The relationships between insomnia, nightmares, and dreams: A systematic review.

Insomnia and nightmares are both prevalent and debilitating sleep difficulties. The present systematic review aims to document the relationships between insomnia and nightmares in individuals without a concomitant psychopathology. The relationships between insomnia and dreams are also addressed. PsycINFO and Medline were searched for papers published in English or French from 1970 to March 2023. Sixty-seven articles were included for review. Most results support positive relationships between insomnia variables and nightmare variables in individuals with insomnia, individuals with nightmares, the general population, students, children and older adults, and military personnel and veterans. These positive relationships were also apparent in the context of the COVID-19 pandemic. Some psychological interventions, such as Imagery Rehearsal Therapy, might be effective in alleviating both nightmares and insomnia symptoms. Regarding the relationships between insomnia and dreams, compared with controls, the dreams of individuals with insomnia are characterized by more negative contents and affects. The results show that insomnia and nightmares are connected and may be mutually aggravating. A model is proposed to explain how insomnia might increase the likelihood of experiencing nightmares, and how nightmares can in turn lead to sleep loss and nonrestorative sleep.

Nocturnal exposure to a preferred ambient scent does not affect dream emotionality or post-sleep core affect valence in young adults.

Emotions experienced within sleep mentation (dreaming) affect mental functioning in waking life. There have been attempts at enhancing dream emotions using olfactory stimulation. Odors readily acquire affective value, but to profoundly influence emotional processing, they should bear personal significance for the perceiver rather than be generally pleasant. The main objective of the present sleep laboratory study was to examine whether prolonged nocturnal exposure to self-selected, preferred ambient room odor while asleep influences emotional aspects of sleep mentation and valence of post-sleep core affect. We asked twenty healthy participants (12 males, mean age 25 ± 4 years) to pick a commercially available scented room diffuser cartridge that most readily evoked positively valenced mental associations. In weekly intervals, the participants attended three sessions. After the adaptation visit, they were administered the odor exposure and odorless control condition in a balanced order. Participants were awakened five minutes into the first rapid eye movement (REM) stage that took place after 2:30 a.m. and, if they had been dreaming, they were asked to rate their mental sleep experience for pleasantness, emotional charge, and magnitude of positive and negative emotions and also to evaluate their post-sleep core affect valence. With rs < 0.20, no practically or statistically significant differences existed between exposure and control in any outcome measures. We conclude that in young, healthy participants, the practical value of olfactory stimulation with self-selected preferred scents for enhancement of dream emotions and post-sleep core affect valence is very limited.

Consciousness and sleep.

Sleep is a universal, essential biological process. It is also an invaluable window on consciousness. It tells us that consciousness can be lost but also that it can be regained, in all its richness, when we are disconnected from the environment and unable to reflect. By considering the neurophysiological differences between dreaming and dreamless sleep, we can learn about the substrate of consciousness and understand why it vanishes. We also learn that the ongoing state of the substrate of consciousness determines the way each experience feels regardless of how it is triggered-endogenously or exogenously. Dreaming consciousness is also a window on sleep and its functions. Dreams tell us that the sleeping brain is remarkably lively, recombining intrinsic activation patterns from a vast repertoire, freed from the requirements of ongoing behavior and cognitive control.

Social media-related nightmare - a potential explanation for poor sleep quality and low affective well-being in the social media era?

Research has posited that social media use during the day may be reflected in nighttime dreams. Nevertheless, no prior studies have explored frightening, unpleasant dreams arising from social media use. This study introduces the construct of the social media-related nightmare by (a) developing and validating a scale capturing negative-valenced dreams with themes of helplessness, loss of control, inhibition, victimization, and making mistakes in social media, and (b) examining relationships between social media use, social media-related nightmares, sleep quality, and affective well-being. A convenience sample of 595 Iranian adult social media users (Mage = 27.45, SDage = 11.42) reported on social media-related nightmare, social media use integration, anxiety, peace of mind, sleep quality, and nightmare distress. The Social Media-Related Nightmare Scale (SMNS) demonstrated a unidimensional structure with sound psychometric properties. The most common nightmares involved the inability to log in to social media and the disruption of relationships with other users. Social media use intensity predicted frequency of social media-related nightmares. These nightmares were correlated with increased anxiety, lower peace of mind, poor sleep quality, and nightmare distress. Importantly, social media-related nightmares mediated the relationship between social media use intensity and low affective well-being (i.e., anxiety and peace of mind), poor sleeping, and nightmare distress. The findings suggest that social media-related nightmares could be a potential pathway through which social media engagement may lead to affective distress and sleep difficulties.

Stations Along the Via Dolorosa Towards Good-Enough Endings.

This article focuses on the prevailing aspiration to reach a "good-enough ending" in analysis, a concept that is partly realistic and partly illusional. I discuss some of the obstacles that interfere with achieving this yearned for goal, and lead to endings that are far from the misleading illusion of the good-enough termination, that many of us believe we have achieved and are many more than it is commonly reported. I describe characteristics, obstacles, blockages, dreads within the analysand, within the analyst and in the space in between, which lead to endings which are far from good enough, by any criteria we might choose. These obstacles include the failure to distinguish between "real" versus "similar to"; emotional excess; emptying out of internal resources and toxemia of therapy/analysis; a fascination with certain levels of mind versus a neglect of others; osmotic pressure for oneness and the terror of perfection; and malignant nostalgia. Reflecting on such complex facets in the analytic process is relevant not only for a deeper understanding of illusions that we and our analysands hold with regard to endings, but also, implicitly, to the understanding of illusions, beliefs, and myths we and our patients have regarding beginnings.

Viral simulations in dreams: The effect of the COVID-19 pandemic on threatening dream content in a Finnish sample of diary dreams.

Previous research indicates that the COVID-19 pandemic has affected dreaming negatively. We compared 1132 dreams collected with prospective two-week dream diary during the pandemic to 166 dreams collected before the pandemic. We hypothesized that the pandemic would increase the number of threatening events, threats related to diseases, and the severity of threats. We also hypothesized that dreams that include direct references to the pandemic will include more threatening events, more disease-related threats, and more severe threats. In contradiction with our hypotheses, results showed no differences between pandemic and pre-pandemic samples in the number of threats, threats related to diseases, or severe threats. However, dreams with direct references to the pandemic had more threats, disease-related threats, and severe threats. Our results thus do not suggest a significant overall increase in nightmarish or threatening dream content during the pandemic but show a more profound effect on a minority of dreams.

Recurring memory reactivation: The offline component of learning.

One can be aware of the effort needed to memorize a new fact or to recall the name of a new acquaintance. Because of experiences like this, learning can seem to have only two components, encoding information and, after some delay, retrieving information. To the contrary, learning entails additional, intervening steps that sometimes are hidden from the learner. For firmly acquiring fact and event knowledge in particular, learners are generally not cognizant of the necessity of offline consolidation. The memories that persist to be available reliably at a later time, according to the present conceptualization, are the ones we repeatedly rehearse and integrate with other knowledge, whether we do this intentionally or unknowingly, awake or asleep. This article examines the notion that learning is not a function of waking brain activity alone. What happens in the brain while we sleep also impacts memory storage, and consequently is a critical component of learning. The idea that memories can change over time and become enduring has long been present in memory research and is foundational for the concept of memory consolidation. Nevertheless, the notion that memory consolidation happens during sleep faced much resistance before eventually being firmly established. Research is still needed to elucidate the operation and repercussions of repeated reactivation during sleep. Comprehensively understanding how offline memory reactivation contributes to learning is vital for both theoretical and practical considerations.

Influencing dreams through sensory stimulation: A systematic 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.

Dreaming in patients with cancer and their partners-an underestimated factor for quality of life?

Sleep disorders are prevalent among patients with cancer and their caregivers as well, affecting their quality of life. But the relationship between sleep quality, dream experiences, and life satisfaction in patients with cancer and their partners is understudied. The present research aimed to quantitatively investigate the dream experiences of oncology patients and explore the interdependence between patients and their partners in terms of dream experiences and life satisfaction. Therefore, a cross-sectional study was conducted with 101 dyads, completing a questionnaire assessing demographic and illness-related data, dream experiences, sleep quality, and life satisfaction. Inferential statistical tests and actor-partner interdependence models were used to analyse the data. Both patients with cancer and their partners reported on average a significant decrease in sleep quality since the cancer diagnosis and for both dyad members significant dreaming predictors for life satisfaction were found. Namely, a positive association for dream stability in patients, and a positive association for positive dream affect as well as a negative association for negative dream affect in partners. Regarding the question of interdependence, dream intensity exhibited a significant group-specific partner effect, but no overall partner effect, leading to inconclusive results that call for more studies in this field. The study suggests that dreaming may affect life satisfaction beyond sleep quality and underscores the significance of acknowledging dream experiences as potential influencers of quality of life in patients with cancer. Additionally, the study stands out for its examination of the role of partners in dyadic dependency, emphasising the importance of understanding their influence on patients' experiences.

Trends in waking salivary alpha-amylase levels following healing lucid dreams.

Introduction: Salivary alpha-amylase (sAA) is considered a marker of autonomic nervous system activity in stress research, and atypical waking sAA responses have been reported for traumatized individuals. Lucid dreams, characterized by a dreamer's awareness of their dream state while remaining asleep, have shown promising preliminary evidence of their potential to enhance mental health. This study's objective was to evaluate sAA in relation to healing lucid dreams. Methods: Participants experiencing PTSD symptoms attended a six-day workshop delivered via live video designed to teach techniques for transforming trauma through dreamwork and dream lucidity. Participants (n = 20) collected saliva samples each morning, immediately upon awakening (Time 1) and 30 min afterward (Time 2). sAA levels were determined by enzymatic assay, and the waking sAA slope was calculated as the difference of Time 2 minus Time 1. Participants completed dream reports each morning, with a dream classified as a 'healing lucid dream' when they reported attaining lucidity and remembered their intention to manifest a healing experience within the dreamscape. Results: Of eight participants experiencing healing lucid dreams, four were able to provide usable saliva samples. Statistical tests on these four participants were not significant because of low power. However, nonsignificant positive associations were observed between experiencing more healing lucid dreams and increased waking sAA slope. Conclusion: The results did not reveal a consistent effect of healing lucid dreams on waking sAA slope. Identifying meaningful patterns in this relationship will require larger samples and more stringent control over saliva collection procedures in future studies.

Dreaming during gastrointestinal endoscopy under propofol, ciprofol, or remimazolam anesthesia: study protocol for a parallel-design double-blind, single-center trial.

BACKGROUND: Dreaming sometimes occurs during sedation. It has been reported that factors such as different anesthetics, depth of anesthesia, age, sex, and preoperative psychological state may affect dreams. Ciprofol and remimazolam are novel choices for painless endoscopy. Herein, we aimed to investigate dreaming during gastrointestinal endoscopy under propofol, ciprofol, and remimazolam anesthesia respectively. METHODS: This is a prospective, parallel-design double-blind, single-center clinical trial. Three hundred and sixty subjects undergoing elective painless gastroscopy, colonoscopy, or gastroenteroscopy will be enrolled. Eligible subjects will undergo propofol-, ciprofol-, or remimazolam-induced anesthesia to finish the examination. Interviews about the modified Brice questionnaire will be conducted in the recovery room. Incidence of dreaming is set as the primary outcome. Secondary outcomes include type of dreams, improvement of sleep quality, evaluation of patients, incidence of insufficient anesthesia, and intraoperative awareness. Safety outcomes are the incidences of hypotension and hypoxia during examination and adverse events during recovery. DISCUSSION: This study may observe different incidences of dreaming and diverse types of dreams, which might lead to different evaluations to the anesthesia procedure. Based on the coming results, anesthesiologists can make a better medication plan for patients who are going to undergo painless diagnosis and treatment. TRIAL REGISTRATION: This trial was registered at the Chinese Clinical Trial Registry on May 18, 2023 (registration number ChiCTR2300071565).

Altered parasympathetic activity during sleep and emotionally arousing wakefulness in frequent nightmare recallers.

Nightmare disorder is characterized by dysfunctional emotion regulation and poor subjective sleep quality reflected in pathophysiological features such as abnormal arousal processes and sympathetic influences. Dysfunctional parasympathetic regulation, especially before and during rapid eye movement (REM) phases, is assumed to alter heart rate (HR) and its variability (HRV) of frequent nightmare recallers (NM). We hypothesized that cardiac variability is attenuated in NMs as opposed to healthy controls (CTL) during sleep, pre-sleep wakefulness and under an emotion-evoking picture-rating task. Based on the polysomnographic recordings of 24 NM and 30 CTL participants, we examined HRV during pre-REM, REM, post-REM and slow wave sleep, separately. Additionally, electrocardiographic recordings of resting state before sleep onset and under an emotionally challenging picture-rating task were also analyzed. Applying repeated measures analysis of variance (rmANOVA), a significant difference was found in the HR of NMs and CTLs during nocturnal segments but not during resting wakefulness, suggesting autonomic dysregulation, specifically during sleep in NMs. As opposed to the HR, the HRV values were not significantly different in the rmANOVA in the two groups, implying that the extent of parasympathetic dysregulation on a trait level might depend on the severeness of dysphoric dreaming. Nonetheless, in the group comparisons, the NM group showed increased HR and reduced HRV during the emotion-evoking picture-rating task, which aimed to model the nightmare experience in the daytime, indicating disrupted emotion regulation in NMs under acute distress. In conclusion, trait-like autonomic changes during sleep and state-like autonomic responses to emotion-evoking pictures indicate parasympathetic dysregulation in NMs.

Longitudinal Study of Early Adversity and Disturbing Dream Frequency: Moderating Role of Early Negative Emotionality.

Although disturbing dreams are prevalent in youth and are associated with psychopathology, little is known about their developmental course and risk factors. We aimed to examine the association between early social environment and subsequent disturbing dream frequency across adolescence as moderated by early negative emotionality. Measures of children's early social environment and negative emotionality were collected from the mothers of 410 children (5-42 months old) and measures of disturbing dream frequency directly from the children (13-18 years old). Preliminary steps identified subgroups of families with distinct profiles of social environment using latent variable mixture modeling, and captured changes in disturbing dream frequency using latent growth modeling. Regression and moderation analyses were conducted to test the study objectives. Results showed that the diverse family patterns were best captured by two profiles reflecting adverse and positive social environments and that overall disturbing dream frequency decreased during adolescence. Moderation analyses showed that when early negative emotionality was higher, DD frequency was not only more elevated in an adverse environment, but lower in a positive environment. These results indicate that the development of disturbing dreams is most strongly associated with a combination of individual and environment factors. Our study adds to the literature by refining our conception of individual traits and disturbing dream development and has implications for the prevention of bad dreams, nightmares, and associated psychopathologies.

Reduced REM and N2 sleep, and lower dream intensity predict increased mind-wandering.

Mind-wandering is a mental state in which attention shifts from the present environment or current task to internally driven, self-referent mental content. Homeostatic sleep pressure seems to facilitate mind-wandering as indicated by studies observing links between increased mind-wandering and impaired sleep. Nevertheless, previous studies mostly relied on cross-sectional measurements and self-reports. We aimed to combine the accuracy of objective sleep measures with the use of self-reports in a naturalistic setting in order to examine if objective sleep parameters predict the tendency for increased mind-wandering on the following day. We used mobile sleep electroencephalographic (EEG) headbands and self-report scales over 7 consecutive nights in a group of 67 healthy participants yielding ~400 analyzable nights. Nights with more wakefulness and shorter REM and slow wave sleep were associated with poorer subjective sleep quality at the intraindividual level. Reduced REM and N2 sleep, as well as less intense dream experiences, predicted more mind-wandering the following day. Our micro-longitudinal study indicates that intraindividual fluctuations in the duration of specific sleep stages predict the perception of sleep quality as assessed in the morning, as well as the intensity of daytime mind-wandering the following hours. The combined application of sleep EEG assessments and self-reports over repeated assessments provides new insights into the subtle intraindividual, night-to-day associations between nighttime sleep and the next day's subjective experiences.

Acetylcholine and metacognition during sleep.

Acetylcholine is a neurotransmitter and neuromodulator involved in a variety of cognitive functions. Additionally, acetylcholine is involved in the regulation of REM sleep: cholinergic neurons in the brainstem and basal forebrain project to and innervate wide areas of the cerebral cortex, and reciprocally interact with other neuromodulatory systems, to produce the sleep-wake cycle and different sleep stages. Consciousness and cognition vary considerably across and within sleep stages, with metacognitive capacity being strikingly reduced even during aesthetically and emotionally rich dream experiences. A notable exception is the phenomenon of lucid dreaming-a rare state whereby waking levels of metacognitive awareness are restored during sleep-resulting in individuals becoming aware of the fact that they are dreaming. The role of neurotransmitters in these fluctuations of consciousness and cognition during sleep is still poorly understood. While recent studies using acetylcholinesterase inhibitors suggest a potential role of acetylcholine in the occurrence of lucid dreaming, the underlying mechanisms by which this effect is produced remains un-modelled and unknown; with the causal link between cholinergic mechanisms and upstream psychological states being complex and elusive. Several theories and approaches targeting the association between acetylcholine and metacognition during wakefulness and sleep are highlighted in this review, moving through microscopic, mesoscopic and macroscopic levels of analysis to detail this phenomenon at several organisational scales. Several exploratory hypotheses will be developed to guide future research towards fully articulating how metacognition is affected by activity at the acetylcholine receptor.

Alexithymia and aspects of dreaming: Differential associations of alexithymia facets with dream variables.

Research on aspects of dreaming associated with alexithymia has yielded mixed results. The present study recruited a young adult online sample of 577 participants who completed validated indices of alexithymia, emotion suppression, negative moods, and eight aspects of dreaming, with a focus on evaluating a counterintuitive previous finding that alexithymia and two of its core facets were associated with greater self-reported typical emotional intensity of dreams. Total alexithymia and facet scores showed differential relationships to aspects of dreaming including dream recall frequency, emotionality, meaningfulness, nightmare frequency, nightmare distress, usefulness of dreams in problem-solving and creativity, and learning about oneself through dreams. Planned hierarchical regression controlling for demographics, alcohol use, and dream recall frequency indicated that the difficulties identifying feelings (DIF) facet of alexithymia was a significant positive predictor of dream emotionality, whereas the externally oriented thinking (EOT) facet was a significant negative predictor. Stress, but not emotion suppression, mediated the positive relationship between DIF and dream emotionality. The likely role of dream emotionality in higher ratings of nightmare distress, dream meaningfulness, and learning about oneself through dreams among those with higher DIF scores is noted, along with other findings and the strengths and limitations of the study.

Learning beyond sensations: How dreams organize neuronal representations.

Semantic representations in higher sensory cortices form the basis for robust, yet flexible behavior. These representations are acquired over the course of development in an unsupervised fashion and continuously maintained over an organism's lifespan. Predictive processing theories propose that these representations emerge from predicting or reconstructing sensory inputs. However, brains are known to generate virtual experiences, such as during imagination and dreaming, that go beyond previously experienced inputs. Here, we suggest that virtual experiences may be just as relevant as actual sensory inputs in shaping cortical representations. In particular, we discuss two complementary learning principles that organize representations through the generation of virtual experiences. First, "adversarial dreaming" proposes that creative dreams support a cortical implementation of adversarial learning in which feedback and feedforward pathways engage in a productive game of trying to fool each other. Second, "contrastive dreaming" proposes that the invariance of neuronal representations to irrelevant factors of variation is acquired by trying to map similar virtual experiences together via a contrastive learning process. These principles are compatible with known cortical structure and dynamics and the phenomenology of sleep thus providing promising directions to explain cortical learning beyond the classical predictive processing paradigm.

Journey through artistic eras depicting dreams, sleep, and its disorders / Viagem por eras artísticas retratando sonhos, sono e seus transtornos

This narrative review presents a comprehensive examination of artistic periods since the Renaissance, paralleling the evolution of neurology and pictorial artistic expression about sleep, ending with the importance of the contemporary digital era. Over the centuries, artists have been drawn to the enigmatic themes of dreams, sleep, and their disorders, using them to explore the complexities of the human condition, emotions, and the interaction between reality and imagination. Thus, drawing references from diverse artistic eras, including their pictorial representations of sleep, alongside milestones in the history of neurology, this study reveals a rich interconnectivity between art, neurological advances, and social change.

Esta revisão narrativa apresenta um exame abrangente dos períodos artísticos desde o Renascimento, em paralelo com a evolução da neurologia e a expressão artística pictórica sobre o sono, terminando com a importância da era digital contemporânea. Ao longo dos séculos, os artistas foram atraídos pelos temas enigmáticos dos sonhos, do sono e dos seus distúrbios, aproveitando-os para explorar as complexidades da condição humana, das emoções e da interação entre a realidade e a imaginação. Assim, extraindo referências de diversas épocas artísticas, incluindo suas representações pictóricas do sono, paralelamente a marcos na história da neurologia, este estudo revela uma rica interconectividade entre arte, avanços neurológicos e mudanças sociais.

The neurocognition of dreaming: key questions and foci.

Until recently, understanding the neurobiology of dreaming has relied upon on correlating a subjective dream report with a measure of brain activity or function sampled from a different occasion. As such, most assumptions about dreaming come from the neuroscience of rapid eye-movement (REM) sleep from which many, but not all, dream reports are recalled. Core features of REM sleep (intense emotional activation, a reduction in activity in most frontal regions, particularly the dorsolateral prefrontal cortex, along with increased dopamine, acetylcholine, cholinergic activation) align with typical dream characteristics (characterised by fear, reduced reality monitoring, increased bizarreness and hyperassociativity, respectively). The default mode network offers a way of understanding the nature of dreaming more independently from a REM sleep context, and electroencephalography methods paired with serial awakenings to elicit dream reports demonstrate how high-frequency activity in posterior regions may be associated with dreaming. Nevertheless, all measures of dreaming rely fundamentally on recall processes, so our understanding of dreaming must embrace and address memory's crucial involvement in dream report production.