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Foffani G. To be or not to be hallucinating: Implications of hypnagogic/hypnopompic experiences and lucid dreaming for brain disorders. PNAS Nexus 2024; 3:pgad442. [PMID: 38178978 PMCID: PMC10766414 DOI: 10.1093/pnasnexus/pgad442] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/29/2023] [Accepted: 12/06/2023] [Indexed: 01/06/2024]
Abstract
The boundaries between waking and sleeping-when falling asleep (hypnagogic) or waking up (hypnopompic)-can be challenging for our ability to monitor and interpret reality. Without proper understanding, bizarre but relatively normal hypnagogic/hypnopompic experiences can be misinterpreted as psychotic hallucinations (occurring, by definition, in the fully awake state), potentially leading to stigma and misdiagnosis in clinical contexts and to misconception and bias in research contexts. This Perspective proposes that conceptual and practical understanding for differentiating hallucinations from hypnagogic/hypnopompic experiences may be offered by lucid dreaming, the state in which one is aware of dreaming while sleeping. I first introduce a possible systematization of the phenomenological range of hypnagogic/hypnopompic experiences that can occur in the transition from awake to REM dreaming (including hypnagogic perceptions, transition symptoms, sleep paralysis, false awakenings, and out-of-body experiences). I then outline how metacognitive strategies used by lucid dreamers to gain/confirm oneiric lucidity could be tested for better differentiating hypnagogic/hypnopompic experiences from hallucinations. The relevance of hypnagogic/hypnopompic experiences and lucid dreaming is analyzed for schizophrenia and narcolepsy, and discussed for neurodegenerative diseases, particularly Lewy-body disorders (i.e. Parkinson's disease, Parkinson's disease dementia, and dementia with Lewy bodies), offering testable hypotheses for empirical investigation. Finally, emotionally positive lucid dreams triggered or enhanced by training/induction strategies or by a pathological process may have intrinsic therapeutic value if properly recognized and guided. The overall intention is to raise awareness and foster further research about the possible diagnostic, prognostic, and therapeutic implications of hypnagogic/hypnopompic experiences and lucid dreaming for brain disorders.
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Affiliation(s)
- Guglielmo Foffani
- HM CINAC (Centro Integral de Neurociencias Abarca Campal), Hospital Universitario HM Puerta del Sur, HM Hospitales, Madrid 28938, Spain
- Hospital Nacional de Parapléjicos, Toledo 45004, Spain
- CIBERNED, Instituto de Salud Carlos III, Madrid 28031, Spain
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Salazar L, Vieira PM, Cascais I, Figueiroa S, Rios M. Quality of life in adolescents with narcolepsy type 1- a transversal study in a tertiary hospital. Sleep Med 2024; 113:215-219. [PMID: 38056083 DOI: 10.1016/j.sleep.2023.11.030] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/26/2023] [Revised: 11/20/2023] [Accepted: 11/20/2023] [Indexed: 12/08/2023]
Abstract
PURPOSE - Narcolepsy type 1 (NT1) is a rare chronic sleep disorder, usually arising by adolescence that negatively impacts quality of life. It is characterized by excessive daytime sleepiness (EDS), cataplexy, hypnagogic/hypnopompic hallucinations, sleep paralysis and sleep fragmentation. The goals of this work were to characterize NT1 adolescents regarding sleep characteristics, health-related quality of life (HRQoL) and future life perspectives and later to compare this group with a control group of healthy adolescents (HA). METHODS - Transversal descriptive/analytical study including NT1 patients followed in a sleep center of a tertiary hospital and 23 HA. Data were collected through an online survey, fulfilled by the participants, including four sections: demographics; questionnaire evaluating sleep and EDS; questionnaire evaluating HRQoL; inquiry regarding future perspectives. An extra section for the NT1 group only, comprising questions about the characterization of narcolepsy, was included. RESULTS 22 NT1 adolescents were included, with a median age of 15.0 years-old. Beyond EDS, all had presented cataplexy - 19 still reported it. Twenty patients took psychostimulants regularly for EDS, while 13 patients took venlafaxine or fluoxetine for cataplexy. Nineteen adolescents took regular naps and 19 maintained psychological appointments. Self-reported sleep quality was similar between groups (p = 0.112). EDS was identified in seven NT1 patients and none in the control group. HRQOL was significantly lower in NT1 patients only for the physical well-being domain (p = 0.001). Regarding future perspectives, results were similar, except for a lower probability of getting a driver's license in NT1 patients, despite no statistical significance (p = 0.104). DISCUSSION Daytime sleepiness is difficult to control in NT1, despite specialized treatment. HRQoL was similar between groups in all domains except for the physical well-being. Despite good adherence to pharmacological and non-pharmacological treatments (namely psychological therapy) that account for these good results, the physical well-being domain is difficult to manage.
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Affiliation(s)
- Luís Salazar
- Serviço de Pediatria, Centro Materno-Infantil do Norte Albino Aroso (CMIN), Centro Hospitalar Universitário de Santo António (CHUdSA), Porto, Portugal.
| | - Paula Manuel Vieira
- Serviço de Pediatria, Centro Materno-Infantil do Norte Albino Aroso (CMIN), Centro Hospitalar Universitário de Santo António (CHUdSA), Porto, Portugal
| | - Inês Cascais
- Serviço de Pediatria, Centro Materno-Infantil do Norte Albino Aroso (CMIN), Centro Hospitalar Universitário de Santo António (CHUdSA), Porto, Portugal
| | | | - Marta Rios
- Serviço de Pediatria, Centro Materno-Infantil do Norte Albino Aroso (CMIN), Centro Hospitalar Universitário de Santo António (CHUdSA), Porto, Portugal
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Hefnawy MT, Amer BE, Amer SA, Moghib K, Khlidj Y, Elfakharany B, Mouffokes A, Alazzeh ZJ, Soni NP, Wael M, Elsayed ME. Prevalence and Clinical Characteristics of Sleeping Paralysis: A Systematic Review and Meta-Analysis. Cureus 2024; 16:e53212. [PMID: 38425633 PMCID: PMC10902800 DOI: 10.7759/cureus.53212] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2024] [Accepted: 01/30/2024] [Indexed: 03/02/2024] Open
Abstract
Sleep paralysis (SP) is a mixed state of consciousness and sleep, combining features of rapid eye movement (REM) sleep with those of wakefulness. The exact cause of SP is unknown, and its prevalence varies among the studies. We aim to identify SP's global prevalence, the affected population's characteristics, and the SP's clinical picture. We searched three databases (PubMed, Scopus, and Web of Science (WoS)) using a unique search strategy to identify eligible studies. All observational studies identifying the prevalence or frequency of sleeping paralysis were included. No exclusions are made based on country, race, or questionnaire. The analysis was performed using the latest version of R software (R Core Team, Vienna, Austria). The analysis included 76 studies from 25 countries with 167,133 participants. The global prevalence of SP was 30% (95% CI (22%, 39%)). There were similar frequencies of isolated SP and SP (33%, 95% CI (26%, 42%), I2 = 97%, P <0.01; 31%, 95% CI (21%, 43%), I2 = 100%, P = 0, respectively). A subgroup analysis showed that the majority of those who experienced SP were psychiatric patients (35%, 95% CI (20%, 55%), I2 = 96%, P <0.01). The prevalence among non-psychiatric patients was among students (34%, 95% CI (23%, 47%), I2 = 100%, P = 0). Auditory and visual hallucinations were reported in 24.25% of patients. Around 4% had only visual hallucinations. Meta-regression showed no association between the frequency of SP and sex. Publication bias was detected among the included studies through visual inspection of funnel plot asymmetry. Our findings revealed that 30% of the population suffered from SP, especially psychiatric patients and students. The majority of SP cases lacked associated hallucinations, while a noteworthy proportion experienced combined visual and auditory hallucinations.
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Affiliation(s)
- Mahmoud T Hefnawy
- Faculty of Medicine, Zagazig University, Zagazig, EGY
- Medical Research Group of Egypt Branch, Negida Academy, Arlington, USA
| | - Basma E Amer
- Faculty of Medicine, Banha University, Banha, EGY
- Medical Research Group of Egypt Branch, Negida Academy, Arlington, USA
| | - Samar A Amer
- Family Medicine, Royal College of General Practice, London, GBR
- Faculty of Public Health and Community Medicine, Zagazig University, Zagazig, EGY
| | | | - Yehya Khlidj
- Faculty of Medicine, University of Algiers Benyoucef Benkhedda, Algiers, DZA
| | - Bahaa Elfakharany
- Faculty of Allied Medical Sciences, Pharos University, Alexandria, EGY
- Medical Research Group of Egypt Branch, Negida Academy, Arlington, USA
| | - Adel Mouffokes
- Internal Medicine, Faculty of Medicine, University of Oran 1 Ahmed Ben Bella, Oran, DZA
| | - Zainab J Alazzeh
- Faculty of Medicine, Jordanian University of Science and Technology, Ar-Ramtha, JOR
| | - Nishant P Soni
- Medicine, Gujarat Medical Education and Research Society Medical College and Hospital, Ahmedabad, IND
| | - Muhannad Wael
- Urology, Saint Joseph Hospital, Jerusalem, PSE
- Faculty of Medicine, An-Najah National University, Nablus, PSE
| | - Mohamed E Elsayed
- Department of Psychiatry, School of Medicine and Health Sciences, Carl von Ossietzky University of Oldenburg, Oldenburg, DEU
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Gallo FT, Spiousas I, Herrero NL, Godoy D, Tommasel A, Gasca-Rolin M, Ramele R, Gleiser PM, Forcato C. Structural differences between non-lucid dreams, lucid dreams and out-of-body experience reports assessed by graph analysis. Sci Rep 2023; 13:19579. [PMID: 37949978 PMCID: PMC10638299 DOI: 10.1038/s41598-023-46817-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2023] [Accepted: 11/06/2023] [Indexed: 11/12/2023] Open
Abstract
Dreaming is a complex phenomenon that occurs during sleep, involving various conscious dream experiences. Lucid dreams (LDs) involve heightened awareness within the dream environment, while out-of-body experiences (OBEs) involve the sensation of being outside one's physical body. OBEs occur during sleep paralysis (SP), where voluntary movements are inhibited during sleep/wake transitions while remaining aware of the surroundings. The relationship between LDs and OBEs is debated, with some viewing them as distinct phenomena and others considering them different manifestations of the same underlying experience. This study aimed to characterize non-lucid dreams, LDs, and OBEs by analyzing dream reports' structural properties. OBE reports displayed a condensed and interconnected network structure compared to non-lucid dreams and LDs. Additionally, OBE reports exhibited a specialized network structure, with specific nodes playing a more central role. These findings suggest that OBE dreams may have a more coherent and unified narrative, with certain nodes being pivotal in the network structure.
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Affiliation(s)
- Francisco T Gallo
- Laboratorio de Sueño y Memoria, Departamento de Ciencias de la Vida, Instituto Tecnológico de Buenos Aires (ITBA), Iguazú 341, (1437) Capital Federal, Buenos Aires, Argentina.
- Consejo Nacional de Investigaciones Científicas y Tecnológicas (CONICET), Godoy Cruz 2290, (1425) Capital Federal, Buenos Aires, Argentina.
| | - Ignacio Spiousas
- Consejo Nacional de Investigaciones Científicas y Tecnológicas (CONICET), Godoy Cruz 2290, (1425) Capital Federal, Buenos Aires, Argentina
- Sensorimotor Dynamics Lab (LDSM), Universidad Nacional de Quilmes, Bernal, Argentina
- Laboratorio Interdisciplinario del Tiempo y la Experiencia (LITERA), Universidad de San Andrés, Victoria, Argentina
| | - Nerea L Herrero
- Laboratorio de Sueño y Memoria, Departamento de Ciencias de la Vida, Instituto Tecnológico de Buenos Aires (ITBA), Iguazú 341, (1437) Capital Federal, Buenos Aires, Argentina
- Consejo Nacional de Investigaciones Científicas y Tecnológicas (CONICET), Godoy Cruz 2290, (1425) Capital Federal, Buenos Aires, Argentina
| | - Daniela Godoy
- Consejo Nacional de Investigaciones Científicas y Tecnológicas (CONICET), Godoy Cruz 2290, (1425) Capital Federal, Buenos Aires, Argentina
- Instituto Superior de Ingeniería de Software Tandil (CONICET/UNCPBA), Tandil, Bs. As., Argentina
| | - Antonela Tommasel
- Consejo Nacional de Investigaciones Científicas y Tecnológicas (CONICET), Godoy Cruz 2290, (1425) Capital Federal, Buenos Aires, Argentina
- Instituto Superior de Ingeniería de Software Tandil (CONICET/UNCPBA), Tandil, Bs. As., Argentina
| | - Miguel Gasca-Rolin
- Asociación Internacional de Onironautas, Carmelo Betore Bergua 2 Casa 6 9C, 50014, Zaragoza, Spain
| | - Rodrigo Ramele
- Centro de Inteligencia Computacional, Instituto Tecnológico de Buenos Aires (ITBA), Iguazú 341, (1437) Capital Federal, Buenos Aires, Argentina
| | - Pablo M Gleiser
- Laboratorio de Neurociencia de Sistemas Complejos, Departamento de Ciencias de la Vida, Instituto Tecnológico de Buenos Aires (ITBA), Iguazú 341, (1437) Capital Federal, Buenos Aires, Argentina
| | - Cecilia Forcato
- Laboratorio de Sueño y Memoria, Departamento de Ciencias de la Vida, Instituto Tecnológico de Buenos Aires (ITBA), Iguazú 341, (1437) Capital Federal, Buenos Aires, Argentina
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Türker B, Musat EM, Chabani E, Fonteix-Galet A, Maranci JB, Wattiez N, Pouget P, Sitt J, Naccache L, Arnulf I, Oudiette D. Behavioral and brain responses to verbal stimuli reveal transient periods of cognitive integration of the external world during sleep. Nat Neurosci 2023; 26:1981-1993. [PMID: 37828228 PMCID: PMC10620087 DOI: 10.1038/s41593-023-01449-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2022] [Accepted: 09/05/2023] [Indexed: 10/14/2023]
Abstract
Sleep has long been considered as a state of behavioral disconnection from the environment, without reactivity to external stimuli. Here we questioned this 'sleep disconnection' dogma by directly investigating behavioral responsiveness in 49 napping participants (27 with narcolepsy and 22 healthy volunteers) engaged in a lexical decision task. Participants were instructed to frown or smile depending on the stimulus type. We found accurate behavioral responses, visible via contractions of the corrugator or zygomatic muscles, in most sleep stages in both groups (except slow-wave sleep in healthy volunteers). Across sleep stages, responses occurred more frequently when stimuli were presented during high cognitive states than during low cognitive states, as indexed by prestimulus electroencephalography. Our findings suggest that transient windows of reactivity to external stimuli exist during bona fide sleep, even in healthy individuals. Such windows of reactivity could pave the way for real-time communication with sleepers to probe sleep-related mental and cognitive processes.
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Affiliation(s)
- Başak Türker
- Sorbonne Université, Institut du Cerveau-Paris Brain Institute-ICM, INSERM, CNRS, Paris, France
| | - Esteban Munoz Musat
- Sorbonne Université, Institut du Cerveau-Paris Brain Institute-ICM, INSERM, CNRS, Paris, France
| | - Emma Chabani
- Sorbonne Université, Institut du Cerveau-Paris Brain Institute-ICM, INSERM, CNRS, Paris, France
| | | | - Jean-Baptiste Maranci
- Sorbonne Université, Institut du Cerveau-Paris Brain Institute-ICM, INSERM, CNRS, Paris, France
- AP-HP, Hôpital Pitié-Salpêtrière, Service des Pathologies du Sommeil, National Reference Centre for Narcolepsy, Paris, France
| | - Nicolas Wattiez
- Sorbonne Université, INSERM, Neurophysiologie Respiratoire Expérimentale et Clinique, Paris, France
| | - Pierre Pouget
- Sorbonne Université, Institut du Cerveau-Paris Brain Institute-ICM, INSERM, CNRS, Paris, France
| | - Jacobo Sitt
- Sorbonne Université, Institut du Cerveau-Paris Brain Institute-ICM, INSERM, CNRS, Paris, France
| | - Lionel Naccache
- Sorbonne Université, Institut du Cerveau-Paris Brain Institute-ICM, INSERM, CNRS, Paris, France
- AP-HP, Hôpital Pitié-Salpêtrière, Service de Neurophysiologie Clinique, Paris, France
| | - Isabelle Arnulf
- Sorbonne Université, Institut du Cerveau-Paris Brain Institute-ICM, INSERM, CNRS, Paris, France
- AP-HP, Hôpital Pitié-Salpêtrière, Service des Pathologies du Sommeil, National Reference Centre for Narcolepsy, Paris, France
| | - Delphine Oudiette
- Sorbonne Université, Institut du Cerveau-Paris Brain Institute-ICM, INSERM, CNRS, Paris, France.
- AP-HP, Hôpital Pitié-Salpêtrière, Service des Pathologies du Sommeil, National Reference Centre for Narcolepsy, Paris, France.
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Blattner M, Maski K. Central Disorders of Hypersomnolence. Continuum (Minneap Minn) 2023; 29:1045-1070. [PMID: 37590822 DOI: 10.1212/con.0000000000001265] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/19/2023]
Abstract
OBJECTIVE The goals of this article are to describe the clinical approach to and management of patients with central disorders of hypersomnolence, and to understand and differentiate available diagnostic tools. LATEST DEVELOPMENTS Updated clinical practice guidelines for the treatment of central disorders of hypersomnolence and narcolepsy specifically highlight new treatment options. Approval for a lower-sodium oxybate formulation that contains 92% less sodium than the standard sodium oxybate for the treatment of narcolepsy and idiopathic hypersomnia adds to the number of medications available for these disorders, allowing for a more tailored management of symptoms. ESSENTIAL POINTS Central disorders of hypersomnolence are characterized by excessive daytime sleepiness that impacts daily functions. These disorders can be differentiated by obtaining a detailed clinical sleep history and by a thoughtful interpretation of sleep diagnostic testing. Tailoring treatment approaches to meet the needs of individuals and accounting for medical and psychiatric comorbidities may improve quality of life.
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Sodré ME, Wießner I, Irfan M, Schenck CH, Mota-Rolim SA. Awake or Sleeping? Maybe Both… A Review of Sleep-Related Dissociative States. J Clin Med 2023; 12:3876. [PMID: 37373570 DOI: 10.3390/jcm12123876] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2023] [Revised: 05/04/2023] [Accepted: 05/05/2023] [Indexed: 06/29/2023] Open
Abstract
Recent studies have begun to understand sleep not only as a whole-brain process but also as a complex local phenomenon controlled by specific neurotransmitters that act in different neural networks, which is called "local sleep". Moreover, the basic states of human consciousness-wakefulness, sleep onset (N1), light sleep (N2), deep sleep (N3), and rapid eye movement (REM) sleep-can concurrently appear, which may result in different sleep-related dissociative states. In this article, we classify these sleep-related dissociative states into physiological, pathological, and altered states of consciousness. Physiological states are daydreaming, lucid dreaming, and false awakenings. Pathological states include sleep paralysis, sleepwalking, and REM sleep behavior disorder. Altered states are hypnosis, anesthesia, and psychedelics. We review the neurophysiology and phenomenology of these sleep-related dissociative states of consciousness and update them with recent studies. We conclude that these sleep-related dissociative states have a significant basic and clinical impact since their study contributes to the understanding of consciousness and the proper treatment of neuropsychiatric diseases.
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Affiliation(s)
| | - Isabel Wießner
- Brain Institute, Federal University of Rio Grande do Norte, Natal 59078-970, RN, Brazil
| | - Muna Irfan
- Department of Neurology, University of Minnesota, Minneapolis, MN 55455, USA
| | - Carlos H Schenck
- Department of Neurology, University of Minnesota, Minneapolis, MN 55455, USA
| | - Sergio A Mota-Rolim
- Brain Institute, Federal University of Rio Grande do Norte, Natal 59078-970, RN, Brazil
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Blattner M, Maski K. Narcolepsy and Idiopathic Hypersomnia. Sleep Med Clin 2023; 18:183-199. [PMID: 37120161 DOI: 10.1016/j.jsmc.2023.01.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/01/2023]
Abstract
Narcolepsy types 1 and 2 and idiopathic hypersomnia are primary Central Nervous System (CNS) disorders of hypersomnolence characterized by profound daytime sleepiness and/or excessive sleep need. Onset of symptoms begins typically in childhood or adolescence, and children can have unique presentations compared with adults. Narcolepsy type 1 is likely caused by immune-mediated loss of orexin (hypocretin) neurons in the hypothalamus; however, the causes of narcolepsy type 2 and idiopathic hypersomnia are unknown. Existing treatments improve daytime sleepiness and cataplexy but there is no cure for these disorders.
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Affiliation(s)
- Margaret Blattner
- Department of Neurology, Beth Israel Deaconess Medical Center, Harvard Medical School, 330 Brookline Avenue, Boston, MA 02215, USA
| | - Kiran Maski
- Department of Neurology, Boston Children's Hospital, Harvard Medical School, 300 Longwood Avenue, BCH3443, Boston, MA 02115, USA.
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Kavi PC. Conscious entry into sleep: Yoga Nidra and accessing subtler states of consciousness. Prog Brain Res 2023; 280:43-60. [PMID: 37714572 DOI: 10.1016/bs.pbr.2022.12.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Human sleep is a dynamic and complex process comprising sleep stages with REM and NREM sleep characteristics that come in cycles. During sleep, there is a loss of responsiveness or a perceptual loss of conscious awareness with increasing thresholds for wakefulness as sleep progresses. There are brief bursts of wakefulness or Wake After Sleep Onset (WASO) throughout a nocturnal sleep. Conscious experience during nocturnal sleep is known to occur during lucid dreaming when one is aware during dreams when the dream is occurring. Most cultures have known lucid dreaming since antiquity. However, conscious experience during dreamless sleep is relatively lesser known. Nevertheless, selected Indo-Tibetan meditation literature has documented it since antiquity. Minimal Phenomenal Experience (MPE) research describes lucid dreamless sleep as its target phenomenology. "Conscious entry into sleep" posits tonic alertness is maintained post sleep onset through the sleep stages for sustained durations of time until an eventual loss of conscious awareness. Entering sleep consciously and being aware during dreamless sleep, including Slow Wave Activity, is plausibly to be in the state of "Yoga Nidra" or Yogic sleep. An attentive sleepful state provides access to subtler states of consciousness and significantly deepens the levels of silence. It is phenomenologically distinct from hypnagogic hallucinations and lucid dreaming. Unfortunately, sleep studies validating this phenomenology are yet to be done. Therefore, an experimental methodology akin to those used in lucid dreaming experiments is described.
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Simor P, Bogdány T, Peigneux P. Predictive coding, multisensory integration, and attentional control: A multicomponent framework for lucid dreaming. Proc Natl Acad Sci U S A 2022; 119. [PMID: 36279459 PMCID: PMC9636904 DOI: 10.1073/pnas.2123418119] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [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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Ohayon M, Pakpour A. Prevalence, incidence, evolution and associated factors of sleep paralysis in a longitudinal study of the US general population. Sleep Med 2022; 98:62-67. [DOI: 10.1016/j.sleep.2022.06.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/12/2022] [Revised: 05/25/2022] [Accepted: 06/05/2022] [Indexed: 10/18/2022]
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Wróbel-Knybel P, Flis M, Rog J, Jalal B, Karakuła-Juchnowicz H. Risk factors of sleep paralysis in a population of Polish students. BMC Psychiatry 2022; 22:383. [PMID: 35672736 PMCID: PMC9171979 DOI: 10.1186/s12888-022-04003-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/13/2021] [Accepted: 05/17/2022] [Indexed: 11/24/2022] Open
Abstract
BACKGROUND Sleep paralysis (SP) is a transitional dissociative state associated with the REM sleep phase that affects approximately 28.3% of the student population during their lifetime. The reasons for the high prevalence of SP in the student population are not entirely clear. Research indicates possible influencing factors such as the intensification of anxiety symptoms, a tendency to worry, the presence of PTSD symptoms, and behavioral factors such as the consumption of psychoactive substances (caffeine, alcohol, nicotine), sleep deprivations and poor sleep hygiene. The study aimed to assess the prevalence of SP and determine the risk factors for the occurrence of SP in the population of Polish students. METHODS The study used a battery online consisting of a set of questionnaires 1) a personal questionnaire, 2) the SP-EPQ, 3) the PCL -5, 4) the STAI-T, 5) the PSWQ. The questionnaire was sent via Facebook to 4500 randomly selected students from different universities in Poland. The questionnaire was completed by 2598 students. To unify the participant sample, people over 35 were excluded from the study (45 students). Ultimately, data from 2553 students were analyzed. RESULTS A total of 33.14% of individuals experienced at least one episode of SP in their lives. The highest odds ratio for SP was associated with: the presence of three or more health problems (OR: 2.3; p = 0.002), the presence of any mental disorder (OR: 1.77; p = 0.002), including mood disorders (OR: 2.07; p = 0.002), suffering from at least one somatic disease (OR: 1.34; p = 0.002), a high level of anxiety as a constant personality trait (OR: 1.20; p = 0.035) and smoking (OR: 1.48; p = 0.0002), alcohol consumption (OR: 1.52; p < 0.0001), physical activity (OR: 1.31; p = 0.001). CONCLUSIONS The results of our research indicate that a large proportion of students experienced isolated sleep paralysis. Mental and somatic health problems and lifestyle factors were found to predispose individuals to this disorder. Due to the numerous risk factors for SP, it is necessary to conduct additional research to confirm the impact of these factors and to investigate the mechanisms of their influence on SP.
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Affiliation(s)
- Paulina Wróbel-Knybel
- I Department of Psychiatry, Psychotherapy and Early Intervention, Medical University of Lublin, Głuska 1 Street, 20-439, Lublin, Poland.
| | - Michał Flis
- grid.411484.c0000 0001 1033 7158I Department of Psychiatry, Psychotherapy and Early Intervention, Medical University of Lublin, Głuska 1 Street, 20-439 Lublin, Poland
| | - Joanna Rog
- grid.411484.c0000 0001 1033 7158I Department of Psychiatry, Psychotherapy and Early Intervention, Medical University of Lublin, Głuska 1 Street, 20-439 Lublin, Poland
| | - Baland Jalal
- grid.38142.3c000000041936754XDepartment of Psychology, Harvard University, 33 Kirkland St, Cambridge, MA 02138 USA ,grid.5335.00000000121885934Department of Psychiatry, University of Cambridge, Downing Street, Cambridge, CB2 3EB UK
| | - Hanna Karakuła-Juchnowicz
- grid.411484.c0000 0001 1033 7158I Department of Psychiatry, Psychotherapy and Early Intervention, Medical University of Lublin, Głuska 1 Street, 20-439 Lublin, Poland
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13
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Baird B, Tononi G, LaBerge S. Lucid dreaming occurs in activated rapid eye movement sleep, not a mixture of sleep and wakefulness. Sleep 2022; 45:6528977. [PMID: 35167686 DOI: 10.1093/sleep/zsab294] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2021] [Revised: 11/10/2021] [Indexed: 01/29/2023] Open
Abstract
STUDY OBJECTIVES (1) To critically test whether a previously reported increase in frontolateral 40 Hz power in lucid REM sleep, used to justify the claim that lucid dreaming is a "hybrid state" mixing sleep and wakefulness, is attributable to the saccadic spike potential (SP) artifact as a corollary of heightened REM density. (2) To replicate the finding that lucid dreams are associated with physiological activation, including heightened eye movement density, during REM sleep. (3) To conduct an exploratory analysis of changes in EEG features during lucid REM sleep. METHODS We analyzed 14 signal-verified lucid dreams (SVLDs) and baseline REM sleep segments from the same REM periods from six participants derived from the Stanford SVLD database. Participants marked lucidity onset with standard left-right-left-right-center (LR2c) eye-movement signals in polysomnography recordings. RESULTS Compared to baseline REM sleep, lucid REM sleep had higher REM density (β = 0.85, p = 0.002). Bayesian analysis supported the null hypothesis of no differences in frontolateral 40 Hz power after removal of the SP artifact (BH = 0.18) and ICA correction (BH = 0.01). Compared to the entire REM sleep period, lucid REM sleep showed small reductions in low-frequency and beta band spectral power as well as increased signal complexity (all p < 0.05), which were within the normal variance of baseline REM sleep. CONCLUSIONS Lucid dreams are associated with higher-than-average levels of physiological activation during REM sleep, including measures of both subcortical and cortical activation. Increases in 40 Hz power in periorbital channels reflect saccadic and microsaccadic SPs as a result of higher REM density accompanying heightened activation.
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Affiliation(s)
- Benjamin Baird
- Department of Psychiatry, Center for Sleep and Consciousness, University of Wisconsin-Madison, Madison, WI, USA
| | - Giulio Tononi
- Department of Psychiatry, Center for Sleep and Consciousness, University of Wisconsin-Madison, Madison, WI, USA
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14
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Abstract
Traditionally, sleep and wakefulness have been considered as two global, mutually exclusive states. However, this view has been challenged by the discovery that sleep and wakefulness are actually locally regulated and that islands of these two states may often coexist in the same individual. Importantly, such a local regulation seems to be the key for many essential functions of sleep, including the maintenance of cognitive efficiency and the consolidation of new skills and memories. Indeed, local changes in sleep-related oscillations occur in brain areas that are used and involved in learning during wakefulness. In turn, these changes directly modulate experience-dependent brain adaptations and the consolidation of newly acquired memories. In line with these observations, alterations in the regional balance between wake- and sleep-like activity have been shown to accompany many pathologic conditions, including psychiatric and neurologic disorders. In the last decade, experimental research has started to shed light on the mechanisms involved in the local regulation of sleep and wakefulness. The results of this research have opened new avenues of investigation regarding the function of sleep and have revealed novel potential targets for the treatment of several pathologic conditions.
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Affiliation(s)
- Giulia Avvenuti
- MoMiLab Research Unit, IMT School for Advanced Studies Lucca, Lucca, Italy
| | - Giulio Bernardi
- MoMiLab Research Unit, IMT School for Advanced Studies Lucca, Lucca, Italy.
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15
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Zhang X, Landsness EC, Chen W, Miao H, Tang M, Brier LM, Culver JP, Lee JM, Anastasio MA. Automated sleep state classification of wide-field calcium imaging data via multiplex visibility graphs and deep learning. J Neurosci Methods 2022; 366:109421. [PMID: 34822945 PMCID: PMC9006179 DOI: 10.1016/j.jneumeth.2021.109421] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2021] [Revised: 11/09/2021] [Accepted: 11/13/2021] [Indexed: 01/02/2023]
Abstract
BACKGROUND Wide-field calcium imaging (WFCI) allows for monitoring of cortex-wide neural dynamics in mice. When applied to the study of sleep, WFCI data are manually scored into the sleep states of wakefulness, non-REM (NREM) and REM by use of adjunct EEG and EMG recordings. However, this process is time-consuming and often suffers from low inter- and intra-rater reliability and invasiveness. Therefore, an automated sleep state classification method that operates on WFCI data alone is needed. NEW METHOD A hybrid, two-step method is proposed. In the first step, spatial-temporal WFCI data is mapped to multiplex visibility graphs (MVGs). Subsequently, a two-dimensional convolutional neural network (2D CNN) is employed on the MVGs to be classified as wakefulness, NREM and REM. RESULTS Sleep states were classified with an accuracy of 84% and Cohen's κ of 0.67. The method was also effectively applied on a binary classification of wakefulness/sleep (accuracy=0.82, κ = 0.62) and a four-class wakefulness/sleep/anesthesia/movement classification (accuracy=0.74, κ = 0.66). Gradient-weighted class activation maps revealed that the CNN focused on short- and long-term temporal connections of MVGs in a sleep state-specific manner. Sleep state classification performance when using individual brain regions was highest for the posterior area of the cortex and when cortex-wide activity was considered. COMPARISON WITH EXISTING METHOD On a 3-hour WFCI recording, the MVG-CNN achieved a κ of 0.65, comparable to a κ of 0.60 corresponding to the human EEG/EMG-based scoring. CONCLUSIONS The hybrid MVG-CNN method accurately classifies sleep states from WFCI data and will enable future sleep-focused studies with WFCI.
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Affiliation(s)
- Xiaohui Zhang
- Department of Bioengineering, University of Illinois Urbana-Champaign, Urbana, IL 61801, USA
| | - Eric C Landsness
- Department of Neurology, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Wei Chen
- Department of Neurology, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Hanyang Miao
- Department of Neurology, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Michelle Tang
- Department of Neurology, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Lindsey M Brier
- Department of Radiology, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Joseph P Culver
- Department of Radiology, Washington University School of Medicine, St. Louis, MO 63110, USA; Department of Biomedical Engineering, Washington University School of Engineering, St. Louis, MO 63130, USA; Department of Electrical and Systems Engineering, Washington University School of Engineering, St. Louis, MO 63130, USA; Department of Physics, Washington University School of Arts and Science, St. Louis, MO 63130, USA
| | - Jin-Moo Lee
- Department of Neurology, Washington University School of Medicine, St. Louis, MO 63110, USA; Department of Radiology, Washington University School of Medicine, St. Louis, MO 63110, USA; Department of Biomedical Engineering, Washington University School of Engineering, St. Louis, MO 63130, USA
| | - Mark A Anastasio
- Department of Bioengineering, University of Illinois Urbana-Champaign, Urbana, IL 61801, USA.
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16
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Leu-Semenescu S, Maranci JB, Lopez R, Drouot X, Dodet P, Gales A, Groos E, Barateau L, Franco P, Lecendreux M, Dauvilliers Y, Arnulf I. Comorbid parasomnias in narcolepsy and idiopathic hypersomnia: more REM than NREM parasomnias. J Clin Sleep Med 2022; 18:1355-1364. [PMID: 34984974 PMCID: PMC9059608 DOI: 10.5664/jcsm.9862] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
STUDY OBJECTIVES To assess the frequency, determinants and clinical impact of clinical NREM and REM parasomnias in adult patients with narcolepsy type 1 (NT1), narcolepsy type 2 (NT2), and idiopathic hypersomnia (IH) compared to healthy controls. METHODS Familial and past and current personal parasomnias were assessed by questionnaire and medical interviews in 710 patients (220 NT1, 199 NT2, and 221 IH) and 595 healthy controls. RESULTS Except for sleep-related eating disorder (SRED), current NREM parasomnias were rare in all patient groups and controls. SRED was more frequent in NT1 patients (7.9%, vs. 1.8% in NT2 patients, 2.1% in IH patients and 1% in controls) and associated with disrupted nighttime sleep (odds ratio [OR] = 3.9) and nocturnal eating in full awareness (OR = 6.9) but not with sex. Clinical REM sleep behavior disorder (RBD) was more frequent in NT1 patients (41.4%, half being violent) than in NT2 patients (13.2%) and affected men more often than women (OR = 2.4). It was associated with disrupted nighttime sleep, depressive symptoms and antidepressant use. Frequent (>1/week) nightmares were reported by 39% of patients with NT1, 29% with NT2 and 27.8% with IH (vs. 8.3% in controls) and were associated with depressive symptoms in narcolepsy. No parasomnia (except sleep-related hallucinations) worsened daytime sleepiness. CONCLUSIONS In patients with central disorders of hypersomnolence, comorbid NREM parasomnias (except SRED) are rare and do not worsen sleepiness. In contrast, REM parasomnias are prevalent (especially in NT1) and associated with male sex, disrupted nighttime sleep, depressive symptoms and antidepressant use.
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Affiliation(s)
- Smaranda Leu-Semenescu
- Sleep Disorders, Pitié-Salpêtrière University Hospital, AP-HP-Sorbonne, F-75013 Paris, France.,National Reference Center for Orphan Diseases, Narcolepsy, Idiopathic hypersomnia and Kleine-Levin Syndrome
| | - Jean-Baptiste Maranci
- Sleep Disorders, Pitié-Salpêtrière University Hospital, AP-HP-Sorbonne, F-75013 Paris, France.,National Reference Center for Orphan Diseases, Narcolepsy, Idiopathic hypersomnia and Kleine-Levin Syndrome.,Sorbonne University, Paris, France
| | - Regis Lopez
- National Reference Center for Orphan Diseases, Narcolepsy, Idiopathic hypersomnia and Kleine-Levin Syndrome.,Sleep Disorders Center, Department of Neurology, Gui-de-Chauliac Hospital, CHU Montpellier.,Institute for Neurosciences of Montpellier (INM), Montpellier University, INSERM, Montpellier, France
| | - Xavier Drouot
- Clinical Neurophysiology Department, La Miletrie University Hospital, Poitiers, France
| | - Pauline Dodet
- Sleep Disorders, Pitié-Salpêtrière University Hospital, AP-HP-Sorbonne, F-75013 Paris, France.,National Reference Center for Orphan Diseases, Narcolepsy, Idiopathic hypersomnia and Kleine-Levin Syndrome
| | - Ana Gales
- Sleep Disorders, Pitié-Salpêtrière University Hospital, AP-HP-Sorbonne, F-75013 Paris, France.,National Reference Center for Orphan Diseases, Narcolepsy, Idiopathic hypersomnia and Kleine-Levin Syndrome
| | - Elisabeth Groos
- Sleep Disorders, Pitié-Salpêtrière University Hospital, AP-HP-Sorbonne, F-75013 Paris, France.,National Reference Center for Orphan Diseases, Narcolepsy, Idiopathic hypersomnia and Kleine-Levin Syndrome
| | - Lucie Barateau
- National Reference Center for Orphan Diseases, Narcolepsy, Idiopathic hypersomnia and Kleine-Levin Syndrome.,Sleep Disorders Center, Department of Neurology, Gui-de-Chauliac Hospital, CHU Montpellier.,Institute for Neurosciences of Montpellier (INM), Montpellier University, INSERM, Montpellier, France
| | - Patricia Franco
- National Reference Center for Orphan Diseases, Narcolepsy, Idiopathic hypersomnia and Kleine-Levin Syndrome.,Pediatric Sleep Unit, Mother-Children Hospital, Hospices Civils de Lyon, University Lyon1, France, Integrative Physiology of Brain Arousal System, CRNL, INSERM-U1028, CNRS UMR5292, University Lyon 1, Lyon, France
| | - Michel Lecendreux
- National Reference Center for Orphan Diseases, Narcolepsy, Idiopathic hypersomnia and Kleine-Levin Syndrome.,Pediatric Sleep Center, Hospital Robert-Debré, AP-HP, Paris, France
| | - Yves Dauvilliers
- National Reference Center for Orphan Diseases, Narcolepsy, Idiopathic hypersomnia and Kleine-Levin Syndrome.,Sleep Disorders Center, Department of Neurology, Gui-de-Chauliac Hospital, CHU Montpellier.,Institute for Neurosciences of Montpellier (INM), Montpellier University, INSERM, Montpellier, France
| | - Isabelle Arnulf
- Sleep Disorders, Pitié-Salpêtrière University Hospital, AP-HP-Sorbonne, F-75013 Paris, France.,National Reference Center for Orphan Diseases, Narcolepsy, Idiopathic hypersomnia and Kleine-Levin Syndrome.,Sorbonne University, Paris, France
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17
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Scarpelli S, Alfonsi V, D'Anselmo A, Gorgoni M, Musetti A, Plazzi G, De Gennaro L, Franceschini C. Dream Activity in Narcoleptic Patients During the COVID-19 Lockdown in Italy. Front Psychol 2021; 12:681569. [PMID: 34122276 PMCID: PMC8187856 DOI: 10.3389/fpsyg.2021.681569] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Accepted: 04/29/2021] [Indexed: 02/05/2023] Open
Abstract
Some studies highlighted that patients with narcolepsy type-1 (NT1) experience high lucid dream frequency, and this phenomenon has been associated with a creative personality. Starting from the well-known “pandemic effect” on sleep and dreaming, we presented a picture of dream activity in pharmacologically treated NT1 patients during the Italian lockdown. Forty-three NT1 patients completed a web-survey during Spring 2021 and were compared with 86 matched-controls. Statistical comparisons revealed that: (a) NT1 patients showed greater sleepiness than controls; (b) controls showed higher sleep disturbances than NT1 patients, and this result disappeared when the medication effect in NT1 was controlled; (c) NT1 patients reported higher lucid dream frequency than controls. Focusing on dreaming in NT1 patients, we found that (a) nightmare frequency was correlated with female gender, longer sleep duration, higher intrasleep wakefulness; (b) dream recall, nightmare and lucid dream frequency were positively correlated with sleepiness. Comparisons between low and high NT1 lucid dreamers showed that patients more frequently experiencing lucid dreams reported a greater influence of dreaming during wakefulness, especially concerning problem-solving and creativity. Overall, our results are consistent with previous studies on pandemic dreaming carried out on healthy subjects. Moreover, we confirmed a link between lucidity and creativity in NT1 patients. Considering the small sample size and the cross-sectional design, our findings cannot provide a causal relationship between lucid dreams and the COVID-19 lockdown. Nevertheless, they represent a first contribution to address future studies on this issue, suggesting that some stable characteristics could interact with changes provoked by the pandemic.
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Affiliation(s)
- Serena Scarpelli
- Department of Psychology, Sapienza University of Rome, Rome, Italy
| | | | - Anita D'Anselmo
- Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy
| | - Maurizio Gorgoni
- Department of Psychology, Sapienza University of Rome, Rome, Italy
| | - Alessandro Musetti
- Department of Humanities, Social Sciences and Cultural Industries, University of Parma, Parma, Italy
| | - Giuseppe Plazzi
- IRCCS Istituto delle Scienze Neurologiche di Bologna, Bologna, Italy.,Department of Biomedical, Metabolic and Neural Sciences, University of Modena and Reggio Emilia, Modena, Italy
| | - Luigi De Gennaro
- Department of Psychology, Sapienza University of Rome, Rome, Italy.,IRCCS Fondazione Santa Lucia, Rome, Italy
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18
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Fronczek R, Arnulf I, Baumann CR, Maski K, Pizza F, Trotti LM. To split or to lump? Classifying the central disorders of hypersomnolence. Sleep 2021; 43:5810298. [PMID: 32193539 PMCID: PMC7420691 DOI: 10.1093/sleep/zsaa044] [Citation(s) in RCA: 50] [Impact Index Per Article: 16.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2019] [Revised: 03/10/2020] [Indexed: 01/20/2023] Open
Abstract
The classification of the central disorders of hypersomnolence has undergone multiple iterations in an attempt to capture biologically meaningful disease entities in the absence of known pathophysiology. Accumulating data suggests that further refinements may be necessary. At the 7th International Symposium on Narcolepsy, a group of clinician-scientists evaluated data in support of keeping or changing classifications, and as a result suggest several changes. First, idiopathic hypersomnia with long sleep durations appears to be an identifiable and meaningful disease subtype. Second, idiopathic hypersomnia without long sleep time and narcolepsy without cataplexy share substantial phenotypic overlap and cannot reliably be distinguished with current testing, and so combining them into a single disease entity seems warranted at present. Moving forward, it is critical to phenotype patients across a wide variety of clinical and biological features, to aid in future refinements of disease classification.
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Affiliation(s)
- Rolf Fronczek
- Department of Neurology, Leiden University Medical Centre, Leiden, The Netherlands.,Sleep-Wakecentre SEIN, Heemstede, The Netherlands
| | - Isabelle Arnulf
- Sorbonne University, National Reference Center for Rare Hypersomnia, Pitie-Salpetriere Hospital, Paris, France
| | - Christian R Baumann
- Department of Neurology, University Hospital Zurich, University of Zurich, Zurich, Switzerland
| | - Kiran Maski
- Department of Neurology, Harvard Medical School, Boston Children's Hospital, Boston, MA
| | - Fabio Pizza
- Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy.,IRCCS Istituto delle Scienze Neurologiche di Bologna, Bologna, Italy
| | - Lynn Marie Trotti
- Department of Neurology, Emory University School of Medicine, Atlanta, GA
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19
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Mainieri G, Maranci JB, Champetier P, Leu-Semenescu S, Gales A, Dodet P, Arnulf I. Are sleep paralysis and false awakenings different from REM sleep and from lucid REM sleep? A spectral EEG analysis. J Clin Sleep Med 2021; 17:719-727. [PMID: 33283752 DOI: 10.5664/jcsm.9056] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
STUDY OBJECTIVES To determine the polysomnography characteristics during sleep paralysis, false awakenings, and lucid dreaming (which are states intermediate to rapid eye movement [REM] sleep and wake but exceptionally observed in sleep laboratory). METHODS In 5 participants, we captured 5 episodes of sleep paralysis (2 time marked with the ocular left-right-left-right code normally used to signal lucid dreaming, 1 time marked by an external noise, and 2 retrospectively reported) and 2 episodes of false awakening. The sleep coding (using 3-second mini-epochs) and spectral electroencephalography analysis were compared during these episodes and normal REM sleep as well as wakefulness in the same 4 of 5 participants and vs lucid REM sleep in 4 other patients with narcolepsy. RESULTS During episodes of sleep paralysis, 70.8% of mini-epochs contained theta electroencephalography rhythm (vs 89.7% in REM sleep and 21.2% in wakefulness), 93.8% contained chin muscle atonia (vs 89.7% in REM sleep and 33.3% in wakefulness), and 6.9% contained rapid eye movements (vs 11.9% in REM sleep and 8.1% in wakefulness). The electroencephalography spectrum during sleep paralysis was intermediate between wakefulness and REM sleep in the alpha, theta, and delta frequencies, whereas the beta frequencies were not different between sleep paralysis and normal REM sleep. The power spectrum during false awakening followed the same profile as in sleep paralysis. CONCLUSIONS The predominant theta electroencephalography rhythm during sleep paralysis and false awakenings (with rare and lower alpha rhythm) suggests that the brain during sleep paralysis is not in an awake but in a dreaming state.
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Affiliation(s)
- Greta Mainieri
- Sleep Disorder Unit, Pitié-Salpêtrière University Hospital, AP-HP, Paris, France.,Department of Medical and Surgical Sciences and Advanced Technologies "G.F. Ingrassia", University of Catania, Catania Via S. Sofia 78, Italy
| | - Jean-Baptiste Maranci
- Sleep Disorder Unit, Pitié-Salpêtrière University Hospital, AP-HP, Paris, France.,Sorbonne University, Paris, France.,Paris Brain Institute, Paris, France
| | - Pierre Champetier
- Sleep Disorder Unit, Pitié-Salpêtrière University Hospital, AP-HP, Paris, France.,Paris Brain Institute, Paris, France.,Ecole Normale Supérieure Paris-Saclay, Université Paris-Saclay, France
| | | | - Ana Gales
- Sleep Disorder Unit, Pitié-Salpêtrière University Hospital, AP-HP, Paris, France
| | - Pauline Dodet
- Sleep Disorder Unit, Pitié-Salpêtrière University Hospital, AP-HP, Paris, France
| | - Isabelle Arnulf
- Sleep Disorder Unit, Pitié-Salpêtrière University Hospital, AP-HP, Paris, France.,Sorbonne University, Paris, France.,Paris Brain Institute, Paris, France
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20
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Konkoly KR, Appel K, Chabani E, Mangiaruga A, Gott J, Mallett R, Caughran B, Witkowski S, Whitmore NW, Mazurek CY, Berent JB, Weber FD, Türker B, Leu-Semenescu S, Maranci JB, Pipa G, Arnulf I, Oudiette D, Dresler M, Paller KA. Real-time dialogue between experimenters and dreamers during REM sleep. Curr Biol 2021; 31:1417-1427.e6. [PMID: 33607035 PMCID: PMC8162929 DOI: 10.1016/j.cub.2021.01.026] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2020] [Revised: 12/08/2020] [Accepted: 01/08/2021] [Indexed: 12/14/2022]
Abstract
Dreams take us to a different reality, a hallucinatory world that feels as real as any waking experience. These often-bizarre episodes are emblematic of human sleep but have yet to be adequately explained. Retrospective dream reports are subject to distortion and forgetting, presenting a fundamental challenge for neuroscientific studies of dreaming. Here we show that individuals who are asleep and in the midst of a lucid dream (aware of the fact that they are currently dreaming) can perceive questions from an experimenter and provide answers using electrophysiological signals. We implemented our procedures for two-way communication during polysomnographically verified rapid-eye-movement (REM) sleep in 36 individuals. Some had minimal prior experience with lucid dreaming, others were frequent lucid dreamers, and one was a patient with narcolepsy who had frequent lucid dreams. During REM sleep, these individuals exhibited various capabilities, including performing veridical perceptual analysis of novel information, maintaining information in working memory, computing simple answers, and expressing volitional replies. Their responses included distinctive eye movements and selective facial muscle contractions, constituting correctly answered questions on 29 occasions across 6 of the individuals tested. These repeated observations of interactive dreaming, documented by four independent laboratory groups, demonstrate that phenomenological and cognitive characteristics of dreaming can be interrogated in real time. This relatively unexplored communication channel can enable a variety of practical applications and a new strategy for the empirical exploration of dreams. Scientific investigations of dreaming have been hampered by the delay between a dream and when people report on their dream, and by a change in state from sleep to wake. To overcome this problem, Konkoly et al. show that individuals in REM sleep can perceive and answer an experimenter’s questions, allowing for real-time communication about a dream.
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Affiliation(s)
- Karen R Konkoly
- Department of Psychology and Cognitive Neuroscience Program, Northwestern University, Evanston, IL, USA
| | - Kristoffer Appel
- Institute of Cognitive Science, Osnabrück University, Osnabrück, Germany; Institute of Sleep and Dream Technologies, Hamburg, Germany
| | - Emma Chabani
- Institut du Cerveau - Paris Brain Institute - ICM, Sorbonne Université, Inserm, CNRS, Paris, France
| | - Anastasia Mangiaruga
- Donders Institute for Brain, Cognition and Behavior, Radboud University Medical Center, Nijmegen, the Netherlands; Department of Medical and Surgical Sciences, University of Bologna, Bologna, Italy
| | - Jarrod Gott
- Donders Institute for Brain, Cognition and Behavior, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Remington Mallett
- Department of Psychology, University of Texas at Austin, Austin, TX, USA
| | - Bruce Caughran
- Department of Psychology and Cognitive Neuroscience Program, Northwestern University, Evanston, IL, USA
| | - Sarah Witkowski
- Department of Psychology and Cognitive Neuroscience Program, Northwestern University, Evanston, IL, USA
| | - Nathan W Whitmore
- Department of Psychology and Cognitive Neuroscience Program, Northwestern University, Evanston, IL, USA
| | - Christopher Y Mazurek
- Department of Psychology and Cognitive Neuroscience Program, Northwestern University, Evanston, IL, USA
| | | | - Frederik D Weber
- Donders Institute for Brain, Cognition and Behavior, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Başak Türker
- Institut du Cerveau - Paris Brain Institute - ICM, Sorbonne Université, Inserm, CNRS, Paris, France
| | - Smaranda Leu-Semenescu
- Institut du Cerveau - Paris Brain Institute - ICM, Sorbonne Université, Inserm, CNRS, Paris, France; AP-HP, Pitié-Salpêtrière Hospital, Sleep Disorders Department, Paris, France
| | - Jean-Baptiste Maranci
- Institut du Cerveau - Paris Brain Institute - ICM, Sorbonne Université, Inserm, CNRS, Paris, France; AP-HP, Pitié-Salpêtrière Hospital, Sleep Disorders Department, Paris, France
| | - Gordon Pipa
- Institute of Cognitive Science, Osnabrück University, Osnabrück, Germany
| | - Isabelle Arnulf
- Institut du Cerveau - Paris Brain Institute - ICM, Sorbonne Université, Inserm, CNRS, Paris, France; AP-HP, Pitié-Salpêtrière Hospital, Sleep Disorders Department, Paris, France
| | - Delphine Oudiette
- Institut du Cerveau - Paris Brain Institute - ICM, Sorbonne Université, Inserm, CNRS, Paris, France
| | - Martin Dresler
- Donders Institute for Brain, Cognition and Behavior, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Ken A Paller
- Department of Psychology and Cognitive Neuroscience Program, Northwestern University, Evanston, IL, USA.
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21
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Scarpelli S, Alfonsi V, Gorgoni M, Giannini AM, De Gennaro L. Investigation on Neurobiological Mechanisms of Dreaming in the New Decade. Brain Sci 2021; 11:brainsci11020220. [PMID: 33670180 PMCID: PMC7916906 DOI: 10.3390/brainsci11020220] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2020] [Revised: 02/06/2021] [Accepted: 02/08/2021] [Indexed: 02/05/2023] Open
Abstract
Dream research has advanced significantly over the last twenty years, thanks to the new applications of neuroimaging and electrophysiological techniques. Many findings pointed out that mental activity during sleep and wakefulness shared similar neural bases. On the other side, recent studies have highlighted that dream experience is promoted by significant brain activation, characterized by reduced low frequencies and increased rapid frequencies. Additionally, several studies confirmed that the posterior parietal area and prefrontal cortex are responsible for dream experience. Further, early results revealed that dreaming might be manipulated by sensory stimulations that would provoke the incorporation of specific cues into the dream scenario. Recently, transcranial stimulation techniques have been applied to modulate the level of consciousness during sleep, supporting previous findings and adding new information about neural correlates of dream recall. Overall, although multiple studies suggest that both the continuity and activation hypotheses provide a growing understanding of neural processes underlying dreaming, several issues are still unsolved. The impact of state-/trait-like variables, the influence of circadian and homeostatic factors, and the examination of parasomnia-like events to access dream contents are all opened issues deserving further deepening in future research.
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Affiliation(s)
- Serena Scarpelli
- Body and Action Lab, IRCCS Fondazione Santa Lucia, 00179 Rome, Italy; (V.A.); (L.D.G.)
- Department of Psychology, Sapienza University of Rome, 00185 Rome, Italy; (M.G.); (A.M.G.)
- Correspondence: ; Tel.: +39-06-4991-7508
| | - Valentina Alfonsi
- Body and Action Lab, IRCCS Fondazione Santa Lucia, 00179 Rome, Italy; (V.A.); (L.D.G.)
| | - Maurizio Gorgoni
- Department of Psychology, Sapienza University of Rome, 00185 Rome, Italy; (M.G.); (A.M.G.)
| | - Anna Maria Giannini
- Department of Psychology, Sapienza University of Rome, 00185 Rome, Italy; (M.G.); (A.M.G.)
| | - Luigi De Gennaro
- Body and Action Lab, IRCCS Fondazione Santa Lucia, 00179 Rome, Italy; (V.A.); (L.D.G.)
- Department of Psychology, Sapienza University of Rome, 00185 Rome, Italy; (M.G.); (A.M.G.)
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22
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Quaedackers L, Pillen S, Overeem S. Recognizing the Symptom Spectrum of Narcolepsy to Improve Timely Diagnosis: A Narrative Review. Nat Sci Sleep 2021; 13:1083-1096. [PMID: 34262379 PMCID: PMC8273742 DOI: 10.2147/nss.s278046] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/15/2021] [Accepted: 06/23/2021] [Indexed: 11/23/2022] Open
Abstract
Narcolepsy is a chronic sleep disorder with a strong negative impact on quality of life, especially when untreated. Diagnostic delay is a persistent problem, with obvious detrimental effects on patients. A diagnosis of narcolepsy may be delayed because of its broad symptom presentation which is much more encompassing than the classical "tetrad" of sleepiness, cataplexy, hallucinations, and sleep paralysis. Furthermore, symptoms can vary over time. Presentation of symptoms can also be markedly different between children and adults. Finally, common sleep-related comorbidities increase the risk of narcolepsy being masked by overlapping symptoms or treatment. In this review, we provide a detailed description of the broad and dynamic symptom spectrum of narcolepsy, with specific attention to the different manifestations in both adults and children. The overarching goal is to help not only sleep specialists, but general practitioners, pediatricians, and other caregivers with early recognition and prompt diagnosis of this severe but treatable disorder.
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Affiliation(s)
| | - Sigrid Pillen
- Sleep Medicine Center Kempenhaeghe, Heeze, the Netherlands
| | - Sebastiaan Overeem
- Biomedical Diagnostics Laboratory, Department of Electrical Engineering, Eindhoven University of Technology, Eindhoven, the Netherlands
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23
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Abstract
Illusions and hallucinations are commonly encountered in both daily life and clinical practice. In this chapter, we review definitions and possible underlying mechanisms of these phenomena and then review what is known about specific conditions that are associated with them, including ophthalmic causes, migraine, epilepsy, Parkinson's disease, and schizophrenia. We then discuss specific syndromes including the Charles Bonnet syndrome, visual snow syndrome, Alice in Wonderland syndrome, and peduncular hallucinosis. The scientific study of illusions and hallucinations has contributed significantly to our understanding of how eye and brain process vision and contribute to perception. Important concepts are the distinction between topologic and hodologic mechanisms underlying hallucinations and the involvement of attentional networks. This chapter examines the various ways in which pathological illusions and hallucinations might arise in relation to the phenomenology and known pathology of the various conditions associated with them.
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Affiliation(s)
- Clare L Fraser
- Department of Ophthalmology, Save Sight Institute, Faculty of Health and Medicine, University of Sydney, Sydney, Australia.
| | - Christian J Lueck
- Department of Neurology, Canberra Hospital, and Australian National University Medical School, Canberra, Australia
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24
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Cipolli C, Pizza F, Bellucci C, Mazzetti M, Tuozzi G, Vandi S, Plazzi G. Dream Generation and Recall in Daytime NREM Sleep of Patients With Narcolepsy Type 1. Front Neurosci 2020; 14:608757. [PMID: 33328876 PMCID: PMC7729059 DOI: 10.3389/fnins.2020.608757] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2020] [Accepted: 10/28/2020] [Indexed: 12/02/2022] Open
Abstract
The less rigid architecture of sleep in patients with narcolepsy type 1 (NT1) compared with healthy subjects may provide new insights into some unresolved issues of dream experience (DE), under the assumption that their DE frequencies are comparable. The multiple transition from wakefulness to REM sleep (sleep onset REM period: SOREMP) during the five trials of the Multiple Sleep Latency Test (MSLT) appears of particular interest. In MSLT studies, NT1 patients reported a DE after about 80% of SOREMP naps (as often as after nighttime REM sleep of themselves and healthy subjects), but only after about 30% of NREM naps compared to 60% of daytime and nighttime NREM sleep of healthy subjects. To estimate accurately the “real” DE frequency, we asked participants to report DE (“dream”) after each MSLT nap and, in case of failure, to specify if they were unable to retrieve any content (“white dream”) or DE did not occur (“no-dream”). The proportions of dreams, white dreams, and no dreams and the indicators of structural organization of DEs reported after NREM naps by 17 adult NT1 patients were compared with those reported by 25 subjects with subjective complaints of excessive daytime sleepiness (sc-EDS), who take multiple daytime NREM naps. Findings were consistent with the hypothesis of a failure in recall after awakening rather than in generation during sleep: white dreams were more frequent in NT1 patients than in sc-EDS subjects (42.86 vs 17.64%), while their frequency of dreams plus white dreams were similar (67.86 and 61.78%) and comparable with that of NREM-DEs in healthy subjects. The longer and more complex NREM-DEs of NT1 patients compared with sc-EDS subjects suggest that the difficulty in DE reporting depends on their negative attitude toward recall of contents less vivid and bizarre than those they usually retrieve after daytime SOREMP and nighttime REM sleep. As this attitude may be reversed by some recall training before MSLT, collecting wider amounts of DE reports after NREM naps would cast light on both the across-stage continuity in the functioning of cognitive processes underlying DE and the difference in content and structural organization of SOREM-DEs preceded by N1 or also N2 sleep.
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Affiliation(s)
- Carlo Cipolli
- Department of Specialty, Diagnostic and Experimental Medicine, University of Bologna, Bologna, Italy
| | - Fabio Pizza
- Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy.,Istituto di Ricovero e Cura a Carattere Scientifico "Istituto delle Scienze Neurologiche" di Bologna, Bologna, Italy
| | - Claudia Bellucci
- Department of Specialty, Diagnostic and Experimental Medicine, University of Bologna, Bologna, Italy
| | - Michela Mazzetti
- Department of Specialty, Diagnostic and Experimental Medicine, University of Bologna, Bologna, Italy
| | - Giovanni Tuozzi
- Department of Psychology, University of Bologna, Bologna, Italy
| | - Stefano Vandi
- Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy.,Istituto di Ricovero e Cura a Carattere Scientifico "Istituto delle Scienze Neurologiche" di Bologna, Bologna, Italy
| | - Giuseppe Plazzi
- Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy.,Department of Biomedical, Metabolic and Neural Sciences, University of Modena and Reggio Emilia, Modena, Italy
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25
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Hagemeyer B, Salomo S, Engelhardt C, Neyer FJ, Rupprecht S. Assessing Individual Differences in the Affective Experience of Dreams: The Jena Dream Inventory–Affect Scales (JeDI-A). Assessment 2020; 27:1946-1959. [DOI: 10.1177/1073191119847767] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The study reports on the validation of a new instrument for the assessment of emotional experiences in dreams. The Jena Dream Inventory–Affect (JeDI-A) contains 21 items and 3 scales, positive dream affect, negative dream affect, and dream intensity, providing a differentiated yet economic assessment of dream affect. Cross-sectional and longitudinal analyses in a sample of university students ( N = 426) and a clinical sample of patients with sleep disorders ( N = 149) supported factorial validity and measurement invariance, high temporal stability (over 1 year and 9 months in the students and patients, respectively), convergent and discriminant validity regarding established measures of dream affect and the Big Five, and criterion validity regarding subjective well-being. Cross-lagged panel models showed reciprocal longitudinal effects between dream affect and waking affect. We conclude that the JeDI-A is a valid instrument for differentiated investigations of individual differences in dream affect in clinical and nonclinical populations.
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26
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Putois B, Leslie W, Asfeld C, Sierro C, Higgins S, Ruby P. Methodological Recommendations to Control for Factors Influencing Dream and Nightmare Recall in Clinical and Experimental Studies of Dreaming. Front Neurol 2020; 11:724. [PMID: 33041958 PMCID: PMC7523469 DOI: 10.3389/fneur.2020.00724] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2019] [Accepted: 06/15/2020] [Indexed: 01/07/2023] Open
Abstract
In order to ensure robust relationships between the dependent and independent variables in clinical dream/nightmare studies, the major factors which influence the frequency of reported dreams must be controlled. This article sets out methodological recommendations to both researchers seeking to ensure the equivalence of experimental groups of participants in group-matching designs, and to clinicians who wish to check that any change in frequency of reported nightmares over the course of a psychological or a pharmacological intervention is not caused by factors other than the experimental treatment itself. The main factors influencing the frequency of dream recall are presented: demographic variables, psychological characteristics, pathological dimensions, and substance consumption. A series of questionnaires is proposed for easily measuring these control variables.
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Affiliation(s)
- Benjamin Putois
- Swiss Distance Learning University, Brig, Switzerland.,Lyon Neuroscience Research Center, CNRS UMR 5292 - INSERM U1028 - Lyon 1 University, Lyon, France
| | - Wendy Leslie
- Clinical Health Psychology, University of Ulster, Ulster, United Kingdom
| | - Claire Asfeld
- Swiss Distance Learning University, Brig, Switzerland
| | | | - Susan Higgins
- Centre Hospitalier Annecy Genevois, Service Pneumologie, Épagny-Metz-Tessy, France
| | - Perrine Ruby
- Lyon Neuroscience Research Center, CNRS UMR 5292 - INSERM U1028 - Lyon 1 University, Lyon, France
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27
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Siclari F, Valli K, Arnulf I. Dreams and nightmares in healthy adults and in patients with sleep and neurological disorders. Lancet Neurol 2020; 19:849-59. [PMID: 32949545 DOI: 10.1016/S1474-4422(20)30275-1] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2019] [Revised: 11/24/2019] [Accepted: 07/14/2020] [Indexed: 12/16/2022]
Abstract
Dreams are experiences that occur during sleep, while we are disconnected from the environment. Thanks to recent progress in neuroimaging techniques, it is now becoming possible to relate dream features to specific patterns of brain activity. Some conditions occurring in patients with neurological disorders, such as lucid dreams and parasomnias, not only have diagnostic value, but also offer a window into the dream process. They show that dreaming is reflected in physiological signals, behaviours, and brain activity patterns, and that the body can enact dream content. Yet, the dream body can also be distinct from the real body; in their dreams, patients with congenital paraplegia can walk, those with sleep apnoea rarely suffocate, and phantom limb pain can disappear. These conditions provide valuable models for future studies investigating the mechanisms that underlie oneiric experiences.
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28
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van der Wijk G, Blaskovich B, Farahzadi Y, Simor P. Unaltered EEG spectral power and functional connectivity in REM microstates in frequent nightmare recallers: are nightmares really a REM parasomnia? Sleep Med 2020; 75:192-200. [PMID: 32858360 DOI: 10.1016/j.sleep.2020.07.014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/16/2020] [Revised: 06/23/2020] [Accepted: 07/10/2020] [Indexed: 11/22/2022]
Abstract
BACKGROUND Frequent nightmares show signs of hyperarousal in NREM sleep. Nevertheless, idiopathic nightmare disorder is considered a REM parasomnia, but the pathophysiology of REM sleep in relation to frequent nightmares is controversial. Cortical oscillatory activity in REM sleep is largely modulated by phasic and tonic REM periods and seems to be linked to different functions and dysfunctions of REM sleep. Here, we examined cortical activity and functional synchronization in frequent nightmare recallers and healthy controls, during phasic and tonic REM. METHODS Frequent nightmare recallers (N = 22) and healthy controls (N = 22) matched for high dream recall spent two nights in the laboratory. Phasic and tonic REM periods from the second nights' recordings were selected to examine differences in EEG spectral power and weighted phase lag index (WPLI) across groups and REM states. RESULTS Phasic REM showed increased power and synchronization in delta and gamma frequency bands, whereas tonic REM featured increased power and synchronization in the alpha and beta bands. In the theta band, power was higher during tonic, and synchronization was higher during phasic REM sleep. No differences across nightmare and control participants or patterns representing interactions between the groups and REM microstates emerged. CONCLUSIONS Our findings do not support the idea that abnormal REM sleep power and synchronization play a role in the pathophysiology of frequent nightmares. Altered REM sleep in nightmare disorder could have been confounded with comorbid pathologies and increased dream recall, or might be linked to more specific state factors (nightmare episodes).
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29
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Raduga M, Kuyava O, Sevcenko N. Is there a relation among REM sleep dissociated phenomena, like lucid dreaming, sleep paralysis, out-of-body experiences, and false awakening? Med Hypotheses 2020; 144:110169. [PMID: 32795836 DOI: 10.1016/j.mehy.2020.110169] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2020] [Revised: 08/04/2020] [Accepted: 08/06/2020] [Indexed: 11/16/2022]
Abstract
During REM sleep we normally experience dreams. However, there are other less common REM sleep phenomena, like lucid dreaming (LD), false awakening (FA), sleep paralysis (SP), and out of body experiences (OBE). LD occurs when one is conscious during dreaming, and FA occurs when one is dreaming but believes that has woken up. SP is characterized by skeletal muscle atonia and occurs mainly during awakening or falling asleep. OBE is the subjective sensation of 'leaving the physical body'. Since all these phenomena happen during REM sleep, their frequency is probably connected. The goal of this research is to explore how these phenomena are connected to each other in terms of frequency. We surveyed 974 people on the streets of Moscow and found significant correlations between the phenomena. Of those surveyed, 88% have experienced at least one of the phenomena of interest (i.e., LD, OBE, FA, and SP), which appeared to be closely correlated to each other. Furthermore, 43% of respondents stated that they often experience at least one of these phenomena. We found that the recurrence of these phenomena correlated with sleep duration and dream recall frequency. The results of the survey provide better understanding of the nature of REM sleep dissociative phenomena. Cross-correlations between REM sleep dissociated phenomena, like lucid dreaming, sleep paralysis, out-of-body experiences, and false awakening, revealed by a survey.
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30
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Cipolli C, Pizza F, Bellucci C, Mazzetti M, Tuozzi G, Vandi S, Plazzi G. Structural organization of dream experience during daytime sleep-onset rapid eye movement period sleep of patients with narcolepsy type 1. Sleep 2020; 43:5735644. [PMID: 32055854 DOI: 10.1093/sleep/zsaa012] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2019] [Revised: 01/21/2020] [Indexed: 01/07/2023] Open
Abstract
STUDY OBJECTIVE To assess the frequency of dream experience (DE) developed during naps at Multiple Sleep Latency Test (MSLT) by patients with narcolepsy type 1 (NT1) and establish, using story-grammar analysis, the structural organization of DEs developed during naps with sleep onset rapid eye movement (REM) period (SOREMP) sleep compared with their DEs during early- and late-night REM sleep. METHODS Thirty drug-free cognitively intact adult NT1 patients were asked to report DE developed during each MSLT nap. Ten NT1 patients also spent voluntarily a supplementary night being awakened during the first-cycle and third-cycle REM sleep. Patients provided dream reports, white dreams, and no dreams, whose frequencies were matched in naps with SOREMP versus non-REM (NREM) sleep. All dream reports were then analyzed using story-grammar rules. RESULTS DE was recalled in detail (dream report) by NT1 patients after 75% of naps with SOREMP sleep and after 25% of naps with NREM sleep. Dream reports were provided by 8 out of 10 NT1 patients after both awakenings from nighttime REM sleep. Story-grammar analysis of dream reports showed that SOREMP-DEs are organized as hierarchically ordered sequences of events (so-called dream-stories), which are longer and more complex in the first and fourth SOREMP naps and are comparable with nighttime REM-DEs. CONCLUSIONS The similar structural organization of SOREMP-DEs with nighttime REM-DEs indicates that their underlying cognitive processes are highly, albeit not uniformly, effective during daytime SOREMP sleep. Given the peculiar neurophysiology of SOREMP sleep, investigating SOREMP-DEs may cast further light on the relationships between the neurophysiological and psychological processes involved in REM-dreaming.
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Affiliation(s)
- Carlo Cipolli
- Department of Experimental, Diagnostic and Specialty Medicine, University of Bologna, Bologna, Italy
| | - Fabio Pizza
- Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy.,IRCSS Istituto delle Scienze Neurologiche di Bologna, Bologna, Italy
| | - Claudia Bellucci
- Department of Experimental, Diagnostic and Specialty Medicine, University of Bologna, Bologna, Italy
| | - Michela Mazzetti
- Department of Experimental, Diagnostic and Specialty Medicine, University of Bologna, Bologna, Italy
| | - Giovanni Tuozzi
- Department of Psychology, University of Bologna, Bologna, Italy
| | - Stefano Vandi
- Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy.,IRCSS Istituto delle Scienze Neurologiche di Bologna, Bologna, Italy
| | - Giuseppe Plazzi
- Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy.,IRCSS Istituto delle Scienze Neurologiche di Bologna, Bologna, Italy
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31
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Gott J, Rak M, Bovy L, Peters E, van Hooijdonk CFM, Mangiaruga A, Varatheeswaran R, Chaabou M, Gorman L, Wilson S, Weber F, Talamini L, Steiger A, Dresler M. Sleep fragmentation and lucid dreaming. Conscious Cogn 2020; 84:102988. [PMID: 32768920 DOI: 10.1016/j.concog.2020.102988] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2019] [Revised: 07/02/2020] [Accepted: 07/13/2020] [Indexed: 12/13/2022]
Abstract
Lucid dreaming-the phenomenon of experiencing waking levels of self-reflection within one's dreams-is associated with more wake-like levels of neural activation in prefrontal brain regions. In addition, alternating periods of wakefulness and sleep might increase the likelihood of experiencing a lucid dream. Here we investigate the association between sleep fragmentation and lucid dreaming, with a multi-centre study encompassing four different investigations into subjective and objective measures of sleep fragmentation, nocturnal awakenings, sleep quality and polyphasic sleep schedules. Results across these four studies provide a more nuanced picture into the purported connection between sleep fragmentation and lucid dreaming: While self-assessed numbers of awakenings, polyphasic sleep and physiologically validated wake-REM sleep transitions were associated with lucid dreaming, neither self-assessed sleep quality, nor physiologically validated numbers of awakenings were. We discuss these results, and their underlying neural mechanisms, within the general question of whether sleep fragmentation and lucid dreaming share a causal link.
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Affiliation(s)
- Jarrod Gott
- Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Centre, Nijmegen, the Netherlands
| | - Michael Rak
- Max Planck Institute of Psychiatry, Munich, Germany
| | - Leonore Bovy
- Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Centre, Nijmegen, the Netherlands
| | - Emma Peters
- Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Centre, Nijmegen, the Netherlands
| | - Carmen F M van Hooijdonk
- School for Mental Health and Neuroscience, Maastricht University, Maastricht, the Netherlands; Rivierduinen Institute for Mental Healthcare, Leiden, the Netherlands
| | - Anastasia Mangiaruga
- Department of Medical and Surgical Sciences, University of Bologna, Bologna, Italy
| | | | | | | | | | | | | | - Axel Steiger
- Max Planck Institute of Psychiatry, Munich, Germany
| | - Martin Dresler
- Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Centre, Nijmegen, the Netherlands.
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Blanchette-Carrière C, Julien SH, Picard-Deland C, Bouchard M, Carrier J, Paquette T, Nielsen T. Attempted induction of signalled lucid dreaming by transcranial alternating current stimulation. Conscious Cogn 2020; 83:102957. [PMID: 32534325 DOI: 10.1016/j.concog.2020.102957] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2020] [Revised: 04/17/2020] [Accepted: 04/24/2020] [Indexed: 10/24/2022]
Abstract
Neurophysiological correlates of self-awareness during sleep ('lucid dreaming') remain unclear despite their importance for clarifying the neural underpinnings of consciousness. Transcranial direct (tDC) and alternating (tAC) current stimulation during sleep have been shown to increase dream self-awareness, but these studies' methodological weaknesses prompted us to undertake additional study. tAC stimulation was associated with signal-verified and self-rated lucid dreams-but so was the sham procedure. Situational factors may be crucial to inducing self-awareness during sleep.
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Affiliation(s)
- Cloé Blanchette-Carrière
- Department of Psychiatry, Université de Montréal, C.P. 6128, succursale Centre-ville, Montréal, Québec H3C 3J7, Canada; Center for Advanced Research in Sleep Medicine, CIUSSS-NÎM - Hôpital du Sacré-Cœur de Montréal, 5400 Gouin Blvd West, Montréal, Québec H4J 1C5, Canada
| | - Sarah-Hélène Julien
- Department of Psychology, Université de Montréal, C.P. 6128, succursale Centre-ville, Montréal, Québec H3C 3J7, Canada; Center for Advanced Research in Sleep Medicine, CIUSSS-NÎM - Hôpital du Sacré-Cœur de Montréal, 5400 Gouin Blvd West, Montréal, Québec H4J 1C5, Canada
| | - Claudia Picard-Deland
- Department of Neurosciences, Université de Montréal, C.P. 6128, succursale Centre-ville, Montréal, Québec H3C 3J7, Canada; Center for Advanced Research in Sleep Medicine, CIUSSS-NÎM - Hôpital du Sacré-Cœur de Montréal, 5400 Gouin Blvd West, Montréal, Québec H4J 1C5, Canada
| | - Maude Bouchard
- Department of Psychology, Université de Montréal, C.P. 6128, succursale Centre-ville, Montréal, Québec H3C 3J7, Canada; Center for Advanced Research in Sleep Medicine, CIUSSS-NÎM - Hôpital du Sacré-Cœur de Montréal, 5400 Gouin Blvd West, Montréal, Québec H4J 1C5, Canada
| | - Julie Carrier
- Department of Psychology, Université de Montréal, C.P. 6128, succursale Centre-ville, Montréal, Québec H3C 3J7, Canada; Center for Advanced Research in Sleep Medicine, CIUSSS-NÎM - Hôpital du Sacré-Cœur de Montréal, 5400 Gouin Blvd West, Montréal, Québec H4J 1C5, Canada
| | - Tyna Paquette
- Center for Advanced Research in Sleep Medicine, CIUSSS-NÎM - Hôpital du Sacré-Cœur de Montréal, 5400 Gouin Blvd West, Montréal, Québec H4J 1C5, Canada
| | - Tore Nielsen
- Department of Psychiatry, Université de Montréal, C.P. 6128, succursale Centre-ville, Montréal, Québec H3C 3J7, Canada; Center for Advanced Research in Sleep Medicine, CIUSSS-NÎM - Hôpital du Sacré-Cœur de Montréal, 5400 Gouin Blvd West, Montréal, Québec H4J 1C5, Canada.
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Scarpelli S, D’Atri A, Bartolacci C, Gorgoni M, Mangiaruga A, Ferrara M, De Gennaro L. Dream Recall upon Awakening from Non-Rapid Eye Movement Sleep in Older Adults: Electrophysiological Pattern and Qualitative Features. Brain Sci 2020; 10:E343. [PMID: 32503215 PMCID: PMC7349242 DOI: 10.3390/brainsci10060343] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2020] [Revised: 05/29/2020] [Accepted: 06/01/2020] [Indexed: 02/05/2023] Open
Abstract
Several findings support the activation hypothesis, positing that cortical arousal promotes dream recall (DR). However, most studies have been carried out on young participants, while the electrophysiological (EEG) correlates of DR in older people are still mostly unknown. We aimed to test the activation hypothesis on 20 elders, focusing on the Non-Rapid Eye Movement (NREM) sleep stage. All the subjects underwent polysomnography, and a dream report was collected upon their awakening from NREM sleep. Nine subjects were recallers (RECs) and 11 were non-RECs (NRECs). The delta and beta EEG activity of the last 5 min and the total NREM sleep was calculated by Fast Fourier Transform. Statistical comparisons (RECs vs. NRECs) revealed no differences in the last 5 min of sleep. Significant differences were found in the total NREM sleep: the RECs showed lower delta power over the parietal areas than the NRECs. Consistently, statistical comparisons on the activation index (delta/beta power) revealed that RECs showed a higher level of arousal in the fronto-temporal and parieto-occipital regions than NRECs. Both visual vividness and dream length are positively related to the level of activation. Overall, our results are consistent with the view that dreaming and the storage of oneiric contents depend on the level of arousal during sleep, highlighting a crucial role of the temporo-parietal-occipital zone.
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Affiliation(s)
- Serena Scarpelli
- IRCCS Fondazione Santa Lucia, 00179 Rome, Italy;
- Department of Psychology, Sapienza University of Rome, 00185 Rome, Italy; (A.D.); (C.B.); (M.G.); (A.M.)
| | - Aurora D’Atri
- Department of Psychology, Sapienza University of Rome, 00185 Rome, Italy; (A.D.); (C.B.); (M.G.); (A.M.)
| | - Chiara Bartolacci
- Department of Psychology, Sapienza University of Rome, 00185 Rome, Italy; (A.D.); (C.B.); (M.G.); (A.M.)
| | - Maurizio Gorgoni
- Department of Psychology, Sapienza University of Rome, 00185 Rome, Italy; (A.D.); (C.B.); (M.G.); (A.M.)
| | - Anastasia Mangiaruga
- Department of Psychology, Sapienza University of Rome, 00185 Rome, Italy; (A.D.); (C.B.); (M.G.); (A.M.)
- Department of Medical and Surgical Sciences (DIMEC), University of Bologna, 40126 Bologna, Italy
| | - Michele Ferrara
- Department of Biotechnological and Applied Clinical Sciences, University of L’Aquila, Via Vetoio (Coppito 2), 67100 Coppito (L’Aquila), Italy;
| | - Luigi De Gennaro
- IRCCS Fondazione Santa Lucia, 00179 Rome, Italy;
- Department of Psychology, Sapienza University of Rome, 00185 Rome, Italy; (A.D.); (C.B.); (M.G.); (A.M.)
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Lacaux C, Izabelle C, Santantonio G, De Villèle L, Frain J, Lubart T, Pizza F, Plazzi G, Arnulf I, Oudiette D. Increased creative thinking in narcolepsy. Brain 2020; 142:1988-1999. [PMID: 31143939 DOI: 10.1093/brain/awz137] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2018] [Revised: 02/18/2019] [Accepted: 03/27/2019] [Indexed: 11/13/2022] Open
Abstract
Some studies suggest a link between creativity and rapid eye movement sleep. Narcolepsy is characterized by falling asleep directly into rapid eye movement sleep, states of dissociated wakefulness and rapid eye movement sleep (cataplexy, hypnagogic hallucinations, sleep paralysis, rapid eye movement sleep behaviour disorder and lucid dreaming) and a high dream recall frequency. Lucid dreaming (the awareness of dreaming while dreaming) has been correlated with creativity. Given their life-long privileged access to rapid eye movement sleep and dreams, we hypothesized that subjects with narcolepsy may have developed high creative abilities. To test this assumption, 185 subjects with narcolepsy and 126 healthy controls were evaluated for their level of creativity with two questionnaires, the Test of Creative Profile and the Creativity Achievement Questionnaire. Creativity was also objectively tested in 30 controls and 30 subjects with narcolepsy using the Evaluation of Potential Creativity test battery, which measures divergent and convergent modes of creative thinking in the graphic and verbal domains, using concrete and abstract problems. Subjects with narcolepsy obtained higher scores than controls on the Test of Creative Profile (mean ± standard deviation: 58.9 ± 9.6 versus 55.1 ± 10, P = 0.001), in the three creative profiles (Innovative, Imaginative and Researcher) and on the Creative Achievement Questionnaire (10.4 ± 25.7 versus 6.4 ± 7.6, P = 0.047). They also performed better than controls on the objective test of creative performance (4.3 ± 1.5 versus 3.7 ± 1.4; P = 0.009). Most symptoms of narcolepsy (including sleepiness, hypnagogic hallucinations, sleep paralysis, lucid dreaming, and rapid eye movement sleep behaviour disorder, but not cataplexy) were associated with higher scores on the Test of Creative Profile. These results highlight a higher creative potential in subjects with narcolepsy and further support a role of rapid eye movement sleep in creativity.
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Affiliation(s)
- Célia Lacaux
- Sorbonne University, IHU@ICM, INSERM, CNRS UMR7225, Paris, France.,AP-HP, Hôpital Pitié-Salpêtrière, Service des Pathologies du Sommeil, National Reference Centre for Narcolepsy, Paris, France
| | - Charlotte Izabelle
- Sorbonne University, IHU@ICM, INSERM, CNRS UMR7225, Paris, France.,AP-HP, Hôpital Pitié-Salpêtrière, Service des Pathologies du Sommeil, National Reference Centre for Narcolepsy, Paris, France
| | - Giulio Santantonio
- Department of Biomedical and Neuromotor Sciences (DIBINEM), University of Bologna, Bologna, Italy.,IRCCS Istituto delle Scienze Neurologiche di Bologna, Bologna, Italy
| | - Laure De Villèle
- Sorbonne University, IHU@ICM, INSERM, CNRS UMR7225, Paris, France.,AP-HP, Hôpital Pitié-Salpêtrière, Service des Pathologies du Sommeil, National Reference Centre for Narcolepsy, Paris, France
| | - Johanna Frain
- Sorbonne University, IHU@ICM, INSERM, CNRS UMR7225, Paris, France.,AP-HP, Hôpital Pitié-Salpêtrière, Service des Pathologies du Sommeil, National Reference Centre for Narcolepsy, Paris, France
| | - Todd Lubart
- Laboratoire de psychologie et d'ergonomie appliquées, Université Paris Descartes, Paris, France
| | - Fabio Pizza
- Department of Biomedical and Neuromotor Sciences (DIBINEM), University of Bologna, Bologna, Italy.,IRCCS Istituto delle Scienze Neurologiche di Bologna, Bologna, Italy
| | - Giuseppe Plazzi
- Department of Biomedical and Neuromotor Sciences (DIBINEM), University of Bologna, Bologna, Italy.,IRCCS Istituto delle Scienze Neurologiche di Bologna, Bologna, Italy
| | - Isabelle Arnulf
- Sorbonne University, IHU@ICM, INSERM, CNRS UMR7225, Paris, France.,AP-HP, Hôpital Pitié-Salpêtrière, Service des Pathologies du Sommeil, National Reference Centre for Narcolepsy, Paris, France
| | - Delphine Oudiette
- Sorbonne University, IHU@ICM, INSERM, CNRS UMR7225, Paris, France.,AP-HP, Hôpital Pitié-Salpêtrière, Service des Pathologies du Sommeil, National Reference Centre for Narcolepsy, Paris, France
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Affiliation(s)
- Sergio Arthuro Mota-Rolim
- Brain Institute, Department of Physiology and Behavior, and Onofre Lopes University Hospital - Federal University of Rio Grande Do Norte, Natal, Brazil
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Chabani E, Vionnet MC, Beauté R, Leu-Semenescu S, Dodet P, Arnulf I. Blackout of my nights: Contentless, timeless and selfless report from the night in patients with central hypersomnias. Conscious Cogn 2020; 81:102931. [PMID: 32339976 DOI: 10.1016/j.concog.2020.102931] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2019] [Revised: 02/20/2020] [Accepted: 04/06/2020] [Indexed: 11/24/2022]
Abstract
At the extreme spectrum of consciousness during sleep, some patients with rare hypersomnias reported experiencing a specific night 'blackout' when sleeping, i.e., an absence of experiences or recall of them from sleep onset to offset. Thus, we explored through questionnaires the conscious experiences (dreaming experience, mind, self) during the night in 133 patients with idiopathic hypersomnia, 108 patients with narcolepsy, and 128 healthy controls. The night blackout was more frequent in idiopathic hypersomnia than in narcolepsy and control groups. Patients with idiopathic hypersomnia and frequent night amnesia had lower dream recall frequencies, and felt more often sleep as deep and mind as blank during the night. They had a higher proportion of slow wave sleep on their (retrospectively collected) sleep recordings than those without night blackout. This night blackout provides a new model for studying loss of consciousness during sleep, here as a contentless, selfless and timeless feeling upon awakening.
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Affiliation(s)
- Emma Chabani
- Sorbonne University, Paris, France; Paris Brain Institute (IHU@ICM; Inserm UMR_S 975; CNRS UMR 7225), Paris, France
| | | | | | - Smaranda Leu-Semenescu
- Paris Brain Institute (IHU@ICM; Inserm UMR_S 975; CNRS UMR 7225), Paris, France; Sleep Disorders Unit, Pitié-Salpêtrière University Hospital, Assistance Publique - Hôpitaux de Paris, Paris, France; National Reference Center on Narcolepsy and Rare Hypersomnias, France
| | - Pauline Dodet
- Paris Brain Institute (IHU@ICM; Inserm UMR_S 975; CNRS UMR 7225), Paris, France; Sleep Disorders Unit, Pitié-Salpêtrière University Hospital, Assistance Publique - Hôpitaux de Paris, Paris, France; National Reference Center on Narcolepsy and Rare Hypersomnias, France
| | - Isabelle Arnulf
- Sorbonne University, Paris, France; Paris Brain Institute (IHU@ICM; Inserm UMR_S 975; CNRS UMR 7225), Paris, France; Sleep Disorders Unit, Pitié-Salpêtrière University Hospital, Assistance Publique - Hôpitaux de Paris, Paris, France; National Reference Center on Narcolepsy and Rare Hypersomnias, France.
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Drinkwater KG, Denovan A, Dagnall N. Lucid Dreaming, Nightmares, and Sleep Paralysis: Associations With Reality Testing Deficits and Paranormal Experience/Belief. Front Psychol 2020; 11:471. [PMID: 32256437 PMCID: PMC7093643 DOI: 10.3389/fpsyg.2020.00471] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2019] [Accepted: 02/28/2020] [Indexed: 01/13/2023] Open
Abstract
Focusing on lucid dreaming, this paper examined relationships between dissociated experiences related to rapid eye movement (REM) sleep (lucid dreaming, nightmares, and sleep paralysis), reality testing, and paranormal experiences/beliefs. The study comprised a UK-based online sample of 455 respondents (110 males, 345 females, Mean age = 34.46 years, SD = 15.70), who had all previously experienced lucid dreaming. Respondents completed established self-report measures assessing control within lucid dreaming, experience and frequency of nightmares, incidence of sleep paralysis, proneness to reality testing deficits (Inventory of Personality Organization subscale, IPO-RT), subjective experience of receptive psi and life after death (paranormal experience), and paranormal belief. Analysis comprised tests of correlational and predictive relationships between sleep-related outcomes, IPO-RT scores, and paranormal measures. Significant positive correlations between sleep and paranormal measures were weak. Paranormal measures related differentially to sleep indices. Paranormal experience correlated with lucid dreaming, nightmares, and sleep paralysis, whereas paranormal belief related only to nightmares and sleep paralysis. IPO-RT correlated positively with all paranormal and sleep-related measures. Within the IPO-RT, the Auditory and Visual Hallucinations sub-factor demonstrated the strongest positive associations with sleep measures. Structural equation modeling indicated that Auditory and Visual Hallucinations significantly positively predicted dissociated experiences related to REM sleep, while paranormal experience did not. However, paranormal experience was a significant predictor when analysis controlled for Auditory and Visual Hallucinations. The moderate positive association between these variables explained this effect. Findings indicated that self-generated, productive cognitive-processes (as encompassed by Auditory and Visual Hallucinations) played a significant role in conscious control and awareness of lucid dreaming, and related dissociative sleep states (sleep paralysis and nightmares).
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Affiliation(s)
- Kenneth G. Drinkwater
- Department of Psychology, Faculty of Health, Psychology and Social Care, Manchester Metropolitan University, Manchester, United Kingdom
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D'Anselmo A, Agnoli S, Filardi M, Pizza F, Mastria S, Corazza GE, Plazzi G. Creativity in Narcolepsy Type 1: The Role of Dissociated REM Sleep Manifestations. Nat Sci Sleep 2020; 12:1191-1200. [PMID: 33364866 PMCID: PMC7751730 DOI: 10.2147/nss.s277647] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/20/2020] [Accepted: 10/22/2020] [Indexed: 12/04/2022] Open
Abstract
PURPOSE A higher creative potential has been reported in narcoleptic patients and linked to lucid dreaming. The aim of the present study was to explore the role of narcolepsy symptoms (presence and severity) in predicting creativity. PATIENTS AND METHODS Sixty-six consecutive type 1 narcolepsy patients (mean age 38.62 ± 17.05, 31 females) took part in this study. Creative achievement in different life domains and creative beliefs were assessed by a self-reported questionnaire and a scale measuring the creative self, respectively; creative performance was measured through a divergent thinking test (generation of alternative original solutions to an open problem). RESULTS We found a key effect of hypnagogic hallucinations in modulating creative behaviour. We therefore tested at first whether hypnagogic hallucinations could interact with specific mental states associated with creativity and in particular mind wandering, a factor associated with both creative performance and achievement. Secondly, we verified if hypnagogic hallucinations could influence the definition of creative identity in type 1 narcolepsy patients, which in turn could predict their creative achievement and creative performance. Results showed that spontaneous mind wandering influenced creative achievement through a moderation effect of sleep paralysis and hypnagogic hallucinations. Moreover, sleep paralysis and hypnagogic hallucinations indirectly influenced, through creative identity, both creative achievement and performance (fluency score). CONCLUSION Our results highlight the role of hypnagogic hallucinations in triggering the process of mind wandering which leads to greater creative success. In addition, this symptom affects creative identity in narcolepsy, leading in turn to higher creative success and creative potential of narcoleptic patients.
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Affiliation(s)
- Anita D'Anselmo
- Department of Biomedical and Neuromotor Sciences (DIBINEM), University of Bologna, Bologna, Italy.,Marconi Institute for Creativity (MIC), Bologna, Italy
| | - Sergio Agnoli
- Marconi Institute for Creativity (MIC), Bologna, Italy.,Department of Electrical, Electronic, and Information Engineering "Guglielmo Marconi", University of Bologna, Bologna, Italy
| | - Marco Filardi
- Department of Biomedical and Neuromotor Sciences (DIBINEM), University of Bologna, Bologna, Italy
| | - Fabio Pizza
- Department of Biomedical and Neuromotor Sciences (DIBINEM), University of Bologna, Bologna, Italy.,IRCCS Istituto delle Scienze Neurologiche di Bologna, Bologna, Italy
| | - Serena Mastria
- Marconi Institute for Creativity (MIC), Bologna, Italy.,Department of Electrical, Electronic, and Information Engineering "Guglielmo Marconi", University of Bologna, Bologna, Italy
| | - Giovanni Emanuele Corazza
- Marconi Institute for Creativity (MIC), Bologna, Italy.,Department of Electrical, Electronic, and Information Engineering "Guglielmo Marconi", University of Bologna, Bologna, Italy.,Université de Paris and Univ Gustave Eiffel, LaPEA, Paris, France
| | - Giuseppe Plazzi
- IRCCS Istituto delle Scienze Neurologiche di Bologna, Bologna, Italy.,Department of Biomedical, Metabolic and Neural Sciences, University of Modena and Reggio Emilia, Modena, Italy
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de Macêdo TCF, Ferreira GH, de Almondes KM, Kirov R, Mota-Rolim SA. My Dream, My Rules: Can Lucid Dreaming Treat Nightmares? Front Psychol 2019; 10:2618. [PMID: 31849749 PMCID: PMC6902039 DOI: 10.3389/fpsyg.2019.02618] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2019] [Accepted: 11/06/2019] [Indexed: 12/11/2022] Open
Abstract
Nightmares are defined as repeated occurrences of extremely dysphoric and well-remembered dreams that usually involve subjective threats to survival, security, or physical integrity. Generally, they occur during rapid eye movement sleep (REMS) and lead to awakenings with distress and insufficient overnight sleep. Nightmares may occur spontaneously (idiopathic) or as recurrent nightmares. Recurrent nightmares cause significant distress and impairment in occupational and social functioning, as have been commonly observed in post-traumatic stress disorder, depression and anxiety. By contrast, during lucid dreaming (LD), subjects get insight they are dreaming and may even control the content of their dreams. These features may open a way to help those who suffer from nightmare disorder through re-significations of the dream scene, i.e., knowing that they are dreaming and having control over their dream content. Thus, lucid dreamers might be able to render nightmares normal dreams, thereby assuring a restoring sleep. The aim of the present study is to review the existing literature of the use of LD as an auxiliary tool for treatment of nightmares. We conducted a careful literature search for eligible studies on the use of LD treatment for nightmares. We observed that whereas LD may be a feasible aid in the treatment of patients with nightmares through minimizing their frequency, intensity and psychological distress, the available literature is still scarce and does not provide consistent results. We conclude therefore that more research is clearly warranted for a better estimation of the effective conductance and therapeutic outcome of LD treatment in clinical practice.
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Affiliation(s)
| | | | - Katie Moraes de Almondes
- Department of Psychology, Postgraduate Program in Psychobiology, Onofre Lopes University Hospital, Federal University of Rio Grande do Norte, Natal, Brazil
| | - Roumen Kirov
- Institute of Neurobiology, Bulgarian Academy of Sciences, Sofia, Bulgaria
| | - Sérgio Arthuro Mota-Rolim
- Brain Institute, Physiology and Behavior Department, Onofre Lopes University Hospital, Federal University of Rio Grande do Norte, Natal, Brazil
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40
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Scarpelli S, Bartolacci C, D'Atri A, Gorgoni M, De Gennaro L. Mental Sleep Activity and Disturbing Dreams in the Lifespan. Int J Environ Res Public Health 2019; 16:E3658. [PMID: 31569467 PMCID: PMC6801786 DOI: 10.3390/ijerph16193658] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 06/26/2019] [Revised: 09/11/2019] [Accepted: 09/27/2019] [Indexed: 02/05/2023]
Abstract
Sleep significantly changes across the lifespan, and several studies underline its crucial role in cognitive functioning. Similarly, mental activity during sleep tends to covary with age. This review aims to analyze the characteristics of dreaming and disturbing dreams at different age brackets. On the one hand, dreams may be considered an expression of brain maturation and cognitive development, showing relations with memory and visuo-spatial abilities. Some investigations reveal that specific electrophysiological patterns, such as frontal theta oscillations, underlie dreams during sleep, as well as episodic memories in the waking state, both in young and older adults. On the other hand, considering the role of dreaming in emotional processing and regulation, the available literature suggests that mental sleep activity could have a beneficial role when stressful events occur at different age ranges. We highlight that nightmares and bad dreams might represent an attempt to cope the adverse events, and the degrees of cognitive-brain maturation could impact on these mechanisms across the lifespan. Future investigations are necessary to clarify these relations. Clinical protocols could be designed to improve cognitive functioning and emotional regulation by modifying the dream contents or the ability to recall/non-recall them.
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Affiliation(s)
- Serena Scarpelli
- Department of Psychology, "Sapienza" University of Rome, Via dei Marsi, 78, 00185 Rome, Italy.
| | - Chiara Bartolacci
- Department of Psychology, "Sapienza" University of Rome, Via dei Marsi, 78, 00185 Rome, Italy.
| | - Aurora D'Atri
- Department of Psychology, "Sapienza" University of Rome, Via dei Marsi, 78, 00185 Rome, Italy.
| | - Maurizio Gorgoni
- Department of Psychology, "Sapienza" University of Rome, Via dei Marsi, 78, 00185 Rome, Italy.
| | - Luigi De Gennaro
- Department of Psychology, "Sapienza" University of Rome, Via dei Marsi, 78, 00185 Rome, Italy.
- IRCCS Santa Lucia Foundation, 00142 Rome, Italy.
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41
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Andrillon T, Windt J, Silk T, Drummond SPA, Bellgrove MA, Tsuchiya N. Does the Mind Wander When the Brain Takes a Break? Local Sleep in Wakefulness, Attentional Lapses and Mind-Wandering. Front Neurosci 2019; 13:949. [PMID: 31572112 PMCID: PMC6753166 DOI: 10.3389/fnins.2019.00949] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2019] [Accepted: 08/22/2019] [Indexed: 01/18/2023] Open
Abstract
Sleep has been classically described as an all-or-nothing global phenomenon. However, recent research strongly suggests that this view requires tempering. Invasive and non-invasive recordings in animals and humans show that neural activity typically associated with sleep can locally occur during wakefulness. Although local sleep is defined neuronally, it has been associated with impaired performance during cognitive tasks. Comparatively, the phenomenology of local sleep (i.e., what it feels like when your brain is partially asleep) has been less explored. Taking into account the literature on the neuronal and behavioral profile of local sleep intrusions in wakefulness, we propose that occurrences of local sleep could represent the neural mechanism underlying many attentional lapses. In particular, we argue that a unique physiological event such as local sleep could account for a diversity of behavioral outcomes from sluggish to impulsive responses. We further propose that local sleep intrusions could impact individuals' subjective experience. Specifically, we propose that the timing and anatomical sources of local sleep intrusions could be responsible for both the behavioral consequences and subjective content of attentional lapses and may underlie the difference between subjective experiences such as mind wandering and mind blanking. Our framework aims to build a parallel between spontaneous experiences in sleep and wakefulness by integrating evidence across neuronal, behavioral and experiential levels. We use the example of attention deficit hyperactivity disorder (ADHD) to illustrate how local sleep could explain complex cognitive profiles which include inattention, impulsivity, mind-wandering and mind-blanking.
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Affiliation(s)
- Thomas Andrillon
- School of Psychological Sciences, Turner Institute for Brain and Mental Health, Monash University, Melbourne, VIC, Australia
| | - Jennifer Windt
- School of Philosophical, Historical and International Studies, Monash University, Melbourne, VIC, Australia
| | - Tim Silk
- School of Psychology, Deakin University, Melbourne, VIC, Australia
- Murdoch Children’s Research Institute, Melbourne, VIC, Australia
- Department of Paediatrics, University of Melbourne, Melbourne, VIC, Australia
| | - Sean P. A. Drummond
- School of Psychological Sciences, Turner Institute for Brain and Mental Health, Monash University, Melbourne, VIC, Australia
| | - Mark A. Bellgrove
- School of Psychological Sciences, Turner Institute for Brain and Mental Health, Monash University, Melbourne, VIC, Australia
| | - Naotsugu Tsuchiya
- School of Psychological Sciences, Turner Institute for Brain and Mental Health, Monash University, Melbourne, VIC, Australia
- Center for Information and Neural Networks (CiNet), National Institute of Information and Communications Technology (NICT), Osaka, Japan
- Advanced Telecommunications Research Computational Neuroscience Laboratories, Kyoto, Japan
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Bassetti CLA, Adamantidis A, Burdakov D, Han F, Gay S, Kallweit U, Khatami R, Koning F, Kornum BR, Lammers GJ, Liblau RS, Luppi PH, Mayer G, Pollmächer T, Sakurai T, Sallusto F, Scammell TE, Tafti M, Dauvilliers Y. Narcolepsy — clinical spectrum, aetiopathophysiology, diagnosis and treatment. Nat Rev Neurol 2019; 15:519-39. [DOI: 10.1038/s41582-019-0226-9] [Citation(s) in RCA: 204] [Impact Index Per Article: 40.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/04/2019] [Indexed: 12/15/2022]
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Schredl M, AG Traum der Deutschen Gesellschaft für Schlafforschung und Schlafmedizin (DGSM), Schmitt J. Dream recall frequency, nightmare frequency, attitude towards dreams, and other dream variables in patients with sleep-related breathing disorders. Somnologie 2019; 23:109-115. [DOI: 10.1007/s11818-019-0199-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Abstract
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.
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Affiliation(s)
- Benjamin Baird
- Wisconsin Institute for Sleep and Consciousness, University of Wisconsin-Madison, Madison, WI, USA.
| | - Sergio A Mota-Rolim
- Brain Institute, Physiology Department and Onofre Lopes University Hospital - Federal University of Rio Grande do Norte, Natal, Brazil
| | - Martin Dresler
- Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Centre, Nijmegen, the Netherlands
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Scarpelli S, Bartolacci C, D'Atri A, Gorgoni M, De Gennaro L. The Functional Role of Dreaming in Emotional Processes. Front Psychol 2019; 10:459. [PMID: 30930809 PMCID: PMC6428732 DOI: 10.3389/fpsyg.2019.00459] [Citation(s) in RCA: 65] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2018] [Accepted: 02/15/2019] [Indexed: 02/05/2023] Open
Abstract
Dream experience (DE) represents a fascinating condition linked to emotional processes and the human inner world. Although the overlap between REM sleep and dreaming has been overcome, several studies point out that emotional and perceptually vivid contents are more frequent when reported upon awakenings from this sleep stage. Actually, it is well-known that REM sleep plays a pivotal role in the processing of salient and emotional waking-life experiences, strongly contributing to the emotional memory consolidation. In this vein, we highlighted that, to some extent, neuroimaging studies showed that the processes that regulate dreaming and emotional salience in sleep mentation share similar neural substrates of those controlling emotions during wakefulness. Furthermore, the research on EEG correlates of the presence/absence of DE and the results on EEG pattern related to the incorporated memories converged to assign a crucial role of REM theta oscillations in emotional re-processing. In particular, the theta activity is involved in memory processes during REM sleep as well as during the waking state, in line with the continuity hypothesis. Also, the gamma activity seems to be related to emotional processes and dream recall as well as to lucid dreams. Interestingly, similar EEG correlates of DE have been found in clinical samples when nightmares or dreams occur. Research on clinical samples revealed that promoting the rehearsal of frightening contents aimed to change them is a promising method to treat nightmares, and that lucid dreams are associated with an attenuation of nightmares. In this view, DE can defuse emotional traumatic memories when the emotional regulation and the fear extinction mechanisms are compromised by traumatic and frightening events. Finally, dreams could represent a sort of simulation of reality, providing the possibility to create a new scenario with emotional mastery elements to cope with dysphoric items included in nightmares. In addition, it could be hypothesized that the insertion of bizarre items besides traumatic memories might be functional to "impoverish" the negative charge of the experiences.
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Affiliation(s)
| | | | | | | | - Luigi De Gennaro
- Department of Psychology, Sapienza University of Rome, Rome, Italy
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46
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D'Atri A, Scarpelli S, Schiappa C, Pizza F, Vandi S, Ferrara M, Cipolli C, Plazzi G, De Gennaro L. Cortical activation during sleep predicts dream experience in narcolepsy. Ann Clin Transl Neurol 2019; 6:445-455. [PMID: 30911568 PMCID: PMC6414482 DOI: 10.1002/acn3.718] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2018] [Accepted: 12/05/2018] [Indexed: 02/05/2023] Open
Abstract
Objective Narcolepsy type 1 widely affects the architecture of sleep with frequent fast transition to REM sleep at both nighttime and daytime sleep onset. The occurrence of repeated sleep onset REM periods over the Multiple Sleep Latency Test offers a unique opportunity to identify EEG patterns predictive of successful dream recall after short periods composed of only REM or NREM sleep. It also permits to disentangle state- from trait-like differences in dream recall, by using a within-subjects design. Methods A consecutive series of 115 first-diagnosed drug-free adult narcolepsy-type 1 patients underwent Multiple Sleep Latency Tests and were asked after each nap opportunity if they had or had not a dream experience. Scalp EEG power and a specific index of cortical activation (delta/beta power ratio), obtained from naps of 43 patients with both presence and absence of dream recall in the same sleep stage, were compared separately for REM and NREM sleep. Results Successful dream recall was associated with an increased EEG desynchronization in both REM and NREM over partially overlapping cortical areas. Compared to unsuccessful recall, it showed (1) lower delta power over centro-parietal areas during both stages, (2) higher beta power in the same cortical areas during NREM, and (3) lower values in the delta/beta ratio during NREM in most scalp locations. Interpretation A more activated electrophysiological milieu in both REM and NREM sleep promotes dream recall, strengthening the notion that the parietal areas are crucial not only in generating dream experience, as shown in brain-damaged patients, but also in the memory processing leading to recall.
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Affiliation(s)
- Aurora D'Atri
- Department of Psychology University of Rome "Sapienza" Rome Italy
| | - Serena Scarpelli
- Department of Psychology University of Rome "Sapienza" Rome Italy
| | - Cinzia Schiappa
- Department of Psychology University of Rome "Sapienza" Rome Italy
| | - Fabio Pizza
- Department of Biomedical and Neuromotor Sciences (DIBINEM) University of Bologna Bologna Italy.,IRCCS Istituto delle Scienze Neurologiche di Bologna Bologna Italy
| | - Stefano Vandi
- Department of Biomedical and Neuromotor Sciences (DIBINEM) University of Bologna Bologna Italy.,IRCCS Istituto delle Scienze Neurologiche di Bologna Bologna Italy
| | - Michele Ferrara
- Department of Biotechnological and Applied Clinical Sciences University of L'Aquila L'Aquila Italy
| | - Carlo Cipolli
- Department of Specialty Diagnostic and Experimental Medicine (DIMES) University of Bologna Bologna Italy
| | - Giuseppe Plazzi
- Department of Biomedical and Neuromotor Sciences (DIBINEM) University of Bologna Bologna Italy.,IRCCS Istituto delle Scienze Neurologiche di Bologna Bologna Italy
| | - Luigi De Gennaro
- Department of Psychology University of Rome "Sapienza" Rome Italy
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Choi YW, Song JH, Kim TW, Kim SM, Cho IH, Hong SC. Two Cases of Narcoleptic patients with sleep paralysis as a Chief Complaint. Sleep Med Res 2018. [DOI: 10.17241/smr.2018.00311] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Schiappa C, Scarpelli S, D’Atri A, Gorgoni M, De Gennaro L. Narcolepsy and emotional experience: a review of the literature. Behav Brain Funct 2018; 14:19. [PMID: 30587203 PMCID: PMC6305999 DOI: 10.1186/s12993-018-0151-x] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 06/22/2018] [Accepted: 12/21/2018] [Indexed: 02/08/2023]
Abstract
Narcolepsy is a chronic sleep disorder characterized by excessive daytime sleepiness, cataplexy, hypnagogic hallucinations, and sleep paralysis. This disease affects significantly the overall patient functioning, interfering with social, work, and affective life. Some symptoms of narcolepsy depend on emotional stimuli; for instance, cataplectic attacks can be triggered by emotional inputs such as laughing, joking, a pleasant surprise, and also anger. Neurophysiological and neurochemical findings suggest the involvement of emotional brain circuits in the physiopathology of cataplexy, which seems to depending on the dysfunctional interplay between the hypothalamus and the amygdala associated with an alteration of hypocretin levels. Furthermore, behavioral studies suggest an impairment of emotions processing in narcolepsy-cataplexy (NC), like a probable coping strategy to avoid or reduce the frequency of cataplexy attacks. Consistently, NC patients seem to use coping strategies even during their sleep, avoiding unpleasant mental sleep activity through lucid dreaming. Interestingly, NC patients, even during sleep, have a different emotional experience than healthy subjects, with more vivid, bizarre, and frightening dreams. Notwithstanding this evidence, the relationship between emotion and narcolepsy is poorly investigated. This review aims to provide a synthesis of behavioral, neurophysiological, and neurochemical evidence to discuss the complex relationship between NC and emotional experience and to direct future research.
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Affiliation(s)
- C. Schiappa
- Department of Psychology, University of Rome “Sapienza”, Via dei Marsi, 78, 00185 Rome, Italy
| | - S. Scarpelli
- Department of Psychology, University of Rome “Sapienza”, Via dei Marsi, 78, 00185 Rome, Italy
| | - A. D’Atri
- Department of Psychology, University of Rome “Sapienza”, Via dei Marsi, 78, 00185 Rome, Italy
| | - M. Gorgoni
- Department of Psychology, University of Rome “Sapienza”, Via dei Marsi, 78, 00185 Rome, Italy
| | - Luigi De Gennaro
- Department of Psychology, University of Rome “Sapienza”, Via dei Marsi, 78, 00185 Rome, Italy
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