Sleep Science Research Articles

Contributions of memory and brain development to the bioregulation of naps and nap transitions in early childhood

The transition from multiple sleep bouts each day to a single overnight sleep bout (i.e., nap transition) is a universal process in human development. Naps are important during infancy and early childhood as they enhance learning through memory consolidation. However, a normal part of development is the transition out of naps. Understanding nap transitions is essential in order to maximize early learning and promote positive long-term cognitive outcomes. Here, we propose a novel hypothesis regarding the cognitive, physiological, and neural changes that accompany nap transitions. Specifically, we posit that maturation of the hippocampal-dependent memory network results in more efficient memory storage, which reduces the buildup of homeostatic sleep pressure across the cortex (as reflected by slow-wave activity), and eventually, contributes to nap transitions. This hypothesis synthesizes evidence of bioregulatory mechanisms underlying nap transitions and sheds new light on an important window of change in development. This framework can be used to evaluate multiple untested predictions from the field of sleep science and ultimately, yield science-based guidelines and policies regarding napping in childcare and early education settings.

Thyrotropin-releasing hormone analog as a stable upper airway-preferring respiratory stimulant with arousal properties.

Taltirelin is a stable, brain-penetrating thyrotropin-releasing hormone (TRH) analog with minimal endocrine activity and potential respiratory stimulant properties. Taltirelin's receptor target shows high differential expression at the hypoglossal motor nucleus, and local taltirelin microperfusion into the hypoglossal motor nucleus causes sustained tongue motor activation compared with the transient activating effects of TRH itself. Here, we performed a randomized, within-subject, repeated-measures design over six separate study days (separated by at least 72 h) in chronically instrumented male (n = 10) and female (n = 9) rats to identify effects on sleep and breathing. Vehicle controls or taltirelin (0.1 and 1 mg/kg) with and without trazodone (30 mg/kg) were administered by intraperitoneal injection. Trazodone was included due to clinical interest in the context of sleep apnea pharmacotherapy as it can suppress arousal without compromising pharyngeal muscle activity. Systemically administered taltirelin (1 but not 0.1 mg/kg) increased tonic and within-breath phasic tonic muscle activity compared with vehicle controls (P ≤ 0.007), with little or no changes in diaphragm amplitude or respiratory rate. Taltirelin also suppressed nonrapid eye movement (non-REM) sleep and increased wakefulness (P ≤ 0.037). Other indices of taltirelin-induced central nervous system arousal included increased trapezius muscle tone in non-REM sleep and decreased total electroencephalogram power and δ (0.5-4 Hz) power (P ≤ 0.046). These effects were especially apparent in non-REM sleep and not prevented by trazodone. These preclinical findings identify taltirelin as a stable upper airway-preferring respiratory stimulant with arousal properties, traits that have potential favorable relevance to some respiratory disorders but not others.NEW & NOTEWORTHY One of the major goals for translational sleep science and medicine is to identify viable and tractable pharmacological targets for obstructive sleep apnea and other respiratory disorders of sleep or sedation. In the present preclinical study in rats, we performed a randomized, within-subject, repeated-measures design over six intervention study days in chronically instrumented male and female rats with systemic peripheral administration of vehicle controls, the thyrotropin-releasing hormone analog taltirelin at two doses, all with and without coadministered trazodone. Trazodone was included due to clinical interest in the context of sleep apnea pharmacotherapy as it can suppress arousal without compromising pharyngeal muscle activity. These preclinical findings newly identify taltirelin as a stable upper airway-preferring respiratory stimulant with arousal properties. These traits have potential favorable relevance to some respiratory disorders but not others, as identified and discussed.

Fatigue Risk Management Systems Diagnostic Tool: Validation of an Organizational Assessment Tool for Shift Work Organizations

BackgroundThis study aimed to determine and define the elements of an Fatigue Risk Management System (FRMS) diagnostic tool to assist an organization in systematically assessing its level of implementation of an FRMS. MethodsA modified Delphi process was used involving 16 participants with expertise in sleep science, chronobiology, and fatigue risk management within occupational settings. The study was undertaken in two stages 1) review of elements and definitions; 2) review of statements for each element. Each stage involved an iterative process, and a consensus rule of ≥ 60% was applied to arrive at a final list of elements, definitions, and statements. ResultsStage 1: a review of elements (n = 12) and definitions resulted in a final list of 14 elements and definitions with a consensus of ≥ 60% achieved after 2 Delphi rounds. Stage 2: a review of statements (n = 131) resulted in a final list of 119 statements with a consensus of ≥ 60% achieved after 2 Delphi rounds. ConclusionThe final FRMS diagnostic tool will enable an organization to systematically assess the level of implementation of their current FRMS and identify gaps and opportunities to reduce risk.

Circadian molecular clock disruption in chronic pulmonary diseases.

The circadian clock is the biochemical oscillator with a near 24-h period that is responsible for generating the circadian rhythms in peripheral organs including the lung. Mounting evidence suggests that circadian clock disruption during chronic lung diseases plays an essential role in augmented oxidative stress, inflammatory response, metabolic imbalances, hypoxia/hyperoxia, mucus secretion, dysregulated autophagy, and alters pulmonary function. Here, we review circadian clock disruption and discuss candidate clock genes that are altered at the transcriptional or translational level in chronic pulmonary diseases. This review aims to provide the current knowledge and understanding of the circadian molecular clock disruption in chronic pulmonary diseases which will further advance the development of novel clock-based therapeutics in the future.

0157 Sleep Icebreakers and Behavioral Change: If You Could Tell People Only One Thing About Sleep, What Should It Be?

Abstract Introduction Insufficient sleep is widespread in the general population, but education and outreach can combat this problem. Informal learning settings, like museums, provide unique opportunities for educating a local community. However, in such settings, engagement with the content relies on the topic’s ability to immediately incite interest. Therefore, we developed and tested a series of sleep “icebreakers” (brief, informal facts) to determine their effectiveness in eliciting interest in sleep science and encouraging behavioral change. Methods Five hundred and twenty-one participants were recruited via the local museum (n=103) and Amazon Mechanical Turk (n=418). Participants viewed eight sleep icebreakers (randomly-selected from a bank of 16 icebreakers) and rated whether they knew it already, if they found it interesting, and if it made them want to learn more. Participants also completed questionnaires on demographics, sleep health/attitudes, and future intended sleep behaviors. Results Both the museum member and general population samples showed substantial interest in sleep science, regardless of age, gender, race/ethnicity, socioeconomic status, neighborhood disadvantage, prior sleep knowledge, and prior sleep health/attitudes. The most effective icebreakers related to REM sleep behavior disorder, sleep in Alzheimer’s disease, unihemispheric sleep, dreaming, and sleep state misperception. Importantly, the more the icebreakers interested participants, the more likely they were to formulate a specific plan to change their sleep behaviors (OR: 1.55, p = .001), express willingness to post to social media platforms (OR: 1.46, p < .01), and indicate willingness to donate to an exhibit on sleep (OR: 2.51, p < .001), even after controlling for psychosocial, sleep health/attitudes, and demographic measures. Conclusion If you could only tell someone one thing about sleep, there are a lot of good options. This interest in sleep science was enjoyed by individuals regardless of psychosocial, educational, and demographic backgrounds, and the icebreakers encouraged half of participants to form an intention to change their sleep behaviors. Coupling icebreakers with opportunities for personalized learning, and providing structure to formulate specific plans to change sleep behaviors, are promising directions for sleep health outreach efforts. Support (If Any) National Science Foundation (1920730 and 1943323)

0084 Consumer Sleep Technologies (CSTs) for Use in Real-World Sleep Research Environments: A Survey of Experts

Abstract Introduction Consumer sleep technologies (CSTs) have been designed for the everyday consumer rather than as a reliable scientific tool, but are becoming sufficiently accurate for use in the research landscape. Despite the growing conversation about the viability of CSTs for research, manufacturers may not be interested in increasing scientific accuracy in their devices unless doing so is expected to result in greater consumer sales. To establish concensus opinion about important device features and economic demand for CSTs for sleep research, professional opinions from sleep medicine experts were elicited to identify what metrics and device features for measuring sleep outside the laboratory are most desirable to the scientific community. This is the first known attempt to establish consensus opinion or economic valuation for scientifically-desirable CST device features and metrics using expert elicitation within the sleep science community. Methods Sleep and/or circadian researchers with experience collecting data in real-world environments were recruited from international academic, government, clinical, and industry research backgrounds using social media and nonprobability sampling techniques. The anonymous survey was hosted through the online tool Qualtrics between April to July 2021. Exposure to survey recruitment techniques were tracked through Twitter Analytics and Qualtrics. Respondents were asked to rank sleep metrics and consumer sleep technology features to estimate their average level of importance (low, medium, or high). A hypothetical purchase task estimated economic valuation for devices with different features by price. Results Survey respondents were 46 real-world sleep research experts with, on average, 11 (range: 1-27; mode: 10) years of experience conducting human research related to sleep in real-world environments. Sixty-six percent (66%) preferred wrist-worn devices and 52% indicated that sleep onset/offset could be determined from a period of inactivity ≤20 minutes. Eighty-three percent (83%) collected data related to napping. Forty-four percent (44%) preferred a continuous observation window between 4-14 days long. Respondents ranked battery life as the most important factor limiting the observation window. Total sleep time was ranked as the most important measure of sleep followed by objective sleep quality while sleep architecture/depth and diagnostic information were ranked as least important. Economic value was greater for hypothetical devices with longer battery life. Conclusion Real-world sleep experts prefer wrist-worn devices that can reliably estimate sleep and short naps. Battery life is important. Based on responses to both rank order questions and the hypothetical purchase task, estimating sleep depth is less important to researchers than measures of sleep duration and quality. These data set a precedent for future studies to determine the scientific relevance of metrics or how scientific endorsement of a product impacts the potential market value of a CST device. Support (If Any) NA

Nine-day continuous recording of EEG and 2-hour of high-density EEG under chronic sleep restriction in mice

This work provides an EEG dataset collected from nine mice during the sleep deprivation (SD) paradigm for the sleep science community. It includes 9-day of continuous recording of the frontal and parietal EEG, accelerometer, and 2-hour of high-density EEG (HD-EEG) under SD and SD-free conditions. Eighteen hours of SD were conducted on 5 consecutive days. The HD-EEG data were saved in the EEGLAB format and stored as the brain imaging data structure (BIDS). These datasets can be used to (i) compare mouse HD-EEG to human HD-EEG, (ii) track oscillatory activities of the sleep EEG (e.g., slow waves, spindles) across the cortical regions under different conditions of sleep pressure, and (iii) investigate the cortical traveling waves in the mouse brain. We also provided Python code for basic analyses of this dataset, including the detection of slow waves and sleep spindles. We hope that our dataset will reveal hidden activities during sleep and lead to a better understanding of the functions and mechanisms of sleep.

A Data-Informed Perspective on Public Preferences for Retaining or Abolishing Biannual Clock Changes.

Scientific, public, and political discourse around the perennial changing of the clocks during the transitions into and out of daylight saving time (DST) is a touchstone issue for the translation of fundamental chronobiology into societal impacts. The Society for Research on Biological Rhythms, along with other sleep science bodies, has issued a position statement that advocates for the abolition of the biannual clock changes and the adoption of permanent standard time for the optimization of population circadian health. However, there is a paucity of data on preexisting public perceptions and preferences with regard to these issues. In this perspective, we examine 5 issues that we believe are pertinent for chronobiologists to consider to enable effective advocacy on these policies; in particular, we discuss public preference for permanent DST and steps that may need to be taken to understand this preference. We inform our discussion with reference to cross-sectional studies we undertook in Spring 2020 and Fall 2019, around the transition out of and into DST Ireland. We conclude that there appears to be a gap between existing public perceptions and preferences around the clock changes and chronobiological and sleep science-informed positions, and that the chronobiology community may benefit from interdisciplinary collaboration with colleagues with specific social sciences expertise to most effectively advocate for these research-informed positions.

Dissertation Topics in Nursing

Few quantitative studies have documented the types of research topics most commonly employed by nursing PhD students and whether they differ by program delivery (in-person vs. online/hybrid programs). We examined a large set of publicly available PhD dissertation abstracts to (a) describe the relative prevalence of different research topics and methods and (b) test whether the primary topics and methods used differed between online or hybrid and in-person PhD programs. A secondary goal was to introduce the reader to modern text-mining approaches to generate insights from a document corpus. Our database consisted of 2,027 dissertation abstracts published between 2015 and 2019. We used a structural topic modeling text-mining approach to explore PhD students' research topics and methods in United States-based doctoral nursing programs. We identified 24 different research topics representing a wide range of research activities. Most of the research topics identified did not differ in prevalence between online/hybrid and in-person programs. However, online/hybrid programs were more likely to engage students in research focused on nursing education, professional development, work environment, simulation, and qualitative analysis. Pediatrics, sleep science, older adults and aging, and chronic disease management were more prevalent topics in in-person-only programs. The range of topics identified highlights the breadth of research nursing PhD students' conduct. Both in-person and online/hybrid programs offer a range of research opportunities, although we did observe some differences in topic prevalence. These differences could be due to the nature of some types of research (e.g., research that requires an in-person presence) or differences in research intensity between programs (e.g., amount of grant funding or proximity to a medical center). Future research should explore why research topic prevalence may vary by program delivery. We hope that this text-mining application serves as an illustrative example for researchers considering how to draw inferences from large sets of text documents. We are particularly interested in seeing future work that might combine traditional qualitative approaches and large-scale text mining to leverage the advantages of each.

Friend or Foe: a Narrative Review of the Impact of Diabetes Technology on Sleep.

The purpose of this review is to present a review of sleep science, the relationship between sleep and type 1 diabetes, and highlight the current literature on sleep outcomes in adult and pediatric diabetes technology research. Sleep quality is associated with glycemic outcomes, diabetes self-management, and mental health in people with type 1 diabetes. Diabetes technologies, including insulin pumps, continuous glucose monitors, and hybrid closed-loop systems improve glycemic outcomes. However, many people find this technology challenging for a variety of reasons, including increased burden and frequent alarms, especially during the night. The impact of different devices on sleep quality and quantity has been mixed. The newest technology, the hybrid closed-loop systems, offers the best opportunity for nocturnal glycemic regulation and has improved patient and family perspectives on sleep quality. However, objective sleep assessment has not shown significant improvement on sleep duration. Sleep quality and quantity in people with type 1 diabetes are widely recognized as an important component of health care, and the literature regarding the impact of diabetes devices on sleep is increasing. However, sleep disruptions are common and a barrier to device use. Despite finding minimal changes to sleep duration with device use, subjective accounts of sleep quality are overall positive, especially in those using hybrid closed-loop systems. Sleep quantity and quality are important outcomes to consider as diabetes technology continues to evolve.

The two-process model of sleep regulation: Beginnings and outlook.

SummaryThe two‐process model serves as a major conceptual framework in sleep science. Although dating back more than four decades, it has not lost its relevance for research today. Retracing its origins, I describe how animal experiments aimed at exploring the oscillators driving the circadian sleep–wake rhythm led to the recognition of gradients of sleep states within the daily sleep period. Advances in signal analysis revealed that the level of slow‐wave activity in non‐rapid eye movement sleep electroencephalogram is high at the beginning of the 12‐light period and then declines. After sleep deprivation, the level of slow‐wave activity is enhanced. By scheduling recovery sleep to the animal's activity period, the conflict between the sleep–wake‐dependent and the circadian influence resulted in a two‐stage recovery pattern. These experiments provided the basis for the first version of the two‐process model. Sleep deprivation experiments in humans showed that the decline of slow‐wave activity during sleep is exponential. The two‐process model posits that a sleep–wake‐dependent homeostatic process (Process S) interacts with a process controlled by the circadian pacemaker (Process C). At present, homeostatic and circadian facets of sleep regulation are being investigated at the synaptic level as well as in the transcriptome and proteome domains. The notion of sleep has been extended from a global phenomenon to local representations, while the master circadian pacemaker has been supplemented by multiple peripheral oscillators. The original interpretation that the emergence of sleep may be viewed as an escape from the rigid control imposed by the circadian pacemaker is still upheld.

Medicolegal aspects of non-rapid eye movement parasomnias

In a subset of adults with non-rapid eye movement (NREM) parasomnias, clinical variants might be violent in nature and can potentially result in unintentional but considerable harm. As such, there is substantial interest on the forensic ramifications of these sleep behaviours. This review examined the diagnostic criteria for parasomnias established in the context of international classification systems; medicolegal case reports; legal frameworks; and court cases in and outside of Singapore, to provide an overview of the implications of NREM parasomnias. Violent or injurious behaviours that occurred in the context of somnambulism, otherwise known as sleepwalking, have challenged traditional legal theories of criminal culpability. Yet little has changed in the application of sleep science to criminal responsibility. In Singapore, the defence of somnambulism has hitherto not been directly raised. Nonetheless, sleep medicine practitioners may increasingly be requested to render their opinions on legal issues pertaining to violent or injurious behaviours allegedly arising during sleep. Although the understanding of NREM parasomnias has improved, there is still a dearth of evidence to support both medical and legal decisions in this area. NREM parasomnias come with disquieting legal and forensic implications for adjudicating criminal responsibility. There is a need to critically examine legal perspectives on behaviours occurring during sleep. More reliable empirical studies investigating the pathophysiology of NREM parasomnias can offer clearer diagnostic guidelines and address complex behaviours of NREM that often come with medicolegal implications.

Sleep Deprivation Does Not Influence Photic Resetting of Circadian Activity Rhythms in Drosophila

Previous investigations in humans and rodent animal models have assessed the interplay of sleep in the circadian system’s phase responses to nighttime light exposure. The resulting data have been mixed, but generally support a modulatory role for sleep in circadian photic resetting (not an absolute requirement). Drosophila have been historically used to provide important insights in the sleep and circadian sciences. However, no experiments to date have evaluated how immediate sleep need or recent sleep history affects their pacemaker’s phase readjustments to light. We did so in the current study by (1) forcing separate groups of animals to stay awake for 1 or 4 h after they were shown a broadspectrum pulse (15 min during the first half of the night, 950 lux), or (2) placing them on a restricted sleep schedule for a week before light presentation without any subsequent sleep disruption. Forced sleep restriction, whether acute or chronic, did not alter the size of light-induced phase shifts. These data are consistent with observations made in other diurnal animals and raise the possibility, more broadly, that phototherapies applied during sleep—such as may be necessary during the winter months—may still be efficacious in individuals experiencing sleep-continuity problems such as insomnia.

Sleep Health and Road Safety: Continuation of Asia-Pacific Economic Cooperation Sleep Technology Agenda.

In 2017, the Asia-Pacific Economic Cooperation Sleep Technology Agenda emphasized the impacts of sleep health on road safety. An official meeting between the Department of Transportation of United States and the International Sleep Science and Technology Association took place in Washington, DC, on February 3, 2020. This was followed by several meetings in Taiwan advocated by the International Sleep Science and Technology Association Taiwan Chapter. We hope to raise the awareness in the government sectors, and to provide the scientific evidence of verified sleep and fatigue-monitoring technologies to avoid numerous tragedies on the road from its root cause.

Sleep and Athletes

Sleep is recognized as an essential component to optimize health and human performance, and as such the topic is of increasing interest to athletes. Yet, the sleep of athletes is affected by multiple sports-specific, and societal factors. Hence the recent emergence of the important role of sleep science in athlete health and performance. This review focuses on the fundamentals of sleep physiology and elaborates on the affects sleep has on athlete health and performance. Despite sports practitioners recognizing the importance of sleep on health and performance, findings report that insufficient sleep, and poor sleep quality are prevalent among athletic populations. This paper will describe sleep in athletes, define sleep characteristics, discuss the impact of sleep restriction following travel and competition, and strategies to mitigate sleep difficulties. Sleep is arguably the most undervalued pillar of health and performance.

Research on the health maintenance habits of university students to have the best health while at university

Concerns about the health of students have been a concern of many parents and schools for decades now. Especially with society's rapid development, students must improve their technical and professional skills. On the other hand, the global economy is also falling into an unstable and rising economic situation, especially in Vietnam when inflation is at an alarming rate. These factors also become a burden for many families. In the research article, the factors that affect the psychology of students will be listed and analyzed. Thereby, the study uses two research methods, quantitative and qualitative, from the research results drawn from many researchers on the topic of student health, and combined with the results. The answers were collected from more than 120 students studying at universities in Ho Chi Minh City about factors and habits that help students maintain their health.   References Aries, E., & Seider, M. (2005). The interactive relationship between class identity and the college experience: The case of lower income students. Qualitative Sociology, 28(4), 419-443.   Wunsch, K., Kasten, N., & Fuchs, R. (2017). The effect of physical activity on sleep quality, well-being, and affect in academic stress periods. Nature and science of sleep, 9, 117.   World Health Organization. (2000). The world health report 2000: health systems: improving performance.World Health Organization.  Sexton, J. B., Thomas, E. J., & Helmreich, R. L. (2000). Error, stress, and teamwork in medicine and aviation: cross sectional surveys. Bmj, 320(7237), 745-749.  Cummins, R. A., & Lau, A. L. (2003). Community integration or community exposure? A review and discussion in relation to people with an intellectual disability. Journal of applied research in intellectual disabilities, 16(2), 145-157.  Miller, A. L., & Chun, M. (2022). Perspectives of two college students labeled with intellectual disability: Supports during the moving in and through stages of transition. Disability Studies Quarterly, 42(1).  Choi, S. E., & Lee, Y. (2022). Comparison of Meal Skipping, Snacking, and Body Weight Perceptions among Urban College Students: On-Campus Living Alone vs. Off-Campus Living with Parents in New York, USA. Journal of the Korean Society of Food Culture, 37(2), 109-118.  Ji, D., & Liu, L. (2022). Fighting COVID-19 by National Mobilization: A Communicative Analysis of the Roles of the Chinese Government. In Manufacturing Government Communication on Covid-19 (pp. 33-58). Springer, Cham.  Pellicane, M. J., & Ciesla, J. A. (2022). Temporal trends in depression, anxiety, and suicidality rates among cisgender sexual minority and heterosexual college students. Psychology of Sexual Orientation and Gender Diversity.  Desrochers, J. E., Bell, A. L., Nisbet, E. K., & Zelenski, J. M. (2022). Does Spending Time in Nature Help Students Cope with the COVID-19 Pandemic?. Sustainability, 14(4), 2401. Mao, B. P., Teichroeb, M. L., Lee, T., Wong, G., Pang, T., & Pleass, H. (2022). Is Online Video-Based Education an Effective Method to Teach Basic Surgical Skills to Students and Surgical Trainees? A Systematic Review and Meta-analysis. Journal of surgical education. Kapllanaj, M., Sianko, N., & Gjedia, R. (2022). Exploring After-School Activities by Socio-Demographic Characteristics and Subjective Well-Being. In Handbook of Children’s Risk, Vulnerability and Quality of Life (pp. 371-389). Springer, Cham. Kartashova, L. A., Prykhodkina, N. O., Makhynia, T. A., Tymoshko, H. M., Sholokh, O. A., & Zhuravlev, F. M. (2022). Social media as a strategic tool in school management: experience of Ukraine and USA. AET 2020, 196. Chateauneuf, J. (2022). Using the Whole School, Whole Child, Whole Community Approach to Improve an Urban Early Learning Center Students’ Social, Emotional, and Physical Health and Wellness. Wolfe, H. E., & Isaacowitz, D. M. (2022). Aging and emotion regulation during the COVID-19 pandemic. Aging & Mental Health, 26(5), 890-897. Koç, G. Ç. (2022). Apricot Fruit Wastes: Chemistry, Processing, and Utilization. In Handbook of Fruit Wastes and By-Products (pp. 193-208). CRC Press. Erbersdobler, H. F., Barth, C. A., & Jahreis, G. (2017). Legumes in human nutrition. Nutrient content and protein quality of pulses. Ernahrungs Umschau, 64(9), 134-139. Flight, I., & Clifton, P. (2006). Cereal grains and legumes in the prevention of coronary heart disease and stroke: a review of the literature. European journal of clinical nutrition, 60(10), 1145-1159. Komalasari, K., Saripudin, D., & Masyitoh, I. S. (2014). Living values education model in learning and extracurricular activities to construct the students’ character. Journal of Education and Practice, 5(7).

Functional approach to sleep disturbance in chronic fatigue: chronic fatigue and sleep disturbance

Sleep is closely related to health behaviors and is also a crucial lifestyle in itself. In this regard, sleep health should be a part of assessing and managing chronic fatigue in the clinical field. First, it is vital to get in the early morning sun and improve sleep hygiene for proper melatonin secretion. Second, relaxation, meditation, or nutritional supplementation can be helpful to prevent sympathetic nervousness in the evening. Third, it is important to re-recognize and regain the health blessings of rapid eye movement sleep in the early morning. Lastly, meals tailored according to the biological clock (chrono-nutrition) can facilitate gut microbiota s healthy flourishing and the 24-hour circadian rhythm. When assessing and treating patients with chronic fatigue, functional medicine approaches are another essential step for improving the quality of life and advanced health care, based on a broad understanding of sleep science.

Feasibility Analysis of Symbolic Representation for Single-Channel EEG-Based Sleep Stages.

Sleep screening based on the construction of sleep stages is one of the major tool for the assessment of sleep quality and early detection of sleep-related disorders. Due to the inherent variability such as inter-users anatomical variability and the inter-systems differences, representation learning of sleep stages in order to obtain the stable and reliable characteristics is runoff for downstream tasks in sleep science. In this paper, we investigated feasibility of the EEG-based symbolic representation for sleep stages. By combining the Latent Dirichlet Allocation topic model and comparing with different feature extraction methods, the work proved the feasibility of multi-topics representation for sleep stages and physiological signals.

Editorial: “The stuff that dreams are made of”

Rafael Benoliel: Dentistry and specifically orofacial pain have been involved in the science of sleep and its interactions with pain and various other relevant disorders for decades. Yet we have not yet explored dreams; an amazing phenomenon occurring during sleep where brain activity can induce a virtual reality that includes visual, auditory, olfactory, taste, and emotional experiences as true as their waketime counterparts. Humans spend about 2 hours dreaming per night, and we have established that most, but not all, of our dreaming occurs during REM (rapid eye movement) sleep. While neuroscientists routinely examine neural activity during sleep, capturing dreams so that they can be evaluated presents obvious challenges. There is general agreement about what dreams are, but ongoing debate remains over why we dream. We may dream to augment rest and repair for our mind and body. We may dream for psychologic reasons. In fact, there are several dream theories, from Sigmund Freud’s interpretations to hypotheses that claim dreams are just random. Many of the theories on the function of dreams are contradicted by the sparse, hallucinatory, and narrative nature of dreams, a nature that seems to lack any specific function; the answer to why we dream remains nebulous. The recent advent of deep neural networks (DNNs) has provided a novel conceptual framework within which to understand the evolved function of dreams¹ —fascinating, but beyond the scope of this editorial. Dreams, it seems, are not just “sleep-time” entertainment. Dreams can provide much information about our state of mind, problems, and wishes for our future. Answers to our problems may be found in our dreams, which may also try to offer solutions.² The “dream machine” works efficiently, with insights and “advice” occurring the night of and about a week after a triggering event. This would suggest that dreams serve social and emotional adaptive functions. Would this include pain-related disorders? A relevant question is: Does pain occur in dreams? It has been shown that realistic, localized painful sensations can be experienced in dreams, either through direct incorporation or from past memories. Nevertheless, the frequency of pain dreams in healthy subjects is low. In one study, dreams often reflected attempts to obtain pain relief.³ So although pain is rare in dreams, it is compatible with the representational code of dreaming.³ Patients suffering from burn pain dream more frequently of pain than controls.<sip>4</sup> Findings have indicated that dreaming about pain may be an added stress for pain patients and may contribute to both poor sleep and higher pain intensity, which could evolve into a cycle of pain–anxiety–sleeplessness.⁴ Researchers have found that during dreams in REM sleep, our stress responses shut down, and the neurochemicals responsible for stressful feelings stop being released.⁵ In addition to this, REM helps reduce the negative effects of difficult memories. Although not studied, this suggests to me that pain may be similarly modulated. Possibly, dreams could be harnessed and manipulated to manage some of the disorders we encounter. There is a definite relationship between bad dreams and chronic pain.⁶ Evidence demonstrates that nightmares sometimes accompany migraine, and this link has been proposed as the result of a number of factors that affect both migraine and nightmares; for example, various stressors.⁷ Clearly the directionality of the relationship and the involvement of comorbidities are not always clear and need further study. A lucid dream is a type of dream where the dreamer becomes aware that they are dreaming. A recent study instructed volunteers to enter a lucid dream and imagine themselves experiencing pain in their arms, following which they were required to wake up immediately. Of the participants, around three-quarters experienced pain during lucid dreaming, and one-fifth felt pain even after waking.⁸ These are thought-provoking findings: A dreamer consciously induced pain, without a nociceptive or other stimulus, and was able to subsequently project this into a conscious physical sensation! This is consistent with studies that establish the brain as the source of pain. It strengthens approaches that pain may be controlled through our consciousness. The psycho-physiologic connection found between dreams and wakefulness could lead to new treatments for pain relief.⁹ From the use of lucid dreams and “dream incubation” (“planting a seed” for a specific dream topic to occur) . . . this is “the stuff of dreams.” Rafael Benoliel Editor-in-Chief

Rosalind Dymond Cartwright (1922-2021).

Memorializes Rosalind Dymond Cartwright (1922-2021). She was a pioneer in the fields of empathy and psychotherapy research and one of the first women to make significant contributions to the science of sleep and dreams and the field of sleep medicine. Upon receiving her PhD in 1949, she took a position at Mount Holyoke College. After 2 years, she moved to the University of Chicago where Carl Rogers hired her to oversee the many studies of audiotaped psychotherapy sessions that he was conducting to test the effectiveness of client-centered therapy. In 1954, she and Rogers coedited the landmark book, Psychotherapy and Personality Change. She also held positions at the University of Illinois College of Medicine, University of Chicago, and Rush University Medical Center. From 1971 to 1993 she was a grant reviewer for the National Institute of Mental Health, a role that allowed her to advocate anonymously for the support of research and training programs that greatly influenced the course of sleep research in the United States. Beginning in 1990, Roz served pro bono as an expert witness for the defense in several murder cases that involved a defense of sleepwalking, a non-REM parasomnia. At age 90 she immersed herself in the technology of spectral analysis scoring of polysomnogram data to argue that recent laboratory-based discoveries about sleepwalkers could be used to determine whether an alleged crime might have been committed during an arousal from sleep in which consciousness was impaired. (PsycInfo Database Record (c) 2022 APA, all rights reserved).