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Revista Brasileira de Terapia Intensiva 2022
Topics: Dreams; Humans
PubMed: 35946650
DOI: 10.5935/0103-507X.20220017-pt -
The International Journal of... Oct 2017This paper attempts to elaborate a fundamental brain mechanism involved in the creation and maintenance of symbolic fields of thought. It will integrate theories of... (Review)
Review
This paper attempts to elaborate a fundamental brain mechanism involved in the creation and maintenance of symbolic fields of thought. It will integrate theories of psychic spaces as explored by Donald Winnicott and Wilfred Bion with the neuroscientific examinations of those with bilateral hippocampal injury to show how evidence from both disciplines sheds important light on this aspect of mind. Possibly originating as a way of maintaining an oriented, first person psychic map, this capacity allows individuals a dynamic narrative access to a realm of layered elements and their connections. If the proposed hypothesis is correct, the hippocampus facilitates the integration of this symbolic field of mind, where narrative forms of thinking, creativity, memory, and dreaming are intertwined. Without the hippocampus, there is an inability to engage many typical forms of thought itself. Also, noting the ways these individuals are not impaired supports theories about other faculties of mind, providing insight into their possible roles within human thought. The evidence of different systems working in conjunction with the symbolic field provides tantalizing clues about these fundamental mechanisms of brain and mind that are normally seamlessly integrated, and hints at future areas of clinical and laboratory research, both within neuroscience and psychoanalysis.
Topics: Amnesia; Dreams; Hippocampus; Humans; Psychoanalytic Theory; Sleep; Thinking
PubMed: 28083959
DOI: 10.1111/1745-8315.12617 -
The American Journal of Psychiatry Apr 2013The hypothesis that rapid eye movement (REM) sleep disturbances are the hallmark of posttraumatic stress disorder (PTSD), proposed by Ross and colleagues in 1989, has... (Review)
Review
The hypothesis that rapid eye movement (REM) sleep disturbances are the hallmark of posttraumatic stress disorder (PTSD), proposed by Ross and colleagues in 1989, has stimulated a wealth of clinical, preclinical, and animal studies on the role of sleep in the pathophysiology of PTSD. The present review revisits this influential hypothesis in light of clinical and experimental findings that have since accumulated. Polysomnographic studies conducted in adults with PTSD have yielded mixed findings regarding REM sleep disturbances, and they generally suggest modest and nonspecific sleep disruptions. Prospective and treatment studies have provided more robust evidence for the relationship between sleep disturbances and psychiatric outcomes and symptoms. Experimental animal and human studies that have probed the relationship between REM sleep and fear responses, as well as studies focused more broadly on sleep-dependent affective and memory processes, also provide strong support for the hypothesis that sleep plays an important role in PTSD-relevant processes. Overall, the literature suggests that disturbed REM or non-REM sleep can contribute to maladaptive stress and trauma responses and may constitute a modifiable risk factor for poor psychiatric outcomes. Clinicians need to consider that the chronic sleep disruption associated with nightmares may affect the efficacy of first-line PTSD treatments, but targeted sleep treatments may accelerate recovery from PTSD. The field is ripe for prospective and longitudinal studies in high-risk groups to clarify how changes in sleep physiology and neurobiology contribute to increased risk of poor psychiatric outcomes.
Topics: Animals; Brain Waves; Dreams; Emotions; Humans; Memory; Polysomnography; REM Sleep Behavior Disorder; Resilience, Psychological; Sleep Initiation and Maintenance Disorders; Stress Disorders, Post-Traumatic
PubMed: 23223954
DOI: 10.1176/appi.ajp.2012.12040432 -
Revista de Neurologia Oct 2014Over the last decade an ever-increasing number of articles have been published on dreams, which reflects the interest that several fields of neuroscience have in the... (Review)
Review
INTRODUCTION
Over the last decade an ever-increasing number of articles have been published on dreams, which reflects the interest that several fields of neuroscience have in the topic. In this work we review the main scientific theories that have contributed to the body of knowledge on how they are produced and what function they serve.
DEVELOPMENT
The article discusses the evolution of their scientific study, following a neurophysiological and neurocognitive approach. The first of these two methods seeks to determine the neurobiological mechanisms that generate them and the brain structures involved, while the second considers dreams to be a kind of cognition interacting with that of wake-fulness. Several different hypotheses about the function of dreams are examined, and more particularly those in which they are attributed with a role in the consolidation of memory and the regulation of emotional states.
CONCLUSIONS
Although the exact mechanism underlying the generation of dreams has not been determined, neurobiological data highlight the importance of the pontine nuclei of the brainstem, several memory systems, the limbic system and the brain reward system and a number of neocortical areas. Neurocognitive data underline the relation between the cognitive and emotional processing that occurs during wakefulness and during sleep, as well as the influence of the surroundings on the content of dreams. With regard to their function, one point to be stressed is their adaptive value, since they contribute to the reprocessing of the information acquired in wakefulness and the control of the emotions. This suggests that dreams participate in the development of the cognitive capabilities.
Topics: Adaptation, Psychological; Adolescent; Arousal; Brain Mapping; Child; Child, Preschool; Cognition; Dreams; Emotions; Female; Humans; Male; Memory; Models, Neurological; Models, Psychological; Nerve Net; Neuroimaging; Sleep Stages
PubMed: 25297479
DOI: No ID Found -
The Journal of Comparative Neurology Feb 2021We review evidence challenging the hypothesis that memories are processed or consolidated in sleep. We argue that the brain is in an unconscious state in sleep, akin to... (Review)
Review
We review evidence challenging the hypothesis that memories are processed or consolidated in sleep. We argue that the brain is in an unconscious state in sleep, akin to general anesthesia (GA), and hence is incapable of meaningful cognitive processing-the sole purview of waking consciousness. At minimum, the encoding of memories in sleep would require that waking events are faithfully transferred to and reproduced in sleep. Remarkably, however, this has never been demonstrated, as waking experiences are never truly replicated in sleep but rather appear in very altered or distorted forms. General anesthetics (GAs) exert their effects through endogenous sleep-wake control systems and accordingly GA and sleep share several common features: sensory blockade, immobility, amnesia and lack of awareness (unconsciousness). The loss of consciousness in non-REM (NREM) sleep or to GAs is characterized by: (a) delta oscillations throughout the cortex; (b) marked reductions in neural activity (from waking) over widespread regions of the cortex, most pronounced in frontal and parietal cortices; and (c) a significant disruption of the functional connectivity of thalamocortical and corticocortical networks, particularly those involved in "higher order" cognitive functions. Several (experimental) reports in animals and humans have shown that disrupting the activity of the cortex, particularly the orbitofrontal cortex, severely impairs higher order cognitive and executive functions. The profound and widespread deactivation of the cortex in the unconscious states of NREM sleep or GA would be expected to produce an equivalent, or undoubtedly a much greater, disruptive effect on mnemonic and cognitive functions. In conclusion, we contend that the unconscious, severely altered state of the brain in NREM sleep would negate any possibility of cognitive processing in NREM sleep.
Topics: Anesthesia, General; Animals; Cerebral Cortex; Cognition; Dreams; Electroencephalography; Humans; Sleep; Unconsciousness; Wakefulness
PubMed: 32472571
DOI: 10.1002/cne.24963 -
Current Psychiatry Reports Mar 2015Increasing research indicates that sleep disturbances may confer increased risk for suicidal behaviors, including suicidal ideation, suicide attempts, and death by... (Review)
Review
Increasing research indicates that sleep disturbances may confer increased risk for suicidal behaviors, including suicidal ideation, suicide attempts, and death by suicide. Despite increased investigation, a number of methodological problems present important limitations to the validity and generalizability of findings in this area, which warrant additional focus. To evaluate and delineate sleep disturbances as an evidence-based suicide risk factor, a systematic review of the extant literature was conducted with methodological considerations as a central focus. The following methodologic criteria were required for inclusion: the report (1) evaluated an index of sleep disturbance; (2) examined an outcome measure for suicidal behavior; (3) adjusted for presence of a depression diagnosis or depression severity, as a covariate; and (4) represented an original investigation as opposed to a chart review. Reports meeting inclusion criteria were further classified and reviewed according to: study design and timeframe; sample type and size; sleep disturbance, suicide risk, and depression covariate assessment measure(s); and presence of positive versus negative findings. Based on keyword search, the following search engines were used: PubMed and PsycINFO. Search criteria generated N = 82 articles representing original investigations focused on sleep disturbances and suicide outcomes. Of these, N = 18 met inclusion criteria for review based on systematic analysis. Of the reports identified, N = 18 evaluated insomnia or poor sleep quality symptoms, whereas N = 8 assessed nightmares in association with suicide risk. Despite considerable differences in study designs, samples, and assessment techniques, the comparison of such reports indicates preliminary, converging evidence for sleep disturbances as an empirical risk factor for suicidal behaviors, while highlighting important, future directions for increased investigation.
Topics: Depression; Depressive Disorder; Dreams; Evidence-Based Medicine; Humans; Risk Factors; Sleep Initiation and Maintenance Disorders; Sleep Wake Disorders; Suicidal Ideation; Suicide; Suicide, Attempted
PubMed: 25698339
DOI: 10.1007/s11920-015-0554-4 -
American Family Physician Apr 2000Dreams occur during all stages of sleep. Nightmares are common. They can be associated with poor sleep and diminished daytime performance. Frequent nightmares are not... (Review)
Review
Dreams occur during all stages of sleep. Nightmares are common. They can be associated with poor sleep and diminished daytime performance. Frequent nightmares are not related to underlying psychopathology in most children and in some "creative" adults. However, recurrent nightmares are the most defining symptom of post-traumatic stress disorder and may be associated with other psychiatric illnesses. Night terrors are arousal disorders that occur most often in children and usually occur early in the sleep period. Patients with rapid-eye-movement behavior disorder often present with nocturnal injury resulting from the acting out of dreams. Dream disorders may respond to medication, but behavioral treatment approaches have shown excellent results, particularly in patients with post-traumatic stress disorder and recurrent nightmares.
Topics: Diagnosis, Differential; Dreams; Humans; Mental Disorders; Night Terrors; Patient Education as Topic; Sleep Wake Disorders; Stress Disorders, Post-Traumatic; Teaching Materials
PubMed: 10779247
DOI: No ID Found -
Medecine Sciences : M/S Oct 2020Sleep is a succession of two stages: slow-wave and rapid eye-movement sleep. The later has mixed characteristics between sleep and wakefulness. Therefore, dreams have...
Sleep is a succession of two stages: slow-wave and rapid eye-movement sleep. The later has mixed characteristics between sleep and wakefulness. Therefore, dreams have been proposed to occur during this stage. This hypothesis is now considered as oversimplified. Dreaming may occur during the two stages though with different characteristics. Deciphering brain structures associated with dreaming is difficult. However, during the two stages, a decrease in low-frequency and an increase in high-frequency electrical activity in posterior cortical regions has been reported that might be the neural correlate of dreaming. The origin of cortex stimulation is under debate, but the mechanisms involved are similar to those acting during wakefulness. Dream function is not known and it might be an epiphenomenon originating from synaptic transmission noise. Depriving subjects of rapid-eye movement sleep for two weeks has no apparent effect on their behavior.
Topics: Brain; Dreams; Electroencephalography; Humans; Neurosciences; Polysomnography; Sleep
PubMed: 33026337
DOI: 10.1051/medsci/2020134 -
The Journal of Neuroscience : the... Feb 1990
Review
Topics: Animals; Body Temperature Regulation; Cognition; Depression; Dreams; Humans; Immune System; Mortality; Narcolepsy; Nervous System; Nervous System Physiological Phenomena; Parasympathetic Nervous System; Sleep; Sleep Apnea Syndromes; Sleep Deprivation; Sleep Wake Disorders; Sleep, REM; Wakefulness
PubMed: 2406379
DOI: 10.1523/JNEUROSCI.10-02-00371.1990 -
Rheumatology (Oxford, England) Jun 2023
Topics: Humans; Dreams; Lupus Vasculitis, Central Nervous System; Lupus Erythematosus, Systemic
PubMed: 36409017
DOI: 10.1093/rheumatology/keac655