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Campillo-Ferrer T, Alcaraz-Sánchez A, Demšar E, Wu HP, Dresler M, Windt J, Blanke O. Out-of-body experiences in relation to lucid dreaming and sleep paralysis: A theoretical review and conceptual model. Neurosci Biobehav Rev 2024; 163:105770. [PMID: 38880408 DOI: 10.1016/j.neubiorev.2024.105770] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2024] [Revised: 05/31/2024] [Accepted: 06/11/2024] [Indexed: 06/18/2024]
Abstract
Out-of-body experiences (OBEs) are characterized by the subjective experience of being located outside the physical body. Little is known about the neurophysiology of spontaneous OBEs, which are often reported by healthy individuals as occurring during states of reduced vigilance, particularly in proximity to or during sleep (sleep-related OBEs). In this paper, we review the current state of research on sleep-related OBEs and hypothesize that maintaining consciousness during transitions from wakefulness to REM sleep (sleep-onset REM periods) may facilitate sleep-related OBEs. Based on this hypothesis, we propose a new conceptual model that potentially describes the relationship between OBEs and sleep states. The model sheds light on the phenomenological differences between sleep-related OBEs and similar states of consciousness, such as lucid dreaming (the realization of being in a dream state) and sleep paralysis (feeling paralyzed while falling asleep or waking up), and explores the potential polysomnographic features underlying sleep-related OBEs. Additionally, we apply the predictive coding framework and suggest a connecting link between sleep-related OBEs and OBEs reported during wakefulness.
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Affiliation(s)
- Teresa Campillo-Ferrer
- Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, the Netherlands; Department of Neuropsychology, Faculty of Psychology, Ruhr University Bochum, Bochum, Germany.
| | - Adriana Alcaraz-Sánchez
- Centre for Philosophical Psychology, Department of Philosophy, University of Antwerp, Antwerp, Belgium
| | - Ema Demšar
- Monash Centre for Consciousness and Contemplative Studies, Melbourne, Australia; Monash University, Department of Philosophy, Melbourne, Australia
| | - Hsin-Ping Wu
- Laboratory of Cognitive Neuroscience, Neuro-X Institute & Brain Mind Institute, Faculty of Life Sciences, Ecole Polytechnique Fédérale de Lausanne, Geneva, Switzerland; Department of Clinical Neuroscience, Geneva University Hospital, Geneva, Switzerland
| | - Martin Dresler
- Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Jennifer Windt
- Monash Centre for Consciousness and Contemplative Studies, Melbourne, Australia; Monash University, Department of Philosophy, Melbourne, Australia
| | - Olaf Blanke
- Laboratory of Cognitive Neuroscience, Neuro-X Institute & Brain Mind Institute, Faculty of Life Sciences, Ecole Polytechnique Fédérale de Lausanne, Geneva, Switzerland; Department of Clinical Neuroscience, Geneva University Hospital, Geneva, Switzerland
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Predictive coding, multisensory integration, and attentional control: A multicomponent framework for lucid dreaming. Proc Natl Acad Sci U S A 2022; 119:e2123418119. [PMID: 36279459 PMCID: PMC9636904 DOI: 10.1073/pnas.2123418119] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/04/2022] Open
Abstract
Lucid dreaming (LD) is a mental state in which we realize not being awake but are dreaming while asleep. It often involves vivid, perceptually intense dream images as well as peculiar kinesthetic sensations, such as flying, levitating, or out-of-body experiences. LD is in the cross-spotlight of cognitive neuroscience and sleep research as a particular case to study consciousness, cognition, and the neural background of dream experiences. Here, we present a multicomponent framework for the study and understanding of neurocognitive mechanisms and phenomenological aspects of LD. We propose that LD is associated with prediction error signals arising during sleep and occurring at higher or lower levels of the processing hierarchy. Prediction errors are resolved by generating a superordinate self-model able to integrate ambiguous stimuli arriving from sensory periphery and higher-order cortical regions. While multisensory integration enables lucidity maintenance and contributes to peculiar kinesthetic experiences, attentional control facilitates multisensory integration by dynamically regulating the balance between the influence of top-down mental models and the precision weighting of bottom-up sensory inputs. Our novel framework aims to link neural correlates of LD with current concepts of sleep and arousal regulation and provide testable predictions on interindividual differences in LD as well as neurocognitive mechanisms inducing lucid dreams.
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Loo MR, Cheng SK. Dream lucidity positively correlates with reality monitoring. Conscious Cogn 2022; 105:103414. [PMID: 36183604 DOI: 10.1016/j.concog.2022.103414] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2022] [Revised: 06/19/2022] [Accepted: 09/17/2022] [Indexed: 01/27/2023]
Abstract
Dream lucidity, the awareness of consciousness in dreams, is linked to functions that support reality monitoring in differentiating between internally and externally generated memories. However, lucid dreams have been argued to result from thin reality-fantasy boundaries that lead to reality monitoring errors. To examine the relationship between dream lucidity and reality monitoring, we recruited 31 college students to rate their dream lucidity for 7 days and then complete a reality monitoring test in Experiment 1, observing a positive correlation between dream lucidity and reality monitoring. In Experiment 2, 109 participants rated dream lucidity and the memory characteristics of perceived and imagined events. Dream lucidity was negatively correlated with differences in sensory details between the memories of perceived and imagined events. The findings indicate that individuals with high dream lucidity have a superior ability to discriminate between externally and internally generated events that are susceptible to reality monitoring errors.
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Affiliation(s)
- Moo-Rung Loo
- Institute of Cognitive Neuroscience, National Central University, Taiwan
| | - Shih-Kuen Cheng
- Institute of Cognitive Neuroscience, National Central University, Taiwan.
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García-Campayo J, Moyano N, Modrego-Alarcón M, Herrera-Mercadal P, Puebla-Guedea M, Campos D, Gascón S. Validation of the Spanish Version of the Lucidity and Consciousness in Dreams Scale. Front Psychol 2021; 12:742438. [PMID: 34744915 PMCID: PMC8566340 DOI: 10.3389/fpsyg.2021.742438] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2021] [Accepted: 09/24/2021] [Indexed: 11/24/2022] Open
Abstract
Lucid dreaming, a specific phenomenon of dream consciousness, refers to the experience being aware that one is dreaming. The primary aim of this research was to validate a Spanish version of the Lucidity and Consciousness in Dreams scale (LuCiD). A secondary aim was to explore whether meditation experience and mindfulness trait were related to LuCiD scores. Data from 367 Spanish men (34.6%) and women (65.4%) who completed LuCiD, the Five Facets of Mindfulness Questionnaire (FFMQ), and the Positive and Negative Affect Schedule (PANAS) were examined. From the total sample, 40.3% indicated some experience with formal meditation (meditators), while 59.7% did not have any meditation experience (non-meditators). A random subsample of 101 participants, who completed LuCiD for a second time after a period of 10–15days, was used for test–retest reliability analysis. The LuCiD scale comprises 28 items distributed across eight factors: insight, control, thought, realism, memory, dissociation, negative emotion, and positive emotion. Factor structure, reliability by both internal consistency and test–retest reliability, and construct and concurrent validity were tested. Confirmatory factor analysis (CFA) confirmed the original eight-factor model, showing goodness of fit in contrast to a single-factor model. Item 15 was deleted from the Dissociation factor as it performed poorly (i.e., skewness and kurtosis, non-normal distribution of responses, and corrected item–total correlation under 0.40). The scale showed adequate values of internal consistency (between α=0.65 for Memory and α=0.83 for Positive Emotion) and test–retest reliability by significant Pearson correlations (p<0.001) for each factor. The scores of meditators were higher for the LuCiD scale Insight and Dissociation factors, in contrast to those of non-meditators. The Observing facet of mindfulness was positively associated with all LuCiD factors, except Realism and Positive Emotion, and the Acting with Awareness facet showed a negative correlation with the LuCiD factor Realism. Finally, positive and negative affects was associated with the LuCiD factors Positive Emotion and Negative Emotion. This study provides a valid and reliable measure for exploring lucidity and consciousness in dreams for a Spanish population, Moreover, the results suggest a relationship with meditation experience, mindfulness trait, and positive and negative affect.
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Affiliation(s)
- Javier García-Campayo
- Department of Medicine, Psychiatry and Dermatology, University of Zaragoza, Zaragoza, Spain.,Primary Care Prevention and Health Promotion Research Network, Madrid, Spain.,Hospital Universitario Miguel Servet, Zaragoza, Spain.,Instituto de Investigación Sanitaria de Aragón (IIS Aragón), Zaragoza, Spain
| | - Nieves Moyano
- Department of Psychology, Faculty of Humanities and Educational Sciences, University of Jaén, Jaén, Spain
| | - Marta Modrego-Alarcón
- Instituto de Investigación Sanitaria de Aragón (IIS Aragón), Zaragoza, Spain.,Department of Psychology and Sociology, Faculty of Humanities and Educational Sciences, University of Zaragoza, Huesca, Spain
| | - Paola Herrera-Mercadal
- Instituto de Investigación Sanitaria de Aragón (IIS Aragón), Zaragoza, Spain.,Department of Psychology and Sociology, Faculty of Humanities and Educational Sciences, University of Zaragoza, Huesca, Spain
| | - Marta Puebla-Guedea
- Instituto de Investigación Sanitaria de Aragón (IIS Aragón), Zaragoza, Spain.,Department of Psychology and Sociology, Faculty of Social and Labor Sciences, University of Zaragoza, Zaragoza, Spain
| | - Daniel Campos
- Instituto de Investigación Sanitaria de Aragón (IIS Aragón), Zaragoza, Spain.,Department of Psychology and Sociology, Faculty of Humanities and Educational Sciences, University of Zaragoza, Huesca, Spain
| | - Santiago Gascón
- Department of Psychology and Sociology, Faculty of Social Sciences and Humanities, University of Zaragoza, Teruel, Spain
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da Mota Gomes M, Nardi AE. Charles Dickens' Hypnagogia, Dreams, and Creativity. Front Psychol 2021; 12:700882. [PMID: 34385963 PMCID: PMC8353174 DOI: 10.3389/fpsyg.2021.700882] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2021] [Accepted: 06/25/2021] [Indexed: 11/15/2022] Open
Affiliation(s)
- Marleide da Mota Gomes
- Laboratory of History of Psychiatry, Neurology, and Mental Health, Institute of Psychiatry, Institute of Neurology, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Antonio E Nardi
- Laboratory of History of Psychiatry, Neurology, and Mental Health, Institute of Psychiatry, Federal University of Rio de Janeiro, Brazilian Academy of Science, National Academy of Medicine, Rio de Janeiro, Brazil
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Krishnan D. Orchestration of dreams: a possible tool for enhancement of mental productivity and efficiency. Sleep Biol Rhythms 2021; 19:207-213. [PMID: 33526967 PMCID: PMC7839624 DOI: 10.1007/s41105-021-00313-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2020] [Accepted: 01/15/2021] [Indexed: 11/29/2022]
Abstract
Deciphering the significance of dreams, remains a dream till date. A little is known about its underlying mechanism, brain regions involved and implications with wake life. This review is aimed to investigate the latest developments to summarize the differences in nature of dreams in Rapid eye movement and Non rapid eye movement sleep, possible role of dreams in day to day life with larger focus on Lucid Dreaming- its significant role in elevating productivity and efficiency. To carry out this review, combination of keywords like Lucid Dreaming, Rapid eye movement, Non rapid eye movement, Sleep Cycle, Dream Patterns, molecular mechanism of dreaming etc. were entered in databases like National library of Medicine, Google Scholar etc. Nature and composition of dreams are distinct in different sleep phases and it tends to influence cognitive skills, memory consolidation, mood and personal temperaments. It was observed that dreams in distinct phases, can be directly/indirectly related to development of cognition, skill enhancements, learning, healing, and even stress management affecting overall performance and productivity of an individual. Understanding the nature of dream contents in different phases can possibly inculcate insights for not only recovery aid in several mental illnesses but for elevated efficiency and productivity in normal individuals as well. Realising dreams as an effective tool for its contribution in daily activities might help organising our mood and overall mental well-being, a foremost component to thrive in the contemporary world which is currently undergoing the chaos of Novel Coronavirus Disease 2019.
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Affiliation(s)
- Dolly Krishnan
- Westfälische Wilhelms-Universität Münster, Münster, Germany
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