Full Night Of Sleep Research Articles

The impact of REM sleep loss on human brain connectivity

Brain function is vulnerable to the consequences of inadequate sleep, an adverse trend that is increasingly prevalent. The REM sleep phase has been implicated in coordinating various brain structures and is hypothesized to have potential links to brain variability. However, traditional imaging research have encountered challenges in attributing specific brain region activity to REM sleep, remained understudied at the whole-brain connectivity level. Through the spilt-night paradigm, distinct patterns of REM sleep phases were observed among the full-night sleep group (n = 36), the early-night deprivation group (n = 41), and the late-night deprivation group (n = 36). We employed connectome-based predictive modeling (CPM) to delineate the effects of REM sleep deprivation on the functional connectivity of the brain (REM connectome) during its resting state. The REM sleep-brain connectome was characterized by stronger connectivity within the default mode network (DMN) and between the DMN and visual networks, while fewer predictive edges were observed. Notably, connections such as those between the cingulo-opercular network (CON) and the auditory network, as well as between the subcortex and visual networks, also made significant contributions. These findings elucidate the neural signatures of REM sleep loss and reveal common connectivity patterns across individuals, validated at the group level.

Evidence of an active role of dreaming in emotional memory processing shows that we dream to forget

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.

Short-term chloral hydrate as an add-on treatment may improve sleep and alleviate agitation in inpatients with treatment resistant schizophrenia: a retrospective case series study.

Chloral hydrate (CH), a medication dating back to 1832, is tranquilizer and sleep promoter still used today. It remains an option for short-term insomnia therapy and sedation before medical procedures, despite its controversial safety profile. This study investigated the potential benefits of chloral hydrate addition for increasing sleep duration and reducing agitation and violence in inpatients with treatment-resistant schizophrenia (TRS). A retrospective, observational case series design was utilized, analyzing data from fourteen patients diagnosed with TRS disorders. CH addition increased the rate of full night sleep and decreased the rates of agitation and verbal and physical violence events. Notably, no adverse events including falls were reported during CH addition. CH shows some short-term benefits in improving sleep disorders and reducing violent and agitated behavior in patients with TRS. Our study has limitations due to its small sample size, retrospective design and lack of a control group. A large-scale, double-blind, randomized trial is needed to further explore the efficacy and safety of CH in psychiatric populations with TRS accompanied by agitation, violence and disturbed sleep.

A neuron–glia lipid metabolic cycle couples daily sleep to mitochondrial homeostasis

Sleep is thought to be restorative to brain energy homeostasis, but it is not clear how this is achieved. We show here that Drosophila glia exhibit a daily cycle of glial mitochondrial oxidation and lipid accumulation that is dependent on prior wake and requires the Drosophila APOE orthologs NLaz and GLaz, which mediate neuron–glia lipid transfer. In turn, a full night of sleep is required for glial lipid clearance, mitochondrial oxidative recovery and maximal neuronal mitophagy. Knockdown of neuronal NLaz causes oxidative stress to accumulate in neurons, and the neuronal mitochondrial integrity protein, Drp1, is required for daily glial lipid accumulation. These data suggest that neurons avoid accumulation of oxidative mitochondrial damage during wake by using mitophagy and passing damage to glia in the form of lipids. We propose that a mitochondrial lipid metabolic cycle between neurons and glia reflects a fundamental function of sleep relevant for brain energy homeostasis.

Cognitive performance of air personnel following sleep deprivation.

Air forces have developed several methods for reducing fatigue-related accidents. In the Israeli Air Force, the "Dead Tired" workshop was developed with the purpose of presenting aircrew with their objective performance under sleep deprivation conditions. The aim of this study was to examine the cognitive abilities of both aircrew and unmanned aerial vehicle operators, both objectively and subjectively. All Israeli aircrew and unmanned aerial vehicle operators participated in a "Dead Tired" workshop. During the workshop, the participants performed the Psychomotor Vigilance Task, a task that tests their attention abilities, while gathering information on their subjective sleepiness in the form of a Karolinska Sleepiness Scale. Data of 366 participants (25 females), of whom 187 were unmanned aerial vehicle operators and 179 were aircrew, were obtained; and the mean age was 21.8 ± 1.2 years (range 19-26 years). A significant decline in task performance was seen following 20 hr of wakefulness in both unmanned aerial vehicle operators and aircrew (p < 0.001). Unmanned aerial vehicle operators' performance was significantly better throughout the majority of the workshop (p < 0.001). Recovery after the full-night's sleep was seen for unmanned aerial vehicle operators, but not for aircrew (p = 0.008). A high correlation was seen between Psychomotor Vigilance Task performance and Karolinska Sleepiness Scale responses (correlation coefficient = 0.93). Sleep deprivation negatively impacted the performance of both groups of participants. Unmanned aerial vehicle operators were found to be more resilient to the effects of sleep deprivation and were quicker to recover in comparison to aircrew.

Post-training sleep modulates motor adaptation and task-related beta oscillations.

Motor adaptation reflects the ability of the brain's sensorimotor system to flexibly deal with environmental changes to generate effective motor behaviour. Whether sleep contributes to the consolidation of motor adaptation remains controversial. In this study, we investigated the impact of sleep on motor adaptation and its neurophysiological correlates in a novel motor adaptation task that leverages a highly automatised motor skill, that is, typing. We hypothesised that sleep-associated memory consolidation would benefit motor adaptation and induce modulations in task-related beta band (13-30 Hz) activity during adaptation. Healthy young male experts in typing on the regular computer keyboard were trained to type on a vertically mirrored keyboard while brain activity was recorded using electroencephalography. Typing performance was assessed either after a full night of sleep with polysomnography or a similar period of daytime wakefulness. Results showed improved motor adaptation performance after nocturnal sleep but not after daytime wakefulness, and decreased beta power: (a) during mirrored typing as compared with regular typing; and (b) in the post-sleep versus the pre-sleep mirrored typing sessions. Furthermore, the slope of the electroencephalography signal, a measure of aperiodic brain activity, decreased during mirrored as compared with regular typing. Changes in the electroencephalography spectral slope from pre- to post-sleep mirrored typing sessions were correlated with changes in task performance. Finally, increased fast sleep spindle density (13-15 Hz) during the night following motor adaptation training was predictive of successful motor adaptation. These findings suggest that post-training sleep modulates neural activity supporting adaptive motor functions.

Identification of full-night sleep parameters using morphological features of ECG signals: A practical alternative to EEG and EOG signals

Electroencephalogram (EEG) signals, which are among the most important recordings used in Polysomnography for sleep staging, are more challenging and demanding than electrocardiography (ECG) signals, both in terms of acquisition and interpretation. When examining the studies of other researchers on sleep parameters in the literature, it is evident that EEG signals are predominantly used for determining arousal (AR), K-complex (Kc), and sleep spindle (Ss) parameters. Furthermore, it is understood that electrooculography (EOG) signals are employed for detecting slow eye movements (SEM) and rapid eye movements (REM) parameters.This study is a continuation of our previous research, where we used only EEG signals for Kc and Ss detection. In this study, an approach that includes ECG signals in the determination of sleep parameters to bring practicality to sleep staging studies was adopted. For this purpose, firstly, 16 morphological features were extracted from ECG recordings taken from a total of 24 subjects after various preprocessing steps. Subsequently, these data were used to work on the detection of five different sleep parameters: AR, Kc, Ss, SEM, and REM, using the Random Subspace (RaSE) ensemble learning algorithm. The results were calculated according to various statistical criteria and a classification accuracy of over 78 % was obtained in all parameters. As a result, the sleep parameters that could be determined most successfully using the ECG signal were SEM and arousal, respectively. In addition, feature elimination was performed for these datasets using Symmetric Uncertainty (SU) ranking. As a result of the reclassification process using 9 and 12 features, the effectiveness of which was determined for both datasets, respectively, significant increases were observed in the performance outputs. Experimental results have shown that ECG signals can be used as an alternative to EEG and EOG signals in the determination of full-night sleep parameters.

0475 Optimal Thresholds for Split-Night Polysomnography with Transitions in Laboratory Hypopnea Scoring Criteria

Abstract Introduction Performance of split-night polysomnography, the application and titration of positive airway pressure (PAP) therapy after an initial diagnostic interval, is a common practice in clinical sleep medicine. There is no currently recommended apnea-hypopnea index (AHI) threshold at which PAP should be applied during polysomnography. Differences in American Academy of Sleep Medicine (AASM) and Centers for Medicare and Medicaid Services (CMS) hypopnea scoring criteria and limitations on real-time hypopnea classification complicates identification of an optimal split-night threshold. Of particular concern is that patients may be “split” under AASM hypopnea rules but have insufficiently severe sleep disordered breathing under CMS rules to be diagnosed or treated appropriately. This study aimed to clarify optimal AHI thresholds for split night polysomnography in the context of a laboratory-wide transition from CMS to AASM hypopnea scoring criteria. Methods Effective October 1, 2021, our laboratory transitioned solely to scoring AASM-defined hypopneas, with additional post hoc identification of CMS hypopneas for reporting purposes. With this change, the split-night threshold was changed from 15 to 30/hr. All diagnostic polysomnograms (without PAP therapy) performed on adult patients through October 31, 2022, were retrospectively analyzed to clarify the effect of changing hypopnea scoring criteria in this context. Results 634 diagnostic polysomnograms were analyzed. An AHI threshold of 15/hr (using AASM hypopnea criteria) in the first two hours of sleep with at least 3 hours of time remaining for PAP titration would have resulted in 96 additional patients receiving treatment with PAP therapy. Among these, only one (1.04%) had CMS AHI below 5/hr. Sixty-eight of these patients had CMS AHI 5-15/hr during the first two hours of sleep. Among these, only eight patients did not have an additional comorbidity or symptom profile under CMS guidelines making them eligible for PAP therapy, however, none had CMS AHI &amp;gt;15/hr when the full night of sleep was analyzed. Conclusion Our study suggests there is little need to raise the split-night threshold when transitioning from CMS to AASM hypopnea criteria, and doing so substantially reduces the number of patients treated with PAP therapy in the sleep laboratory. Support (if any) None

0126 CVD biomarker profiling reveals distinct responses to acute exercise under conditions of recurrent sleep loss in healthy humans

Abstract Introduction Physical exercise impacts a plethora of signaling pathways, which mediate the acute and long-term benefits of exercise. Whereas the acute effects of exercise on overall metabolism and cardiovascular disease (CVD) risk factors have been extensively studied in humans, little is known about how a wider range of CVD biomarkers change in response to acute exercise under conditions of sleep loss. Thus, here we examined whether a few nights of short sleep alter the diurnal and exercise-induced levels of a range of CVD biomarkers. Methods In a randomized two-condition crossover study, 16 men partook in two sessions, comprising three consecutive nights of full-night sleep (NS, 8.5 hours sleep/night) and three nights of partial sleep restriction (SR, 4.25 hours/night). In both conditions, blood was repeatedly sampled in the evening and about 12 hours later (for evening-to-morning analysis) as well as repeatedly before and after a 30-min bout of high-intensity exercise (at 75% VO2maxReserve). Olink's CVD II panel and ELISAs were used to measure 92 CVD protein biomarkers. Results Under pre-exercise sedentary conditions, the diurnal changes of several CVD biomarkers differed in response to SR compared with NS. However, several proteins exhibited diurnal changes regardless of sleep condition (as also confirmed in a separate a cohort with overnight wakefulness). In response to exercise, we observed that most proteins increased vs. decreased in their relative levels, including inflammatory markers. Furthermore, some proteins exhibited an early vs. more delayed increase. However, following SR, the exercise-induced induction of CVD biomarkers was markedly dampened, compared with the NS condition, and SR resulted in an altered exercise-induced response for several inflammatory-related CVD biomarkers. Conclusion Recurrent sleep restriction impacts the evening-to-morning dynamics of several CVD biomarkers, and the extent to which blood-based CVD biomarkers are induced by acute, high-intensity exercise. This may indicate that some of the cardiometabolic responses to vigorous exercise differ under conditions of sleep loss. Whether such changes alter the long-term benefits of aerobic exercise under conditions of chronic sleep loss, and whether these changes differ in e.g. older subjects or CVD, remains to be investigated. Support (if any) Swedish Society for Medical Research, Swedish Cancer Foundation, Diabetesfonden, Göran Gustafsson, Hjärnfonden

Exposure to a more unhealthy diet impacts sleep microstructure during normal sleep and recovery sleep: A randomized trial.

Although intake of specific macronutrients has been associated with sleep parameters, interventional evidence is lacking. Therefore, thisrandomized trial was conductedto examine how a more unhealthy high-fat/high-sugar (HFHS) diet impacts sleep in humans. In a crossover study, 15 healthy young men consumed two isocaloric diets in random order for a week: an HFHS and a low-fat/low-sugar diet. Following each diet, in-lab sleep was recorded using polysomnography during a full night of sleep and during recovery sleep after extended wakefulness. Sleep duration, macrostructure, and microstructure (oscillatory pattern and slow waves) were investigated using machine learning-based algorithms. Sleep duration did not differ across the diets based on actigraphy and the in-lab polysomnography. Sleep macrostructure was similar after 1 week on each diet. Compared with the low-fat/low-sugar diet, consumption of the HFHS diet resulted in reduced delta power, delta to beta ratio, and slow wave amplitude but increased alpha and theta power during deep sleep. During recovery sleep, similar sleep oscillatory changes were observed. Short-term consumption of a more unhealthy diet alters sleep oscillatory features that regulate the restorative properties of sleep. Whether such changes can mediate adverse health outcomes associated with consumption of an unhealthier diet warrants investigation.

L-DOPA increases slow-wave sleep duration and selectively modulates memory persistence in older adults.

Millions of people worldwide take medications such as L-DOPA that increase dopamine to treat Parkinson's disease. Yet, we do not fully understand how L-DOPA affects sleep and memory. Our earlier research in Parkinson's disease revealed that the timing of L-DOPA relative to sleep affects dopamine's impact on long-term memory. Dopamine projections between the midbrain and hippocampus potentially support memory processes during slow wave sleep. In this study, we aimed to test the hypothesis that L-DOPA enhances memory consolidation by modulating NREM sleep. We conducted a double-blind, randomised, placebo-controlled crossover trial with healthy older adults (65-79 years, n = 35). Participants first learned a word list and were then administered long-acting L-DOPA (or placebo) before a full night of sleep. Before sleeping, a proportion of the words were re-exposed using a recognition test to strengthen memory. L-DOPA was active during sleep and the practice-recognition test, but not during initial learning. The single dose of L-DOPA increased total slow-wave sleep duration by approximately 11% compared to placebo, while also increasing spindle amplitudes around slow oscillation peaks and around 1-4 Hz NREM spectral power. However, behaviourally, L-DOPA worsened memory of words presented only once compared to re-exposed words. The coupling of spindles to slow oscillation peaks correlated with these differential effects on weaker and stronger memories. To gauge whether L-DOPA affects encoding or retrieval of information in addition to consolidation, we conducted a second experiment targeting L-DOPA only to initial encoding or retrieval and found no behavioural effects. Our results demonstrate that L-DOPA augments slow wave sleep in elderly, perhaps tuning coordinated network activity and impacting the selection of information for long-term storage. The pharmaceutical modification of slow-wave sleep and long-term memory may have clinical implications. Eudract number: 2015-002027-26; https://doi.org/10.1186/ISRCTN90897064, ISRCTN90897064.

The Effect of Partial Sleep Deprivation and Time-on-Task on Young Drivers’ Subjective and Objective Sleepiness

Despite sleepiness being considered one of the main factors contributing to road crashes, and even though extensive efforts have been made in the identification of techniques able to detect it, the assessment of fitness-to-drive regarding driving fatigue and sleepiness is still an open issue. In the literature on driver sleepiness, both vehicle-based measures and behavioral measures are used. Concerning the former, the one considered more reliable is the Standard Deviation of Lateral Position (SDLP) while the PERcent of eye CLOSure over a defined period of time (PERCLOS) seems to be the most informative behavioral measure. In the present study, using a within-subject design, we assessed the effect of a single night of partial sleep deprivation (PSD, less than 5 h sleeping time) compared to a control condition (full night of sleep, 8 h sleeping time) on SDLP and PERCLOS, in young adults driving in a dynamic car simulator. Results show that time-on-task and PSD affect both subjective and objective sleepiness measures. Moreover, our data confirm that both objective and subjective sleepiness increase through a monotonous driving scenario. Considering that SDLP and PERCLOS were often used separately in studies on driver sleepiness and fatigue detection, the present results have potential implications for fitness-to-drive assessment in that they provide useful information allowing to combine the advantages of the two measures for drowsiness detection while driving.

Sleep strengthens resting-state functional communication between brain areas involved in the consolidation of problem-solving skills.

Sleep consolidates procedural memory for motor skills, and this process is associated with strengthened functional connectivity in hippocampal-striatal-cortical areas. It is unknown whether similar processes occur for procedural memory that requires cognitive strategies needed for problem-solving. It is also unclear whether a full night of sleep is indeed necessary for consolidation to occur, compared with a daytime nap. We examined how resting-state functional connectivity within the hippocampal-striatal-cortical network differs after offline consolidation intervals of sleep, nap, or wake. Resting-state fMRI data were acquired immediately before and after training on a procedural problem-solving task that requires the acquisition of a novel cognitive strategy and immediately prior to the retest period (i.e., following the consolidation interval). ROI to ROI and seed to whole-brain functional connectivity analyses both specifically and consistently demonstrated strengthened hippocampal-prefrontal functional connectivity following a period of sleep versus wake. These results were associated with task-related gains in behavioral performance. Changes in functional communication were also observed between groups using the striatum as a seed. Here, we demonstrate that at the behavioral level, procedural strategies benefit from both a nap and a night of sleep. However, a full night of sleep is associated with enhanced functional communication between regions that support problem-solving skills.

Targeted Memory Reactivation During REM Sleep in Patients With Social Anxiety Disorder.

BackgroundSocial anxiety disorder (SAD) is characterized by a significant amount of fear when confronted to social situations. Exposure therapy, which is based on fear extinction, does not often lead to full remission. Here, based on evidence showing that rapid eye movement (REM) sleep promotes the consolidation of extinction memory, we used targeted memory reactivation (TMR) during REM sleep to enhance extinction learning in SAD.MethodsForty-eight subjects with SAD were randomly assigned to two groups: control or TMR group. All patients had two successive exposure therapy sessions in a virtual reality (VR) environment, where they were asked to give a public talk in front of a virtual jury. At the end of each session, and only in the TMR group (N = 24), a sound was paired to the positive feedback phase of therapy (i.e., approval of their performance), which represented the memory to be strengthened during REM sleep. All participants slept at home with a wearable headband device which automatically identified sleep stages and administered the sound during REM sleep. Participants' anxiety level was assessed using measures of parasympathetic (root mean square of successive differences between normal heartbeats, RMSSD) and sympathetic (non-specific skin conductance responses, ns-SCRs) activity, and subjective measures (Subjective Units of Distress Scale, SUDS), during the preparation phase of their talks before (T1) and after (T2) one full-night's sleep and after 1 week at home (T3). Participants also filled in a dream diary.ResultsWe observed an effect of time on subjective measures of anxiety (SUDS). We did not find any difference in the anxiety levels of the two groups after 1 week of TMR at home. Importantly, the longer the total duration of REM sleep and the more stimulations the TMR group had at home, the less anxious (increased RMSSD) these participants were. Finally, fear in dreams correlated positively with ns-SCRs and SUDS at T3 in the TMR group.ConclusionTMR during REM sleep did not significantly modulate the beneficial effect of therapy on subjective anxiety. Yet, our results support that REM sleep can contribute to extinction processes and substantiate strong links between emotions in dreams and waking stress levels in these patients.

Chest area segmentation in 3D images of sleeping patients.

Although the field of sleep study has greatly developed over recent years, the most common and efficient way to detect sleep issues remains a sleep examination performed in a sleep laboratory. This examination measures several vital signals by polysomnograph during a full night's sleep using multiple sensors connected to the patient's body. Nevertheless, despite being the gold standard, the sensors and the unfamiliar environment's connection inevitably impact the quality of the patient's sleep and the examination itself. Therefore, with the novel development of accurate and affordable 3D sensing devices, new approaches for non-contact sleep studyhave emerged. These methods utilize different techniques to extract the same breathing parameters but with contactless methods. However, to enable reliable remote extraction, these methods require accurate identification of the basic region of interest (ROI), i.e., the patient's chest area. The lack of automated ROI segmenting of 3D time series is currently holding back the development process. We propose an automatic chest area segmentation algorithm that given a time series of 3D frames containing a sleeping patient as input outputs a segmentation image with the pixels that correspond to the chest area. Beyond significantly speeding up the development process of the non-contact methods, accurate automatic segmentation can enable a more precise feature extraction. In addition, further tests of the algorithm on existing data demonstrate its ability to improve the sensitivity of a prior solution that uses manual ROI selection. The approach is on average 46.9% more sensitive with a maximal improvement of 220% when compared to manual ROI. All mentioned can pave the way for placing non-contact algorithms as leading candidates to replace existing traditional methods used today.

Coercion, Violation of Privacy and Everyday Difficulties as the Cause of Patient Refusal Treatment in Psychiatric Hospitals in Russia

Treatment in a psychiatric hospital is accompanied by a restriction of independence, violation of privacy, coercion, which causes displeasure of patients. The aim of the study was to verify the scale of everyday problems, violations of privacy and coercion in a psychiatric hospital to develop recommendations for the organization of a therapeutic environment. The study included 191 patients in a psychiatric hospital. Anonymous questionnaire was used. Statistical processing of the database was carried out by nonparametric methods. The majority of patients (67%) estimated the conditions of stay in a psychiatric hospital at 7-10 points (10-point scale), but half of them complained about the need for self-purchase of drugs. A full night's sleep was disturbed by the snoring of others (56.5%), an uncomfortable bed (36.6%), bright light (26.2%). The poor diet was indicated by 45.5% of patients. Patients indicated coercion by medical staff: retention (11.5%), forced administration of drugs (12%), coercion to consent to treatment (22%), refusal to discharge from hospital (35.1%). It was reported that there was a violation of privacy in the toilet (36.6%), difficulties to observe the intimate hygiene (16.8%). These problems caused patients to refuse inpatient treatment if there was the possibility of outpatient treatment (65.2% of men and 52.6% of women). Despite the low level of claims of patients to living conditions, it is important to respect their rights in psychiatric hospitals to privacy, creating a comfortable living space, the organization of differentiated methods of observation by medical staff.

The Brain Selectively Tunes to Unfamiliar Voices during Sleep

The brain continues to respond selectively to environmental stimuli during sleep. However, the functional role of such responses, and whether they reflect information processing or rather sensory inhibition, is not fully understood. Here, we present 17 human sleepers (14 females) with their own name and two unfamiliar first names, spoken by either a familiar voice (FV) or an unfamiliar voice (UFV), while recording polysomnography during a full night of sleep. We detect K-complexes, sleep spindles, and microarousals, and assess event-related and frequency responses as well as intertrial phase synchronization to the different stimuli presented during nonrapid eye movement (NREM) sleep. We show that UFVs evoke more K-complexes and microarousals than FVs. When both stimuli evoke a K-complex, we observe larger evoked potentials, more precise time-locking of brain responses in the delta band (1–4 Hz), and stronger activity in the high frequency (>16 Hz) range, in response to UFVs relative to FVs. Crucially, these differences in brain responses disappear completely when no K-complexes are evoked by the auditory stimuli. Our findings highlight discrepancies in brain responses to auditory stimuli based on their relevance to the sleeper and propose a key role for K-complexes in the modulation of sensory processing during sleep. We argue that such content-specific, dynamic reactivity to external sensory information enables the brain to enter a sentinel processing mode in which it engages in the important internal processes that are ongoing during sleep while still maintaining the ability to process vital external sensory information.SIGNIFICANCE STATEMENT Previous research has shown that sensory processing continues during sleep. Here, we studied the capacity of the sleeping brain to extract and process relevant sensory information. We presented sleepers with their own names and unfamiliar names spoken by either an FV or a UFV. During NREM sleep, UFVs elicited more K-complexes and microarousals than FVs. By contrasting stimuli that evoked K-complexes, we demonstrate that UFVs evoked larger, more synchronized brain responses as well as stronger power at high frequencies (>16 Hz) relative to FVs. These differences in brain responses disappeared when no K-complexes were evoked. Our results suggest a pivotal role for K-complexes in the selective processing of relevant information during NREM sleep.

Сутність та аналіз оздоровчих систем

In the article, based on the analysis of data from special literature, generalization of the experience of leading experts and personal experience, a number of conclusions are made. Regarding the essence and analysis of health systems, an extremely important solution to the problem of introducing valeological education and training specialists with a high level of knowledge of individual health and ways to achieve them has been proved. It has been established that this approach makes it possible to formulate a new attitude towards health in society, the cultivation of a healthy lifestyle. Proved additional responsibility for physical education and health education for the training of specialists to work in this direction. It was revealed that health systems are systems of theoretical knowledge and practical methods that ensure the preservation of health, the formation of a healthy lifestyle. It has been proven that health systems contribute to the preservation and strengthening of the health of applicants for education gradually and naturally without applying complex methods and artificial preparations to the body. Respiratory exercises are recognized as relevant among the health systems. Scientific research confirms that breathing exercises are an important and effective therapeutic tool. Systematic special breathing training can significantly increase the efficiency and economy of external breathing and at the same time increase, make more stable the physiological reserves and adaptive capabilities of the body. In the process of scientific research, it was found that there is a significant variety of health systems. The analyzed health systems combine certain common components. These include: the correct mode of work and rest; daily physical activity; a full night's sleep; optimism and the ability to control emotions; the ability to withstand stress, relax and have a good rest, etc. It is recommended to use health systems for the prevention of diseases, as well as for effective healing of the body as a whole.

Automated sleep apnea detection in pregnant women using wavelet-based features

Sleep apnea is a severe sleep disorder that degrades the quality of sleep and causes patients to feel restless and fatigued even after a full night's sleep. Sleep-disordered breathing (SDB) research has grown its importance in recent decades, owing to patients' substantial health effects and poor quality of life. Obstructive sleep apnea (OSA), the most prevalent kind of sleep disorder, that is caused due to a partial blockage in the nasal airway, resulting in low oxygen levels in the patient's blood. The drop in oxygen level may cause high blood pressure, which can lead to major cardiac issues. Further, OSA is also a risk for pregnancy complications in first-time pregnant women (nulliparous pregnancy), as emerging research and studies suggest a strong relationship between sleep-disordered breathing patients and critical pregnancy outcomes like preeclampsia, preterm birth, gestational diabetes, and intrauterine growth retardation.Polysomnography (PSG) recordings with multiple-channel various modalities signals are often used to detect sleep problems. This study aims to detect sleep apnea in nulliparous pregnant women using a simplified PSG-based system that employed only airflow signals. We used the ‘nulliparous pregnancy outcomes study monitoring mothers-to-be (nuMOM2b)’ database, containing 3012 women subjects for sleep-disordered breathing (SDB) related sub-studies. To the best of our knowledge, this is the first computer-aided diagnostic tool developed to automatically identify sleep apnea in pregnant women. In this work on the detection of OSA, we proposed the use of a single-channel airflow (AF) signal in combination with an orthogonal wavelet filter bank. The L1 − norm features are extracted from wavelet coefficients. The selected features are then fed into various machine learning classifiers to automatically detect apnea. The developed model obtained a highest accuracy of 83.9% with an F1 score of 0.91 using the RUSBoosted tree classifier with ten-fold cross-validation (CV) strategy. The system proposed can be used in a home-based compact clinical setup to detect apnea in pregnant women.

Sleep Enhances Consolidation of Memory Traces for Complex Problem-Solving Skills.

Sleep consolidates memory for procedural motor skills, reflected by sleep-dependent changes in the hippocampal-striatal-cortical network. Other forms of procedural skills require the acquisition of a novel strategy to solve a problem, which recruit overlapping brain regions and specialized areas including the caudate and prefrontal cortex. Sleep preferentially benefits strategy and problem-solving skills over the accompanying motor execution movements. However, it is unclear how acquiring new strategies benefit from sleep. Here, participants performed a task requiring the execution of a sequence of movements to learn a novel cognitive strategy. Participants performed this task while undergoing fMRI before and after an interval of either a full night sleep, a daytime nap, or wakefulness. Participants also performed a motor control task, which precluded the opportunity to learn the strategy. In this way, we subtracted motor execution-related brain activations from activations specific to the strategy. The sleep and nap groups experienced greater behavioral performance improvements compared to the wake group on the strategy-based task. Following sleep, we observed enhanced activation of the caudate in addition to other regions in the hippocampal-striatal-cortical network, compared to wakefulness. This study demonstrates that sleep is a privileged time to enhance newly acquired cognitive strategies needed to solve problems.