1. ‘Morning larks’ have weaker sleep spindles during night than ‘night owls’

    November 12, 2017 by Ashley

    From the University of Helsinki press release:

    A new study from the University of Helsinki, Finland, shows that individual circadian preference is associated with brain activity patterns during the night.

    Sleep spindles are bursts of oscillatory brain activity visible on an EEG that occur mainly during stage 2 sleep. Sleep spindles are linked for example to sleep maintenance and strengthening of the memory traces during sleep.

    The study explored the association between individual circadian preference and sleep spindle activity among 170 17-year-old participants, who underwent a sleep EEG monitoring at their home environment.

    “We observed a significantly weaker spindle activity among the morning preference group compared to other groups. The spindle activity also decreased more towards the morning hours, explains the principal investigator,” Professor Anu-Katriina Pesonen. “This might be a potential facilitator underlying earlier circadian rhythm.”

    The study published in Scientific Reports shows for the first time a link between circadian preference and sleep maintaining sleep microstructures, indicated by sleep spindle activity.


  2. How memories ripple through the brain

    November 11, 2017 by Ashley

    From the NIH/National Institute of Neurological Disorders and Stroke press release:

    Using an innovative “NeuroGrid” technology, scientists showed that sleep boosts communication between two brain regions whose connection is critical for the formation of memories. The work, published in Science, was partially funded by the Brain Research through Advancing Innovative Neurotechnologies (BRAIN) Initiative, a project of the National Institutes of Health devoted to accelerating the development of new approaches to probing the workings of the brain.

    “Using new technologies advanced by the BRAIN Initiative, these researchers made a fundamental discovery about how the brain creates and stores new memories,” said Nick Langhals, Ph.D., program director at NIH’s National Institute of Neurological Disorders and Stroke.

    A brain structure called the hippocampus is widely thought to turn new information into permanent memories while we sleep. Previous work by the new study’s senior author, New York University professor György Buzsáki, M.D., Ph.D., revealed high-frequency bursts of neural firing called ripples in the hippocampus during sleep and suggested they play a role in memory storage. The current study confirmed the presence of ripples in the hippocampus during sleep and found them in certain parts of association neocortex, an area on the brain’s surface involved in processing complex sensory information.

    “When we first observed this, we thought it was incorrect because it had never been observed before,” said Dion Khodagholy, Ph.D., the study’s co-first author and assistant professor at Columbia University in New York.

    Using a cutting-edge NeuroGrid system they invented, along with recording electrodes placed deeper into the brain, the researchers examined activity in several parts of rats’ brains during non-rapid eye movement (NREM) sleep, the longest stage of sleep. Their NeuroGrid consists of a collection of tiny electrodes linked together like the threads of a blanket, which is then laid across an area of the brain so that each electrode can continuously monitor the activity of a different set of neurons.

    “This particular device allows us to look at multiple areas of the brain at the same time,” said Jennifer Gelinas, M.D., Ph.D., the study’s co-first author and assistant professor at Columbia University.

    The team was also surprised to find that the ripples in the association neocortex and hippocampus occurred at the same time, suggesting the two regions were communicating as the rats slept. Because the association neocortex is thought to be a storage location for memories, the researchers theorized that this neural dialogue could help the brain retain information.

    To test that idea, they examined brain activity during NREM sleep in rats trained to locate rewards in a maze and in rats that explored the maze in a random fashion. In the latter group of animals, the ripples in the hippocampus and cortex were no more synchronized before exploring the maze than afterwards. In the trained rats, the learning task increased the cross-talk between those areas, and a second training session boosted it even more, further suggesting that such communication is important for the creation and storage of memories.

    The group hopes to use the NeuroGrid in people undergoing brain surgery for other reasons to determine if the same ripples occur in the human brain. The researchers also plan to investigate if manipulating that neural firing in animals can boost or suppress memory formation in order to confirm that ripples are important for that process.

    “Identifying the specific neural patterns that go along with memory formation provides a way to better understand memory and potentially even address disorders of memory,” said Dr. Gelinas.


  3. Study suggests removing digital devices from the bedroom can improve sleep for children, teens

    November 9, 2017 by Ashley

    From the Penn State press release:

    Removing electronic media from the bedroom and encouraging a calming bedtime routine are among recommendations Penn State researchers outline in a recent manuscript on digital media and sleep in childhood and adolescence.

    The manuscript appears in the first-ever special supplement on this topic in Pediatrics and is based on previous studies that suggest the use of digital devices before bedtime leads to insufficient sleep.

    The recommendations, for clinicians and parents, are:

      • 1. Make sleep a priority by talking with family members about the importance of sleep and healthy sleep expectations;

    2. Encourage a bedtime routine that includes calming activities and avoids electronic media use;

    3. Encourage families to remove all electronic devices from their child or teen’s bedroom, including TVs, video games, computers, tablets and cell phones;

    4. Talk with family members about the negative consequences of bright light in the evening on sleep; and

    5. If a child or adolescent is exhibiting mood or behavioral problems, consider insufficient sleep as a contributing factor.

    “Recent reviews of scientific literature reveal that the vast majority of studies find evidence for an adverse association between screen-based media consumption and sleep health, primarily delayed bedtimes and reduced total sleep duration,” said Orfeu Buxton, associate professor of biobehavioral health at Penn State and an author on the manuscript.

    The reasons behind this adverse association likely include time spent on screens replacing time spent sleeping; mental stimulation from media content; and the effects of light interrupting sleep cycles, according to the researchers.

    Buxton and other researchers are further exploring this topic. They are working to understand if media use affects the timing and duration of sleep among children and adolescents; the role of parenting and family practices; the links between screen time and sleep quality and tiredness; and the influence of light on circadian physiology and sleep health among children and adolescents.


  4. Study indicates sleep deprivation leads to mental lapses

    November 3, 2017 by Ashley

    From the University of California – Los Angeles Health Sciences press release:

    Ever sleep poorly and then walk out of the house without your keys? Or space out on the highway and nearly hit a stalled car?

    A new study is the first to reveal how sleep deprivation disrupts our brain cells’ ability to communicate with each other, leading to temporary mental lapses that affect memory and visual perception.

    “We discovered that starving the body of sleep also robs neurons of the ability to function properly,” said senior author Dr. Itzhak Fried, professor of neurosurgery at the David Geffen School of Medicine at UCLA and Tel Aviv University. “This paves the way for cognitive lapses in how we perceive and react to the world around us.”

    Fried led an international team in studying 12 UCLA epileptic patients who had electrodes implanted in their brains in order to pinpoint the origin of their seizures prior to surgery. Because lack of sleep can provoke seizures, these patients stay awake all night to speed the onset of an epileptic episode and shorten their hospital stay.

    The team asked the patients to categorize a variety of images as fast as possible while their electrodes recorded the firing of nearly 1,500 single brain cells across the group in real time. The scientists zeroed in on the temporal lobe, which regulates visual perception and memory.

    Performing the task grew more challenging as the patients grew sleepier. As the patients slowed down, their brain cells did, too.

    “We were fascinated to observe how sleep deprivation dampened brain cell activity,” said lead author Dr. Yuval Nir of Tel-Aviv University. “Unlike the usual rapid reaction, the neurons responded slowly, fired more weakly and their transmissions dragged on longer than usual.”

    Lack of sleep interfered with the neurons’ ability to encode information and translate visual input into conscious thought.

    The same phenomenon can occur when a sleep-deprived driver notices a pedestrian stepping in front of his car.

    “The very act of seeing the pedestrian slows down in the driver’s over-tired brain,” he explained. “It takes longer for his brain to register what he’s perceiving.”

    In a second finding, the researchers discovered that slower brain waves accompanied sluggish cellular activity in the same regions of the patients’ brains.

    “Slow sleep-like waves disrupted the patients’ brain activity and performance of tasks,” said Fried. “This phenomenon suggests that select regions of the patients’ brains were dozing, causing mental lapses, while the rest of the brain was awake and running as usual,” said Fried.

    The study’s findings provoke questions for how society views sleep deprivation.

    “Inadequate sleep exerts a similar influence on our brain as drinking too much,” said Fried. “Yet no legal or medical standards exist for identifying over-tired drivers on the road the same way we target drunk drivers.”

    Fried and his colleagues plan to dive more deeply into the benefits of sleep. Future studies aim to unravel the mechanism responsible for the cellular glitches that precede mental lapses.

    Previous studies have tied sleep deprivation to a heightened risk of depression, obesity, diabetes, heart attacks and stroke, as well as medical errors.


  5. Study identifies neurons that rouse the brain to breathe

    November 1, 2017 by Ashley

    From the Beth Israel Deaconess Medical Center press release:

    A common and potentially serious sleep disorder, obstructive sleep apnea affects at least one quarter of U.S. adults and is linked to increased risk of diabetes, obesity and cardiovascular disease. In a paper published in the journal Neuron, researchers at Beth Israel Deaconess Medical Center (BIDMC) identified specific neural circuitry responsible for rousing the brain of mice in simulated apnea conditions. The findings could lead to potential new drug therapies to help patients with obstructive sleep apnea get more rest.

    Often but not always marked by loud snoring, sleep apnea occurs when a sleeping person’s airway collapses and closes off breathing. Dipping oxygen (O2) levels and rising carbon dioxide (CO2) levels in the blood alert the sleeping brain to the problem, rousing the sleeper just long enough to re-establish breathing.

    “A person with apnea wakes up and starts breathing again and this cycle can repeat hundreds of time per night, so the person never gets very deeply asleep,” said senior author Clifford B. Saper, MD, Chair of the Department of Neurology at BIDMC. “In the morning, they may not remember that they have not had a restful night’s sleep but will feel very tired.”

    Fragmented sleep can leave people with apnea with significant impairments to cognition, mood and daytime alertness; it may also increase cardiovascular risk. But what if scientists could prevent the brain from rousing itself hundreds of times per night in response to rising CO2 levels, while allowing it to reestablish regular respiration again?

    “Our goal was to identify the circuitry responsible for waking the brain up during sleep apnea, which is distinct from the part of the brain that controls breathing,” said Saper, who is also the James Jackson Putnam Professor of Neurology and Neuroscience at Harvard Medical School. “If we could keep the brain from waking up during apneas and activate only the part of the brain that opens up the airways, people with obstructive sleep apnea would still be able to get a good night’s rest.”

    Using an enclosure with adjustable atmospheric levels of O2 and CO2, Saper and colleagues mimicked the effects of OSA in mice by changing the ratio of the two gases every five minutes for 30 seconds.

    Then, Saper and colleagues focused on a subset of neurons — called PBelCGRP cells- known to show activity in response to elevated CO2 levels. The team used mice with these cells genetically-altered in such a way that researchers could activate or suppress the neurons at will using light or drugs to trigger genetic switches. Known as optogenetics and chemogenetics, these experiments demonstrated that activating these cells will wake mice up and keep them up for hours. They also showed that suppressing PBelCGRP cells’ activity would let mice sleep even as CO2 levels in the air around them rose. Taken together, these findings show that the PBelCGRP cells wake up the brain and are necessary for arousal.

    In the final experiment, the researchers followed the PBelCGRPneurons’ long-reaching branches (called axons) to the cells they connect with in other regions of the brain. Without disrupting the cells’ entire activity, the researchers switched off PBelCGRPneurons’ connection to a key site in the basal forebrain. That resulted in a nearly complete loss of sensitivity to CO2 arousal.

    Saper and colleagues note that rising CO2 levels may not be the only factor that repeatedly rouses people with sleep apnea throughout the night. Negative air pressure in the collapsed upper airway may also send “wake-up” messages to the brain via another neuronal circuit. Or PBelCGRP neurons may rouse a sleeping brain in response to a variety of stimuli, not just rising CO2 levels, the researchers suggest. Learning which neurons regulate arousal could allow scientists to develop drugs to treat obstructive sleep apnea and other sleep disorders.

    “The long-term goal of this research is to come up with drugs that will affect specific pathways in the brain,” Saper said. “The next step is to see if we can use drugs to prevent the wake-up response while augmenting the opening of the airway. That way, having an apnea won’t wake a person up.”


  6. Study suggests sleepwalkers may have multitasking advantage over non-sleepwalkers when awake

    October 31, 2017 by Ashley

    From the Ecole Polytechnique Fédérale de Lausanne press release:

    Try counting backwards from 200 in steps of 7 while walking en-route to your favourite café. Chances are, you will slow down or even freeze mid-stride, unless you are a sleepwalker.

    Breakthrough research using virtual reality has revealed significant differences in how the brains of sleepwalkers and non-sleepwalkers control and perceive body movement — a first in cognitive science. Sleepwalkers exhibit increased automation in their movements with respect to non-sleepwalkers. The results are published in Current Biology on October 23, 2017.

    Wearing a full-body motion capture suit in a room full of IR-tracking cameras at EPFL (Ecole polytechnique fédérale de Lausanne), sleepwalkers and non-sleepwalkers were asked to walk towards a target object, in this case a virtual cylinder. The subject was shown a life-size avatar that could truthfully replicate or deviate from the subject’s actual trajectory in real-time. Participants could therefore be tricked into walking along a modified trajectory to compensate for the avatar deviation. Their walking speed and accuracy of movement along with their movement awareness were then recorded and analysed.

    There was no difference between sleepwalkers and non-sleepwalkers while performing this first task — just as previous research would have suggested. When the researchers added a layer of complexity, however, a clear distinction emerged between the two groups.

    Subjects were asked to count backwards in steps of 7 starting from 200. Non-sleepwalkers significantly slowed down when having to count backwards while walking, yet sleepwalkers maintained a similar walking velocity in both conditions, showing a strong link between sleepwalking and automatic control of locomotion not during nocturnal episodes of sleepwalkers, but during full wakefulness. Furthermore, sleepwalkers were more accurate at detecting changes in the virtual reality feedback when faced with the mental arithmetic task.

    “We found that sleepwalkers continued to walk at the same speed, with the same precision as before and were more aware of their movements than non-sleepwalkers,” says EPFL neuroscientist Olaf Blanke. “The research is also a first in the field of action-monitoring, providing important biomarkers for sleepwalkers — while they are awake.” Sleepwalkers are known to perform complex movements such as walking in the absence of full consciousness. This ability may translate into a multi-tasking advantage for sleepwalkers while awake. Somnambulism, or sleepwalking, currently affects between 2-4% of adults and over 10% in children. The condition can cause movements ranging from small gestures, to complex actions such as walking and even behaviours like getting dressed, driving a car, or playing a musical instrument, — all while asleep.

    Sleepwalking is caused by a partial arousal from slow-wave or deep sleep, however it is not know which functional brain mechanisms are affected by this pathophysiology. The new relationship between sleepwalking and conscious movement control offers new insights into the brain mechanisms of sleepwalking and could potentially be used to aid diagnosis of sleepwalking while the subject is awake, rather than requiring an overnight stay in a sleep laboratory. “Traditionally, little has been known about daytime markers of sleepwalking, mostly because of the difficulty in investigating this condition experimentally,” explains Oliver Kannape from the University of Central Lancashire (UCLan) and lead author of the study. “Our research offers novel insight into this common sleep disorder and provides a clear scientific link between action monitoring, consciousness, and sleepwalking.”


  7. Study suggests that brain region for balance, movement also involved in processing traumatic memories

    October 29, 2017 by Ashley

    From the Thomas Jefferson University press release:

    Patients diagnosed and treated for a long-term potentially fatal diseases such as cancer, can accumulate distressing and traumatic experiences along the way. A new study from the Marcus Institute of Integrative Health at Thomas Jefferson University examines how the brain is activated when the Neuro Emotional Technique (NET) is used to help cancer patients process traumatic memories. The research, published in the Journal of Cancer Survivorship, also adds to the basic understanding of the pathophysiology of traumatic stress in general and the underlying mechanisms involved with resolving it.

    “The results of this study are a breakthrough in understanding how an intervention like NET works, particularly in regard to the cerebellum’s role in the regulation of emotional experiences. We now understand that the cerebellum does much more than coordinate motor activity,” said principal investigator Daniel Monti, MD, MBA, Director of the Marcus Institute of Integrative Health who is also a member of the Sidney Kimmel Cancer Center at Jefferson.

    The intervention, Neuro Emotional Technique (NET), is unique in allowing the practitioner to not only gauge the patient’s subjective distress but also how the nervous system is reacting to that stress, using biofeedback tools. This provides information that is not usually part of standard interventions, and is what potentially makes NET an especially efficient and efficacious therapeutic solution for traumatic stress. By showing the link between the cerebellum, limbic (emotional) centers, and autonomic nervous system, the present study expands current understanding of traumatic memories and how and intervention like NET can significantly alleviate the suffering associated with them.

    “This is the first study that offers a demonstrable solution for cancer patients with traumatic stress symptoms. It also expands our understanding of the importance of the cerebellum in coordinating traumatic emotions, and the body’s response to them,” said Dr. Monti.

    This new data suggests that a brief therapeutic course of the NET intervention substantially alters the brain’s response to traumatic memories, and it elucidates the potential importance of the cerebellum in regulating the brain and body’s response to traumatic stress. (Previous research from the Marcus Institute demonstrated the efficacy of the NET intervention for relieving stress in cancer patients.)

    “Just four to five brief NET sessions result in significantly less emotional and physical distress, and these improvements are associated with connectivity changes throughout the brain,” said Dr. Monti. “Patients, even those who were skeptical at first, have reported the NET intervention as ‘diffusing a bomb’ on ‘the worst anxiety ever.'”


  8. Study suggests rapid eye movement sleep may dampen sensitivity to fearful stimuli

    October 27, 2017 by Ashley

    From the Society for Neuroscience press release:

    Higher quality sleep patterns are associated with reduced activity in brain regions involved in fear learning, according to a study of young adults published in JNeurosci. The results suggest that baseline sleep quality may be a useful predictor of susceptibility to post-traumatic stress disorder (PTSD).

    Sleep disturbances are a common feature of PTSD. While previous research has focused on understanding how single nights of sleep influence the maintenance of already-established fear memories, few studies have investigated whether an individual’s regular sleeping habits prior to trauma contributes to the acquisition of these fear memories.

    Itamar Lerner, Shira Lupkin and their colleagues at Rutgers University had students monitor their sleep at home for one week using unobtrusive sleep monitoring tools, including a headband that measures brain waves, a bracelet that measures arm movements, and a sleep log. The students then participated in a neuroimaging experiment during which they learned to associate a neutral image with a mild electric shock. Students who spent more time in rapid eye movement (REM) sleep — the phase when dreaming occurs — exhibited weaker modulation of activity in, and connectivity between, their amygdala, hippocampus and ventromedial prefrontal cortex during fear learning.

    The authors replicated these results in a second study using traditional polysomnographic monitoring of sleep during the night just prior to fear learning. Taken together, the findings are consistent with the idea that REM sleep reduces levels of norepinephrine in the brain, which may dampen an individual’s sensitivity to fearful stimuli.


  9. Study suggests more teens than ever aren’t getting enough sleep

    by Ashley

    From the San Diego State University press release:

    If you’re a young person who can’t seem to get enough sleep, you’re not alone: A new study led by San Diego State University Professor of Psychology Jean Twenge finds that adolescents today are sleeping fewer hours per night than older generations. One possible reason? Young people are trading their sleep for smartphone time.

    Most sleep experts agree that adolescents need 9 hours of sleep each night to be engaged and productive students; less than 7 hours is considered to be insufficient sleep. A peek into any bleary-eyed classroom in the country will tell you that many youths are sleep-deprived, but it’s unclear whether young people today are in fact sleeping less.

    To find out, Twenge, along with psychologist Zlatan Krizan and graduate student Garrett Hisler — both at Iowa State University in Ames — examined data from two long-running, nationally representative, government-funded surveys of more than 360,000 teenagers. The Monitoring the Future survey asked U.S. students in the 8th, 10th and 12th grades how frequently they got at least 7 hours of sleep, while the Youth Risk Behavior Surveillance System survey asked 9th-12th-grade students how many hours of sleep they got on an average school night.

    Combining and analyzing data from both surveys, the researchers found that about 40% of adolescents in 2015 slept less than 7 hours a night, which is 58% more than in 1991 and 17% more than in 2009.

    Delving further into the data, the researchers learned that the more time young people reported spending online, the less sleep they got. Teens who spent 5 hours a day online were 50% more likely to not sleep enough than their peers who only spent an hour online each day.

    Beginning around 2009, smartphone use skyrocketed, which Twenge believes might be responsible for the 17% bump between 2009 and 2015 in the number of students sleeping 7 hours or less. Not only might teens be using their phones when they would otherwise be sleeping, the authors note, but previous research suggests the light wavelengths emitted by smartphones and tablets can interfere with the body’s natural sleep-wake rhythm. The researchers reported their findings in the journal Sleep Medicine.

    “Teens’ sleep began to shorten just as the majority started using smartphones,” said Twenge, author of iGen: Why Today’s Super-Connected Kids Are Growing Up Less Rebellious, More Tolerant, Less Happy — And Completely Unprepared for Adulthood. “It’s a very suspicious pattern.”

    Students might compensate for that lack of sleep by dozing off during daytime hours, adds Krizan.

    “Our body is going to try to meet its sleep needs, which means sleep is going to interfere or shove its nose in other spheres of our lives,” he said. “Teens may catch up with naps on the weekend or they may start falling asleep at school.”

    For many, smartphones and tablets are an indispensable part of everyday life, so they key is moderation, Twenge stresses. Limiting usage to 2 hours a day should leave enough time for proper sleep, she says. And that’s valuable advice for young and old alike.

    “Given the importance of sleep for both physical and mental health, both teens and adults should consider whether their smartphone use is interfering with their sleep,” she says. “It’s particularly important not to use screen devices right before bed, as they might interfere with falling asleep.”


  10. Study suggests that there are techniques to increase chance of lucid dreaming

    October 25, 2017 by Ashley

    From the University of Adelaide press release:

    New research at the University of Adelaide has found that a specific combination of techniques will increase people’s chances of having lucid dreams, in which the dreamer is aware they’re dreaming while it’s still happening and can control the experience.

    Although many techniques exist for inducing lucid dreams, previous studies have reported low success rates, preventing researchers from being able to study the potential benefits and applications of lucid dreaming.

    Dr Denholm Aspy’s research in the University of Adelaide’s School of Psychology is aimed at addressing this problem and developing more effective lucid dream induction techniques.

    The results from his studies, now published in the journal Dreaming, have confirmed that people can increase their chances of having a lucid dream.

    The study involved three groups of participants, and investigated the effectiveness of three different lucid dream induction techniques:

    1. reality testing – which involves checking your environment several times a day to see whether or not you’re dreaming.

    2. wake back to bed – waking up after five hours, staying awake for a short period, then going back to sleep in order to enter a REM sleep period, in which dreams are more likely to occur.

    3. MILD (mnemonic induction of lucid dreams) – which involves waking up after five hours of sleep and then developing the intention to remember that you are dreaming before returning to sleep, by repeating the phrase: “The next time I’m dreaming, I will remember that I’m dreaming.” You also imagine yourself in a lucid dream.

    Among the group of 47 people who combined all three techniques, participants achieved a 17% success rate in having lucid dreams over the period of just one week – significantly higher compared to a baseline week where they didn’t practise any techniques. Among those who were able to go to sleep within the first five minutes of completing the MILD technique, the success rate of lucid dreaming was much higher, at almost 46% of attempts.

    The MILD technique works on what we call ‘prospective memory’ – that is, your ability to remember to do things in the future. By repeating a phrase that you will remember you’re dreaming, it forms an intention in your mind that you will, in fact, remember that you are dreaming, leading to a lucid dream,” says Dr Aspy, Visiting Research Fellow in the University’s School of Psychology.

    “Importantly, those who reported success using the MILD technique were significantly less sleep deprived the next day, indicating that lucid dreaming did not have any negative effect on sleep quality,” he says.

    “These results take us one step closer to developing highly effective lucid dream induction techniques that will allow us to study the many potential benefits of lucid dreaming, such as treatment for nightmares and improvement of physical skills and abilities through rehearsal in the lucid dream environment,” Dr Aspy says.