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Hudachek L, Wamsley EJ. A meta-analysis of the relation between dream content and memory consolidation. Sleep 2023; 46:zsad111. [PMID: 37058584 DOI: 10.1093/sleep/zsad111] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2022] [Revised: 03/11/2023] [Indexed: 04/16/2023] Open
Abstract
The frequent appearance of newly learned information in dreams suggests that dream content is influenced by memory consolidation. Many studies have tested this hypothesis by asking whether dreaming about a learning task is associated with improved memory, but results have been inconsistent. We conducted a meta-analysis to determine the strength of the association between learning-related dreams and post-sleep memory improvement. We searched the literature for studies that (1) trained participants on a pre-sleep learning task and then tested their memory after sleep, and (2) associated post-sleep memory improvement with the extent to which dreams incorporated learning task content. Sixteen studies qualified for inclusion, which together reported 45 effects. Integrating across effects, we report a strong and statistically significant association between task-related dreaming and memory performance (SMD = 0.51 [95% CI 0.28, 0.74], p < 0.001). Among studies using polysomnography, this relationship was statistically significant for dreams collected from non-rapid eye movement (NREM) sleep (n = 10) but not for dreams collected from rapid eye movement (REM) sleep (n = 12). There was a significant association between dreaming and memory for all types of learning tasks studied. This meta-analysis provides further evidence that dreaming about a learning task is associated with improved memory performance, suggesting that dream content may be an indication of memory consolidation. Furthermore, we report preliminary evidence that the relationship between dreaming and memory may be stronger in NREM sleep compared to REM.
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Affiliation(s)
- Lauren Hudachek
- Furman University Department of Psychology and Program in Neuroscience, Greenville, SC, 29613, USA
| | - Erin J Wamsley
- Furman University Department of Psychology and Program in Neuroscience, Greenville, SC, 29613, USA
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2
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Garel N, Thibault Lévesque J, Sandra DA, Lessard-Wajcer J, Solomonova E, Lifshitz M, Richard-Devantoy S, Greenway KT. Imprinting: expanding the extra-pharmacological model of psychedelic drug action to incorporate delayed influences of sets and settings. Front Hum Neurosci 2023; 17:1200393. [PMID: 37533588 PMCID: PMC10390742 DOI: 10.3389/fnhum.2023.1200393] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2023] [Accepted: 06/22/2023] [Indexed: 08/04/2023] Open
Abstract
Background Psychedelic drug experiences are shaped by current-moment contextual factors, commonly categorized as internal (set) and external (setting). Potential influences of past environments, however, have received little attention. Aims To investigate how previous environmental stimuli shaped the experiences of patients receiving ketamine for treatment-resistant depression (TRD), and develop the concept of "imprinting" to account for such time-lagged effects across diverse hallucinogenic drugs. Methods Recordings of treatment sessions and phenomenological interviews from 26 participants of a clinical trial investigating serial intravenous ketamine infusions for TRD, conducted from January 2021 to August 2022, were retrospectively reviewed. A broad literature search was undertaken to identify potentially underrecognized examples of imprinting with both serotonergic and atypical psychedelics, as well as analogous cognitive processes and neural mechanisms. Results In naturalistic single-subject experiments of a 28-year-old female and a 34-year-old male, subjective ketamine experiences were significantly altered by varying exposures to particular forms of digital media in the days preceding treatments. Higher levels of media exposure reduced the mystical/emotional qualities of subsequent psychedelic ketamine experiences, overpowering standard intention-setting practices and altering therapeutic outcomes. Qualitative data from 24 additional patients yielded eight further spontaneous reports of past environmental exposures manifesting as visual hallucinations during ketamine experiences. We identified similar examples of imprinting with diverse psychoactive drugs in past publications, including in the first-ever report of ketamine in human subjects, as well as analogous processes known to underly dreaming. Conclusions/interpretation Past environmental exposures can significantly influence the phenomenology and therapeutic outcomes of psychedelic experiences, yet are underrecognized and understudied. To facilitate future research, we propose expanding the contextual model of psychedelic drug actions to incorporate imprinting, a novel concept that may aid clinicians, patients, and researchers to better understand psychedelic drug effects. Clinical trial registration ClinicalTrials.gov, identifier NCT04701866.
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Affiliation(s)
- Nicolas Garel
- Department of Psychiatry, McGill University, Montreal, QC, Canada
| | | | - Dasha A. Sandra
- Department of Psychology, McGill University, Montreal, QC, Canada
| | | | - Elizaveta Solomonova
- Department of Psychiatry, McGill University, Montreal, QC, Canada
- Neurophilosophy Lab, Department of Philosophy, McGill University, Montreal, QC, Canada
| | - Michael Lifshitz
- Department of Psychiatry, McGill University, Montreal, QC, Canada
- Lady Davis Institute for Medical Research, Jewish General Hospital, Montreal, QC, Canada
| | - Stéphane Richard-Devantoy
- Department of Psychiatry, McGill University, Montreal, QC, Canada
- McGill Group for Suicide Studies, Douglas Mental Health University Institute, LaSalle, QC, Canada
| | - Kyle T. Greenway
- Department of Psychiatry, McGill University, Montreal, QC, Canada
- Lady Davis Institute for Medical Research, Jewish General Hospital, Montreal, QC, Canada
- Department of Medicine, Centre for Psychedelic Research, Imperial College London, London, United Kingdom
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3
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Cunningham TJ. The next step in understanding the function of dreams. Sleep 2023; 46:zsad010. [PMID: 36656722 PMCID: PMC10091084 DOI: 10.1093/sleep/zsad010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2023] [Indexed: 01/20/2023] Open
Affiliation(s)
- Tony J Cunningham
- Center for Sleep and Cognition, Psychiatry Department, Beth Israel Deaconess Medical Center, Boston, MA, USA
- Division of Sleep Medicine, Harvard Medical School, Boston, MA, USA
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4
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Picard-Deland C, Konkoly K, Raider R, Paller KA, Nielsen T, Pigeon WR, Carr M. The memory sources of dreams: serial awakenings across sleep stages and time of night. Sleep 2023; 46:zsac292. [PMID: 36462190 PMCID: PMC10091095 DOI: 10.1093/sleep/zsac292] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2022] [Revised: 09/27/2022] [Indexed: 12/05/2022] Open
Abstract
Memories of waking-life events are incorporated into dreams, but their incorporation is not uniform across a night of sleep. This study aimed to elucidate ways in which such memory sources vary by sleep stage and time of night. Twenty healthy participants (11 F; 24.1 ± 5.7 years) spent a night in the laboratory and were awakened for dream collection approximately 12 times spread across early, middle, and late periods of sleep, while covering all stages of sleep (N1, N2, N3, REM). In the morning, participants identified and dated associated memories of waking-life events for each dream report, when possible. The incorporation of recent memory sources in dreams was more frequent in N1 and REM than in other sleep stages. The incorporation of distant memories from over a week ago, semantic memories not traceable to a single event, and anticipated future events remained stable throughout sleep. In contrast, the relative proportions of recent versus distant memory sources changed across the night, independently of sleep stage, with late-night dreams in all stages having relatively less recent and more remote memory sources than dreams earlier in the night. Qualitatively, dreams tended to repeat similar themes across the night and in different sleep stages. The present findings clarify the temporal course of memory incorporations in dreams, highlighting a specific connection between time of night and the temporal remoteness of memories. We discuss how dream content may, at least in part, reflect the mechanisms of sleep-dependent memory consolidation.
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Affiliation(s)
| | - Karen Konkoly
- Department of Psychology, Northwestern University, Evanston, IL, USA
| | - Rachel Raider
- Department of Psychiatry, University of Rochester Medical Center, Rochester, NY, USA
| | - Ken A Paller
- Department of Psychology, Northwestern University, Evanston, IL, USA
| | - Tore Nielsen
- Department of Psychiatry and Addictology, University of Montreal, Montreal, Quebec, Canada
| | - Wilfred R Pigeon
- Department of Psychiatry, University of Rochester Medical Center, Rochester, NY, USA
| | - Michelle Carr
- Department of Psychiatry, University of Rochester Medical Center, Rochester, NY, USA
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5
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Picard-Deland C, Bernardi G, Genzel L, Dresler M, Schoch SF. Memory reactivations during sleep: a neural basis of dream experiences? Trends Cogn Sci 2023; 27:568-582. [PMID: 36959079 DOI: 10.1016/j.tics.2023.02.006] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2022] [Revised: 02/18/2023] [Accepted: 02/28/2023] [Indexed: 03/25/2023]
Abstract
Newly encoded memory traces are spontaneously reactivated during sleep. Since their discovery in the 1990s, these memory reactivations have been discussed as a potential neural basis for dream experiences. New results from animal and human research, as well as from the rapidly growing field of sleep and dream engineering, provide essential insights into this question, and reveal both strong parallels and disparities between the two phenomena. We suggest that, although memory reactivations may contribute to subjective experiences across different states of consciousness, they are not likely to be the primary neural basis of dreaming. We identify important limitations in current research paradigms and suggest novel strategies to address this question empirically.
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Affiliation(s)
- Claudia Picard-Deland
- Dream and Nightmare Laboratory, Center for Advanced Research in Sleep Medicine, University of Montreal, Montreal, QC, Canada
| | - Giulio Bernardi
- Institutions, Markets, Technologies (IMT) School for Advanced Studies Lucca, Lucca, Italy
| | - Lisa Genzel
- Donders Institute for Brain, Cognition, and Behaviour, Radboud University, Nijmegen, The Netherlands
| | - Martin Dresler
- Donders Institute for Brain, Cognition, and Behaviour, Radboud University Medical Centre, Nijmegen, The Netherlands
| | - Sarah F Schoch
- Donders Institute for Brain, Cognition, and Behaviour, Radboud University Medical Centre, Nijmegen, The Netherlands; Center of Competence Sleep and Health Zurich, University of Zurich, Zurich, Switzerland.
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6
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Fasiello E, Scarpelli S, Gorgoni M, Alfonsi V, Galbiati A, De Gennaro L. A systematic review of dreams and nightmares recall in patients with rapid eye movement sleep behaviour disorder. J Sleep Res 2022; 32:e13768. [PMID: 36316953 DOI: 10.1111/jsr.13768] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2022] [Revised: 09/08/2022] [Accepted: 10/03/2022] [Indexed: 11/06/2022]
Abstract
Rapid eye movement (REM) sleep behaviour disorder is a REM sleep parasomnia characterised by the loss of the physiological muscle atonia during REM sleep, resulting in dream enactment behaviours that may cause injuries to patients or their bed partners. The nocturnal motor episodes seem to respond to the dream contents, which are often vivid and violent. These behavioural and oneiric features make the REM sleep behaviour disorder a potential model to study dreams. This review aims to unify the literature about dream recall in REM sleep behaviour disorder as a privileged approach to study dreams, systematically reviewing studies that applied retrospective and prospective experimental designs to provide a comprehensive overview of qualitative and quantitative aspects of dream recall in this REM sleep parasomnia. The present work highlights that the study of dreaming in REM sleep behaviour disorder is useful to understand unique aspects of this pathology and to explore neurobiological, electrophysiological, and cognitive mechanisms of REM sleep and dreaming.
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Affiliation(s)
| | - Serena Scarpelli
- Department of Psychology Sapienza ‐ University of Rome Rome Italy
| | - Maurizio Gorgoni
- Department of Psychology Sapienza ‐ University of Rome Rome Italy
- Body and Action Lab IRCCS Fondazione Santa Lucia Rome Italy
| | | | - Andrea Galbiati
- “Vita‐Salute” San Raffaele University Milan Italy
- Department of Clinical Neuroscience, Neurology and Sleep Disorders Center IRCCS San Raffaele Scientific Institute Milan Italy
| | - Luigi De Gennaro
- Department of Psychology Sapienza ‐ University of Rome Rome Italy
- Body and Action Lab IRCCS Fondazione Santa Lucia Rome Italy
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7
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Abstract
Memories of the past help us adaptively respond to similar situations in the future. Originally described by Schacter & Addis in 2007, the "constructive episodic simulation" hypothesis proposes that waking thought combines fragments of various past episodes into imagined simulations of events that may occur in the future. This same framework may be useful for understanding the function of dreaming. N = 48 college students were asked to identify waking life sources for a total of N = 469 dreams. Participants frequently traced dreams to at least one past or future episodic source (53.5% and 25.7% of dreams, respectively). Individual dreams were very often traced to multiple waking sources (43.9% of all dreams with content), with fragments of past memory incorporated into scenarios that anticipated future events. Waking-life dream sources are described in terms of their phenomenology and distribution across time and sleep stage, providing new evidence that dreams not only reflect the past, but also utilize memory in simulating potential futures.
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Affiliation(s)
- Erin J. Wamsley
- Department of Psychology and Program in Neuroscience, Furman University, Greenville, South Carolina, United States of America
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8
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Borghese F, Henckaerts P, Guy F, Perez Mayo C, Delplanque S, Schwartz S, Perogamvros L. Targeted Memory Reactivation During REM Sleep in Patients With Social Anxiety Disorder. Front Psychiatry 2022; 13:904704. [PMID: 35845468 PMCID: PMC9281560 DOI: 10.3389/fpsyt.2022.904704] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/25/2022] [Accepted: 05/27/2022] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND Social anxiety disorder (SAD) is characterized by a significant amount of fear when confronted to social situations. Exposure therapy, which is based on fear extinction, does not often lead to full remission. Here, based on evidence showing that rapid eye movement (REM) sleep promotes the consolidation of extinction memory, we used targeted memory reactivation (TMR) during REM sleep to enhance extinction learning in SAD. METHODS Forty-eight subjects with SAD were randomly assigned to two groups: control or TMR group. All patients had two successive exposure therapy sessions in a virtual reality (VR) environment, where they were asked to give a public talk in front of a virtual jury. At the end of each session, and only in the TMR group (N = 24), a sound was paired to the positive feedback phase of therapy (i.e., approval of their performance), which represented the memory to be strengthened during REM sleep. All participants slept at home with a wearable headband device which automatically identified sleep stages and administered the sound during REM sleep. Participants' anxiety level was assessed using measures of parasympathetic (root mean square of successive differences between normal heartbeats, RMSSD) and sympathetic (non-specific skin conductance responses, ns-SCRs) activity, and subjective measures (Subjective Units of Distress Scale, SUDS), during the preparation phase of their talks before (T1) and after (T2) one full-night's sleep and after 1 week at home (T3). Participants also filled in a dream diary. RESULTS We observed an effect of time on subjective measures of anxiety (SUDS). We did not find any difference in the anxiety levels of the two groups after 1 week of TMR at home. Importantly, the longer the total duration of REM sleep and the more stimulations the TMR group had at home, the less anxious (increased RMSSD) these participants were. Finally, fear in dreams correlated positively with ns-SCRs and SUDS at T3 in the TMR group. CONCLUSION TMR during REM sleep did not significantly modulate the beneficial effect of therapy on subjective anxiety. Yet, our results support that REM sleep can contribute to extinction processes and substantiate strong links between emotions in dreams and waking stress levels in these patients.
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Affiliation(s)
- Francesca Borghese
- Department of Basic Neurosciences, Faculty of Medicine, University of Geneva, Geneva, Switzerland
| | - Pauline Henckaerts
- Department of Basic Neurosciences, Faculty of Medicine, University of Geneva, Geneva, Switzerland
| | - Fanny Guy
- Department of Basic Neurosciences, Faculty of Medicine, University of Geneva, Geneva, Switzerland
| | - Coral Perez Mayo
- Department of Basic Neurosciences, Faculty of Medicine, University of Geneva, Geneva, Switzerland
| | - Sylvain Delplanque
- Swiss Center for Affective Sciences, University of Geneva, Geneva, Switzerland
| | - Sophie Schwartz
- Department of Basic Neurosciences, Faculty of Medicine, University of Geneva, Geneva, Switzerland.,Swiss Center for Affective Sciences, University of Geneva, Geneva, Switzerland.,Human Neuroscience Platform, Fondation Campus Biotech Geneva, Geneva, Switzerland
| | - Lampros Perogamvros
- Department of Basic Neurosciences, Faculty of Medicine, University of Geneva, Geneva, Switzerland.,Swiss Center for Affective Sciences, University of Geneva, Geneva, Switzerland.,Human Neuroscience Platform, Fondation Campus Biotech Geneva, Geneva, Switzerland.,Center for Sleep Medicine, Geneva University Hospitals, Geneva, Switzerland.,Department of Psychiatry, Geneva University Hospitals, Geneva, Switzerland
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9
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Abstract
The phenomenon of dreaming about the laboratory when participating in a sleep study is common. The content of such dreams draws upon episodic memory fragments of the participant's lab experience, generally, experimenters, electrodes, the lab setting, and experimental tasks. However, as common as such dreams are, they have rarely been given a thorough quantitative or qualitative treatment. Here we assessed 528 dreams (N = 343 participants) collected in a Montreal sleep lab to 1) evaluate state and trait factors related to such dreams, and 2) investigate the phenomenology of lab incorporations using a new scoring system. Lab incorporations occurred in over a third (35.8%) of all dreams and were especially likely to occur in REM sleep (44.2%) or from morning naps (48.4%). They tended to be related to higher depression scores, but not to sex, nightmare-proneness or anxiety. Common themes associated with lab incorporation were: Meta-dreaming, including lucid dreams and false awakenings (40.7%), Sensory incorporations (27%), Wayfinding to, from or within the lab (24.3%), Sleep as performance (19.6%), Friends/Family in the lab (15.9%) and Being an object of observation (12.2%). Finally, 31.7% of the lab incorporation dreams included relative projections into a near future (e.g., the experiment having been completed), but very few projections into the past (2.6%). Results clarify sleep stage and sleep timing factors associated with dreamed lab incorporations. Phenomenological findings further reveal both the typical and unique ways in which lab memory elements are incorporated de novo into dreaming. Identified themes point to frequent social and skillful dream scenarios that entail monitoring of one's current state (in the lab) and projection of the self into dream environments elaborated around local space and time. The findings have implications for understanding fundamental dream formation mechanisms but also for appreciating both the advantages and methodological pitfalls of conducting laboratory-based dream collection.
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Affiliation(s)
- Claudia Picard-Deland
- Dream & Nightmare Laboratory, Center for Advanced Research in Sleep Medicine, CIUSSS-NÎM – Hôpital du Sacré-Coeur de Montréal, Montréal, Canada
- Department of Neuroscience, Université de Montréal, Montréal, Québec, Canada
| | - Tore Nielsen
- Dream & Nightmare Laboratory, Center for Advanced Research in Sleep Medicine, CIUSSS-NÎM – Hôpital du Sacré-Coeur de Montréal, Montréal, Canada
- Department of Psychiatry and Addictology, Université de Montréal, Montréal, Québec, Canada
- * E-mail:
| | - Michelle Carr
- Department of Psychiatry, University of Rochester Medical Center, Rochester, New York, United States of America
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10
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de la Chapelle A, Frauscher B, Valomon A, Ruby PM, Peter-Derex L. Relationship Between Epilepsy and Dreaming: Current Knowledge, Hypotheses, and Perspectives. Front Neurosci 2021; 15:717078. [PMID: 34552464 PMCID: PMC8451887 DOI: 10.3389/fnins.2021.717078] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2021] [Accepted: 08/16/2021] [Indexed: 11/13/2022] Open
Abstract
The interactions between epilepsy and sleep are numerous and the impact of epilepsy on cognition is well documented. Epilepsy is therefore likely to influence dreaming as one sleep-related cognitive activity. The frequency of dream recall is indeed decreased in patients with epilepsy, especially in those with primary generalized seizures. The content of dreams is also disturbed in epilepsy patients, being more negative and with more familiar settings. While several confounding factors (anti-seizure medications, depression and anxiety disorders, cognitive impairment) may partly account for these changes, some observations suggest an effect of seizures themselves on dreams. Indeed, the incorporation of seizure symptoms in dream content has been described, concomitant or not with a focal epileptic discharge during sleep, suggesting that epilepsy might directly or indirectly interfere with dreaming. These observations, together with current knowledge on dream neurophysiology and the links between epilepsy and sleep, suggest that epilepsy may impact not only wake- but also sleep-related cognition.
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Affiliation(s)
| | - Birgit Frauscher
- Analytical Neurophysiology Lab, Montreal Neurological Institute and Hospital, McGill University, Montreal, QC, Canada
| | - Amandine Valomon
- Lyon Neuroscience Research Center, CNRS UMR 5292, INSERM U1028-PAM Team, Lyon, France
| | - Perrine Marie Ruby
- Lyon Neuroscience Research Center, CNRS UMR 5292, INSERM U1028-PAM Team, Lyon, France
| | - Laure Peter-Derex
- Lyon Neuroscience Research Center, CNRS UMR 5292, INSERM U1028-PAM Team, Lyon, France.,Center for Sleep Medicine and Respiratory Diseases, Lyon University Hospital, Lyon 1 University, Lyon, France
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11
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Picard-Deland C, Aumont T, Samson-Richer A, Paquette T, Nielsen T. Whole-body procedural learning benefits from targeted memory reactivation in REM sleep and task-related dreaming. Neurobiol Learn Mem 2021; 183:107460. [PMID: 34015442 DOI: 10.1016/j.nlm.2021.107460] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2021] [Revised: 04/20/2021] [Accepted: 05/12/2021] [Indexed: 10/21/2022]
Abstract
Sleep facilitates memory consolidation through offline reactivations of memory traces. Dreaming may play a role in memory improvement and may reflect these memory reactivations. To experimentally address this question, we used targeted memory reactivation (TMR), i.e., application, during sleep, of a stimulus that was previously associated with learning, to assess whether it influences task-related dream imagery (or task-dream reactivations). Specifically, we asked if TMR or task-dream reactivations in either slow-wave (SWS) or rapid eye movement (REM) sleep benefit whole-body procedural learning. Healthy participants completed a virtual reality (VR) flying task prior to and following a morning nap or rest period during which task-associated tones were readministered in either SWS, REM sleep, wake or not at all. Findings indicate that learning benefits most from TMR when applied in REM sleep compared to a Control-sleep group. REM dreams that reactivated kinesthetic elements of the VR task (e.g., flying, accelerating) were also associated with higher improvement on the task than were dreams that reactivated visual elements (e.g., landscapes) or that had no reactivations. TMR did not itself influence dream content but its effects on performance were greater when coexisting with task-dream reactivations in REM sleep. Findings may help explain the mechanistic relationships between dream and memory reactivations and may contribute to the development of sleep-based methods to optimize complex skill learning.
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Affiliation(s)
- Claudia Picard-Deland
- Dream & Nightmare Laboratory, Center for Advanced Research in Sleep Medicine, CIUSSS-NÎM - Hôpital du Sacré-Coeur de Montréal, Québec, Canada; Department of Neuroscience, Université de Montréal, Montréal, Québec, Canada
| | - Tomy Aumont
- Dream & Nightmare Laboratory, Center for Advanced Research in Sleep Medicine, CIUSSS-NÎM - Hôpital du Sacré-Coeur de Montréal, Québec, Canada; Department of Biomedical Sciences, Université de Montréal, Montréal, Québec, Canada
| | - Arnaud Samson-Richer
- Dream & Nightmare Laboratory, Center for Advanced Research in Sleep Medicine, CIUSSS-NÎM - Hôpital du Sacré-Coeur de Montréal, Québec, Canada
| | - Tyna Paquette
- Dream & Nightmare Laboratory, Center for Advanced Research in Sleep Medicine, CIUSSS-NÎM - Hôpital du Sacré-Coeur de Montréal, Québec, Canada
| | - Tore Nielsen
- Dream & Nightmare Laboratory, Center for Advanced Research in Sleep Medicine, CIUSSS-NÎM - Hôpital du Sacré-Coeur de Montréal, Québec, Canada; Department of Psychiatry and Addictology, Université de Montréal, Montréal, Québec, Canada.
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12
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Sleep parameters improvement in PTSD soldiers after symptoms remission. Sci Rep 2021; 11:8873. [PMID: 33893376 PMCID: PMC8065125 DOI: 10.1038/s41598-021-88337-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2019] [Accepted: 04/06/2021] [Indexed: 11/08/2022] Open
Abstract
Eye movement desensitization and reprocessing (EMDR) is a psychotherapy for the treatment of posttraumatic stress disorder (PTSD). It is still unclear whether symptoms remission through EMDR therapy is associated with a beneficial effect on one of the PTSD symptoms, sleep disturbance. Our objective was therefore to study sleep parameters before and after symptom remission in soldiers with PTSD. The control group consisted of 20 healthy active duty military men who slept in a sleep lab with standard polysomnography (PSG) on two sessions separated by one month. The patient group consisted of 17 active duty military with PTSD who underwent EMDR therapy. PSG-recorded sleep was assessed 1 week before the EMDR therapy began and 1 week after PTSD remission. We found that the increased REMs density after remission was positively correlated with a greater decrease of symptoms. Also, the number of EMDR sessions required to reach remission was correlated with intra-sleep awakenings before treatment. These results confirm the improvement of some sleep parameters in PTSD after symptoms remission in a soldier's population and provide a possible predictor of treatment success. Further experiments will be required to establish whether this effect is specific to the EMDR therapy.
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13
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Vallat R, Nicolas A, Ruby P. Brain functional connectivity upon awakening from sleep predicts interindividual differences in dream recall frequency. Sleep 2020; 43:5864676. [PMID: 32597973 DOI: 10.1093/sleep/zsaa116] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2020] [Revised: 05/14/2020] [Indexed: 12/28/2022] Open
Abstract
Why do some individuals recall dreams every day while others hardly ever recall one? We hypothesized that sleep inertia-the transient period following awakening associated with brain and cognitive alterations-could be a key mechanism to explain interindividual differences in dream recall at awakening. To test this hypothesis, we measured the brain functional connectivity (combined electroencephalography-functional magnetic resonance imaging) and cognition (memory and mental calculation) of high dream recallers (HR, n = 20) and low dream recallers (LR, n = 18) in the minutes following awakening from an early-afternoon nap. Resting-state scans were acquired just after or before a 2 min mental calculation task, before the nap, 5 min after awakening from the nap, and 25 min after awakening. A comic was presented to the participants before the nap with no explicit instructions to memorize it. Dream(s) and comic recall were collected after the first post-awakening scan. As expected, between-group contrasts of the functional connectivity at 5 min post-awakening revealed a pattern of enhanced connectivity in HR within the default mode network (DMN) and between regions of the DMN and regions involved in memory processes. At the behavioral level, a between-group difference was observed in dream recall, but not comic recall. Our results provide the first evidence that brain functional connectivity right after awakening is associated with interindividual trait differences in dream recall and suggest that the brain connectivity of HR at awakening facilitates the maintenance of the short-term memory of the dream during the sleep-wake transition.
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Affiliation(s)
- Raphael Vallat
- Department of Psychology, Center for Human Sleep Science, University of California, Berkeley, CA.,Lyon Neuroscience Research Center (CRNL), Brain Dynamics and Cognition team (DYCOG), INSERM UMRS 1028, CNRS UMR 5292, Université Claude Bernard Lyon 1, Université de Lyon, Lyon, France
| | - Alain Nicolas
- Lyon Neuroscience Research Center (CRNL), Brain Dynamics and Cognition team (DYCOG), INSERM UMRS 1028, CNRS UMR 5292, Université Claude Bernard Lyon 1, Université de Lyon, Lyon, France
| | - Perrine Ruby
- Lyon Neuroscience Research Center (CRNL), Brain Dynamics and Cognition team (DYCOG), INSERM UMRS 1028, CNRS UMR 5292, Université Claude Bernard Lyon 1, Université de Lyon, Lyon, France
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14
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Nicolas A, Ruby PM. Dreams, Sleep, and Psychotropic Drugs. Front Neurol 2020; 11:507495. [PMID: 33224081 PMCID: PMC7674595 DOI: 10.3389/fneur.2020.507495] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2019] [Accepted: 09/28/2020] [Indexed: 02/04/2023] Open
Abstract
Over the past 60 years, the impact of psychotropic drugs on dream recall and content has been scarcely explored. A review of the few existing experimental results on the topic leads us to the following conclusions. For antidepressant drugs, in the great majority, they reduce dream recall frequency (DRF), and the improvement of depressive symptoms is associated with an increase of positive emotion in dream content. For sedative psychotropic drugs, their improvement of sleep quality is associated with a reduction of DRF, but the effect on dream content is less clear. Few occurrences of nightmare frequency increase have been reported, with intake of molecules disturbing sleep or with the withdrawal of some psychotropic drugs. Importantly, the impact of psychotropic drugs on rapid eye movement (REM) sleep does not explain DRF modulations. The reduction of intra-sleep awakenings seems to be the parameter explaining best the modulation of DRF by psychotropic drugs. Indeed, molecules that improve sleep continuity by reducing intra-sleep awakenings also reduce the frequency of dream recall, which is coherent with the “arousal-retrieval model” stating that nighttime awakenings enable dreams to be encoded into long-term memory and therefore facilitate dream recall. DRF is nonetheless influenced by several other factors (e.g., interest in dreams, the method of awakening, and personality traits), which may explain a large part of the variability of results observed and cited in this article.
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Affiliation(s)
- Alain Nicolas
- Lyon Neuroscience Research Center, CNRS UMR 5292 - INSERM U1028 - Lyon 1 University, Lyon, France
| | - Perrine M Ruby
- Lyon Neuroscience Research Center, CNRS UMR 5292 - INSERM U1028 - Lyon 1 University, Lyon, France
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15
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Ruby PM. The Neural Correlates of Dreaming Have Not Been Identified Yet. Commentary on "The Neural Correlates of Dreaming. Nat Neurosci. 2017". Front Neurosci 2020; 14:585470. [PMID: 33192271 PMCID: PMC7662438 DOI: 10.3389/fnins.2020.585470] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2020] [Accepted: 09/28/2020] [Indexed: 12/18/2022] Open
Affiliation(s)
- Perrine Marie Ruby
- Lyon Neuroscience Research Center, CNRS UMR 5292 - INSERM U1028 - Lyon 1 University, Lyon, France
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16
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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] [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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17
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Aru J, Siclari F, Phillips WA, Storm JF. Apical drive-A cellular mechanism of dreaming? Neurosci Biobehav Rev 2020; 119:440-455. [PMID: 33002561 DOI: 10.1016/j.neubiorev.2020.09.018] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2020] [Revised: 09/08/2020] [Accepted: 09/13/2020] [Indexed: 11/17/2022]
Abstract
Dreams are internally generated experiences that occur independently of current sensory input. Here we argue, based on cortical anatomy and function, that dream experiences are tightly related to the workings of a specific part of cortical pyramidal neurons, the apical integration zone (AIZ). The AIZ receives and processes contextual information from diverse sources and could constitute a major switch point for transitioning from externally to internally generated experiences such as dreams. We propose that during dreams the output of certain pyramidal neurons is mainly driven by input into the AIZ. We call this mode of functioning "apical drive". Our hypothesis is based on the evidence that the cholinergic and adrenergic arousal systems, which show different dynamics between waking, slow wave sleep, and rapid eye movement sleep, have specific effects on the AIZ. We suggest that apical drive may also contribute to waking experiences, such as mental imagery. Future studies, investigating the different modes of apical function and their regulation during sleep and wakefulness are likely to be richly rewarded.
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Affiliation(s)
- Jaan Aru
- Institute of Computer Science, University of Tartu, Estonia; Institute of Biology, Humboldt University Berlin, Germany.
| | - Francesca Siclari
- Center for Investigation and Research on Sleep, Centre Hospitalier Universitaire Vaudois, Lausanne, Switzerland; Department of Clinical Neurosciences, Centre Hospitalier Universitaire Vaudois, Lausanne, Switzerland; Faculty of Natural Sciences, Psychology, University of Stirling, Stirling, United Kingdom.
| | - William A Phillips
- Faculty of Natural Sciences, Psychology, University of Stirling, Stirling, United Kingdom.
| | - Johan F Storm
- Brain Signalling Group, Section for Physiology, Faculty of Medicine, Domus Medica, University of Oslo, PB 1104 Blindern, 0317 Oslo, Norway.
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18
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Schredl M, Anderson LM, Kahlert LK, Kumpf CS. Work-Related Dreams: An Online Survey. Clocks Sleep 2020; 2:273-281. [PMID: 33089204 PMCID: PMC7573803 DOI: 10.3390/clockssleep2030021] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2020] [Accepted: 07/15/2020] [Indexed: 11/16/2022] Open
Abstract
Professional work is an integral part of modern life. According to the continuity hypothesis of dreaming, which states that dreams reflect waking life, work-related dreams should be quite common. As most dream content analytic studies are carried out in student samples, the topic of work in dreams is understudied. A few small studies indicate that the stress levels associated with the job are especially reflected in work-related dreams. Here, a total of 1695 people (960 women, 735 men) completed an online survey that included questions about the estimated percentage of work-related dreams, the overall emotional tone of work-related dreams, and waking-life experiences related to their current job situation (working or not working). The findings indicate that every fifth dream is related to current or previous work. Individuals who are working dreamed more often about work, with jobs that are experienced as being more stressful being more likely to affect dream content. The emotional tone of work-related dreams was related to stress and the emotions related to work in waking life. Overall, the findings demonstrate that professional life has a profound effect on dreaming in many individuals-even after years. The next steps would be to study the dream content of work-related dreams and relate these contents to specific characteristics about the jobs, e.g., professional field, hierarchical position and autonomy, etc.
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Affiliation(s)
- Michael Schredl
- Central Institute of Mental Health, Medical Faculty Mannheim, Heidelberg University, Gesundheit, Postfach 12 21 20, 68072 Mannheim, Germany; (L.M.A.); (L.K.K.); (C.S.K.)
| | - Lilian Marie Anderson
- Central Institute of Mental Health, Medical Faculty Mannheim, Heidelberg University, Gesundheit, Postfach 12 21 20, 68072 Mannheim, Germany; (L.M.A.); (L.K.K.); (C.S.K.)
| | - Lea Katharina Kahlert
- Central Institute of Mental Health, Medical Faculty Mannheim, Heidelberg University, Gesundheit, Postfach 12 21 20, 68072 Mannheim, Germany; (L.M.A.); (L.K.K.); (C.S.K.)
| | - Celine Sophie Kumpf
- Central Institute of Mental Health, Medical Faculty Mannheim, Heidelberg University, Gesundheit, Postfach 12 21 20, 68072 Mannheim, Germany; (L.M.A.); (L.K.K.); (C.S.K.)
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19
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Mallett R. Partial memory reinstatement while (lucid) dreaming to change the dream environment. Conscious Cogn 2020; 83:102974. [PMID: 32615463 DOI: 10.1016/j.concog.2020.102974] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2020] [Revised: 04/30/2020] [Accepted: 06/04/2020] [Indexed: 11/15/2022]
Abstract
Lucid dreams often coincide with having control over dream events in real-time, although the limitations of dream control are not completely understood. The current study probed the ability of lucid dreamers to reinstate waking scene memories while dreaming. After brief exposure to an experimental scene, participants were asked to reinstate the scene while lucid dreaming (i.e., change dream scenery to match real-world scene). Qualitative analysis revealed that successful dream scene reinstatements were overwhelmingly inaccurate with respect to the original experimental scene. Importantly, reinstatement inaccuracies held even when the dreamer was aware of them during the dream, suggesting a dissociation between memory access while dreaming and dream imagery. The ability to change the environment of a dream speaks to the high amount of lucid dream control, yet the inaccuracies speak to a lack of detailed control. Reinstating context during lucid sleep offers an experimental method to investigate sleep, dreams, and memory.
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Affiliation(s)
- Remington Mallett
- Department of Psychology, University of Missouri at St. Louis, USA; Department of Psychology, University of Texas at Austin, USA.
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20
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Incorporation of fragmented visuo-olfactory episodic memory into dreams and its association with memory performance. Sci Rep 2019; 9:15687. [PMID: 31666536 PMCID: PMC6821835 DOI: 10.1038/s41598-019-51497-y] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2019] [Accepted: 09/26/2019] [Indexed: 01/10/2023] Open
Abstract
The question of a possible link between dream content and memory consolidation remains open. After a comprehensive review of the literature, we present novel findings from an experiment testing whether the incorporation of recently learned stimuli into dream reports is associated with improved post-sleep memory performance. Thirty-two high dream recallers freely explored new visuo-olfactory episodes for 3 consecutive days. During the nights following each non-explicit encoding, participants wore a wrist actimeter, and woke up at 5am and their usual waking time to record their dreams (intensity of all oneiric sensory perception was assessed using scales). A total of 120 dreams were reported and elements related to the encoding phase were identified in 37 of them, either learning-related (mainly visual- and rarely olfactory-related elements), or experiment-related (lab- or experimenters-related elements). On the 4th day, we found that participants with learning-related (n = 16) and participants with learning-related and/or experiment-related dreams (n = 21) had similar odor recognition and odor-evoked episodic memory with the other participants. However, they had significantly better visuo-spatial memory of the episodes in comparison to the other participants. Our results support the hypothesis that the learning phase is loosely incorporated into dreams and that this incorporation is associated with sleep related memory consolidation.
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21
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Sterpenich V, Perogamvros L, Tononi G, Schwartz S. Fear in dreams and in wakefulness: Evidence for day/night affective homeostasis. Hum Brain Mapp 2019; 41:840-850. [PMID: 31663236 PMCID: PMC7267911 DOI: 10.1002/hbm.24843] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2019] [Revised: 10/04/2019] [Accepted: 10/15/2019] [Indexed: 12/14/2022] Open
Abstract
Recent neuroscientific theories have proposed that emotions experienced in dreams contribute to the resolution of emotional distress and preparation for future affective reactions. We addressed one emerging prediction, namely that experiencing fear in dreams is associated with more adapted responses to threatening signals during wakefulness. Using a stepwise approach across two studies, we identified brain regions activated when experiencing fear in dreams and showed that frightening dreams modulated the response of these same regions to threatening stimuli during wakefulness. Specifically, in Study 1, we performed serial awakenings in 18 participants recorded throughout the night with high‐density electroencephalography (EEG) and asked them whether they experienced any fear in their dreams. Insula and midcingulate cortex activity increased for dreams containing fear. In Study 2, we tested 89 participants and found that those reporting higher incidence of fear in their dreams showed reduced emotional arousal and fMRI response to fear‐eliciting stimuli in the insula, amygdala and midcingulate cortex, while awake. Consistent with better emotion regulation processes, the same participants displayed increased medial prefrontal cortex activity. These findings support that emotions in dreams and wakefulness engage similar neural substrates, and substantiate a link between emotional processes occurring during sleep and emotional brain functions during wakefulness.
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Affiliation(s)
- Virginie Sterpenich
- Department of Basic Neurosciences, Faculty of Medicine, University of Geneva, Geneva, Switzerland.,Swiss Center for Affective Sciences, University of Geneva, Geneva, Switzerland
| | - Lampros Perogamvros
- Department of Basic Neurosciences, Faculty of Medicine, University of Geneva, Geneva, Switzerland.,Swiss Center for Affective Sciences, University of Geneva, Geneva, Switzerland.,Center for Sleep Medicine, Division of Pulmonology, Department of Medicine, Geneva University Hospitals, Geneva, Switzerland.,Wisconsin Institute for Sleep and Consciousness, Department of Psychiatry, University of Wisconsin - Madison, Madison, Wisconsin
| | - Giulio Tononi
- Wisconsin Institute for Sleep and Consciousness, Department of Psychiatry, University of Wisconsin - Madison, Madison, Wisconsin
| | - Sophie Schwartz
- Department of Basic Neurosciences, Faculty of Medicine, University of Geneva, Geneva, Switzerland.,Swiss Center for Affective Sciences, University of Geneva, Geneva, Switzerland
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22
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Schredl M, Göritz AS. Social Media, Dreaming, and Personality: An Online Study. CYBERPSYCHOLOGY BEHAVIOR AND SOCIAL NETWORKING 2019; 22:657-661. [PMID: 31580735 DOI: 10.1089/cyber.2019.0385] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Social media consumption plays an important role in everyday life and, thus, one would expect that this topic is reflected in dreams. This online survey included 1,349 participants (763 women, 586 men) completing questions about social media use in waking, percentage of social media dreams, and the Big Five personality dimensions. Social media dreams were quite rare (two percent of all remembered dreams), but their frequency correlated with neuroticism and extraversion-in addition to the amount of time using social media in waking-supporting the hypothesis that social media have a stronger effect on those person's inner life due to the higher importance attached to this channel of communication. For future research it would be of interest to elicit emotions related to social media in waking and the emotional tones of social media dreams to study whether positive and/or negative aspects of waking-life social media use are directly reflected in dreams.
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Affiliation(s)
- Michael Schredl
- Sleep Laboratory, Central Institute of Mental Health, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
| | - Anja S Göritz
- Psychology Department, University of Freiburg, Freiburg im Breisgau, Germany
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23
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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. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND 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] [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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24
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When the meditating mind wanders. Curr Opin Psychol 2019; 28:133-137. [DOI: 10.1016/j.copsyc.2018.12.006] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2018] [Revised: 12/04/2018] [Accepted: 12/05/2018] [Indexed: 11/19/2022]
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25
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Schredl M, Geißler C, Göritz AS. Factors influencing the frequency of erotic dreams: an online study. PSYCHOLOGY & SEXUALITY 2019. [DOI: 10.1080/19419899.2019.1638297] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Affiliation(s)
- Michael Schredl
- Central Institute of Mental Health, Medical Faculty Mannheim/Heidelberg University, Mannheim, Germany
| | - Caspar Geißler
- Central Institute of Mental Health, Medical Faculty Mannheim/Heidelberg University, Mannheim, Germany
| | - Anja S. Göritz
- Psychology Department, University of Freiburg, Freiburg, Germany
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26
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Blagrove M, Hale S, Lockheart J, Carr M, Jones A, Valli K. Testing the Empathy Theory of Dreaming: The Relationships Between Dream Sharing and Trait and State Empathy. Front Psychol 2019; 10:1351. [PMID: 31281278 PMCID: PMC6596280 DOI: 10.3389/fpsyg.2019.01351] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2018] [Accepted: 05/24/2019] [Indexed: 12/30/2022] Open
Abstract
In general, dreams are a novel but realistic simulation of waking social life, with a mixture of characters, motivations, scenarios, and positive and negative emotions. We propose that the sharing of dreams has an empathic effect on the dreamer and on significant others who hear and engage with the telling of the dream. Study 1 tests three correlations that are predicted by the theory of dream sharing and empathy: that trait empathy will be correlated with frequency of telling dreams to others, with frequency of listening to others' dreams, and with trait attitude toward dreams (ATD) (for which higher scores indicate positive attitude). 160 participants completed online the Toronto Empathy Questionnaire and the Mannheim Dream Questionnaire. Pearson partial correlations were conducted, with age and sex partialled out. Trait empathy was found to be significantly associated with the frequency of listening to the dreams of others, frequency of telling one's own dreams to others, and attitude toward dreams. Study 2 tests the effects of discussing dreams on state empathy, using an adapted version of the Shen (2010) state empathy scale, for 27 pairs of dream sharers and discussers. Dream discussion followed the stages of the Ullman (1996) dream appreciation technique. State empathy of the dream discusser toward the dream sharer was found to increase significantly as a result of the dream discussion, with a medium effect size, whereas the dream sharer had a small decrease in empathy toward the discusser. A proposed mechanism for these associations and effects is taken from the robust findings in the literature that engagement with literary fiction can induce empathy toward others. We suggest that the dream acts as a piece of fiction that can be explored by the dreamer together with other people, and can thus induce empathy about the life circumstances of the dreamer. We discuss the speculation that the story-like characteristics of adult human dreams may have been selected for in human evolution, including in sexual selection, as part of the selection for emotional intelligence, empathy, and social bonding.
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Affiliation(s)
- Mark Blagrove
- Department of Psychology, Swansea University, Swansea, United Kingdom
| | - Sioned Hale
- Department of Psychology, Swansea University, Swansea, United Kingdom
| | - Julia Lockheart
- Swansea College of Art, University of Wales Trinity Saint David, Swansea, United Kingdom.,Goldsmiths, University of London, London, United Kingdom
| | - Michelle Carr
- Department of Psychology, Swansea University, Swansea, United Kingdom
| | - Alex Jones
- Department of Psychology, Swansea University, Swansea, United Kingdom
| | - Katja Valli
- Department of Psychology, University of Turku, Turku, Finland.,Department of Cognitive Neuroscience and Philosophy, The University of Skövde, Skövde, Sweden
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27
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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] [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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28
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Eichenlaub JB, van Rijn E, Gaskell MG, Lewis PA, Maby E, Malinowski JE, Walker MP, Boy F, Blagrove M. Incorporation of recent waking-life experiences in dreams correlates with frontal theta activity in REM sleep. Soc Cogn Affect Neurosci 2019; 13:637-647. [PMID: 29868897 PMCID: PMC6022568 DOI: 10.1093/scan/nsy041] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2017] [Accepted: 05/29/2018] [Indexed: 12/18/2022] Open
Abstract
Rapid eye movement (REM) sleep and its main oscillatory feature, frontal theta, have been related to the processing of recent emotional memories. As memories constitute much of the source material for our dreams, we explored the link between REM frontal theta and the memory sources of dreaming, so as to elucidate the brain activities behind the formation of dream content. Twenty participants were woken for dream reports in REM and slow wave sleep (SWS) while monitored using electroencephalography. Eighteen participants reported at least one REM dream and 14 at least one SWS dream, and they, and independent judges, subsequently compared their dream reports with log records of their previous daily experiences. The number of references to recent waking-life experiences in REM dreams was positively correlated with frontal theta activity in the REM sleep period. No such correlation was observed for older memories, nor for SWS dreams. The emotional intensity of recent waking-life experiences incorporated into dreams was higher than the emotional intensity of experiences that were not incorporated. These results suggest that the formation of wakefulness-related dream content is associated with REM theta activity, and accords with theories that dreaming reflects emotional memory processing taking place in REM sleep.
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Affiliation(s)
| | | | | | - Penelope A Lewis
- School of Psychological Science, Manchester University, Manchester, UK
| | - Emmanuel Maby
- Lyon Neuroscience Research Center, INSERM, CNRS, University of Lyon, Lyon, France
| | | | - Matthew P Walker
- Sleep and Neuroimaging Laboratory, University of California, Berkeley, CA, USA
| | - Frederic Boy
- Department of Psychology, Swansea University, Swansea, UK
| | - Mark Blagrove
- Department of Psychology, Swansea University, Swansea, UK
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29
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The role of the basolateral amygdala in dreaming. Cortex 2018; 113:169-183. [PMID: 30660955 DOI: 10.1016/j.cortex.2018.12.016] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2018] [Revised: 09/09/2018] [Accepted: 12/06/2018] [Indexed: 01/04/2023]
Abstract
Neuroimaging studies have repeatedly shown amygdala activity during sleep (REM and NREM). Consequently, various theorists propose central roles for the amygdala in dreaming - particularly in the generation of dream affects, which seem to play a major role in dream plots. However, a causal role for the amygdala in dream phenomena has never been demonstrated. The traditional first step in determining this role is to observe the functional effects of isolated lesions to the brain structure in question. However, circumscribed bilateral amygdala lesions are extremely rare. Furthermore, the treatment of the amygdala as a unitary structure is problematic, as the basolateral and centromedial amygdala (BLA and CMA) may serve very different functions. We analysed 23 dream reports collected from eight adult patients with bilateral calcification of the BLA as a result of a very rare genetic condition called Urbach-Wiethe Disease (UWD). We compared these dream reports to 52 reports collected from 17 matched controls. Given that the BLA has been implicated in various affective processes in waking life, we predicted that the emotional content of the patients' dreams would differ from that of controls. Due to the exploratory nature of this research, a range of different dream characteristics were analysed. A principal components analysis run on all data returned three key factors, namely pleasantness, length and danger. The UWD patients' dream reports were significantly more pleasant and significantly shorter and less complex than control reports. No differences were found in levels of threat or danger. The results support some current hypotheses concerning the amygdala's role in dreaming, and call others into question. Future research should examine whether these UWD patients show generally impaired emotional episodic memory due to BLA damage, which could explain some of the current findings.
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Vallat R, Eichenlaub JB, Nicolas A, Ruby P. Dream Recall Frequency Is Associated With Medial Prefrontal Cortex White-Matter Density. Front Psychol 2018; 9:1856. [PMID: 30319519 PMCID: PMC6171441 DOI: 10.3389/fpsyg.2018.01856] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2018] [Accepted: 09/11/2018] [Indexed: 01/25/2023] Open
Abstract
Recent findings indicate that dream recall frequency (DRF) is associated with neurophysiological traits, and notably the regional cerebral blood flow at rest within the medial prefrontal cortex (MPFC) and the temporo-parietal junction (TPJ). To test whether, such physiological traits are rooted in anatomical specificities, we used voxel-based morphometry to compare the white matter and gray matter density in regions related to dream recall (either at the experimental or theoretical level, MPFC, TPJ, hippocampus and amygdala) between 46 high dream recallers (HR, DRF = 5.98 ± 1.25 days per week with a dream report) and 46 low dream recallers (LR, DRF = 0.34 ± 0.29). We found an increased medial prefrontal cortex white-matter density in HR compared to LR but no other significant difference between the two groups. These results are consistent with previous studies showing that lesions within the white matter of medial prefrontal cortex are associated with a partial or total cessation of dream reporting and suggest an implication of this region in dream recall or, more likely, in dream production.
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Affiliation(s)
| | | | | | - Perrine Ruby
- Lyon Neuroscience Research Center, Brain Dynamics and Cognition Team (DYCOG), INSERM UMRS 1028, CNRS UMR 5292, Université Claude Bernard Lyon 1, Université de Lyon, Lyon, France
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Vallat R, Chatard B, Blagrove M, Ruby P. Correction: Characteristics of the memory sources of dreams: A new version of the content-matching paradigm to take mundane and remote memories into account. PLoS One 2018; 13:e0193440. [PMID: 29466438 PMCID: PMC5821380 DOI: 10.1371/journal.pone.0193440] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
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Abstract
Brain and sleep maturation covary across different stages of life. At the same time, dream generation and dream recall are intrinsically dependent on the development of neural systems. The aim of this paper is to review the existing studies about dreaming in infancy, adulthood, and the elderly stage of life, assessing whether dream mentation may reflect changes of the underlying cerebral activity and cognitive processes. It should be mentioned that some evidence from childhood investigations, albeit still weak and contrasting, revealed a certain correlation between cognitive skills and specific features of dream reports. In this respect, infantile amnesia, confabulatory reports, dream-reality discerning, and limitation in language production and emotional comprehension should be considered as important confounding factors. Differently, growing evidence in adults suggests that the neurophysiological mechanisms underlying the encoding and retrieval of episodic memories may remain the same across different states of consciousness. More directly, some studies on adults point to shared neural mechanisms between waking cognition and corresponding dream features. A general decline in the dream recall frequency is commonly reported in the elderly, and it is explained in terms of a diminished interest in dreaming and in its emotional salience. Although empirical evidence is not yet available, an alternative hypothesis associates this reduction to an age-related cognitive decline. The state of the art of the existing knowledge is partially due to the variety of methods used to investigate dream experience. Very few studies in elderly and no investigations in childhood have been performed to understand whether dream recall is related to specific electrophysiological pattern at different ages. Most of all, the lack of longitudinal psychophysiological studies seems to be the main issue. As a main message, we suggest that future longitudinal studies should collect dream reports upon awakening from different sleep states and include neurobiological measures with cognitive performances.
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Affiliation(s)
| | - Serena Scarpelli
- Department of Psychology, University of Rome "Sapienza", Rome, Italy
| | - Chiara Bartolacci
- Department of Psychology, University of Rome "Sapienza", Rome, Italy
| | - Luigi De Gennaro
- Department of Psychology, University of Rome "Sapienza", Rome, Italy
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