-
The Journal of Comparative Neurology Dec 2020The presence of dreams in human sleep, especially in REM sleep, and the detection of physiologically similar states in mammals has led many to ponder whether animals... (Review)
Review
The presence of dreams in human sleep, especially in REM sleep, and the detection of physiologically similar states in mammals has led many to ponder whether animals experience similar sleep mentation. Recent advances in our understanding of the anatomical and physiological correlates of sleep stages, and thus dreaming, allow a better understanding of the possibility of dream mentation in nonhuman mammals. Here, we explore the potential for dream mentation, in both non-REM and REM sleep across mammals. If we take a hard-stance, that dream mentation only occurs during REM sleep, we conclude that it is unlikely that monotremes, cetaceans, and otariid seals while at sea, have the potential to experience dream mentation. Atypical REM sleep in other species, such as African elephants and Arabian oryx, may alter their potential to experience REM dream mentation. Alternatively, evidence that dream mentation occurs during both non-REM and REM sleep, indicates that all mammals have the potential to experience dream mentation. This non-REM dream mentation may be different in the species where non-REM is atypical, such as during unihemispheric sleep in aquatic mammals (cetaceans, sirens, and Otariid seals). In both scenarios, the cetaceans are the least likely mammalian group to experience vivid dream mentation due to the morphophysiological independence of their cerebral hemispheres. The application of techniques revealing dream mentation in humans to other mammals, specifically those that exhibit unusual sleep states, may lead to advances in our understanding of the neural underpinnings of dreams and conscious experiences.
Topics: Animals; Dreams; Electroencephalography; Humans; Sleep Stages
PubMed: 31960424
DOI: 10.1002/cne.24860 -
Consciousness and Cognition Oct 2021The understanding of biological functions of sleep has improved recently, including an understanding of the deep evolutionary roots of sleep among animals. However,... (Review)
Review
The understanding of biological functions of sleep has improved recently, including an understanding of the deep evolutionary roots of sleep among animals. However, dreaming as an element of sleep may be particularly difficult to address in non-human animals because in humans dreaming involves a non-wakeful form of awareness typically identified through verbal report. Here, we argue that parallels that exist between the phenomenology, physiology, and sleep behaviors during human dreaming provide an avenue to investigate dreaming in non-human animals. We review three alternative measurements of human dreaming - neural correlates of dreaming, 'replay' of newly-acquired memories, and dream-enacting behaviors - and consider how these may be applied to non-human animal models. We suggest that while animals close in brain structure to humans (such as mammals and birds) may be optimal models for the first two of these measurements, cephalopods, especially octopuses, may be particularly good candidates for the third.
Topics: Animals; Brain; Dreams; Humans; Sleep; Sleep, REM
PubMed: 34653784
DOI: 10.1016/j.concog.2021.103214 -
Consciousness and Cognition Aug 2020We explore the application of a wide range of sensory stimulation technologies to the area of sleep and dream engineering. We begin by emphasizing the causal role of the... (Review)
Review
We explore the application of a wide range of sensory stimulation technologies to the area of sleep and dream engineering. We begin by emphasizing the causal role of the body in dream generation, and describe a circuitry between the sleeping body and the dreaming mind. We suggest that nearly any sensory stimuli has potential for modulating experience in sleep. Considering other areas that might afford tools for engineering sensory content in simulated worlds, we turn to Virtual Reality (VR). We outline a collection of relevant VR technologies, including devices engineered to stimulate haptic, temperature, vestibular, olfactory, and auditory sensations. We believe these technologies, which have been developed for high mobility and low cost, can be translated to the field of dream engineering. We close by discussing possible future directions in this field and the ethics of a world in which targeted dream direction and sleep manipulation are feasible.
Topics: Dreams; Humans; Physical Stimulation; Sensation; Sleep, REM
PubMed: 32652511
DOI: 10.1016/j.concog.2020.102955 -
Annals of the New York Academy of... Oct 2017This article describes the future prospects of scientific dream research. Three frontiers of investigation hold special promise: neuroscientific studies of the... (Review)
Review
This article describes the future prospects of scientific dream research. Three frontiers of investigation hold special promise: neuroscientific studies of the brain-mind system's activities during sleep (such as during lucid dreaming); systematic analyses of large collections of dream reports from diverse populations of people; and psychotherapeutic explorations of the multiple dimensions of personal and collective meaning woven into the dream experiences of each individual. Several helpful books on the science of sleep and dreaming are mentioned for further study.
Topics: Awareness; Biomedical Research; Dreams; Forecasting; Humans; Psychotherapy; Sleep, REM
PubMed: 28628226
DOI: 10.1111/nyas.13415 -
Philosophical Transactions of the Royal... Sep 2018This paper approaches the debate whether perceptual consciousness requires cognitive access from the perspective of dream studies, and investigates what kind of findings... (Review)
Review
This paper approaches the debate whether perceptual consciousness requires cognitive access from the perspective of dream studies, and investigates what kind of findings could support the opposing views of this debate. Two kinds of arguments are discussed, one that claims that the hypoactivity of the dorsolateral prefrontal cortex in rapid eye movement sleep is directly relevant, and another that proposes that locating the neural correlates of dream experiences can indirectly inform the debate. It is argued that under closer reflection, neither the classical claim about dorsolateral prefrontal cortex hypoactivity nor the more recent emphasis on general posterior hot zone activity during dreaming stand up to scrutiny. White dreaming is identified as the phenomenon that, nevertheless, holds the most promise to have an impact on the debate. Going beyond the topic if studying dreams can contribute to this debate, it is argued that cognitive access is not a monolithic phenomenon, and its neural correlates are not well understood. There seems to be a relevant form of cognitive access that can operate in the absence of activity in the dorsolateral prefrontal cortex, and maybe also in the whole frontal region. If so, then exclusive posterior activation during conscious experiences might very well be compatible with the hypothesis that perceptual consciousness requires cognitive access.This article is part of the theme issue 'Perceptual consciousness and cognitive access'.
Topics: Consciousness; Dreams; Electroencephalography; Humans; Mental Recall; Perception; Prefrontal Cortex; Sleep, REM
PubMed: 30061469
DOI: 10.1098/rstb.2017.0356 -
Journal of Clinical Sleep Medicine :... Aug 2022The mechanisms involved in the origin of dreams remain one of the great unknowns in science. In the 21st century, studies in the field have focused on 3 main topics:... (Review)
Review
UNLABELLED
The mechanisms involved in the origin of dreams remain one of the great unknowns in science. In the 21st century, studies in the field have focused on 3 main topics: functional networks that underlie dreaming, neural correlates of dream contents, and signal propagation. We review neuroscientific studies about dreaming processes, focusing on their cortical correlations. The involvement of frontoparietal regions in the dream-retrieval process allows us to discuss it in light of the Global Workspace theory of consciousness. However, dreaming in distinct sleep stages maintains relevant differences, suggesting that multiple generators are implicated. Then, given the strong influence of light perception on sleep regulation and the mostly visual content of dreams, we investigate the effect of blindness on the organization of dreams. Blind individuals represent a worthwhile population to clarify the role of perceptual systems in dream generation, and to make inferences about their top-down and/or bottom-up origin. Indeed, congenitally blind people maintain the ability to produce visual dreams, suggesting that bottom-up mechanisms could be associated with innate body schemes or multisensory integration processes. Finally, we propose the new dream-engineering technique as a tool to clarify the mechanisms of multisensory integration during sleep and related mental activity, presenting possible implications for rehabilitation in sensory-impaired individuals. The Theory of Proto-consciousness suggests that the interaction of brain states underlying waking and dreaming ensures the optimal functioning of both. Therefore, understanding the origin of dreams and capabilities of our brain during a dreamlike state, we could introduce it as a rehabilitative tool.
CITATION
Vitali H, Campus C, De Giorgis V, Signorini S, Gori M. The vision of dreams: from ontogeny to dream engineering in blindness. . 2022;18(8):2051-2062.
Topics: Blindness; Brain; Dreams; Humans; Sleep
PubMed: 35499135
DOI: 10.5664/jcsm.10026 -
Trends in Cognitive Sciences Feb 2010Dreams are a remarkable experiment in psychology and neuroscience, conducted every night in every sleeping person. They show that the human brain, disconnected from the... (Review)
Review
Dreams are a remarkable experiment in psychology and neuroscience, conducted every night in every sleeping person. They show that the human brain, disconnected from the environment, can generate an entire world of conscious experiences by itself. Content analysis and developmental studies have promoted understanding of dream phenomenology. In parallel, brain lesion studies, functional imaging and neurophysiology have advanced current knowledge of the neural basis of dreaming. It is now possible to start integrating these two strands of research to address fundamental questions that dreams pose for cognitive neuroscience: how conscious experiences in sleep relate to underlying brain activity; why the dreamer is largely disconnected from the environment; and whether dreaming is more closely related to mental imagery or to perception.
Topics: Brain; Consciousness; Dreams; Emotions; Environment; Humans; Imagination; Neurophysiology; Perception; Psychophysiology
PubMed: 20079677
DOI: 10.1016/j.tics.2009.12.001 -
The American Journal of Psychiatry Mar 2001This article offers selective reviews of cogent sectors of research regarding the dream in contemporary psychiatry. (Review)
Review
OBJECTIVE
This article offers selective reviews of cogent sectors of research regarding the dream in contemporary psychiatry.
METHOD
First, the author discusses relatively recent research (1953-1999) on the neurobiology and clinical psychophysiology of dreaming sleep; second, he reviews experimental cognitive neuroscientific studies of perception, emotion, and memory and the putative interrelationships among them in generating dream imagery; and third, he interprets psychoanalytic studies (1900-1999) on related aspects of dreams and the dream process.
RESULTS
Exploration for interrelationships among information from these three areas entails discussion of the mind/brain problem. These considerations illuminate some of the logical and interpretive dilemmas that enter into debates about Freud's theory of the dream.
CONCLUSIONS
The author proposes a preliminary psychobiologic concept of the dream process and discusses, in light of the foregoing considerations, the importance of collaborative research for developing a realistic perspective concerning the proper place of the dream in contemporary psychiatry.
Topics: Biological Evolution; Brain; Dreams; History, 20th Century; Humans; Memory; Models, Neurological; Psychiatry; Psychoanalysis; Psychoanalytic Interpretation; Psychoanalytic Theory; Sleep, REM
PubMed: 11229972
DOI: 10.1176/appi.ajp.158.3.351 -
Trends in Cognitive Sciences Jun 2023Newly encoded memory traces are spontaneously reactivated during sleep. Since their discovery in the 1990s, these memory reactivations have been discussed as a potential... (Review)
Review
Newly encoded memory traces are spontaneously reactivated during sleep. Since their discovery in the 1990s, these memory reactivations have been discussed as a potential neural basis for dream experiences. New results from animal and human research, as well as from the rapidly growing field of sleep and dream engineering, provide essential insights into this question, and reveal both strong parallels and disparities between the two phenomena. We suggest that, although memory reactivations may contribute to subjective experiences across different states of consciousness, they are not likely to be the primary neural basis of dreaming. We identify important limitations in current research paradigms and suggest novel strategies to address this question empirically.
Topics: Animals; Humans; Dreams; Sleep; Consciousness
PubMed: 36959079
DOI: 10.1016/j.tics.2023.02.006 -
Consciousness and Cognition Dec 2011Dreaming in patients with schizophrenia was and is of particular interest to researchers and clinicians due to the phenomenological similarities between the dreaming... (Review)
Review
Dreaming in patients with schizophrenia was and is of particular interest to researchers and clinicians due to the phenomenological similarities between the dreaming state and schizophrenic daytime symptomatology such as bizarre thoughts or hallucinations. Extensive literature reviews have shown that dream studies in the field of psychopathology often do not fulfill common scientific criteria. The present paper focuses on the methodological issues like sampling methods, the dream collection method, and dream content analysis that are crucial with regard to the validity of the findings. It is also suggested that the so-called dimensional approach (linking severity of daytime symptoms directly to specific dream characteristics) will be very helpful for identifying which psychopathological symptoms of schizophrenia are most closely linked to dream content.
Topics: Antipsychotic Agents; Biomedical Research; Case-Control Studies; Data Interpretation, Statistical; Dreams; Humans; Schizophrenia; Schizophrenic Psychology
PubMed: 20537924
DOI: 10.1016/j.concog.2010.05.004