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Sleep is vital to associating emotion with memory, study finds -- ScienceDaily

The researchers found that when they disrupted sleep after they showed the subjects an image and had given them a mild foot shock, there was no fear associated with the visual stimulus. Those with unmanipulated sleep learned to fear the specific visual stimulus that had been paired with the foot shock. "We found that these mice actually became afraid of every visual stimulus we showed them," Aton said. "From the time they go to the chamber where the visual stimuli are presented, they seem to know there's a reason to feel fear, but they don't know what specifically they're afraid of." This likely shows that, in order for them to make an accurate fear association with a visual stimulus, they have to have sleep-associated reactivation of the neurons encoding that stimulus in the sensory cortex, according to Aton. This allows a memory specific to that visual cue to be generated.The researchers think that at the same time, that sensory cortical area must communicate with other brain structures, to marry the sensory aspect of the memory to the emotional aspect.

A sleep disorder associated with shift work may affect gene function: Going on holiday has a restorative effect on changes in DNA -- ScienceDaily

A total of 32 shift workers participated in the study, of whom 21 suffered from shift work disorder and 11 were in the control group. Dynamic changes to DNA methylation were investigated through a genome-wide analysis during work and after a holiday period. Changes to DNA methylation which affected gene function were identified in study subjects suffering from a sleep disorder caused by shift work. The findings demonstrated that rest and recovery during holiday periods also resulted in the restoration of DNA methylation in cases where changes had been observed during the work period. The study proved the dynamic nature of DNA methylation, which was particularly emphasised in the activity of NMDA glutamate receptors. The strongest evidence was gained from the GRIN2C receptor: the methylation level of a specific CpG base pair in the regulatory region was lower during the work period in subjects suffering from shift work disorder. However, this change was reversed after the holiday period.

Day-to-day variability in sleep parameters and depression risk: a prospective cohort study of training physicians | npj Digital Medicine

Within individuals, increased TST (b = 0.06, p < 0.001), later wake time (b = 0.09, p < 0.001), earlier bedtime (b = − 0.07, p < 0.001), as well as lower day-to-day shifts in TST (b = −0.011, p < 0.001) and in wake time (b = −0.004, p < 0.001) were associated with improved next-day mood.

The science of siestas: New research reveals the genetic basis for daytime napping -- ScienceDaily

For this study, the MGH researchers and their colleagues used data from the UK Biobank, which includes genetic information from 452,633 people. All participants were asked whether they nap during the day "never/rarely," "sometimes" or "usually." The GWAS identified 123 regions in the human genome that are associated with daytime napping. A subset of participants wore activity monitors called accelerometers, which provide data about daytime sedentary behavior, which can be an indicator of napping. This objective data indicated that the self-reports about napping were accurate. "That gave an extra layer of confidence that what we found is real and not an artifact," says Dashti. Several other features of the study bolster its results. For example, the researchers independently replicated their findings in an analysis of the genomes of 541,333 people collected by 23andMe, the consumer genetic-testing company. Also, a significant number of the genes near or at regions identified by the GWAS are already known to play a role in sleep. One example is KSR2, a gene that the MGH team and collaborators had previously found plays a role in sleep regulation.

Ancient echoes: Moonlight affects human sleep patterns | YaleNews

nt’s sleep duration across the lunar cycle ranged from 20 minutes to more than 90 minutes with little difference between the three indigenous groups, according to the study. Changes in the time that people fell asleep varied from a half hour to 80 minutes, the study found. The findings among the college students were consistent with these ranges. In all cases, people went to bed latest, and slept the least amount of time, three to five days before a full moon, according to the study. Interviews with Toba/Qom individuals indicated that moonlit nights are a particularly rich period for social activities, and elders reported that sufficient moonlight enables nighttime hunting and fishing, according to the study.

Fruit-fly study sheds light on why vibrations help rock baby to sleep | by Psych News Daily | Dec, 2020 | Medium

The flies’ sleep duration is longer when they are “rocked,” and intrusive lights are less likely to wake them up. Vibrations also make the fruit flies sleep better — they are more alert afterwards, and behave as if they had slept longer than they actually had. This in turn lets them function better, even when they have had less sleep.

Blue-light glasses improve sleep and workday productivity, study finds -- ScienceDaily

Across two studies, researcher collected data from 63 company managers and 67 call center representatives at Brazil-based offices for a U.S. multinational financial firm and measured task performance from clients. Participants were randomly chosen to test glasses that filtered blue light or those that were placebo glasses. "Employees are often required to work early mornings, which may lead to a misalignment between their internal clock and the externally controlled work time," the researchers said, adding that their analyses showed a general pattern that blue-light filtration can have a cumulative effect on key performance variables, at least in the short term. "Blue-light exposure should also be of concern to organizations," Guarana said. "The ubiquity of the phenomenon suggests that control of blue-light exposure may be a viable first step for organizations to protect the circadian cycles of their employees from disruption."

Past your bedtime? Inconsistency may increase risk to cardiovascular health -- ScienceDaily

Researchers at the University of Notre Dame studied the correlation between bedtime regularity and resting heart rate (RHR) and found that individuals going to bed even 30 minutes later than their usual bedtime presented a significantly higher resting heart rate that lasted into the following day. "We already know an increase in resting heart rate means an increased risk to cardiovascular health," said Nitesh Chawla, the Frank M. Freimann professor of Computer Science and Engineering at Notre Dame, director of the Center for Network and Data Science and a lead author of the study. "Through our study, we found that even if you get seven hours of sleep a night, if you're not going to bed at the same time each night, not only does your resting heart rate increase while you sleep, it carries over into the next day."
Sleep has been conceptualized as “activity-dependent”, hence a response to prior waking experience, and proposed to be “the price the brain pays for plasticity during wakefulness”. We here propose that at the level of neuronal networks, particularly those arising from isolated embryonic thalamocortical cells maintained in culture, it represents a default mode of functioning. We show that cell assemblies in ex vivo cultures express powerful sleep specific patterns of oscillatory activity, as well as metabolic and molecular signatures of the sleep state.

Refined carbs may trigger insomnia, finds study -- ScienceDaily

They found that the higher the dietary glycemic index -- particularly when fueled by the consumption of added sugars and processed grains -- the greater the risk of developing insomnia. They also discovered that women who consumed more vegetables and whole fruits (not juices) were less likely to develop insomnia. "Whole fruits contain sugar, but the fiber in them slow the rate of absorption to help prevent spikes in blood sugar," says Gangwisch. "This suggests that the dietary culprit triggering the women's insomnia was the highly processed foods that contain larger amounts of refined sugars that aren't found naturally in food." Since most people, not just postmenopausal women, experience a rapid rise in blood sugar after eating refined carbohydrates, the authors suspect that these findings may also hold true in a broader population.

Sleep Therapy for the Masses May Be Coming to You Soon - The New York Times

CVS Health said it was carefully reviewing the scientific literature on digital therapies to decide which ones to offer employers. The company selected Sleepio first partly because the app was backed by rigorous, published studies, said Dr. Troyen A. Brennan, CVS Health’s chief medical officer.

Teens sleep 43 more minutes per night after combo of two treatments -- ScienceDaily

The treatment had two components: brief, early morning flashes of bright, broad-spectrum white light to reset the teens' circadian clocks, and cognitive behavioral therapy that motivated them to try earlier bedtimes. The findings will be published online Sept. 25 in JAMA Network Open. "Using a passive light therapy during sleep, we can help teens get an extra 43 minutes of sleep every single night," said senior author Jamie Zeitzer, PhD, associate professor of psychiatry and behavioral sciences. The light was delivered by a device in the teens' bedrooms that was programmed to deliver 3-millisecond flashes of light every 20 seconds during the last few hours of sleep. The brief flashes of light did not wake the teens. Zeitzer's previous research on jet lag had shown that exposure to short flashes of light can trick the brain into adjusting to a new time zone, even during sleep.

Introducing 'phyjama,' a physiological-sensing pajama - ScienceBlog.com

“Such pressured regions of the textile are potential locations where we can measure ballistic movements caused by heartbeats and breathing,” he explains, “and these can be used to extract physiological variables.” The difficulty is that these signals can be individually unreliable, particularly in loose-fitting clothing, but signals from many sensors placed across different parts of the body can be intelligently combined to get a more accurate composite reading.

Sleep is essential for business leaders seeking next successful venture -- ScienceDaily

In the second part of the study, a smaller group of participants evaluated the pitches over several weeks while charting their sleep patterns. Those participants who had at least seven hours of sleep each night consistently selected the best pitches identified by the expert panel. Those who had less sleep or restless sleep did not consistently pick the best pitches. "The evidence suggests that less sleep leads to less accurate beliefs about the commercial potential of a new venture idea," Gish says. "Since we compared individual performance over multiple days, we can say that these results are consistent even for entrepreneurs who don't sleep as much on average as the general population."

Pink noise boosts deep sleep in mild cognitive impairment patients: Sound stimulation in deep sleep improved recall for some in small pilot study -- ScienceDaily

Each participant received sounds on one of the nights and no sounds on the other. The order of which night had sounds or no sounds was randomly assigned. Participants did memory testing the night before and again in the morning. Scientists then compared the difference in slow-wave sleep with sound stimulation and without sounds, and the change in memory across both nights for each participant. The participants were tested on their recall of 44 word pairs. The individuals who had 20% or more increase in their slow wave activity after the sound stimulation recalled about two more words in the memory test the next morning. One person with a 40% increase in slow wave activity remembered nine more words. The sound stimulation consisted of short pulses of pink noise, similar to white noise but deeper, during the slow waves. The system monitored the participant's brain activity. When the person was asleep and slow brain waves were seen, the system delivered the sounds. If the patient woke up, the sounds stopped playing.

'Goldilocks' neurons promote REM sleep -- ScienceDaily

This is the first time that an area of the brain has been found to control REM sleep as a function of room temperature. "Our discovery of these neurons has major implications for the control of REM sleep," says Schmidt. "It shows that the amount and timing of REM sleep are finely tuned with our immediate environment when we do not need to thermoregulate. It also con-firms how dream sleep and the loss of thermoregulation are tightly integrated." REM sleep is known to play an important role in many brain functions such as memory consolidation. REM sleep comprises approximately one quarter of our total sleep time. "These new data suggest that the function of REM sleep is to activate important brain functions specifically at times when we do not need to expend energy on thermoregulation, thus optimizing use of energy resources," says Schmidt.

A nap a day keeps high blood pressure at bay: Catching some midday shut-eye linked to similar drops in blood pressure seen with other lifestyle changes, some medications -- ScienceDaily

"Midday sleep appears to lower blood pressure levels at the same magnitude as other lifestyle changes. For example, salt and alcohol reduction can bring blood pressure levels down by 3 to 5 mm Hg," said Manolis Kallistratos, MD, cardiologist at the Asklepieion General Hospital in Voula, Greece, and one of the study's co-authors, adding that a low-dose antihypertensive medication usually lowers blood pressure levels by 5 to 7 mm Hg, on average. Overall, taking a nap during the day was associated with an average 5 mm Hg drop in blood pressure, which researchers said is on par with what would be expected from other known blood pressure-lowering interventions. In addition, for every 60 minutes of midday sleep, 24-hour average systolic blood pressure decreased by 3 mm Hg. "These findings are important because a drop in blood pressure as small as 2 mm Hg can reduce the risk of cardiovascular events such as heart attack by up to 10 percent," Kallistratos said. "Based on our findings, if someone has the luxury to take a nap during the day, it may also have benefits for high blood pressure. Napping can be easily adopted and typically doesn't cost anything."

Disrupted circadian rhythms may drive anxiety and exacerbate brain disorders

"The studies presented today help deepen our understanding of why sleep is disrupted in so many patients," said press conference moderator Clifford Saper, MD, Ph.D., of Harvard Medical School, who's work focuses on integrated functions maintained by hypothalamus which includes the regulation of wake-sleep cycles. "They also suggest that sleep-focused therapies, such as treatments to regulate circadian rhythms, may be beneficial in the prevention or treatment of a vast array of diseases, including Alzheimer's disease and anxiety disorder and furthermore emphasize the critical need of good sleep for everyone's health."

Light pollution may cause insomnia in older adults: Artificial, outdoor light exposure at night is significantly associated with hypnotic drug prescription -- ScienceDaily

Results show that increasing nighttime levels of artificial, outdoor light exposure, stratified by quartile, were associated with an increased prevalence of hypnotic prescriptions and daily dose intake. Furthermore, older adults exposed to higher levels of artificial, outdoor light at night were more likely to use hypnotic drugs for longer periods or higher daily dosages. "This study observed a significant association between the intensity of outdoor, artificial, nighttime lighting and the prevalence of insomnia as indicated by hypnotic agent prescriptions for older adults in South Korea," said Kyoung-bok Min, PhD, an associate professor in the Department of Occupational and Environmental Medicine at Seoul National University College of Medicine in South Korea. "Our results are supportive data that outdoor, artificial, nighttime light could be linked to sleep deprivation among those while inside the house."

Lack of sleep intensifies anger, impairs adaptation to frustrating circumstances -- ScienceDaily

"In general, anger was substantially higher for those who were sleep restricted," Krizan said. "We manipulated how annoying the noise was during the task and as expected, people reported more anger when the noise was more unpleasant. When sleep was restricted, people reported even more anger, regardless of the noise."

The Human Brain Is a Time Traveler - The New York Times

Andreasen’s background outside neuroscience might have helped her perceive the value lurking in the rest state, where her peers saw only trouble. As a professor of Renaissance literature, she published a scholarly appraisal of John Donne’s “conservative revolutionary” poetics. After switching fields in her 30s, she eventually began exploring the mystery of creativity through the lens of brain imaging. “Although neither a Freudian nor a psychoanalyst, I knew enough about human mental activity to quickly perceive what a foolish ‘control task’ rest was,” she would later write. “Most investigators made the convenient assumption that the brain would be blank or neutral during ‘rest.’ From introspection I knew that my own brain is often at its most active when I stretch out on a bed or sofa and close my eyes.”

'Nested sequences': An indispensable mechanism for forming memories -- ScienceDaily

Which of these sequences, slow or nested, is necessary for the appearance of sequence reactivations, and therefore causes the consolidation of memories during sleep? Using an ingenious system, the researchers discovered what deactivates nested sequences, without affecting slow sequences: the animals are transported on an electric train, in a car with a treadmill (see image). When the treadmill is stopped, the nested sequences disappear; they return when the treadmill starts again. The researchers then observed that after several circuits in the train with the treadmill stopped, place cells in the rats' hippocampi did not reactivate during sleep in the same order as when awake. On the contrary, after one train circuit with the treadmill on, the sequence reactivations are indeed present. So it is these nested theta sequences during movement that are indispensable for the consolidation of memory during sleep.

It's not just for kids -- even adults appear to benefit from a regular bedtime: Adults with varied sleep-wake times weigh more, have higher blood sugar, risk of disease -- ScienceDaily

Of all three measures, however, regularity was the best at predicting someone's heart and metabolic disease risk, the researchers found. As one might expect, irregular sleepers experienced more sleepiness during the day and were less active -- perhaps because they were tired, Lunsford-Avery said. Researchers plan to conduct more studies over longer periods in hopes of determining how biology causes changes in sleep regularity and vice-versa. "Perhaps there's something about obesity that disrupts sleep regularity," Lunsford-Avery said. "Or, as some research suggests, perhaps poor sleep interferes with the body's metabolism which can lead to weight gain, and it's a vicious cycle. With more research, we hope to understand what's going on biologically, and perhaps then we could say what's coming first or which is the chicken and which is the egg."

Brain connectivity study helps explain the neural link between depression and poor sleep quality

The researchers examined data from 1,017 participants who were included in the March 2017 public data release from the Human Connectome Project. They found that both poor sleep quality and depressive symptoms were associated with neural connectivities involving the lateral orbitofrontal cortex, the dorsolateral prefrontal cortex, the cingulate cortex, and the precuneus. “Our analysis shows that the functional connections between the areas of the brain associated with short-term memory, the self, and negative emotions are increased in both poor sleep and depressive participants. So people with poor sleep or depression may focus too much on the negative things and dwell on bad thoughts, which leads to a poor quality of sleep,” Feng told PsyPost.

Poor sleep triggers viral loneliness and social rejection: Lack of sleep generates social anxiety that infects those around us -- ScienceDaily

Notably, researchers found that brain scans of sleep-deprived people as they viewed video clips of strangers walking toward them showed powerful social repulsion activity in neural networks that are typically activated when humans feel their personal space is being invaded. Sleep loss also blunted activity in brain regions that normally encourage social engagement. "The less sleep you get, the less you want to socially interact. In turn, other people perceive you as more socially repulsive, further increasing the grave social-isolation impact of sleep loss," Walker added. "That vicious cycle may be a significant contributing factor to the public health crisis that is loneliness." National surveys suggest that nearly half of Americans report feeling lonely or left out. Furthermore, loneliness has been found to increase one's risk of mortality by more than 45 percent -- double the mortality risk associated with obesity.

Sensitivity of the circadian system to evening bright light in preschool‐age children

We found robust melatonin suppression (87.6 ± 10.0%) in response to the bright light stimulus. Melatonin levels remained attenuated for 50‐min after termination of the light stimulus (P < 0.008). Furthermore, melatonin levels did not return to 50% of those observed in the dim light condition 50‐min after the light exposure for 7/10 children.