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Neuroscience and Biobehavioral Reviews May 2019Lucid dreaming refers to the phenomenon of becoming aware of the fact that one is dreaming during ongoing sleep. Despite having been physiologically validated for... (Review)
Review
Lucid dreaming refers to the phenomenon of becoming aware of the fact that one is dreaming during ongoing sleep. Despite having been physiologically validated for decades, the neurobiology of lucid dreaming is still incompletely characterized. Here we review the neuroscientific literature on lucid dreaming, including electroencephalographic, neuroimaging, brain lesion, pharmacological and brain stimulation studies. Electroencephalographic studies of lucid dreaming are mostly underpowered and show mixed results. Neuroimaging data is scant but preliminary results suggest that prefrontal and parietal regions are involved in lucid dreaming. A focus of research is also to develop methods to induce lucid dreams. Combining training in mental set with cholinergic stimulation has shown promising results, while it remains unclear whether electrical brain stimulation could be used to induce lucid dreams. Finally, we discuss strategies to measure lucid dreaming, including best-practice procedures for the sleep laboratory. Lucid dreaming has clinical and scientific applications, and shows emerging potential as a methodology in the cognitive neuroscience of consciousness. Further research with larger sample sizes and refined methodology is needed.
Topics: Awareness; Brain; Brain Mapping; Brain Waves; Cognitive Neuroscience; Dreams; Humans; Magnetic Resonance Imaging; Metacognition; Transcranial Direct Current Stimulation
PubMed: 30880167
DOI: 10.1016/j.neubiorev.2019.03.008 -
Neurotherapeutics : the Journal of the... Jan 2021Nightmare disorder and recurrent isolated sleep paralysis are rapid eye movement (REM) parasomnias that cause significant distress to those who suffer from them.... (Review)
Review
Nightmare disorder and recurrent isolated sleep paralysis are rapid eye movement (REM) parasomnias that cause significant distress to those who suffer from them. Nightmare disorder can cause insomnia due to fear of falling asleep through dread of nightmare occurrence. Hyperarousal and impaired fear extinction are involved in nightmare generation, as well as brain areas involved in emotion regulation. Nightmare disorder is particularly frequent in psychiatric disorders and posttraumatic stress disorder. Nonmedication treatment, in particular imagery rehearsal therapy, is especially effective. Isolated sleep paralysis is experienced at least once by up to 40% of the general population, whereas recurrence is less frequent. Isolated sleep paralysis can be accompanied by very intense and vivid hallucinations. Sleep paralysis represents a dissociated state, with persistence of REM atonia into wakefulness. Variations in circadian rhythm genes might be involved in their pathogenesis. Predisposing factors include sleep deprivation, irregular sleep-wake schedules, and jetlag. The most effective therapy consists of avoiding those factors.
Topics: Dreams; Humans; Sleep Paralysis; Sleep, REM
PubMed: 33230689
DOI: 10.1007/s13311-020-00966-8 -
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 -
ELife Jun 2020Deep inside the temporal lobe of the brain, the hippocampus has a central role in our ability to remember, imagine and dream.
Deep inside the temporal lobe of the brain, the hippocampus has a central role in our ability to remember, imagine and dream.
Topics: Brain; Dreams; Hippocampus; Mental Recall
PubMed: 32508304
DOI: 10.7554/eLife.58874 -
Nature Neuroscience Jun 2017Consciousness never fades during waking. However, when awakened from sleep, we sometimes recall dreams and sometimes recall no experiences. Traditionally, dreaming has...
Consciousness never fades during waking. However, when awakened from sleep, we sometimes recall dreams and sometimes recall no experiences. Traditionally, dreaming has been identified with rapid eye-movement (REM) sleep, characterized by wake-like, globally 'activated', high-frequency electroencephalographic activity. However, dreaming also occurs in non-REM (NREM) sleep, characterized by prominent low-frequency activity. This challenges our understanding of the neural correlates of conscious experiences in sleep. Using high-density electroencephalography, we contrasted the presence and absence of dreaming in NREM and REM sleep. In both NREM and REM sleep, reports of dream experience were associated with local decreases in low-frequency activity in posterior cortical regions. High-frequency activity in these regions correlated with specific dream contents. Monitoring this posterior 'hot zone' in real time predicted whether an individual reported dreaming or the absence of dream experiences during NREM sleep, suggesting that it may constitute a core correlate of conscious experiences in sleep.
Topics: Adult; Aged; Cerebral Cortex; Dreams; Electroencephalography; Female; Humans; Male; Mental Recall; Middle Aged; Polysomnography; Sleep Stages; Young Adult
PubMed: 28394322
DOI: 10.1038/nn.4545 -
Journal of Sleep Research Aug 2019This consensus paper provides an overview of the state of the art in research on the aetiology and treatment of nightmare disorder and outlines further perspectives on... (Review)
Review
This consensus paper provides an overview of the state of the art in research on the aetiology and treatment of nightmare disorder and outlines further perspectives on these issues. It presents a definition of nightmares and nightmare disorder followed by epidemiological findings, and then explains existing models of nightmare aetiology in traumatized and non-traumatized individuals. Chronic nightmares develop through the interaction of elevated hyperarousal and impaired fear extinction. This interplay is assumed to be facilitated by trait affect distress elicited by traumatic experiences, early childhood adversity and trait susceptibility, as well as by elevated thought suppression and potentially sleep-disordered breathing. Accordingly, different treatment options for nightmares focus on their meaning, on the chronic repetition of the nightmare or on maladaptive beliefs. Clinically, knowledge of healthcare providers about nightmare disorder and the delivery of evidence-based interventions in the healthcare system is discussed. Based on these findings, we highlight some future perspectives and potential further developments of nightmare treatments and research into nightmare aetiology.
Topics: Child; Dreams; Female; Humans; Imagery, Psychotherapy; Male
PubMed: 30697860
DOI: 10.1111/jsr.12820 -
Journal of Clinical Sleep Medicine :... Aug 2010Prazosin is recommended for treatment of Posttraumatic Stress Disorder (PTSD)-associated nightmares. Level A. Image Rehearsal Therapy (IRT) is recommended for treatment...
Prazosin is recommended for treatment of Posttraumatic Stress Disorder (PTSD)-associated nightmares. Level A. Image Rehearsal Therapy (IRT) is recommended for treatment of nightmare disorder. Level A. Systematic Desensitization and Progressive Deep Muscle Relaxation training are suggested for treatment of idiopathic nightmares. Level B. Venlafaxine is not suggested for treatment of PTSD-associated nightmares. Level B. Clonidine may be considered for treatment of PTSD-associated nightmares. Level C. The following medications may be considered for treatment of PTSD-associated nightmares, but the data are low grade and sparse: trazodone, atypical antipsychotic medications, topiramate, low dose cortisol, fluvoxamine, triazolam and nitrazepam, phenelzine, gabapentin, cyproheptadine, and tricyclic antidepressants. Nefazodone is not recommended as first line therapy for nightmare disorder because of the increased risk of hepatotoxicity. Level C. The following behavioral therapies may be considered for treatment of PTSD-associated nightmares based on low-grade evidence: Exposure, Relaxation, and Rescripting Therapy (ERRT); Sleep Dynamic Therapy; Hypnosis; Eye-Movement Desensitization and Reprocessing (EMDR); and the Testimony Method. Level C. The following behavioral therapies may be considered for treatment of nightmare disorder based on low-grade evidence: Lucid Dreaming Therapy and Self-Exposure Therapy. Level C No recommendation is made regarding clonazepam and individual psychotherapy because of sparse data.
Topics: Adult; Clonidine; Cognitive Behavioral Therapy; Dreams; Evidence-Based Medicine; Eye Movement Desensitization Reprocessing; Humans; Hypnosis; Norepinephrine; Prazosin; Psychotropic Drugs; Randomized Controlled Trials as Topic; Relaxation Therapy; Stress Disorders, Post-Traumatic
PubMed: 20726290
DOI: No ID Found -
The Israel Journal of Psychiatry and... 2013The Holocaust left its visible and invisible marks not only on the survivors, but also on their children. Instead of numbers tattooed on their forearms, however, they... (Review)
Review
The Holocaust left its visible and invisible marks not only on the survivors, but also on their children. Instead of numbers tattooed on their forearms, however, they may have been marked epigenetically with a chemical coating upon their chromosomes, which would represent a kind of biological memory of what the parents experienced. as a result, some suffer from a general vulnerability to stress while others are more resilient. Previous research assumed that such transmission was caused by environmental factors, such as the parents' childrearing behavior. New research, however, indicates that these transgenerational effects may have been also (epi) genetically transmitted to their children. Integrating both hereditary and environmental factors, epigenetics adds a new and more comprehensive psychobiological dimension to the explanation of transgenerational transmission of trauma. Specifically, epigenetics may explain why latent transmission becomes manifest under stress. a general theoretical overview of epigenetics and its relevance to research on trauma transmission is presented.
Topics: Dreams; Epigenesis, Genetic; Holocaust; Humans; Intergenerational Relations; Stress Disorders, Post-Traumatic
PubMed: 24029109
DOI: No ID Found -
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 -
Current Neuropharmacology 2020The cannabinoids, Δ9 tetrahydrocannabinol and its analogue, nabilone, have been found to reliably attenuate the intensity and frequency of post-traumatic nightmares.... (Review)
Review
The cannabinoids, Δ9 tetrahydrocannabinol and its analogue, nabilone, have been found to reliably attenuate the intensity and frequency of post-traumatic nightmares. This essay examines how a traumatic event is captured in the mind, after just a single exposure, and repeatedly replicated during the nights that follow. The adaptive neurophysiological, endocrine and inflammatory changes that are triggered by the trauma and that alter personality and behavior are surveyed. These adaptive changes, once established, can be difficult to reverse. But cannabinoids, uniquely, have been shown to interfere with all of these post-traumatic somatic adaptations. While cannabinoids can suppress nightmares and other symptoms of post-traumatic stress disorder, they are not a cure. There may be no cure. The cannabinoids may best be employed, alone, but more likely in conjunction with other agents, in the immediate aftermath of a trauma to mitigate or even abort the metabolic changes which are set in motion by the trauma and which may permanently alter the reactivity of the nervous system. Steps in this direction have already been taken.
Topics: Animals; Brain; Cannabinoids; Dreams; Fear; Humans; Memory; Pain; Sleep; Stress Disorders, Post-Traumatic
PubMed: 31934840
DOI: 10.2174/1570159X18666200114142321