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Human Brain Mapping Mar 2016We investigated the role of the dopamine system [i.e., subcortical-medial prefrontal cortex (mPFC) network] in dreaming, by studying patients with Parkinson's Disease...
We investigated the role of the dopamine system [i.e., subcortical-medial prefrontal cortex (mPFC) network] in dreaming, by studying patients with Parkinson's Disease (PD) as a model of altered dopaminergic transmission. Subcortical volumes and cortical thickness were extracted by 3T-MR images of 27 PD patients and 27 age-matched controls, who were asked to fill out a dream diary upon morning awakening for one week. PD patients do not substantially differ from healthy controls with respect to the sleep, dream, and neuroanatomical measures. Multivariate correlational analyses in PD patients show that dopamine agonist dosage is associated to qualitatively impoverished dreams, as expressed by lower bizarreness and lower emotional load values. Visual vividness (VV) of their dream reports positively correlates with volumes of both the amygdalae and with thickness of the left mPFC. Emotional load also positively correlates with hippocampal volume. Beside the replication of our previous finding on the role of subcortical nuclei in dreaming experience of healthy subjects, this represents the first evidence of a specific role of the amygdala-mPFC dopaminergic network system in dream recall. The association in PD patients between higher dopamine agonist dosages and impoverished dream reports, however, and the significant correlations between VV and mesolimbic regions, however, provide an empirical support to the hypothesis that a dopamine network plays a key role in dream generation. The causal relation is however precluded by the intrinsic limitation of assuming the dopamine agonist dosage as a measure of the hypodopaminergic state in PD. Periodicals, Inc.
Topics: Adult; Aged; Antiparkinson Agents; Brain; Dopamine Agonists; Dreams; Emotions; Female; Humans; Magnetic Resonance Imaging; Male; Mental Recall; Middle Aged; Neuropsychological Tests; Organ Size; Parkinson Disease; Sleep
PubMed: 26704150
DOI: 10.1002/hbm.23095 -
PloS One 2018Lucid dreaming is a remarkable state of consciousness in which one is aware of the fact that one is dreaming while continuing to dream. Based on the strong relationship... (Randomized Controlled Trial)
Randomized Controlled Trial
Lucid dreaming is a remarkable state of consciousness in which one is aware of the fact that one is dreaming while continuing to dream. Based on the strong relationship between physiological activation during rapid eye-movement sleep and lucid dreaming, our pilot research investigated whether enhancing cortical activation via acetylcholinesterease inhibition (AChEI) would increase the frequency of lucid dreams and found AChEI to be a promising method for lucid dream induction. In the current study we sought to quantify the size and reliability of the effect of AChEI on lucid dreaming, dream recall and dream content as well as to test the effectiveness of an integrated lucid dream induction protocol which combined cholinergic stimulation with other methods for lucid dream induction. Participants (N = 121) with high dream recall and an interest in lucid dreaming were randomly assigned counterbalanced orders of 3 doses of galantamine (0, 4 and 8 mg). On 3 consecutive nights, they awoke approximately 4.5 hours after lights out, recalled a dream, ingested the capsules and stayed out of bed for at least 30 minutes. Participants then returned to bed and practiced the Mnemonic Induction of Lucid Dreams technique while returning to sleep. The percentage of participants who reported a lucid dream was significantly increased for both 4 mg (27%, odds ratio = 2.29) and 8 mg doses (42%, odds ratio = 4.46) compared to the active placebo procedure (14%). Galantamine also significantly increased dream recall, sensory vividness and complexity (p<0.05). Dream recall, cognitive clarity, control, positive emotion, vividness and self-reflection were increased during lucid compared to non-lucid dreams (p<0.0001). These results show that galantamine increases the frequency of lucid dreams in a dose-related manner. Furthermore, the integrated method of taking galantamine in the last third of the night with at least 30 minutes of sleep interruption and with an appropriately focused mental set is one of the most effective methods for inducing lucid dreams available today.
Topics: Acetylcholinesterase; Adult; Aged; Awareness; Cholinesterase Inhibitors; Cognition; Consciousness; Cross-Over Studies; Double-Blind Method; Dreams; Female; Galantamine; Humans; Male; Mental Recall; Middle Aged; Placebo Effect; Sleep; Sleep, REM; Wakefulness
PubMed: 30089135
DOI: 10.1371/journal.pone.0201246 -
Journal of Clinical Sleep Medicine :... Sep 2019In nightmare etiology, trait and state factors play important roles. However, the interaction of state and trait factors has never been studied in a longitudinal design.
STUDY OBJECTIVES
In nightmare etiology, trait and state factors play important roles. However, the interaction of state and trait factors has never been studied in a longitudinal design.
METHODS
The current sample included 406 pregnant women who were followed up approximately 6 months after giving birth (n = 375) and 4 years later (n = 302). A nightmare frequency scale and several stress-related questionnaires were presented at three measurement points.
RESULTS
Despite the major life events in this sample, nightmare frequency was very stable over this time period and decreased slightly. In line with previous findings, cross-sectional analyses showed that stressors were associated with current nightmare frequency but longitudinal analyses indicated that previously measured nightmare frequency showed even stronger effects on current nightmare frequency.
CONCLUSIONS
Because the nightmare frequencies were very stable, it would be desirable to carry out intervention studies treating nightmares as early as possible-even in childhood-and study whether nightmare occurrence is lower even years after the intervention.
CITATION
Schredl M, Gilles M, Wolf I, Peus V, Scharnholz B, Sütterlin M, Bardtke S, Send TS, Samaras A, Deuschle M. Nightmares and stress: a longitudinal study. J Clin Sleep Med. 2019;15(9):1209-1215.
Topics: Adolescent; Adult; Cross-Sectional Studies; Dreams; Female; Follow-Up Studies; Humans; Longitudinal Studies; Pregnancy; Pregnancy Complications; Stress, Psychological; Surveys and Questionnaires; Young Adult
PubMed: 31538591
DOI: 10.5664/jcsm.7904 -
Learning & Memory (Cold Spring Harbor,... 2004Do our memories remain static during sleep, or do they change? We argue here that memory change is not only a natural result of sleep cognition, but further, that such... (Review)
Review
Do our memories remain static during sleep, or do they change? We argue here that memory change is not only a natural result of sleep cognition, but further, that such change constitutes a fundamental characteristic of declarative memories. In general, declarative memories change due to retrieval events at various times after initial learning and due to the formation and elaboration of associations with other memories, including memories formed after the initial learning episode. We propose that declarative memories change both during waking and during sleep, and that such change contributes to enhancing binding of the distinct representational components of some memories, and thus to a gradual process of cross-cortical consolidation. As a result of this special form of consolidation, declarative memories can become more cohesive and also more thoroughly integrated with other stored information. Further benefits of this memory reprocessing can include developing complex networks of interrelated memories, aligning memories with long-term strategies and goals, and generating insights based on novel combinations of memory fragments. A variety of research findings are consistent with the hypothesis that cross-cortical consolidation can progress during sleep, although further support is needed, and we suggest some potentially fruitful research directions. Determining how processing during sleep can facilitate memory storage will be an exciting focus of research in the coming years.
Topics: Animals; Dreams; Humans; Mental Recall; Recognition, Psychology; Sleep; Thinking
PubMed: 15576883
DOI: 10.1101/lm.75704 -
Current Psychiatry Reports Sep 2013Insomnia has been established as a risk factor for depression and mental illness for decades, but a growing body of evidence has recently exposed insomnia to be an... (Review)
Review
Insomnia has been established as a risk factor for depression and mental illness for decades, but a growing body of evidence has recently exposed insomnia to be an independent risk factor for suicide that encompasses all age ranges. This discovery has invigorated investigation to elucidate the relationship between insomnia and suicide, and over 20 studies reinforcing this association in adults have been published since 2010 alone. This article analyzes relevant research and emphasizes studies published within the last three years with the intent of proposing theoretical mechanisms explaining the link between suicide and insomnia. These mechanisms may then be used as targets for future investigation of treatment.
Topics: Cross-Sectional Studies; Dreams; Humans; Prospective Studies; Risk Factors; Serotonin; Sleep Initiation and Maintenance Disorders; Suicide
PubMed: 23949486
DOI: 10.1007/s11920-013-0389-9 -
The Journal of Thoracic and... Oct 2018
Topics: Dreams; Glycoproteins; Humans; Pericardium; Proteoglycans; Surgeons; Tissue Adhesions
PubMed: 29730108
DOI: 10.1016/j.jtcvs.2018.04.035 -
The Journal of Neuroscience : the... Jun 2019Affective experiences are central not only to our waking life but also to rapid eye movement (REM) sleep dreams. Despite our increasing understanding of the neural...
EEG Frontal Alpha Asymmetry and Dream Affect: Alpha Oscillations over the Right Frontal Cortex during REM Sleep and Presleep Wakefulness Predict Anger in REM Sleep Dreams.
Affective experiences are central not only to our waking life but also to rapid eye movement (REM) sleep dreams. Despite our increasing understanding of the neural correlates of dreaming, we know little about the neural correlates of dream affect. Frontal alpha asymmetry (FAA) is considered a marker of affective states and traits as well as affect regulation in the waking state. Here, we explored whether FAA during REM sleep and during evening resting wakefulness is related to affective experiences in REM sleep dreams. EEG recordings were obtained from 17 human participants (7 men) who spent 2 nights in the sleep laboratory. Participants were awakened 5 min after the onset of every REM stage after which they provided a dream report and rated their dream affect. Two-minute preawakening EEG segments were analyzed. Additionally, 8 min of evening presleep and morning postsleep EEG were recorded during resting wakefulness. Mean spectral power in the alpha band (8-13 Hz) and corresponding FAA were calculated over the frontal (F4-F3) sites. Results showed that FAA during REM sleep, and during evening resting wakefulness, predicted ratings of dream anger. This suggests that individuals with greater alpha power in the right frontal hemisphere may be less able to regulate (i.e., inhibit) strong affective states, such as anger, in dreams. Additionally, FAA was positively correlated across wakefulness and REM sleep. Together, these findings imply that FAA may serve as a neural correlate of affect regulation not only in the waking but also in the dreaming state. We experience emotions not only during wakefulness but also during dreaming. Despite our increasing understanding of the neural correlates of dreaming, we know little about the neural correlates of dream emotions. Here we used electroencephalography to explore how frontal alpha asymmetry (FAA)-the relative difference in alpha power between the right and left frontal cortical areas that is associated with emotional processing and emotion regulation in wakefulness-is related to dream emotions. We show that individuals with greater FAA (i.e., greater right-sided alpha power) during rapid eye movement sleep, and during evening wakefulness, experience more anger in dreams. FAA may thus reflect the ability to regulate emotions not only in the waking but also in the dreaming state.
Topics: Adult; Affect; Alpha Rhythm; Anger; Attention; Dreams; Electroencephalography; Female; Humans; Male; Polysomnography; Prefrontal Cortex; Sleep, REM; Wakefulness; Young Adult
PubMed: 30988168
DOI: 10.1523/JNEUROSCI.2884-18.2019 -
Clinical Psychology Review Aug 2009This paper reviews studies that have examined associations between unusual sleep experiences (including nightmares, vivid dreaming, narcolepsy symptoms, and complex... (Review)
Review
This paper reviews studies that have examined associations between unusual sleep experiences (including nightmares, vivid dreaming, narcolepsy symptoms, and complex nighttime behaviors) and dissociation and schizotypy. Using correlational studies and structural analyses, evidence is provided that unusual sleep experiences, dissociation, and schizotypy belong to a common domain. It is demonstrated that unusual sleep experiences show specificity to dissociation and schizotypy compared to other daytime symptoms (e.g., anxiety, depression, substance use) and other sleep disturbances (e.g., insomnia, lassitude/fatigue). The paper also outlines the methodological limitations of the existing evidence and makes suggestions for future research. Finally, three models for the overlap of daytime and nighttime symptoms are reviewed, including biological abnormalities, trauma, and personality traits. Although further research is needed, it is suggested that daytime and nighttime symptoms result from problems with sleep-wake state boundaries, which may be precipitated by stress or trauma. In addition, association between daytime and nighttime symptoms can be attributed to the higher order personality trait of Oddity.
Topics: Dissociative Disorders; Dreams; Factor Analysis, Statistical; Humans; Personality; Schizotypal Personality Disorder; Sleep Wake Disorders; Sleep, REM; Stress, Psychological
PubMed: 19581031
DOI: 10.1016/j.cpr.2009.06.004 -
Arquivos Brasileiros de Oftalmologia 2021
Topics: Dreams; Humans
PubMed: 34550216
DOI: 10.5935/0004-2749.202100112 -
Sleep Medicine Reviews Apr 2024Sleep is typically considered a state of disconnection from the environment, yet instances of external sensory stimuli influencing dreams have been reported for... (Review)
Review
Sleep is typically considered a state of disconnection from the environment, yet instances of external sensory stimuli influencing dreams have been reported for centuries. Explaining this phenomenon could provide valuable insight into dreams' generative and functional mechanisms, the factors that promote sleep continuity, and the processes that underlie conscious awareness. Moreover, harnessing sensory stimuli for dream engineering could benefit individuals suffering from dream-related alterations. This PRISMA-compliant systematic review assessed the current evidence concerning the influence of sensory stimulation on sleep mentation. We included 51 publications, of which 21 focused on auditory stimulation, ten on somatosensory stimulation, eight on olfactory stimulation, four on visual stimulation, two on vestibular stimulation, and one on multimodal stimulation. Furthermore, nine references explored conditioned associative stimulation: six focused on targeted memory reactivation protocols and three on targeted lucid reactivation protocols. The reported frequency of stimulus-dependent dream changes across studies ranged from 0 to ∼80%, likely reflecting a considerable heterogeneity of definitions and methodological approaches. Our findings highlight a lack of comprehensive understanding of the mechanisms, functions, and neurophysiological correlates of stimulus-dependent dream changes. We suggest that a paradigm shift is required for meaningful progress in this field.
Topics: Humans; Dreams; Sleep; Cognition; Consciousness
PubMed: 38417380
DOI: 10.1016/j.smrv.2024.101908