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Acta Bio-medica : Atenei Parmensis May 2022The ability to remember dreams can depend on a wide range of factors such as personality, creativity, mental state, cognitive functions as well as somatic symptoms. In...
The ability to remember dreams can depend on a wide range of factors such as personality, creativity, mental state, cognitive functions as well as somatic symptoms. In the course of their studies, medical researchers have demonstrated that about 80% patients, woken up at their Rapid Eye Movement (REM) sleep phase, can remember their own dreams, whereas, in clinical practice, young adults can remember their dreams on their awakenings only once or twice a week. Let us now come to the point: in this study we suggest some hypotheses that could explain the reason why patients suffering from psychosomatic disorders seem to remember dreams much less frequently than healthy individuals.
Topics: Cognition; Dreams; Humans; Mental Recall; Psychophysiologic Disorders; Sleep, REM; Young Adult
PubMed: 35546027
DOI: 10.23750/abm.v93i2.11218 -
Neuroscience and Biobehavioral Reviews Dec 2020Dreams are internally generated experiences that occur independently of current sensory input. Here we argue, based on cortical anatomy and function, that dream... (Review)
Review
Dreams are internally generated experiences that occur independently of current sensory input. Here we argue, based on cortical anatomy and function, that dream experiences are tightly related to the workings of a specific part of cortical pyramidal neurons, the apical integration zone (AIZ). The AIZ receives and processes contextual information from diverse sources and could constitute a major switch point for transitioning from externally to internally generated experiences such as dreams. We propose that during dreams the output of certain pyramidal neurons is mainly driven by input into the AIZ. We call this mode of functioning "apical drive". Our hypothesis is based on the evidence that the cholinergic and adrenergic arousal systems, which show different dynamics between waking, slow wave sleep, and rapid eye movement sleep, have specific effects on the AIZ. We suggest that apical drive may also contribute to waking experiences, such as mental imagery. Future studies, investigating the different modes of apical function and their regulation during sleep and wakefulness are likely to be richly rewarded.
Topics: Arousal; Dreams; Humans; Sleep; Sleep, REM; Wakefulness
PubMed: 33002561
DOI: 10.1016/j.neubiorev.2020.09.018 -
Revue Neurologique Oct 2023Since the discovery of REM (Rapid Eye Movement) sleep in 1953, misconceptions have arisen as to the evidence for its adaptive function and its relation to dreams. Eye... (Review)
Review
Since the discovery of REM (Rapid Eye Movement) sleep in 1953, misconceptions have arisen as to the evidence for its adaptive function and its relation to dreams. Eye movements recorded during REM sleep have not been consistently reported to mirror the eye movements predicted by dream reports. But evidence on eye movement and somatic motor expression from patients with REM sleep behavior disorder (RBD) is consistent with dream enacting behavior. The assumption that dreaming occurs only in REM sleep is incorrect, with numerous reports of nonREM dreaming. However, there may be qualitative differences between REM and nonREM dreams. Early studies that suggested a vital role for REM sleep in psychological well-being are refuted by studies of pharmacologically induced partial or complete REM sleep suppression. Studies of sleep across species show that the primitive monotreme mammals, platypus and echidna, have far more REM sleep than any other homeotherm group, whereas birds have far less REM sleep than any other homeotherm group. Human REM sleep amounts are not unusual, are correlated with nonREM sleep durations but are not correlated with intelligence. Across groups of homeotherms, REM sleep time is highly and inversely correlated (r=-0.975, P=0.02) with average core body temperature, suggesting that REM sleep cycles with nonREM sleep to regulate brain temperature during sleep. Cetacean mammals (dolphins and whales) do not have REM sleep despite their very large brain sizes and impressive cognitive abilities. Reports of "REM sleep-like states" in arachnids, cephalopods and in zebrafish larvae are lacking critical evidence that the observed behaviors are occurring during sleep and that the behaviors are homologous to mammalian REM sleep.
Topics: Animals; Humans; Sleep, REM; Dreams; Mythology; Zebrafish; Mammals
PubMed: 37625974
DOI: 10.1016/j.neurol.2023.08.002 -
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 -
Consciousness and Cognition Jan 2024Acetylcholine is a neurotransmitter and neuromodulator involved in a variety of cognitive functions. Additionally, acetylcholine is involved in the regulation of REM... (Review)
Review
Acetylcholine is a neurotransmitter and neuromodulator involved in a variety of cognitive functions. Additionally, acetylcholine is involved in the regulation of REM sleep: cholinergic neurons in the brainstem and basal forebrain project to and innervate wide areas of the cerebral cortex, and reciprocally interact with other neuromodulatory systems, to produce the sleep-wake cycle and different sleep stages. Consciousness and cognition vary considerably across and within sleep stages, with metacognitive capacity being strikingly reduced even during aesthetically and emotionally rich dream experiences. A notable exception is the phenomenon of lucid dreaming-a rare state whereby waking levels of metacognitive awareness are restored during sleep-resulting in individuals becoming aware of the fact that they are dreaming. The role of neurotransmitters in these fluctuations of consciousness and cognition during sleep is still poorly understood. While recent studies using acetylcholinesterase inhibitors suggest a potential role of acetylcholine in the occurrence of lucid dreaming, the underlying mechanisms by which this effect is produced remains un-modelled and unknown; with the causal link between cholinergic mechanisms and upstream psychological states being complex and elusive. Several theories and approaches targeting the association between acetylcholine and metacognition during wakefulness and sleep are highlighted in this review, moving through microscopic, mesoscopic and macroscopic levels of analysis to detail this phenomenon at several organisational scales. Several exploratory hypotheses will be developed to guide future research towards fully articulating how metacognition is affected by activity at the acetylcholine receptor.
Topics: Humans; Metacognition; Acetylcholine; Acetylcholinesterase; Sleep; Dreams; Wakefulness
PubMed: 38042119
DOI: 10.1016/j.concog.2023.103608 -
Sports Medicine and Arthroscopy Review Mar 2022Arthrofibrosis (AF) is an exaggerated immune response to a proinflammatory insult leading to pathologic periarticular fibrosis and symptomatic joint stiffness. The knee,... (Review)
Review
Arthrofibrosis (AF) is an exaggerated immune response to a proinflammatory insult leading to pathologic periarticular fibrosis and symptomatic joint stiffness. The knee, elbow, and shoulder are particularly susceptible to AF, often in the setting of trauma, surgery, or adhesive capsulitis. Prevention through early physiotherapeutic interventions and anti-inflammatory medications remain fundamental to avoiding motion loss. Reliable nonoperative modalities exist and outcomes are improved when etiology, joint involved, and level of dysfunction are considered in the clinical decision making process. Surgical procedures should be reserved for cases recalcitrant to nonoperative measures. The purpose of this review is to provide an overview of the current understanding of AF pathophysiology, identify common risk factors, describe prevention strategies, and outline both nonoperative and surgical treatment options. This manuscript will focus specifically on sterile AF of the knee, elbow, and shoulder.
Topics: Bursitis; Dreams; Humans; Joint Diseases; Knee Joint; Range of Motion, Articular
PubMed: 35113841
DOI: 10.1097/JSA.0000000000000324 -
International Journal of... Aug 2013Dreaming occurs during non-rapid eye movement (NREM) and rapid eye movement (REM) sleep, which both are regulated by homeostatic, ultradian, and circadian processes.... (Review)
Review
Dreaming occurs during non-rapid eye movement (NREM) and rapid eye movement (REM) sleep, which both are regulated by homeostatic, ultradian, and circadian processes. However, the magnitude of how ultradian REM and NREM sleep and its EEG correlates impact onto dream recall remains fairly unknown. In this review, we address three questions: 1. Is there an ultradian NREM-REM sleep modulation in successful dream recall, which is gated by the circadian clock? 2. What are the key electrophysiological correlates that account for dream recall during NREM and REM sleep and 3. Are there age-related changes in the ultradian and circadian regulation in dream recall and its electrophysiological correlates? Knowledge on the specific frequency and topography NREM and REM sleep differences prior to dream recall may pinpoint to the cerebral correlates that account for this cognitive process, and hint to their possible physiological meaning.
Topics: Activity Cycles; Aging; Circadian Rhythm; Dreams; Electroencephalography; Humans; Mental Recall
PubMed: 23524011
DOI: 10.1016/j.ijpsycho.2013.03.006 -
PloS One 2021The phenomenon of dreaming about the laboratory when participating in a sleep study is common. The content of such dreams draws upon episodic memory fragments of the...
The phenomenon of dreaming about the laboratory when participating in a sleep study is common. The content of such dreams draws upon episodic memory fragments of the participant's lab experience, generally, experimenters, electrodes, the lab setting, and experimental tasks. However, as common as such dreams are, they have rarely been given a thorough quantitative or qualitative treatment. Here we assessed 528 dreams (N = 343 participants) collected in a Montreal sleep lab to 1) evaluate state and trait factors related to such dreams, and 2) investigate the phenomenology of lab incorporations using a new scoring system. Lab incorporations occurred in over a third (35.8%) of all dreams and were especially likely to occur in REM sleep (44.2%) or from morning naps (48.4%). They tended to be related to higher depression scores, but not to sex, nightmare-proneness or anxiety. Common themes associated with lab incorporation were: Meta-dreaming, including lucid dreams and false awakenings (40.7%), Sensory incorporations (27%), Wayfinding to, from or within the lab (24.3%), Sleep as performance (19.6%), Friends/Family in the lab (15.9%) and Being an object of observation (12.2%). Finally, 31.7% of the lab incorporation dreams included relative projections into a near future (e.g., the experiment having been completed), but very few projections into the past (2.6%). Results clarify sleep stage and sleep timing factors associated with dreamed lab incorporations. Phenomenological findings further reveal both the typical and unique ways in which lab memory elements are incorporated de novo into dreaming. Identified themes point to frequent social and skillful dream scenarios that entail monitoring of one's current state (in the lab) and projection of the self into dream environments elaborated around local space and time. The findings have implications for understanding fundamental dream formation mechanisms but also for appreciating both the advantages and methodological pitfalls of conducting laboratory-based dream collection.
Topics: Adult; Dreams; Female; Humans; Laboratories; Male; Memory, Episodic; Mental Recall; Polysomnography; Sleep; Sleep Stages; Sleep, REM; Young Adult
PubMed: 34614021
DOI: 10.1371/journal.pone.0257738 -
Neuroscience and Biobehavioral Reviews Apr 2023Dreams are often viewed as fascinating but irrelevant mental epihenomena of the sleeping mind with questionable functional relevance. Despite long hours of oneiric... (Review)
Review
Dreams are often viewed as fascinating but irrelevant mental epihenomena of the sleeping mind with questionable functional relevance. Despite long hours of oneiric activity, and high individual differences in dream recall, dreams are lost into oblivion. Here, we conceptualize dreaming and dream amnesia as inherent aspects of the reactive and predictive homeostatic functions of sleep. Mental activity during sleep conforms to the interplay of restorative processes and future anticipation, and particularly during the second half of the night, it unfolds as a special form of non-constrained, self-referent, and future-oriented cognitive process. Awakening facilitates constrained, goal-directed prospection that competes for shared neural resources with dream production and dream recall, and contributes to dream amnesia. We present the neurophysiological aspects of reactive and predictive homeostasis during sleep, highlighting the putative role of cortisol in predictive homeostasis and forgetting dreams. The theoretical and methodological aspects of our proposal are discussed in relation to the study of dreaming, dream recall, and sleep-related cognitive processes.
Topics: Humans; Dreams; Sleep, REM; Sleep; Mental Processes; Amnesia; Mental Recall
PubMed: 36804397
DOI: 10.1016/j.neubiorev.2023.105104 -
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