Book Review:
Don't sleep through dream book

The Oracle of Night: The History and Science of Dreams

Sidarta Riberio, 2019

Sidarta Ribeiro's book, The Oracle of Night:  The History and Science of Dreams is an extraordinary book. This review includes a discussion of the implications of Ribeiro's account of dreams for the biological evolution of mind in animals and for the understanding of consciousness. 


Ribeiro is a Brazilian neuroscientist who has done extensive research regarding the brain processes involved in dreaming,  and he has encyclopedic knowledge of the history of the neuroscience of dreams. He is also widely read and insightful re the cultural anthropology of dreaming and dreams, early human development,  the psychology of dreams and about debates regarding the nature of consciousness. Ribeiro is a fertile creative thinker strongly grounded in brain science with an unusual ability to discuss scholarly ideas with which he disagrees without venom and as a collective effort to understand a mental phenomenon experienced by everyone nightly, but which has remained opaque to science until recently. Within recent decades, some famous scientists have advanced the view that the content of dreams is a meaningless byproduct of electrical activity in the brain during sleep,  or that memories of dreams are a subjective illusion of the waking mind, i.e., dreams don't really exist, memories of dreams are fictions. According to Ribeiro, there was a strong anti-Freudian reaction in neuroscience for decades based on the widespread view that Freud's ideas were not scientifically testable, a view with which Ribeiro strongly disagrees. Ribeiro believes that Freud and Jung were on the right track, i.e., in viewing dreams as embodying desires and fears, though Ribeiro's account of dreams goes well beyond the idea of dreams as wish fulfillment. Dreams are just as likely to be about the frustration of desire, or its potential disastrous consequences, as about the satisfaction of desire. 


Ribeiro places great emphasis on the division of sleep into slow wave phases characterized by reduced electrical activity in the brain and Rapid Eye Movement (REM) sleep with greatly enhanced electrical activity. Until recent years, many neuroscientists believed that dreams were a product of REM sleep, given that most dreams remembered immediately after waking occur in REM sleep. However in recent years, it has become apparent that dreaming occurs throughout the night in both phases of sleep, though it is far more difficult to remember dreams that occur in slow wave "deep" sleep due to reduced electrical activity in the brain. According to Ribeiro, sleep serves a variety of functions, including detoxing the brain. Sleep deprivation is a serious health risk with both short term and long term effects on mood and cognitive functioning, especially memory. In Ribeiro's account, one of the functions of sleep and of dreams is to consolidate memories and enhance learning. Many dreams, Ribeiro maintains, reflect (as Freud believed) the "residue" of the day. A good night's sleep and naps after learning activities enhance learning. Ribeiro asserts that the enhancement of memory occurs in sleep through electrical "reverberation" and reactivation of memories. In his view, slow wave sleep achieves, or attempts to achieve, a faithful replication of memories while REM sleep allows memories to be reorganized and creatively altered. The implication of this view is that memories altered in REM sleep may not be completely accurate however strongly people believe in their validity. Imagination works on memory in REM sleep. 


In past decades, many neuroscientists believed that dreaming occurred sporadically during sleep as slow wave sleep alternated with periods of REM sleep that became gradually longer throughout the night. Ribeiro's view is that dreams are like stars which are always present but can only be seen clearly after dark. During sleep, Ribeiro asserts, dreams occur without ceasing but can usually only be remembered immediately after waking. He also speculates that human brains may be capable of multiple simultaneous dreams; and (of course) everyone is familiar with day dreaming. One possible implication of the idea that dreaming may be far more common both during sleep and while waking than previously believed is ( per Daniel Kahneman) that conscious awareness exacts a large psychic and energetic cost,  and that the restoration of psychic energy requires a relaxation of the rules and brain mechanisms that allow and guide rational conscious awareness. According to this hypothesis, behind Kahneman's System1 a dream state exists which replenishes the mind. Waking consciousness, i.e., awareness subject to rational control, exists within Dreamtime. This is my speculation, not Ribeiro's.  


Recent research studies have demonstrated the importance of REM sleep for the consolidation and reorganization of memories which includes both reverberation, i.e., strengthening memories through electrical processes in the brain, and also through selective forgetting, e.g.,  pruning of synapses. Dreams (as discussed below) usually concern an authorial, autobiographical self which is continually shaped during waking hours through internal self talk that adds to one's personal narrative and in sleep through dreams that  retain and strengthen some memories, based mostly on emotional salience, and discards others. The human mind is shaping and reshaping its subjective sense of self at every moment, both while awake and asleep. Dreams play a crucial role in this process. A philosophical implication is that the self is not so much an illusion, or an actual psychic entity, as an imaginary creation of self talk and dreaming. 


Ribeiro discusses Gerald Edelman's view that "the brain is the dynamic product of a constant competition between groups of neurons and their synapses which are positively or negatively selected according to the interaction with environment. ... To Edelman, the brain more closely resembled a jungle than a computer ... neurons compete among themselves for access to neural activity and for those substances that are necessary to metabolism." In this formulation, "the development and maturation of the a product of the competition between distinct neural populations." A few months ago, I wrote and sent out a theory of the biological evolution of mind in which the main goal and achievement of animals with central nervous systems was to achieve unitary awareness in organisms consisting of millions or billions of cells. The key indicator of unitary awareness is that an injury to one part of an organism is experienced as an injury to the whole organism. According to Ribeiro, dreaming became increasingly important in the brains of mammals about 220 million years ago. It is a enhancement of imaginary mental activity that occurred (at the latest) 200-340 million years ago. My speculation is that dreaming occurred early in the evolution of animals because it served the goal of maintaining and strengthening unitary awareness during sleep, which threatened to lead to mental fragmentation. 


The Probabilistic Oracle of Night  


Ribeiro states: "To mammals living free in nature, and to those groups of humans closest to it, dreaming continues to be an essential biological function for warning against dangers, mapping out possible  outcomes for the problems .. prevalent in the dreamer's life, selecting adaptive strategies and integrating successive learnings into a coherent whole. A dream is a privileged moment for prospecting the unconscious...a dream can be seen as a way of testing out a theory in a simulated environment, with cycles of sleep strengthening memories during slow- wave sleep due to electrical reverberation .. and a restructuring of memories during long episodes of REM sleep.. the sleeping brain consolidates the best strategies it is able to devise in dreams."  (pp.. 293-94) And "The evidence is converging toward the idea that mammals' dreams are probabilistic simulations of past events and future expectations. The main function of these simulations would be to test out specific innovative behaviors against a replica of the world from memory., instead of the real world, leading to learning tat is risk free." (p. 294)  According to the theory Ribeiro's book brilliantly articulates, dreams are not prophecies -- though at times they can be eerily prophetic -- and their predictions are not infallible.  Ribeiro writes: "Dream images do not .. reveal the dreamer's destiny tomorrow, but only the apparent course they are on today .."  by utilizing the complete resources of a mental library which goes far beyond the dreamer's personal experience. Like Freud, Ribeiro believes that "The elucidating of any dream requires the identification of the dreamer's dominant wish."  Dreams are not about abstractions, or aesthetics; they have a practical import to the dreamer. Many ancient peoples and indigenous tribes believed (and still believe) that dreams are a means of communicating with spirits, gods, and the dead but the purpose of these dream simulations is to inform the dreamer how to go about achieving their mundane desires or avoiding their worst fears. The purpose of dreams is not to explore invisible worlds of spirits and gods, but to use communications with these powers to inform current and future actions in this world for concrete down- to- earth goals. 


Ribeiro 's book includes a fascinating discussion of lucid dreaming in which the dreamer awakes within her/ his dream, realizes she/ he is dreaming and then exercises intentional control of dream outcomes. Ribeiro alternates between giving advice re how to develop the power of lucid dreaming, e.g., set an intention in the mind re the desired dream subject before going to sleep and then choose a simple indicator that one is "awake" in the dream, such as raising one hand; and then proceeding by small steps to increase control of the dream, to hand wringing over the possible misuse of lucid dreaming for evil purposes. My view is that there is no more possibility of widespread mastery of lucid dreaming than of the mastery of shamanic powers,  which were potentially available to ancient peoples for many thousands of years, and for the same reasons: too difficult to acquire, too scary and unknown, especially when near god- like technological powers are prized by our civilization. There is, however,  a caveat which Ribeiro considers: neuroscience develops a technology that makes it easier to remember and control dreams, in which case all bets are off; Frankenstein's creator meets neuroscience with incalculable outcomes. Fortunately, I will not live to experience this world if it develops - unlikely but not impossible. 


The Symbolic Language of Dreams


One of the few flaws in Ribeiro's account of dreaming and dreams is the lack of adequate discussion of how dreams symbolically represent experience. Ribeiro recognizes that dreams are thoroughly infused with emotion, so much so that many dreams mainly use memories of sensory perceptions to embody emotional states. However, Ribeiro appears to be unaware of robust and rapidly growing research on interoception, i.e., the awareness of the body and its internal operations and the combination of interoception with affect. In my articles on the evolution of mind I have been influenced by the thinking of Antonio Damasio regarding affect as the foundation of mind in organisms with central nervous systems. What this means concretely is that there are arguably no affect free sensory perceptions or bodily feelings in the minds of animals or humans. Sensory perception, body awareness and affect  with positive or negative valence are enmeshed, an enmeshment reflected in dreaming which has a much longer and deeper evolutionary history than human language. To the rational mind, the strange bizarre world of dreams are symbolic representations that do not play by rational rules or respect natural laws. However, from the standpoint of the dreaming mind it may be that our rational conscious experience is a symbolic representation of dream states. To make this point another way, dream logic in which any memory of sensory perception can represent emotional states is surely closer to how the minds of animals developed hundreds of million years ago than the verbal reflections and rational understanding of modern humans. Modern humans, including neuroscientists, do not appreciate the extent to which humans have learned to experience (I almost said "see the world")  the world as it appears to us. History and culture, as well as biology, has shaped the immediate experience of humans. Naïve realism is an illusion, albeit a powerful one. 


Reibero offers a fascinating account of how and why ancient peoples and some still existing indigenous tribes had and have a far greater interest and belief in the potential of dreams than modern thinkers. Ribeiro believes that the increased importance of language and of the ability to symbolically represent experience in words rather than images gradually led to the devaluation of dreams as a means of understanding ourselves. However, in ancient civilizations the ability to translate dream experience into words allowed large communities to share dream experiences and make cultural use of a vast array of dreams, not just the dreams of shamans and tribal leaders. However, eventually symbolic representations of experience in literature and in other arts and the capacity to create representations of representations, seemingly without limit, pushed dreaming to the periphery of efforts to understand the world. Dreams came to be viewed as a curious bizarre phenomenon given limited, if any, value by philosophers and scientists, but somewhat more importance by some artists with a much greater interest in their unconscious minds. It seems that science, after decades of cluelessness regarding the neuroscience and psychological function of dreaming, is finally "on the scent",  and is making rapid progress as only a coordinated and decentralized large scale social scientific exploration can. 


There is a final question to consider: were dreams designed to be verbally articulated and remembered or does their power and scope depend on the difficulty of verbal articulation and the evanescent quality of dreams? Dreaming "made possible a hidden internal space for mental work capable of simulating the conquest of objectives, situations and probabilities of outcome, safely and with no interference in real behavior ... and with no limits to the horizon of the future under consideration." ( p. 312) It is possible that the power of dreams depends in part on the inability to remember most of them or make sense of the ones we do remember. The neuroscientist Jonathan Winston opined: "Dreams were never designed to be remembered, but they are the keys to who we are." (p. 302) Dreams resolve motivational ambiguity in a way that the Hamlet of consciousness rarely can, i.e., the whole organism receives a motivational message that for good or ill cannot be undone by words, or by the confusion of waking life. 


Finally, it s worth reflecting on the early evolutionary development of dreaming in animals, and especially in  mammals, an indication that the power to imagine would be as important in the development of consciousness as the ability to figure out the world rationally, to conceptualize and plan. Ribeiro points out that the capacity to imagine the world through dreams appears at the origin of consciousness ; it is not a late development, not an epiphenomenon of enhanced brain capacity reflected in improved tool kits and more complex levels of social organization. Ribeiro states that "human consciousness .. with its immense capacity for recounting the past and imagining the future , stems from an invasion of waking life by dreams. The first mental space for stimulating ideas must have been dreams, long before our ancestors learned to do this while wake." (p. 314) As early humans became more knowledgeable, with better technologies, they also became more imaginative, through cave art, stories, myth and music. It was the enhanced imaginations of early humans that created cultures, the most powerful imaginative creation ever developed by a species whose average life spans probably did not exceed 30 thousands of years ago,  and did not exceed 40 until the early 20th century.             

-- Dee Wilson