The purpose of the present study was to determine the recurrent traumatic dreams of university students and to examine their dreams based on a psychodynamic viewpoint. The study group of this research, which is based on qualitative research design, was determined using the criterion sampling method, which is one of the purposive sampling methods. In this way, 64 people who met the following criteria were reached and a total of 130 repeated dreams were obtained. After the thematic analysis of the dreams, four main themes and four sub-themes were identified: (1) The Threat Theme, (2) The Theme of Dissociation and Somatic Response, (3) The Theme of Abandonment Depression and Self-Activation, and (4) The Theme of Forced Birth. The study not only categorizesf recurrent traumatic dreams and reveals the type of these dreams, but also emphasizes the importance of psychic functioning in the context of the psychodynamic perspective. In this respect, it is considered that talking about the repetitive traumatic dreams of individuals who apply for psychological counseling and analyzing such dreams will contribute to a more detailed study of the subject brought to counseling sessions.

Sleep, a state of reduced responsiveness and distinct brain activity, is crucial across the animal kingdom. This review explores the potential adaptive functions of REM sleep in adapting to stress, emphasizing its role in memory consolidation, emotional regulation, and threat processing. We further explore the underlying neural mechanisms linking stress responses to REM sleep. By synthesizing current findings, we propose that REM sleep allows animals to "rehearse" or simulate responses to danger in a secure, offline state, while also maintaining emotional balance. Environmental factors, such as predation risk and social dynamics, further influence REM sleep. This modulation may enhance survival by optimizing stress responses while fulfilling physiological needs in animals. Insights into REM sleep's role in animals may shed light on human sleep in the context of modern stressors and sleep disruptions. This review also explores the complex interplay between stress, immunity, sleep disruptions-particularly involving REM sleep-and their evolutionary underpinnings.

To many influential dream researchers, dreaming consciousness is not of the same kind as waking. In its most radical and paradoxical form, this theoretical stance consists in maintaining that dream is a case of conscious experience lacking cognitive access. In a more moderate and common form, dreamers have cognitive access to their oneiric experience but lack any executive function: they have no conscious control over their thoughts and actions within the dream. Consideration of dreaming consciousness, in other words, would imply the loss of self-regulation. Neither of these two theories holds. First, because the very reason showing dreams are consciously experienced, i.e. the fact we can recollect them on awakening, implies they are access conscious in the minimal sense that the dreamer noticed them. Second, because, consistent with this first evidence, dream reports also indicate dreamers are able to rationally assess their situation within the dream and self-regulate their dream behavior as a result. I argue, however, that dreamers have reduced, if altered, extended consciousness with limited access to their waking autobiographical self, and that this could explain why many researchers have the retrospective illusion that the dream ego has no rational control over its thoughts and actions in the dream. Indeed, it is not the same autobiographical self that regulates and recollects the dream. Finally, the fact that a dream takes place in the particular conditions of a sleeping brain should not prevent us from recognizing that it is a conscious experience in its own right.

Dream-like and psychedelic experiences often display internally illogical structures. Recent theories propose that these experiences function as "spontaneous offline simulations" related to specific brain processes. This study investigates whether such perceived illogicality reflects a distinct, premodern mode of cognition-commonly referred to as "mythic" cognition-rather than a cognitive deficit.

Thirty-one participants underwent four 90-minute flotation REST (Restricted Environmental Stimulation Technique) sessions designed to induce altered, dream-like states. After each session, participants completed the Phenomenology of Consciousness Inventory (PCI) and additional questions targeting features associated with mythic cognition.

Participants showed significant phenomenological shifts toward experiences characteristic of mythic cognition. Specifically, their altered states during flotation exhibited ontological parallels with mythic conceptions of space, time, and substance.

The findings support the hypothesis that the perceived illogicality in altered states arises from a distinct cognitive framework rather than from deficits.

Cognitive self-organization rests on activity-dependent plasticity to extend the ontogenetic process of neural differentiation and integration of the cerebral cortex in each act of cognition. This account of neurocognitive growth can be formulated in terms of active inference and learning. The organism regulates synaptic connectivity as it seeks its goals actively, through excitatory, feedforward expectancies that manifest its species-specific affordances. These adaptive expectancies are modified reactively, through inhibitory feedback error-correction to fit and predict environmental encounters. Although adaptive behavior, and concomitant synaptic plasticity, occur during waking, the synaptic architecture requires ongoing consolidation and refinement during sleep. We propose that memory consolidation during sleep is a continuation of the neurodevelopmental process that proceeds through a kind of inversion of waking active inference: NREM sleep first refines the brain's representations of new, unpredicted experiences during waking, implementing inhibitory mechanisms of long-term depression that both differentiate and stabilize new representations for consolidation. REM sleep then updates the organism's generative world model in light of this new learning through excitatory long-term potentiation of synaptic plasticity. REM thereby reconsolidates and integrates the organism's adaptive, feedforward predictions, the Bayesian priors for effective coping.

Childhood trauma is a known risk factor for frequent nightmares in youth, but the effects of single and multiple traumas remain unclear. This cross-sectional study aimed to investigate the association between single and multiple childhood traumas and frequent nightmares.

Youth aged 12-25 years completed online questionnaires on childhood trauma and nightmares. Cumulative scores and latent class analyses were used to identify multiple childhood traumas. Logistic regression was used to investigate the association between childhood trauma types and frequent nightmares.

Of the 6145 participants, 27.2 % (n = 1670) reported frequent nightmares during the past year. Adjusted analyses showed emotional abuse (OR: 1.45, 95 %CI: 1.23-1.87) and emotional neglect (OR: 1.19, 95 %CI: 1.03-1.37) significantly increased the risk of nightmares. The risk of frequent nightmares increased with the number of traumas: 26 % for one, 36 % for two, and 51 % for three or more, compared with none. The latent class analysis identified three multiple trauma patterns: "low abuse, low neglect" (n = 3837), "low abuse, high neglect" (n = 2089), and "high abuse, high neglect" (n = 219), with increased nightmares risks of 26 % and 47 % in the latter two, respectively, versus the first. However, no significant difference was observed between "low abuse, high neglect" and "high abuse, high neglect" (OR: 1.17, 95 % CI: 0.85-1.60).

Our findings enhance the understanding of the heterogeneity of childhood trauma and its association with nightmares. Prevention and treatment programs for nightmares should be tailored according to different patterns of childhood trauma.

Dreaming, a common yet mysterious cognitive phenomenon, is an involuntary process experienced by individuals during sleep. Although the fascination with dreams dates back to ancient times and gained therapeutic significance through psychoanalysis in the early twentieth century, its scientific investigation only gained momentum with the discovery of rapid eye movement (REM) sleep in the 1950s. This review synthesises current research on the neurobiological and psychological aspects of dreaming, including factors influencing dream recall and content, neurophysiological correlates, and experimental models, and discusses the implications for clinical practice.

Fragmented rapid eye movement (REM) sleep disrupts the overnight resolution of emotional distress, a process crucial for emotion regulation. Emotion dysregulation, which is common across psychiatric disorders, is often associated with sleep disturbances. This systematic review explores how REM sleep and nightmares affect emotion processing and regulation in individuals with psychiatric disorders where emotion dysregulation is a key concern, suggesting novel sleep-related treatment pathways.

We performed a PRISMA-compliant systematic search of the PUBMED, Web of Science, and EBSCO databases from January 1994-February 2023. This systematic review targeted studies on REM sleep, nightmares, and emotion regulation in a postpubescent clinical population with affective dysregulation. The quality of the studies was assessed via the Newcastle‒Ottawa Scale (NOS), adapted for cross-sectional studies.

From the 714 screened records, 28 articles met the inclusion criteria and focused on REM sleep, dreams, or nightmares in individuals with mood disorders (k = 8), anxiety disorders (k = 1), posttraumatic stress disorder (PTSD) (k = 16), non-suicidal self-injury (NSSI), personality disorders (k = 2), and autism (k = 1). Fifteen studies used objective sleep measures, seventeen used self-reported assessments, six included treatment components, eight investigated nightmares, and three examined dreams. NOS scores ranged from moderate to high.

REM sleep disturbances represent a transdiagnostic feature across psychiatric disorders and are crucial for emotion regulation. Nightmares are associated with suicidal behaviour and emotion dysregulation. Targeted sleep interventions may improve emotion regulation and mental health outcomes. Future research should explore the role of REM sleep in disorder prognosis to develop tailored interventions.

According to some theories of emotion regulation, dreams could modify negative emotions and ultimately reduce their intensity. We introduce here the idea of cathartic dream, a specific and separate type of emotional dream, which is characterized by a dynamic plot with emotional twists, and where negative emotions are expressed and ultimately decreased. This process would reflect psychological relief (catharsis according to the Aristotelian definition) and fulfil an emotion regulation function. We developed and validated a tool using a large language model to emotionally categorize the different dreams from dream diaries. Based on this tool, we were able to detect the prevalence of cathartic dreams in datasets of both healthy participants and patients with nightmares. Additionally, we observed the increase of cathartic dreams during 2 weeks of imagery rehearsal therapy and targeted memory reactivation during rapid eye movement sleep. We also demonstrate how the increase of cathartic dreams correlates significantly with the decrease of depression scores in patients with nightmares under therapy, thus supporting their likely functional role in well-being and their distinct nature among other emotional dreams.

During most dreams, the dreamer does not realize that they are in a dream. In contrast, lucid dreaming allows to become aware of the current state of mind, often accompanied by considerable control over the ongoing dream episode. Lucid dreams can happen spontaneously or be induced through diverse behavioural, cognitive or technological strategies. Such induction techniques have spurred research into the potential therapeutic aspects of lucid dreams. In this review, we gather evidence on the link between lucid dreams and conditions like nightmare disorder, depression, anxiety, psychosis, and dissociative states, and highlight the possible neurobiological basis of these associations. Furthermore, we explore contemplative sleep practices that train lucid states during sleep, such as Dream/Sleep Yoga and Yoga Nidrâ. The potential drawbacks of lucid dreaming interventions are outlined, accompanied by an examination of the impacts of lucid dreams on individuals without clinical conditions. By shedding light on these intricate relationships, the review contributes to a deeper understanding of the therapeutic possibilities and implications of lucid dreaming.

The MAPS (Multidisciplinary Association for Psychedelic Studies) sponsored MDMA-assisted therapy protocol has had greater success in treating trauma in preliminary clinical trials than any prior psychotherapeutic, pharmacologic, or combined approach. It is predicated on a synergy between drug action and the participant's inner healing intelligence. The latter is described mainly by analogy with the body's capacity to heal itself, and the treatment is characterized as a means of activating or accessing this capacity. How is this rather mysterious-sounding process so effective? I suggest that the therapist's full commitment to, and trust in this treatment framework, along with the medication's subjective enhancement of trust, encourages individuals who have suffered trauma and have difficulty trusting others to engage the therapist as a kind of witness. I discuss parallels between the therapeutic attitude implied in the inner healing intelligence model and the way a therapist can act as witness in the resolution of dissociative enactment in relational psychoanalysis. Trusting the healing capacity of one's inner healing intelligence is dynamically equivalent to trusting the relational process. This makes trusting one's inner healing intelligence a process of feeling witnessed. In both settings, the therapist's willingness to acknowledge her technical limitations or failings, coupled with a conviction that the participant/patient's primary need in processing trauma is to feel witnessed, facilitates the integration of dissociated experience.

The gestational period is a sensitive time marked by significant changes that can affect women's sleep and dreaming processes, with an augmented frequency and recall of dreams suggesting that dreaming represents an adaptive mechanism of emotional regulation. This study investigates the relationship between pregnancy-related variables, alexithymia, and depressive symptoms in influencing dream characteristics in women during the first trimester of pregnancy. A total of 118 pregnant women were recruited at the Obstetric Outpatient Service of an Italian University Hospital and completed the Mannheim Dream Questionnaire, the Toronto Alexithymia Scale-20, and the Edinburgh Postnatal Depression Scale. Regression analysis, t-test, and moderation analysis were conducted through Jamovi. Dream recall frequency was predicted by age, parity, and depressive symptoms. Nightmare frequency and lucid dream frequency were significantly predicted by depressive symptoms, while nightmare distress was predicted by an unplanned pregnancy. Alexithymia was linked to higher nightmare frequency and nightmare distress. Moderation analysis revealed that the presence of depressive symptoms predicted increased nightmare frequency only in women with higher levels of alexithymia. These findings highlight the role of emotional regulation in dreaming during pregnancy, particularly among women exhibiting alexithymic traits and depressive symptoms. Nightmare frequency may serve as an indicator of impaired emotional regulation, emphasising the need for targeted interventions to enhance emotional coping strategies in this population. Future research should examine the content of nightmares to further understand their implications for maternal mental health.

While there is evidence of continuity between waking life and dream content, findings with regard to personality are questionable due to methodological issues. In addition, previous studies have used explicit measures, although one could assume that dream content, which is formed implicitly, should have a closer relationship with implicit measures of personality. We investigated how explicit and implicit measures of self-esteem are related to two possibly pertinent variables of dream content. We analyzed 1359 dreams collected from 85 participants. We found that one dream content variable, the proportion of self-esteem-relevant dreams, was significantly related to self-esteem, corroborating the idea of a continuity between waking life and dreaming. Interestingly, the relationship was present only for dreams relevant to social self-esteem. This finding can be considered an example of the well-known sociality bias of dreams. Contrary to our expectations, these results were obtained only for explicit measures but not for implicit ones.

Dreams have always fascinated humans [...].

Suicidality in adolescents has been associated with emotional distress, stressful life events, relationship issues, and nightmares to name a few. This study explored the actual dream content and the mood at pre-sleep, during a reported dream, and in the morning in 33 adolescents admitted to the hospital on account of a suicide attempt. In all aspects, hospitalized adolescents were compared to 33 matched adolescents who had followed the same protocol. In accordance with the Continuity and the Threat Simulation theories of dream formation, it was hypothesized that the waking-life experiences of suicidal adolescents would transpire in both dream mood and content as well as in the frequency of nightmares. Dreams were analyzed by independent judges using traditional dream content scales, including for the presence of negative and destructive themes and types of interpersonal relationships. As predicted, more suicidal adolescents experienced frequent nightmares, which was significant. A higher negative mood at pre-sleep, within dreams, and at post-sleep was also observed. Furthermore, their dreams contained a higher prevalence of destructive themes and failures, as well as self-directed and death-resulting aggressions. Regression analyses indicated that morning mood was most accurately predicted by positive and negative dream mood in the normative adolescents, whereas only negative dream mood appeared to predict subsequent waking affect in suicidal participants. Our results underline the valuable potential of implementing nightmare-reducing therapies in the presence of suicidal adolescents who suffer from frequent nightmares.

Empirical investigations that search for a link between dreaming and sleep-dependent memory consolidation have focused on testing for an association between dreaming of what was learned, and improved memory performance for learned material. Empirical support for this is mixed, perhaps owing to the inherent challenges presented by the nature of dreams, and methodological inconsistencies. The purpose of this paper is to address critically prevalent assumptions and practices, with the aim of clarifying and enhancing research on this topic, chiefly by providing a theoretical synthesis of existing models and evidence. Also, it recommends the method of Targeted Memory Reactivation (TMR) as a means for investigating if dream content can be linked to specific cued activations. Other recommendations to enhance research practice and enquiry on this subject are also provided, focusing on the HOW and WHY we search for memory sources in dreams, and what purpose (if any) they might serve.

Changes in sleep and dreams are often observed during pregnancy. Dreaming may represent privileged access to the inner world of individuals, providing relevant information about their well-being. For this reason, a growing but heterogeneous literature has investigated dream experiences of pregnant women. The present paper aimed to systematically review the available evidence on the relationship between pregnancy and oneric activity, focusing on dream and nightmare frequency, dream contents, and emotional features. Moreover, dream changes between pre-partum and post-partum periods and the impact of previous pregnancy-related adverse events on dreaming have been summarized. Overall, 17 studies have been examined. The reviewed evidence suggests that women tend to have an abundant production of dreams and nightmares during pregnancy, and some results support the view that a high rate of dream recall is associated with poor sleep quality. Most studies have shown a high presence of pregnancy-related dream content, likely reflecting waking experiences and concerns. Additionally, dreaming may promote psychological preparation and activation of functional coping strategies to face life changes after childbirth.

It has long been argued that there are dream metaphors which express waking-life experiences indirectly. Most of empirical evidence concerning this topic was in a qualitative way, while few studies explored the topic in a quantitative way. Under this background, we investigated whether dreaming of the typical theme 'being chased or pursued' was a metaphorical expression for waking-life experiences related to 'negative relationships with others'.

One hundred and sixty participants reported their waking-life experiences and dreams for a single day. Following this, two external judges rated whether there were any elements related to 'negative relationships with others' in both waking-life experiences and dreams. In addition, the judges assessed if there was any content related to 'being chased or pursued' in both waking-life experiences and dreams.

The frequency of dreaming of 'negative relationships with others' was higher than the frequency of the same topic in waking-life experiences, which in turn was higher than the frequency of typical theme dreaming of 'being chased or pursued'. In addition, 'negative relationships with others' in waking-life experiences were correlated with both dreaming of 'being chased or pursued', and 'negative relationships with others' in dreams.

These results suggested that the typical theme 'being chased or pursued' in dreams may represent some waking-life experiences metaphorically. In addition, the results support the threat simulation theory of dreaming, which suggests that threatening events in waking life increase the possibility of threatening events in dreams.

Michel Jouvet (1925-2017) is one of the most important figures in the contemporary history of the neuroscience of sleep and dreams, and one of the most awarded French researchers of the last century. Yet this former CNRS gold medalist and winner of the Cino Del Duca World Prize remains little known-not to say unknown-outside the field of sleep medicine, especially in non-French-speaking countries, where the name of his American counterpart, William C. Dement, is more familiar. Often reduced to his experiments on cats and the discovery of what he called "paradoxical sleep," Jouvet left behind a rather unique body of work that includes not only countless publications on sleep and dreams-neurophysiological as well as ethnological and psychological-but also major contributions to clinical medicine, two novels and an impressive collection of personal dream accounts and drawings, which now make it possible to explore the nocturnal side of the last 50 years of his life. This article draws on unpublished archives to illuminate all these little-known and unknown aspects of Jouvet's life and work, highlighting his hidden links with 19th-century scientific oneirology and bringing to light its paradoxes.

The question of why music evolved has been contemplated and debated for centuries across multiple disciplines. While many theories have been posited, they still do not fully answer the question of why humans began making music. Adding to the effort to solve this mystery, we propose the socio-affective fiction (SAF) hypothesis. Humans have a unique biological need for emotion regulation strengthening. Simulated emotional situations, like dreams, can help address that need. Immersion is key for such simulations to successfully exercise people's emotions. Therefore, we propose that music evolved as a signal for SAF to increase the immersive potential of storytelling and thereby better exercise people's emotions. In this review, we outline the SAF hypothesis and present cross-disciplinary evidence.

A body of experimental research has aimed to investigate processes underlying dream formation by examining the effects of a range of pre-sleep stimuli and events on subsequent dream content. Given its ever-growing presence and salience in people's everyday lives, pre-sleep media consumption stands out as a key variable that could influence people's dreams. We conducted a scoping review to evaluate the experimental evidence of the effects of pre-sleep exposure to visual media on dream content. A systematic search on PubMed, PsycInfo, and Web of Science using terms related to moving visual media and dreams yielded 29 studies meeting the inclusion criteria. Overall, we found modest yet varied effects of pre-sleep exposure to visual media on dream content, with rates of stimulus-related incorporation ranging from 3% to 43% for REM dream reports, 4% to 30% for NREM sleep mentation reports, and between 11% and 35% for home dream reports. Our review highlights the large methodological heterogeneity and gaps across studies, the general difficulty in influencing dream content using pre-sleep exposure to visual media, and suggests promising venues for future research to advance our understanding of how and why digital media may impact people's dreams.

The human need to find meaning in life and the human need for connection may be two sides of the same coin, a coin forged in the developmental crucible of attachment. Our need for meaningfulness can be traced to our developmental need for connection in the attachment relationship. The free energy principle dictates that in order to resist a natural tendency towards disorder self-organizing systems must generate models that predict the hidden causes of phenomenal experience. In other words, they must make sense of things. In both an evolutionary and ontogenetic sense, the narrative self develops as a model that makes sense of experience. However, the self-model skews the interpretation of experience towards that which is predictable, or already "known." One may say it causes us to "take things personally." Meaning is felt more acutely when defenses are compromised, when the narrative self is offline. This enables meaning-making that is less egocentrically motivated. Dreams, psychosis, and psychedelic states offer glimpses of how we make sense of things absent a coherent narrative self. This has implications for the way we understand such states, and lays bare the powerful reach of attachment in shaping what we experience as meaningful.

Minecraft is a game known for its limitless potential for creation, allowing players to construct elaborate structures, explore vast landscapes, and encounter a variety of creatures and scenarios, all within a controlled, virtual environment. Similarly, our dreams are constructed by the subconscious mind, using the "blocks" of memories, emotions, and sensory experiences accumulated during waking life. This editorial highlights the intricate relationship between the dream worlds created in sleep and the virtual landscapes we explore in Minecraft, highlighting how both territories are constructed from the building blocks of our subconscious mind. It emphasizes the role of dreams as simulators for real-life events, particularly in mitigating potential risks, much like Minecraft allows players to engage in risk-free exploration and problem-solving within its pixelated universe. In addition, this editorial aims to illuminate the functions of dreams in memory consolidation, emotional processing, and brain development while showcasing the importance of creativity and imagination in enhancing our mental health and understanding of reality.

Dreaming is a universal human behavior that has inspired searches for meaning across many disciplines including art, psychology, religion, and politics, yet its function remains poorly understood. Given the suggested role of sleep in emotional memory processing, we investigated whether reported overnight dreaming and dream content are associated with sleep-dependent changes in emotional memory and reactivity, and whether dreaming plays an active or passive role. Participants completed an emotional picture task before and after a full night of sleep and they recorded the presence and content of their dreams upon waking in the morning. The results replicated the emotional memory trade-off (negative images maintained at the cost of neutral memories), but only in those who reported dreaming (Dream-Recallers), and not in Non-Dream-Recallers. Results also replicated sleep-dependent reductions in emotional reactivity, but only in Dream-Recallers, not in Non-Dream-Recallers. Additionally, the more positive the dream report, the more positive the next-day emotional reactivity is compared to the night before. These findings implicate an active role for dreaming in overnight emotional memory processing and suggest a mechanistic framework whereby dreaming may enhance salient emotional experiences via the forgetting of less relevant information.

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.

Good sleep quality, associated with few arousals, no daytime sleepiness and self-satisfaction with one's sleep, is pivotal for adolescent growth, maturation, cognition and overall health. This article aims to identify what ecological factors impact adolescent sleep quality across three distinct sleep ecologies representing a gradient of dense urbanity to small, rural environments with scarce artificial lighting and no Internet.

We analyze variation of sleep efficiency, a quantitative measure of sleep quality-defined as the ratio of total time spent asleep to total time dedicated to sleep-in two agricultural indigenous populations and one post-industrial group in Mexico (Campeche = 44, Puebla = 51, Mexico City = 50, respectively). Data collection included actigraphy, sleep diaries, questionnaires, interviews and ethnographic observations. We fit linear models to examine sleep efficiency variation within and between groups.

We found that sleep efficiency varied significantly across sites, being highest in Mexico City (88%) and lowest in Campeche (75%). We found that variation in sleep efficiency was significantly associated with nightly exposure to light and social sleep practices.

Our findings point toward contextual cost-benefits of sleep disruption in adolescence. We highlight the need to prioritize research on adolescent sleep quality across distinct developmental ecologies and its impact on health to improve adolescent wellbeing through evidence-based health practices.

The function of dreams is a longstanding scientific research question. Simulation theories of dream function, which are based on the premise that dreams represent evolutionary past selective pressures and fitness improvement through modified states of consciousness, have yet to be tested in cross-cultural populations that include small-scale forager societies. Here, we analyze dream content with cross-cultural comparisons between the BaYaka (Rep. of Congo) and Hadza (Tanzania) foraging groups and Global North populations, to test the hypothesis that dreams in forager groups serve a more effective emotion regulation function due to their strong social norms and high interpersonal support. Using a linear mixed effects model we analyzed 896 dreams from 234 individuals across these populations, recorded using dream diaries. Dream texts were processed into four psychosocial constructs using the Linguistic Inquiry and Word Count (LIWC-22) dictionary. The BaYaka displayed greater community-oriented dream content. Both the BaYaka and Hadza exhibited heightened threat dream content, while, at the same time, the Hadza demonstrated low negative emotions in their dreams. The Global North Nightmare Disorder group had increased negative emotion content, and the Canadian student sample during the COVID-19 pandemic displayed the highest anxiety dream content. In conclusion, this study supports the notion that dreams in non-clinical populations can effectively regulate emotions by linking potential threats with non-fearful contexts, reducing anxiety and negative emotions through emotional release or catharsis. Overall, this work contributes to our understanding of the evolutionary significance of this altered state of consciousness.

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.

Dreams are often viewed as fascinating but irrelevant mental epihenomena of the sleeping mind with questionable functional relevance. Despite long hours of oneiric activity, and high individual differences in dream recall, dreams are lost into oblivion. Here, we conceptualize dreaming and dream amnesia as inherent aspects of the reactive and predictive homeostatic functions of sleep. Mental activity during sleep conforms to the interplay of restorative processes and future anticipation, and particularly during the second half of the night, it unfolds as a special form of non-constrained, self-referent, and future-oriented cognitive process. Awakening facilitates constrained, goal-directed prospection that competes for shared neural resources with dream production and dream recall, and contributes to dream amnesia. We present the neurophysiological aspects of reactive and predictive homeostasis during sleep, highlighting the putative role of cortisol in predictive homeostasis and forgetting dreams. The theoretical and methodological aspects of our proposal are discussed in relation to the study of dreaming, dream recall, and sleep-related cognitive processes.

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.

Dream sharing is a universal practice, and various incentives have been identified, including emotional processing, emotional relief, and demands for containment. Shared dreams can contribute to an individual's understanding of social reality during traumatic and stressful events. The present study examined dreams shared on social network sites (SNS) during the first COVID-19 lockdown, applying a group-analytic approach. A qualitative dream content analysis conducted by a group of researchers analyzed 30 dreams shared on SNS, focusing on their contents, dominant emotions, and unique group processes. The dream content analysis yielded three meaningful and coherent themes: (1) dominant threats: enemy, danger, and COVID-19; (2) emotional fusion: confusion and despair alongside recovery and hope; and (3) group processes characterized by movement between being alone and being together. The results deepen our understanding of both unique social and psychological group processes and of people's main experiences and key psychological coping mechanisms in times of collective trauma and natural disasters. They also demonstrate the transformative potential of dreamtelling for individuals' coping experiences and building hope through the creative social relationships formed within SNS groups.

Evolutionary theories suggest that dreams function as a world simulator of events that maximizes our ability to surmount social and threat-related challenges critical to survivorship and reproduction. Here, in contrast to the incorporation continuity hypothesis, we test the (1) social bias hypothesis, which states that dreams will overrepresent positive social interactions relative to waking life, (2) the mutually exclusive threat bias hypothesis, the idea that dream content will be negative relative to waking life, (3) the strengthening hypothesis, which states that dreams will rehearse more positive interactions with individuals the self is familiar with relative to waking life, and (4) the compensation hypothesis, which states that social contents in dreams increases during periods of social seclusion. Dream (n = 168) and wake (n = 184) reports were collected through a standardized online survey from 24 undergraduate students. Recalls were analyzed using the Social Content Scale. Generalized linear mixed effects models were used, and the following fixed-effects were considered for the study; the number of reports contributed, report state, biological sex, stress, social support, and media exposures. Results showed support for the threat bias hypothesis, we found that dreams were more negative and featured more unfamiliar individuals in contrast to waking life. Additionally, we found partial support for the social bias and the strengthening hypotheses, however no support was shown for the compensation hypothesis. Overall, these results demonstrate support for the threat simulation function of dreams.

Learning from only real-world collected data can be unrealistic and time consuming in many scenario. One alternative is to use synthetic data as learning environments to learn rare situations and replay buffers to speed up the learning. In this work, we examine the hypothesis of how the creation of the environment affects the training of reinforcement learning agent through auto-generated environment mechanisms. We take the autonomous vehicle as an application. We compare the effect of two approaches to generate training data for artificial cognitive agents. We consider the added value of curriculum learning-just as in human learning-as a way to structure novel training data that the agent has not seen before as well as that of using a replay buffer to train further on data the agent has seen before. In other words, the focus of this paper is on characteristics of the training data rather than on learning algorithms. We therefore use two tasks that are commonly trained early on in autonomous vehicle research: lane keeping and pedestrian avoidance. Our main results show that curriculum learning indeed offers an additional benefit over a vanilla reinforcement learning approach (using Deep-Q Learning), but the replay buffer actually has a detrimental effect in most (but not all) combinations of data generation approaches we considered here. The benefit of curriculum learning does depend on the existence of a well-defined difficulty metric with which various training scenarios can be ordered. In the lane-keeping task, we can define it as a function of the curvature of the road, in which the steeper and more occurring curves on the road, the more difficult it gets. Defining such a difficulty metric in other scenarios is not always trivial. In general, the results of this paper emphasize both the importance of considering data characterization, such as curriculum learning, and the importance of defining an appropriate metric for the task.

We analyzed similarities and differences between dream and waking reports in a collection by Kahan and Sullivan (2012). We compared word frequencies in the reports using the automatic text analysis software, Linguistic Inquiry and Word Count (LIWC). Social words were more frequent in dream than waking reports, support for Social Simulation Theory. Positive emotion words were less frequent in dream than waking reports, support for Threat Simulation theory. Amount of cognition was the same in dream and waking reports, i. e., the number of words in the summary category "Cognitive Processes" was not significantly different. But specific categories of cognitive words differed in frequency. We also applied a machine learning technique to dream research and built a support vector machine to achieve binary characteristics detection (here, whether a report is about waking or dream) based on LIWC word counts. Performance metrics for the support vector machine were high.

Dreams are still an enigma of human cognition, studied extensively in psychoanalysis and neuroscience. According to the Freudian dream theory and Solms' modifications of the unconscious derived from it, the fundamental task of meeting our emotional needs is guided by the principle of homeostasis. Our innate value system generates conscious feelings of pleasure and unpleasure, resulting in the behavior of approaching or withdrawing from the world of objects. Based on these experiences, a hierarchical generative model of predictions (priors) about the world is constantly created and modified, with the aim to optimize the meeting of our needs by reducing prediction error, as described in the predictive processing model of cognition. Growing evidence from neuroimaging supports this theory. The same hierarchical functioning of the brain is in place during sleep and dreaming, with some important modifications like a lack of sensual and motor perception and action. Another characteristic of dreaming is the predominance of primary process thinking, an associative, non-rational cognitive style, which can be found in similar altered states of consciousness like the effect of psychedelics. Mental events that do not successfully fulfill an emotional need will cause a prediction error, leading to conscious attention and adaptation of the priors that incorrectly predicted the event. However, this is not the case for repressed priors (RPs), which are defined by the inability to become reconsolidated or removed, despite ongoing error signal production. We hypothesize that Solms' RPs correspond with the conflictual complexes, as described by Moser in his dream formation theory. Thus, in dreams and dream-like states, these unconscious RPs might become accessible in symbolic and non-declarative forms that the subject is able to feel and make sense of. Finally, we present the similarities between dreaming and the psychedelic state. Insights from psychedelic research could be used to inform dream research and related therapeutic interventions, and vice versa. We propose further empirical research questions and methods and finally present our ongoing trial "Biological Functions of Dreaming" to test the hypothesis that dreaming predicts intact sleep architecture and memory consolidation, via a lesion model with stroke patients who lost the ability to dream.

Dreams are mental experiences, including perceptions, thoughts, and emotions, that occur during sleep. In dreams, hallucinatory perceptions, particularly visual and motoric, are often accompanied by negative emotions. When people dream, they perceive them as real even though they are bizarre and distorted in time and space. People often cannot recall their dreams, even though people dream every night. Dreaming is a strange physiological phenomenon. Research has demonstrated that dreaming is closely associated with rapid eye movement (REM) sleep. It is known that dreaming also occurs during non-REM (NREM) sleep, but the content appears to be different. Dreams during REM sleep tend to be longer, more vivid, more story-like, and more bizarre than those during NREM sleep. In this review, the neural circuits underlying dreaming and the physiological functions associated with it are summarized. Two major theories have been proposed regarding the neural circuits involved in dreaming. One is that dreams are generated by the activation of neural activity in the brainstem and its signal transmission to the cortex. The other is that dreams are caused by forebrain activation by dopamine. Whereas the physiological function of dreams remains unclear, several hypotheses have been proposed that are associated with memory and emotions.

The 'day residue' - the presence of waking memories into dreams - is a century-old concept that remains controversial in neuroscience. Even at the psychological level, it remains unclear how waking imagery cedes into dreams. Are visual and affective residues enhanced, modified, or erased at sleep onset? Are they linked, or dissociated? What are the neural correlates of these transformations? To address these questions we combined quantitative semantics, sleep EEG markers, visual stimulation, and multiple awakenings to investigate visual and affect residues in hypnagogic imagery at sleep onset. Healthy adults were repeatedly stimulated with an affective image, allowed to sleep and awoken seconds to minutes later, during waking (WK), N1 or N2 sleep stages. 'Image Residue' was objectively defined as the formal semantic similarity between oral reports describing the last image visualized before closing the eyes ('ground image'), and oral reports of subsequent visual imagery ('hypnagogic imagery). Similarly, 'Affect Residue' measured the proximity of affective valences between 'ground image' and 'hypnagogic imagery'. We then compared these grounded measures of two distinct aspects of the 'day residue', calculated within participants, to randomly generated values calculated across participants. The results show that Image Residue persisted throughout the transition to sleep, increasing during N1 in proportion to the time spent in this stage. In contrast, the Affect Residue was gradually neutralized as sleep progressed, decreasing in proportion to the time spent in N1 and reaching a minimum during N2. EEG power in the theta band (4.5-6.5 Hz) was inversely correlated with the Image Residue during N1. The results show that the visual and affective aspects of the 'day residue' in hypnagogic imagery diverge at sleep onset, possibly decoupling visual contents from strong negative emotions, in association with increased theta rhythm.

Nightmare disorder (ND) is characterized by dreams with strong negative emotions occurring during rapid eye movement (REM) sleep. ND is mainly treated by imagery rehearsal therapy (IRT), where the patients are asked to change the negative story line of their nightmare to a more positive one. We here used targeted memory reactivation (TMR) during REM sleep to strengthen IRT-related memories and accelerate remission of ND. Thirty-six patients with ND were asked to perform an initial IRT session and, while they generated a positive outcome of their nightmare, half of the patients were exposed to a sound (TMR group), while no such pairing took place for the other half (control group). During the next 2 weeks, all patients performed IRT every evening at home and were exposed to the sound during REM sleep with a wireless headband, which automatically detected sleep stages. The frequency of nightmares per week at 2 weeks was used as the primary outcome measure. We found that the TMR group had less frequent nightmares and more positive dream emotions than the control group after 2 weeks of IRT and a sustained decrease of nightmares after 3 months. By demonstrating the effectiveness of TMR during sleep to potentiate therapy, these results have clinical implications for the management of ND, with relevance to other psychiatric disorders too. Additionally, these findings show that TMR applied during REM sleep can modulate emotions in dreams.

The realism of body and actions in dreams is thought to be induced by simulations based on internal representations used during wakefulness. As somatosensory signals contribute to the updating of body and action representations, these are impaired when somatosensory signals are lacking. Here, we tested the hypothesis that individuals with somatosensory deafferentation have impaired body and actions in their dreams, as in wakefulness. We questioned three individuals with a severe, acquired sensory neuropathy on their dreams. While deafferented participants were impaired in daily life, they could dream of themselves as able-bodied, with some sensations (touch, proprioception) and actions (such as running or jumping) which had not been experienced in physical life since deafferentation. We speculate that simulation in dreams could be based on former, "healthy" body and action representations. Our findings are consistent with the idea that distinct body and action representations may be used during dreams and wakefulness.

Sleep talking (ST) is characterized by the production of unaware verbal vocal activations (VBs) during sleep. ST seems potentially linked to linguistic and memory consolidation processes. However, sleep and dream characteristics and the relationship between verbal vocalizations (VBs) and cognitive functions are still unknown. Our study aimed to investigate qualitative sleep and dream features in sleep talkers (STs) compared to healthy subjects (CNTs) through retrospective and longitudinal measures and explore the relationship between ST and memory consolidation.

We recruited N = 29 STs and N = 30 CNTs (age range of 18-35). Participants recorded their dreams and filled out sleep logs for seven consecutive days. Vocal activations of STs were audio-recorded. On the eighth day, we administered a word-pair task.

We showed that STs had significantly worse self-reported sleep quality. VBs were positively correlated with sleep fragmentation and negatively associated with the oneiric emotional load. No difference between groups was found in the memory consolidation rate.

Although ST is a benign phenomenon, we revealed that ST is associated with more sleep alterations and lower emotional intensity of dreams. In this vein, we support that ST depends on sleep fragmentation and could represent a potential window into sleep-dependent cognitive processes.

Sleep parasomnias have drawn the interest of sleep experts because they represent a valuable window to directly monitor dream activity and sleep mentation associated with nocturnal events. Indeed, parasomnias and their manifestations are helpful in investigating dream activity and features, overcoming methodological limits that affect dream study. Specifically, REM sleep Behavior Disorder (RBD) is a parasomnia characterized by enacted dream episodes during Rapid Eye Movements (REM) sleep, caused by the loss of physiological atonia. Patients suffering from RBD report a peculiar oneiric activity associated with motor episodes characterized by high Dream Recall Frequency (DRF) and vivid dreams. Additionally, isolated RBD (iRBD) represents a prodromal stage of neurodegeneration preceding the development of α-synucleinopathies. This narrative review aims to combine evidence describing dream activity in RBD and similarities and differences with other NREM parasomnias. Moreover, a special focus has been reserved for those conditions in which RBD is associated with α-synucleinopathies to clarify the potential role of dreams in neurodegenerative processes.

Frequent nightmare behavior or deep nightmare experiences may harm the physical and mental health and performance of athletes. This study explores the nightmare experiences of athletes, and includes non-athletes with similar experiences for comparison.

The Nightmare Experience Questionnaire (NEQ); Zuckerman-Kuhlman-Aluja Personality Questionnaire, Shortened Form (ZKA-PQ/SF); and Self-Rating Anxiety Scale (SAS) were used. The subjects were 187 athletes (mean age = 20.44 years, SD = 0.85; 91 females, 96 males) and 90 non-athletes (mean age = 20.34 years, SD = 1.65; 52 females, 38 males) who reported having nightmares.

A total of 87 athletes (46.5%) reported having nightmare experiences. The athlete nightmare group scored significantly higher in neuroticism than the non-nightmare group, and their anxiety scores were significantly higher than those of non-athletes, who scored higher in aggressiveness, neuroticism, and sensation seeking. Moreover, anxiety, neuroticism, and sensation seeking positively predicted athletes' nightmare experiences.

Personality traits and anxiety levels can be effectively applied to predict athletes' nightmare experiences.

According to several influential models, dreams can be affected by state- and trait-like factors, sleep features, and diurnal experiences. The COVID-19 pandemic globally affected daily habits, emotional experiences, and sleep. Previous studies suggested an influence of collective traumatic events on dreaming. Starting from these premises, several studies assessed the effect of the pandemic on dreams. This paper aims to review findings concerning the oneiric activity during the COVID-19 pandemic. We report pandemic-related changes in dreams and nightmares, and we consider the possible factors associated with dreaming. Moreover, we provide results about changes in the oneiric activity in different phases of the pandemic. The reviewed findings suggest a pandemic-related enhancement of dream and nightmare frequency, emotional intensity, and distressing contents, modulated by modifications in restrictive measures and associated with diurnal experiences, emotional status, and sleep pattern. We highlight several methodological issues and a large heterogeneity in the present literature, limiting results' generalizability. However, we provide possible interpretations of the most consistent findings in light of the main theoretical frameworks about dreaming.

Dreaming and insomnia are important markers of distress in times of crisis. Here, we present a longitudinal, mixed-methods study examining changes in dreaming between individuals with and without insomnia symptoms and their relationship to mental health during the COVID-19 pandemic. A global survey examining insomnia symptoms, dreams and mental health was launched in April 2020 and followed participants over 12 months. Of 2240 participants, 1009 (45%) reported dream changes at baseline. A higher proportion of participants with new-onset insomnia reported dream changes (55%) than those with pre-existing insomnia (45%) or good sleepers (36%). Overall, thematic analysis identified key dream change themes of increased dream activity, with participants dreaming vividly, in high-definition, and with a strong negative charge. Themes around survival, adjusting to pandemic life, meaning-making and poor sleep quality were also noted. Linguistic Inquiry Word Count showed that individuals with insomnia used more negative words to describe their dream changes than good sleepers. Specifically, the new-onset insomnia group used more anxious and death-related words than those who slept well. Notably, all groups experienced a significant reduction in dream activity by 3-month follow-up. Lastly, dream changes were associated with worse mental health symptoms over time, and this effect was more pronounced in individuals with insomnia. Our results highlight that insomnia symptoms, especially new-onset insomnia, are associated with more negative dream changes during collective stressful events, potentially compounding daytime distress and mental health symptoms over time. During times of crisis, dreaming and insomnia may reveal an important target for mental health interventions.

Sharing dreams is a common practice, and several motives, such as emotional processing, emotional relief, and request for containment, have been identified. An exploratory single case study research design was used to explore the experiences of the COVID-19 pandemic and local military conflict among a group of Israeli students. The group discussed a dream previously shared in social network sites during the first COVID-19 lockdown. A qualitative content analysis of the meeting transcript yielded three meaningful and coherent themes: feeling blocked and helpless in front of a barrier; a sense of intrusion, defense, and psychological coping; belonging to the group as a means of coping with an individual and a collective threat. Each of these themes reflected personal, interpersonal, and social aspects of the participants' experiences. The results deepen the understanding of people's dominant experiences and main psychological coping mechanisms during a collective stressful event. Further, they support the positive effect of the dreamtelling approach on individuals' coping experiences and on enhancing hope by sharing and discussing dreams with others.

We summarize here the progress in identifying the neuronal network as well as the function of paradoxical sleep and the gaps of knowledge that should be filled in priority. The core system generating paradoxical sleep localized in the brainstem is now well identified, and the next step is to clarify the role of the forebrain in particular that of the hypothalamus including the melanin-concentrating hormone neurons and of the basolateral amygdala. We discuss these two options, and also the discovery that cortical activation during paradoxical sleep is restricted to a few limbic cortices activated by the lateral supramammillary nucleus and the claustrum. Such activation nicely supports the findings recently obtained showing that neuronal reactivation occurs during paradoxical sleep in these structures, and induces both memory consolidation of important memory and forgetting of less relevant ones. The question that still remains to be answered is whether paradoxical sleep is playing more crucial roles in processing emotional and procedural than other types of memories. One attractive hypothesis is that paradoxical sleep is responsible for erasing negative emotional memories, and that this function is not properly functioning in depressed patients. On the other hand, the presence of a muscle atonia during paradoxical sleep is in favour of a role in procedural memory as new types of motor behaviours can be tried without harm during the state. In a way, it also fits with the proposed role of paradoxical sleep in setting up the sensorimotor system during development.

Treatment outcomes for PTSD with current psychological therapies are poor, with very few patients achieving sustained symptom remission. A number of authors have identified physiological and immune disturbances in Post Traumatic Stress Disorder (PTSD) patients, but there is no unifying hypothesis that explains the myriad features of the disorder.

The medical literature was reviewed over a 6-year period primarily using the medical database PUBMED.

The literature contains numerous papers that have identified a range of physiological and immune dysfunction in association with PTSD. This paper proposes that unrestrained cytokine signaling induces epigenetic changes that promote an evolutionary survival adaptation, which maintains a defensive PTSD phenotype. The brain can associate immune signaling with past threat and initiate a defensive behavioral response. The sympathetic nervous system is pro-inflammatory, while the parasympathetic nervous system is anti-inflammatory. Prolonged cholinergic withdrawal will promote a chronic inflammatory state. The innate immune cytokine IL-1β has pleiotropic properties and can regulate autonomic, glucocorticoid, and glutamate receptor functions, sleep, memory, and epigenetic enzymes. Changes in epigenetic enzyme activity can potentially alter phenotype and induce an adaptation. Levels of IL-1β correlate with severity and duration of PTSD and PTSD can be prevented by bolus administration of hydrocortisone in acute sepsis, consistent with unrestrained inflammation being a risk factor for PTSD. The nervous and immune systems engage in crosstalk, governed by common receptors. The benefits of currently used psychiatric medication may arise from immune, as well as synaptic, modulation. The psychedelic drugs (3,4-Methylenedioxymethamphetamine (MDMA), psilocybin, and ketamine) have potent immunosuppressive and anti-inflammatory effects on the adaptive immune system, which may contribute to their reported benefit in PTSD. There may be distinct PTSD phenotypes induced by innate and adaptive cytokine signaling.

In order for an organism to survive, it must adapt to its environment. Cytokines signal danger to the brain and can induce epigenetic changes that result in a persistent defensive phenotype. PTSD may be the price individuals pay for the genomic flexibility that promotes adaptation and survival.