerge from the telling of the dream (dream narrative).  If we consider the above neurological findings and their influence on the dream experience and narrative, the specific nature of that “language” also emerges.  

 1) Dreams Appear Irrational but Only to the Waking Mind

 Even though we may be conscious in our dreams, the normal experience of waking consciousness eludes us because much of our brain responsible for rational reasoning (site A) is off-line.  Information that is processed in the dreaming brain is therefore not organized by this higher rational level of processing, nor referenced against our waking model of reality.  Even though the logical “filters” are not applied, meaningful processing may still be taking place within the dreaming brain.  Perhaps we perceive all of the bizarre combinations of events and images as normal in a dream, because the active brain centers are sharing and interpreting information in their own normal healthy fashion, their own internal “processing language”.  

 Dream thought is not totally irrational, and may be making very meaningful rational connections as we will see later.  The neural network for dreaming contains enough cognitive processing areas, such as the medial frontal cortex and anterior cingulate cortex, and perhaps the orbital-frontal cortex, to produce coherent dramatizations that often portray the dreamer's conceptions and concerns in waking life.⁶³  

 Even the bizarre imagery combinations in dreams may have a somewhat rational basis. Dreams appear to combine associated material by combining imagery fragments into composite visual images, each fragment perhaps representing a separate association. This is a psychological principle known as “condensation.”  This tendency to combine associated materials in a meaningful pattern may be one contribution of the right hemisphere.  The right hemisphere is involved in matching objects by similar appearance and processing relationships as a whole (in a Gestalt fashion) from many parts.⁹   These imagery combinations might therefore be a natural synthesis function of the right brain, which is combining related emotions, perceptions and memories to form a more complete holistic representation of the situation the dreaming brain is dealing with.

 A further review of table 2 reveals a processing taking place in the right hemisphere, which is more active in dreaming⁴⁰ and seems more “dreamlike” in nature, while the left hemisphere process is more like waking thought.   Even though we may be more conscious of the left-brain processes when we're awake, both right and left-brain are active, operational, and influencing our waking actions and thoughts.  Edwards³⁶ describes right hemisphere information processing in the waking state as: visual imagery processing; perceptual awareness of things with minimal connection to words; no sense of linear time; not requiring a basis for reason or facts; relating to things as they are in all their perceptual complexity. The process also includes seeing likeness and relationships between things; seeing metaphors and analogies; seeing how parts fit together to form a whole or gestalt; seeing the whole all at once; insight and intuition; and perceiving many facets of a problem simultaneously which often leads to divergent or multiple conclusions. This processing, which seems apparent as we observe the nature of our dreams, also occurs in waking life but perhaps below our threshold of awareness.  The point is that the processing taking place in dreams may indeed be not too far from that of normal waking state processing, thus not something abnormal or bizarre, but something we are not normally cognizant of in the waking state.

 2) Emotional Associations May Dominate Dream Imagery

 The material which is interpreted as imagery associations by the higher centers of the brain, may result from the processing of selected unresolved emotional events of the day.  Emotion is a key factor in Hobson and McCarley’s hypothesis that the intensity of dreams is reflected in the dreamer’s respiratory rate, heart rate and skin potential.^{cited in 67}  Hobson¹⁴ states that whereas dreams may appear bizarre, emotion in dreams is never bizarre. This implies that emotion, once triggered, is the driving force of the dream plot – and that the forebrain responds by surfacing associations with those emotions (in the form of dream imagery and actions) regardless of how loose those associations might be.  Seligman & Yeller also view dream emotion as the primary shaper of the dream plot, rather than a reaction to it.^{cited in 39}  Marquet¹⁴  proposes that the function of the apparent orchestration of cortical activity by the amygdala during REM sleep may be the selective processing of emotionally relevant memories.  From the standpoint of hemispheric processing, the right hemisphere is also known to be involved in the comprehension of emotions.³⁸  

 Dream imagery (and its hidden meaning) may be a result of what Berne and Savary term “Limbic Logic”.⁶⁴  They state that the brain operates on at least three different types of logic. 1) Linear Logic, which principally resides in the left hemisphere of the cerebral cortex (off-line during dreaming), is our system for gaining knowledge, problem-solving, making choices, decisions and reasoning.  2) Kinesthetic Logic, which resides in the brain stem, responds to immediate physical sensations with the goal of finding pleasure and avoiding pain. 3) Limbic Logic, which resides in the amygdala and other limbic centers (active during dreaming), has a goal of safety and survival in times of danger, and thus associates an emotion to the sensory data it encounters.  

 This limbic system, which is highly active during dreams, grasps images and emotions and processes them by association. The limbic system recognizes inner data such as emotions, and associates an emotion to the sensory data it encounters.⁶⁴ Whereas in the waking state the limbic system sees a world full of images and links them to emotions, in the dreaming state it is possible that the limbic system recovers emotional memories of our daily events and is instrumental in creating the associated dream imagery.  

 Dreams also often contain what is termed the “Central Image” or “Contextualizing” image (CI).  The CI can be a striking, arresting, or compelling image, which stands out by virtue of being especially powerful, vivid, bizarre, or detailed. According to Ernest Hartmann⁷⁵ the dream, especially the Central Image, pictures the emotion of the dreamer. This is most easily seen when there is a single powerful emotion in the dream. An example of this is the frequent vivid dream of being overwhelmed by a tidal wave, in someone who has recently experienced a traumatic event.  Hartmann contends that the intensity of the central image is a measure of the strength of the emotion. The more powerful the emotion, the more intense the central imagery of the dream will be. He indicates that central image intensity can be measured reliably, as supported by research, including a recent systematic study of dreams before and after 9/11/01.⁷⁵  Hartmann indicates further that dreaming is hyper-connective, that is, the mind (brain) makes connections more broadly in dreaming than in waking (where we operate on linear, over-learned logical connections).  However, the dreaming connections are not random. They are guided by the emotion of the dreamer. Dreams picture, or contextualize, the underlying emotion. For Hartmann, emotion is at the core of the language of the dream.

 3) Dreams – a Language of Association

 What we see as the dream are the active “consciousness” centers of our brain, responding to and interpreting processing taking place at the deeper levels. As indicated above,  Hobson¹⁴ states that that the forebrain responds to projections from the midbrain by surfacing associations (in the form of dream imagery and actions) regardless of how loose those associations might be.  Note from table 1 that it is the Visual Association cortex  which is active in dreams while the visual cortex remains inactive. Visual images in dreams are therefore associations.  Therefore the resulting dream is not seen as a linear storyline of rationally defined images and experiences, but rather as a holistic sequencing of visual associations resulting from the projections of material being processed at a deeper level.

 Carl Jung,⁴ a pioneer of basic theories upon which certain modern dreamwork is based, indicated that the various elements in a dream are “symbols’ that represent a complex combination of emotions, precepts, and thoughts. A dream representation can therefore be considered a “language” of sorts, if we consider that the dream images are “symbolic” of internal associations, derived from a meaningful processing of information, and that these dream “symbols” are combined in meaningful patterns and relationships.  These meaningful combinations of dream “symbols” might be considered a language just as individual letters (symbols) and words are combined to form meaningful sentences in our spoken and written language.

 4) Dreams – a Language of Metaphor

 According to Domhoff⁴⁰ there is a simple explanation for the extensive use, by the human mind, of metaphor in speech and dreams.  It occurs because metaphors provide a cross-modal mapping of well-understood basic experiences (such as warmth) to more difficult concepts (such as friendship) - ex: "we had a warm relationship.”  They map physiological processes (sweetness) to more complex emotional experiences (pleasure) - for example: "what a sweet deal that was!"  He states that each person learns a system of conceptual metaphors, as a result of repeated experiences in the course of childhood development.

 As table 1 indicates the right inferior parietal cortex (area BA40) is active in dreaming.  The inferior parietal cortex is also involved in spatial perception, orientation and movement, or creating a spatial perception of our waking world and our relation to it.  It thus likely plays a similar role in the formation of a dream space composed of imagery and movements placed in relationship to their respective associations.  

V. S. Ramachandran at the University of California San Diego⁵⁵ has also found that the inferior parietal lobe is a cross-modal processing area responsible for processing speech metaphors.  This cross-modal processing creates links between such things as images and sounds.  In particular, Ramachandrans research illustrated sharp shapes linked to sounds with “sharp” components, and rounded or soft shapes being linked to sounds with “soft” components.  If the right side (which is active in dreaming) is included in the inferior parietal cortical region that Ramachandran studied, this may be a reason that when we tell the dream, we often use metaphors to describe the actions, feelings and imagery in the dream. These metaphors are figures of speech that not only describe the dream, but link it to similar events and feelings in our waking life.  The dream is a pictorial metaphor.Thus dreams stories become a collage of emotionally significant associations and pictorial metaphors with meaningful relationships to waking life concerns.

5) Dreams – a Language of Context

 As we discovered above, dreams are processed in a part of the brain that talks in a non-verbal language, one that deals with relationship, properties and pattern.  The right hemisphere tends to identify an object by its relational and emotional context and the left hemisphere by its title or name.⁹

 One of the early cures for certain seizure conditions was the surgical separation of the corpus callosum, the nerve paths connecting the two hemispheres.  What resulted was an individual with two distinct brain halves, processing and perceiving independently ¹².    A test was done where a subject’s left visual field (connected to the right hemisphere) was blocked so that only his left hemisphere could see.  He was shown a fork, which he correctly identified as “a fork.”  Then the right visual field (connected to the left hemisphere) was blocked so that only the right hemisphere could see.  He could no longer identify the object as a fork, but rather called it “something I eat with.”   The right brain could not title the object; it could only identify its context or function.

 Knowing that the right brain identifies an object by function or purpose, or its contextual role, is an important key to understanding the language of dream imagery.  In order to identify a dream image (a largely right brain creation), we simply reverse the process.  Ask the dreamer to describe the “function” or  “purpose” of a dream image, and you will learn a little bit about what it represents to them on a personal level.  

6) Words Rarely Convey a Literal Message

 So what about dreams that contain speech and written or spoken words? With some exceptions, words in dreams, whether written or spoken, seldom convey literal meaning or “messages.” The language centers in the left hemisphere (that communicate with words) are inactive in the dream state. The language processing of the right hemisphere (that of meaning, emotion, visualization, context, memory and association) may be represented in dreams.  This “right brain” speech processing however does not represent meaning with terminology that follows a set of rationally dictated rules. This perhaps explains why written words in a dream morph or change as we try to read them.  Most often, words that appear in dreams are strange combinations of sounds and phrases that have no rational meaning, but that have a very direct symbolic meaning.  

 In waking life we communicate by forming messages from combinations of words and letters which follow a set of culturally learned rules of logic. In contrast, the dreaming brain communicates by forming messages from combinations of images which follow natural rules of association.  In waking life we combine word symbols to form meaningful verbal stories composed of sentences; while in dreams we combine symbolic images to form meaningful dream stories of images, and metaphors.

3.2.3  The Focus of Dreams

 1) Dreams Deal With Daily Events – but Omit the Event Itself

 Dreams appear to be associated with recent waking life events and concerns, even though the event itself is not played out in the dream. This “continuity principle” is supported by evidence that dreams contain content that is continuous with daytime events or “day residue.”  Studies by Fosse, Fosse, Hobson and Stickgold (2003)¹³ found that 65% of dream reports contain residues of previous waking activity, but only 1.4% of them represented a replay of the full waking episode.  Day-residue is generally found in dreams from the prior day, falling off significantly after a few days.  A dream-lag effect has also been observed, which shows a surprising incorporation of daytime experiences that occurred approximately one week prior to the dream.⁴²  Most therapeutic dreamwork supports this principle, in that it generally shows the dream to be related with some recent situation, or unresolved past traumatic event, in the dreamer’s waking life.

 Although dreams appear to be stimulated by a recent waking life event, the dream rarely contains the event.  But if so, only as vague fragments of the feelings, actions and characters involved.  The event, or waking episode, seems “hidden” which is perhaps the source of most confusion about dreams in relationship to waking life.  This is because the link between the parts of the brain responsible for episodic and visual recall becomes inactive during the REM stage of sleep (the communication link between the dorsal lateral prefrontal cortex and the precuneus).  Further, a number of researchers believe that the reason that we cannot recall episodes during dreaming is because of the change in the direction of information flow.  In the waking state, information flows from the hippocampus to the cortical areas.  Short-term memories are thereby transferred to longer-term memories and episodic memories are recalled when the flow is in this direction.  During dreaming, however, it is reversed.  Information flows from cortical area to the hippocampus.⁶⁵  In contrast to this, the centers responsible for recall of emotional memories (the limbic region) are very active.  As described above, it appears that the emotional context and memory associations stimulated by the waking event are represented in the dream, but the event itself is not, all due to the unique way in which memory is processed during sleep.⁶¹  This may also be because the unresolved emotional impact of the event is being processed in the dream state, not the memory itself. Therefore, representing the event is of no consequence to what the dream is dealing with.

 2) Dreams Focus On Self

 The typical dream appears to focus on concerns about self.  According to Panksepp,⁴³ dreams are laden with self-referential configurations and permutations of emotional problems to be solved.  Revonsuo states that threat perception and harm avoidance lie at the heart of many dreams. ^{cited in 39}     This may be a result of the activation of the Limbic system, Rt. Hypothalamus & Basal Forebrain which  is involved in instinctual functions such as attaching an emotional association to imagery, motivation and reward, and fight or flight in the face of threat. Ratey states that the function of the Limbic system and hippocampus is important to our “social brain”, who we see ourselves to be in relationship to others and life’s overall picture.  These active centers are involved in anomaly and error detection, which map the external experience against an internal model of reality and the social self.  The Right Inferior Parietal Cortex (BA40) which may play a key role in the spatial construction of dream imagery in a “dream space,” is also involved in our visual image of self and the space around us in relationship ourselves.

 3)  Dreams Focus on Anomalies and Conflict and Project Appropriate Action

 Nofzinger et. al. (1997; 2001) highlight the importance of the anterior cingulate cortex in dreams, which plays a role in attentional states, performance monitoring, and error detection in waking thought.⁴⁰    Although there is still some controversy over its role, some research concludes that the Anterior Cingulate monitors conflict and also detects and monitors errors, evaluates the degree of the error, and then suggests an appropriate form of action to be implemented.   The Anterior Cingulate in conjunction with other rational processing centers, such as the medial frontal cortex and orbital-frontal cortex, provide a degree of rational processing.  This produces coherent dramatizations that often portray the dreamer's conceptions and concerns in waking life.⁶³   Due to the activity error and conflict monitoring function, the resultant dream stories can focus on conflict and anomaly resolution in our lives, making dreams somewhat forward looking and predictive.  Thus dreams often end with a projected direction, path or solution, even if it is not always a positive one or the direction fully formed prior to waking.  This is supported by Jan Born and his colleagues at the University of Lubeck, who used a mathematical number test with a hidden trick in it, and found evidence that dream sleep more than doubled the probability of participants detecting the trick.^{cited in 66}

 According to Ratey,³⁸ the limbic system and parts of the brain stem also play a major role in arousing attention, particularly novelty detection and reward.  The reticular formation alerts our cognitive mind when a stimulus is novel or persistent.  The hippocampus compares the present with the past, and thus relates events as either novel or ordinary.  It inhibits reaction to ordinary events, and orients us to the novel, that which doesn’t fit our memory store.  As above, Ratey states that this process is integral to the functioning of our emotional and social brain (who we see ourselves to be in relationship to others and life’s overall picture).  The dream story may therefore be stimulated by daily events that are an anomaly or don’t “fit” the internal perception of self and our social world.

 Furthermore, certain brain centers which are active during dreaming (including the amygdala, right inferior parietal lobe and much of the right hemisphere), are responsible for recognizing emotional body and facial expressions and are involved in processing our social interactions.³⁸  Dr David Kahn⁶² indicates that within a dream, the dreamer is often aware of other people’s thoughts and feelings.  In a study of 35 subjects (who submitted 320 dream reports containing more than 1200 dream characters), he found that in a majority of their dream reports (77%), they were aware in the dream that their dream characters had feelings about them.  One explanation Kahn offers is that our awareness of the feelings and thoughts of others in our dreams prepares us for social encounters when awake.  

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