You're not getting sleepy: Six myths and misconceptions about hypnosis from an expert

July 11, 2023

Science Daily/Binghamton University

A strange mystic swings a pocket watch back and forth, repeating the phrase "You're getting sleepy, very sleepy," giving them absolute command over their subject. That's not how hypnotism really works, but it's the way it's often depicted in pop culture. Even some clinicians and hypnosis educators propagate harmful myths about hypnosis.

Steven Jay Lynn, a professor of psychology at Binghamton University, State University of New York, is an expert on hypnosis who has made major contributions to the judicial system for his insight on the practice. Lynn believes that hypnosis has many useful clinical applications, but that myths keep it from being utilized to its full potential.

In a recent paper published in BJPsych Advances, "Reconciling myths and misconceptions about hypnosis with scientific evidence," he and his colleagues, Madeline Stein and Devin Terhune from the Institute of Psychiatry, Psychology & Neuroscience at King's College, addressed a number of errors and misconceptions regarding the characteristics and practice of hypnosis. These are a few of the common myths that are widely believed and commonly circulated in popular culture.

Hypnotized people can't resist suggestions

A deeply hypnotized person is believed to display "blind obedience," going along automatically with whatever the hypnotist suggests. Yet individuals do not lose control over their actions during hypnosis -- contrary to the notion the media reinforces that hypnosis is something done to you and that hypnosis can be used to control someone. In fact, people can resist and even oppose hypnotic suggestions. Their experience of control during hypnosis depends on their intentions and expectations regarding whether or not they retain voluntary control.

Hypnosis is a "special state"

Hypnosis is often mischaracterized as a "special state" where defense mechanisms are reduced and a "unique state of physical relaxation and conscious unconsciousness' allows us to 'enter our subconscious depths through hypnosis. However, people can respond to hypnotic suggestions even while they are alert and on an exercise bicycle. Aside from being a contradiction in terms, 'conscious unconsciousness' is an inaccurate depiction, because during hypnosis even the most highly suggestible individuals remain fully conscious and cognizant of their surroundings. It is more accurate to consider hypnosis as a set of procedures in which verbal suggestions are used to modulate awareness, perception and cognition, rather than to unnecessarily invoke 'special states.'

People are either hypnotizable or they are not

People's responsiveness to hypnosis can be relatively stable over time. Yet it is inaccurate to assume that people are either hypnotizable or not. People vary greatly in their responsiveness and often respond to some suggestions but not others. Still, most people are sufficiently hypnotizable to reap substantial benefits from therapeutic suggestions.

Responsiveness to suggestions reflects nothing more than compliance or faking

Suggested behaviors during hypnosis can seem so much a departure from the mundane that questions inevitably arise regarding whether hypnotic responses are genuine. However, neuroimaging studies reveal that the effects of hypnotic suggestions activate brain regions (e.g, visual processing) consistent with suggested events (e.g., hallucinating an object).These findings provide convincing evidence that hypnotic effects are represented at the neurophysiological level consistent with what people report.

Hypnotic methods require great skill to administer

One popular misconception is that of the mesmerist, or magician-like hypnotist with special powers of influence who can "hypnotize" anyone. This widespread idea is pure myth; in actuality, administering a hypnotic induction and specific suggestions do not require any special skills or abilities beyond those required for basic social interactions and administration of experimental or clinical procedures, such as the ability to establish rapport. However, hypnosis should be practiced only by professionals trained in the use of hypnosis.

Hypnotic age regression can retrieve accurate memories from the distant past

TV shows and movies often feature people being able to recall extremely accurate memories from a distant past life under hypnosis. But research suggests a contrary view. When researchers check the accuracy of memories of people who are "age regressed" to an earlier time (e.g., 10th century) against factual information from the suggested period, they find that the information is almost invariably incorrect. What people report is mostly consistent with information experimenters provide regarding their supposed past life experiences and identities (e.g., different race, culture, sex). These findings imply that "recall" reflects participants' expectancies, fantasies, and beliefs regarding personal characteristics and events during a given historical period.

https://www.sciencedaily.com/releases/2023/07/230711133126.htm

Gum disease linked to buildup of Alzheimer's plaque formation

Oral bacteria traveling to the brain causes brain cells to become dysfunctional, promoting neuroinflammation

July 10, 2023

Science Daily/Forsyth Institute

Although most people don't associate oral disease with serious health problems, increasing evidence shows that oral bacteria play a significant role in systemic diseases like colon cancer and heart disease. Now, new research from the Forsyth Institute shows a link between periodontal (gum) disease and the formation of amyloid plaque, a hallmark of Alzheimer's disease.

In their paper, "Microglial cell response to experimental periodontal disease," published in the Journal of Neuroinflammation, Forsyth scientists and their collaborators at Boston University demonstrate that gum disease can lead to changes in brain cells called microglial cells, which are responsible for defending the brain from amyloid plaque. This plaque is a type of protein that is associated with cell death, and cognitive decline in people with Alzheimer's. The study provides important insight into how oral bacteria makes its way to the brain, and the role of neuroinflammation in Alzheimer's disease.

"We knew from one of our previous studies that inflammation associated with gum disease activates an inflammatory response in the brain," said Dr. Alpdogan Kantarci, senior member of staff at Forsyth and a senior author of the study. "In this study, we were asking the question, can oral bacteria cause a change in the brain cells?"

The microglial cells the researchers studied are a type of white blood cell responsible for digesting amyloid plaque. Forsyth scientists found that when exposed to oral bacteria the microglial cells became overstimulated and ate too much. "They basically became obese" Dr. Kantarci said. "They no longer could digest plaque formations."

The finding is significant for showing the impact of gum disease on systemic health. Gum disease causes lesions to develop between the gums and teeth. The area of this lesion is the size of your palm. Dr. Kantarci explained, "It's an open wound that allows the bacteria in your mouth to enter your bloodstream and circulate to other parts of your body." These bacteria can pass through the blood/brain barrier and stimulate the microglial cells in your brain.

Using mouse oral bacteria to cause gum disease in lab mice, the scientists were able to track periodontal disease progression in mice and confirm that the bacteria had traveled to the brain.

They then isolated the brain microglial cells and exposed them to the oral bacteria. This exposure stimulated the microglial cells, activated neuroinflammation and changed how microglial cells dealt with amyloid plaques.

"Recognizing how oral bacteria causes neuroinflammation will help us to develop much more targeted strategies," said Dr. Kantarci. "This study suggests that in order to prevent neuroinflammation and neurodegeneration, it will be critical to control the oral inflammation associated with periodontal disease. The mouth is part of the body and if you don't take care of oral inflammation and infection, you cannot really prevent systemic diseases, like Alzheimer's, in a reproducible way."

This study is the first time that scientists caused periodontal disease with mouse-specific bacteria and could study the effects of same-species oral microbiome on the brain. Having same-species bacteria and cells brings the test closer to replicating what the process looks like in humans.

https://www.sciencedaily.com/releases/2023/07/230710180512.htm

Deep-sleep brain waves predict blood sugar control

July 7, 2023

Science Daily/University of California - Berkeley

Researchers have uncovered a potential mechanism in humans that explains how and why deep-sleep brain waves at night are able to regulate the body's sensitivity to insulin, which in turn improves blood sugar control the next day. It's an exciting advance because sleep is a modifiable lifestyle factor that could now be used as part of a therapeutic and painless adjunct treatment for those with high blood sugar or Type 2 diabetes.

Researchers have known that a lack of quality sleep can increase a person's risk of diabetes. What has remained a mystery, however, is why.

Now, new findings from a team of sleep scientists at the University of California, Berkeley, are closer to an answer. The researchers have uncovered a potential mechanism in humans that explains how and why deep-sleep brain waves at night are able to regulate the body's sensitivity to insulin, which in turn improves blood sugar control the next day.

"These synchronized brain waves act like a finger that flicks the first domino to start an associated chain reaction from the brain, down to the heart, and then out to alter the body's regulation of blood sugar," said Matthew Walker, a UC Berkeley professor of neuroscience and psychology and senior author of the new study. "In particular, the combination of two brain waves, called sleep spindles and slow waves, predict an increase in the body's sensitivity to the hormone called insulin, which consequentially and beneficially lowers blood glucose levels."

The researchers say this is an exciting advance because sleep is a modifiable lifestyle factor that could now be used as part of a therapeutic and painless adjunct treatment for those with high blood sugar or Type 2 diabetes.

Scientists also noted an additional benefit besides the potential new mechanistic pathway.

"Beyond revealing a new mechanism, our results also show that these deep-sleep brain waves could be used as a sensitive marker of someone's next-day blood sugar levels, more so than traditional sleep metrics," said Vyoma D. Shah, a researcher at Walker's Center for Human Sleep Science and co-author of the study. "Adding to the therapeutic relevance of this new discovery, the findings also suggest a novel, non-invasive tool -- deep-sleep brain waves -- for mapping and predicting someone's blood sugar control."

The team's findings were published today in the journal Cell Reports Medicine.

For years, researchers have studied how the coupling of non-rapid eye movement sleep spindles and deep, slow brain waves corresponded to an entirely different function -- that of learning and memory. Indeed, the same team of UC Berkeley researchers previously found that deep-sleep brain waves improved the ability of the hippocampus -- the part of the brain associated with learning -- to retain information.

But this new research builds on a 2021 rodent study and reveals a novel and previously unrecognized role for these combined brain waves in humans when it comes to the critical bodily function of blood sugar management.

The UC Berkeley researchers first examined sleep data in a group of 600 individuals. They found that this particular coupled set of deep-sleep brain waves predicted next-day glucose control, even after controlling for other factors such as age, gender and the duration and quality of sleep.

"This particular coupling of deep-sleep brain waves was more predictive of glucose than an individual's sleep duration or sleep efficiency," said Raphael Vallat, a UC Berkeley postdoctoral fellow and co-author of the study. "That indicates there is something uniquely special about the electrophysiological quality and coordinated ballet of these brain oscillations during deep sleep."

Next, the team then set out to explore the descending pathway that might explain the connection between these deep-sleep brain waves sending a signal down into the body, ultimately predicting the regulation of blood glucose.

The findings from the team reveal an unfolding set of steps that could help explain how and why these deep-sleep brain waves are related to superior blood sugar control. First, they found that stronger and more frequent coupling of the deep-sleep brain waves predicted a switch in the body's nervous system state into the more quiescent and calming branch, called the parasympathetic nervous system. They measured that change in the body and the shift to this low-stress state using heart rate variability as a proxy.

Next, the team turned its attention to the final step of blood sugar balance.

The researchers further discovered that this deep sleep switch to the calming branch of the nervous system further predicted an increased sensitivity of the body to the glucose-regulating hormone called insulin, which instructs cells to absorb glucose from the bloodstream, preventing a deleterious blood sugar spike.

That's particularly important for people trying to back away from hyperglycemia and Type 2 diabetes.

"In the electrical static of sleep at night, there is a series of connected associations, such that deep-sleep brain waves telegraph a recalibration and calming of your nervous system the following day," Walker said. "This rather marvelous associated soothing effect on your nervous system is then associated with a reboot of your body's sensitivity to insulin, resulting in a more effective control of blood sugar the next day."

The researchers subsequently replicated the same effects by examining a separate group of 1,900 participants.

"Once we replicated the findings in a different cohort, I think we actually started to feel more confident in the results ourselves," Walker said. "But I'll wait for others to replicate it before I truly start believing, such is my British skepticism."

The scientists said the research is particularly exciting given the potential clinical significance years down the line. Diabetes treatments already on the market can sometimes be difficult for patients to adhere to. The same is true of the recommended lifestyle changes, including different eating habits and regular exercise.

Sleep, however, is a largely painless experience for most people.

And while sleep is not going to be the single magic bullet, the prospect of new technologies that can safely alter brain waves during deep sleep that this new research has uncovered may help people better manage their blood sugar. That, the research team said, is reason for hope.

https://www.sciencedaily.com/releases/2023/07/230707153826.htm

Creative people enjoy idle time more than others

July 6, 2023

Science Daily/University of Arizona

For those with creative minds, screen-free downtime can be fruitful and entertaining: Creative people use their idle time by letting one idea lead to another.

Creative people are more likely to make the most of their downtime during a typical day by exploring their mind, a new study by University of Arizona researchers suggests.

The study, published in the Creativity Research Journal, finds that creative people are more likely to fruitfully use idle time by letting one idea lead to another. Study participants who were more creative felt less bored when they sat alone in a room, researchers found. And during the COVID-19 pandemic, a time when the world experienced unusually extended periods of unstructured time, creative people were less bored and more engaged with their thoughts.

"I am particularly interested in creativity because we wanted to know what's going on in the mind of creative individuals, especially in situations where nothing constrains their thoughts," said lead study author Quentin Raffaeli, a graduate student in the UArizona Department of Psychology.

In psychology and neuroscience, most studies on human thoughts either prompt participants to think in a certain way or ask them to report on thoughts they experienced, but less is known about how thoughts naturally arise and unfold over time in unprompted contexts, said Jessica Andrews-Hanna, an associate professor in the Department of Psychology and senior author of the paper.

"This is where our study comes in," Andrews-Hanna said.

History is filled with anecdotes of famous scientists, artists and philosophers who enjoyed being alone with their thoughts, and those people often generated some of their best ideas during idle time, Andrews-Hanna said.

"In today's busy and digitally connected society, time to be alone with one's thoughts without distraction may be becoming a rare commodity," she added.

The researchers divided the study into two parts. For the first experiment, the researchers asked each participant to sit alone in a room for 10 minutes without any access to digital devices. In the absence of any particular prompt, the participants were asked to voice their thoughts aloud in real time. The recorded files from 81 participants were then transcribed and analyzed.

The researchers assessed the participants' creativity through a "divergent thinking test," a lab-based verbal test that measures a person's ability to think outside of the box. Participants who performed well in the divergent thinking test had thoughts that flowed freely and were associated with one another, often indicated by phrases such as "this reminds me of" or "speaking of which."

"While many participants had a tendency to jump between seemingly unrelated thoughts, creative individuals showed signs of thinking more associatively," Raffaeli said.

The first experiment also found that creative people were more engaged in their thoughts when they were left alone without distractions, such as cell phone and internet.

"Creative people rated themselves as being less bored, even over those 10 minutes. They also spoke more words overall, which indicated that their thoughts were more likely to move freely," Andrews-Hanna said.

To complement their initial findings, the researchers extended their study in the context of a much larger span of time -- the COVID-19 pandemic -when many people were alone with their thoughts more often.

For the second experiment, over 2,600 adults answered questions through a smartphone app called Mind Window, developed by Andrews-Hanna and her graduate student Eric Andrews. Participants who self-identified as being creative reported being less bored during the pandemic.

"As we become more overworked, overscheduled and addicted to our digital devices, I think we need to do a better job in our homes, our workplaces and our schools to cultivate time to simply relax with our thoughts," Andrews-Hanna said.

The researchers are continuing this line of work using their Mind Window app. They encourage people to download and use the app to help scientists understand how people across the world think in their everyday lives.

"Understanding why different people think the way they do may lead to promising interventions to improve health and well-being," Andrews-Hanna said.

https://www.sciencedaily.com/releases/2023/07/230706124528.htm

Lack of sleep lessens cognitive benefits of physical activity

July 5, 2023

Science Daily/University College London

A new study looked at cognitive function over 10 years in 8,958 people aged 50 and over in England. The research team investigated how different combinations of sleep and physical activity habits might affect people's cognitive function over time.

Regular physical activity may protect against cognitive decline as we get older, but this protective effect may be diminished for people who are not getting enough sleep, according to a new study by UCL researchers.

The study, published in The Lancet Healthy Longevity, looked at cognitive function over 10 years in 8,958 people aged 50 and over in England. The research team investigated how different combinations of sleep and physical activity habits might affect people's cognitive function over time.

They found that people who were more physically active but had short sleeps -- less than six hours on average -- had faster cognitive decline overall, meaning that after 10 years their cognitive function was equivalent to peers who did less physical activity.

Lead author Dr Mikaela Bloomberg (UCL Institute of Epidemiology & Health Care) said: "Our study suggests that getting sufficient sleep may be required for us to get the full cognitive benefits of physical activity. It shows how important it is to consider sleep and physical activity together when thinking about cognitive health.

"Previous studies examining how sleep and physical activity might combine to affect cognitive function have primarily been cross-sectional -- only focusing on a snapshot in time -- and we were surprised that regular physical activity may not always be sufficient to counter the long-term effects of lack of sleep on cognitive health."

The study found, in line with previous research, that sleeping between six and eight hours per night and higher levels of physical activity were linked to better cognitive function.

Those who were more physically active also had better cognitive function regardless of how long they slept at the start of the study. This changed over the 10-year period, with more physically active short sleepers (less than six hours) experiencing more rapid cognitive decline.

This rapid decline was true for those in their 50s and 60s in this group, but for older participants (aged 70 and over) the cognitive benefits of exercise appeared to be maintained, despite short sleep.

Co-author Professor Andrew Steptoe (UCL Institute of Epidemiology & Health Care) said: "It is important to identify the factors that can protect cognitive function in middle and later life as they can serve to prolong our cognitively healthy years and, for some people, delay a dementia diagnosis.

"The World Health Organisation already identifies physical activity as a way to maintain cognitive function, but interventions should also consider sleep habits to maximise long-term benefits for cognitive health."

For the study, the researchers used data from the English Longitudinal Study of Ageing (ELSA), a nationally representative cohort study of the English population. Participants were asked how long they slept on an average weeknight and were split into three sleep groups: short (less than six hours), optimal (six to eight hours) and long (greater than eight hours).

They were also given a score based on the frequency and intensity of self-reported physical activity and divided into two groups: more physically active (the top third of scorers) and less physically active (the other two thirds). Cognitive function was assessed on the basis of an episodic memory test (asking participants to recall a 10-word list, both immediately and after a delay) and a verbal fluency test (asking participants to name as many animals as they can in a minute).

The researchers adjusted for a number of confounding factors, such as participants having done the same cognitive test before and therefore being likely to perform better. They also excluded people with self-reported dementia diagnoses and those whose test scores indicated some cognitive impairment, so that behaviour changes linked to preclinical Alzheimer's disease (such as sleep disturbance) did not inadvertently affect the results.

In terms of study limitations, the researchers relied on participants self-reporting their sleep duration and physical activity. The next steps, the researchers said, may be to repeat the results in more diverse study populations, examine more cognitive domains and more domains of sleep quality, and use objective measures such as a wearable physical activity tracker.

The research was funded by the UK's Economic and Social Research Council.

https://www.sciencedaily.com/releases/2023/07/230705194620.htm

Taking good care of your teeth may be good for your brain

Poor dental health linked to decline in brain volume

July 5, 2023

Science Daily/American Academy of Neurology

Taking good care of your teeth may be linked to better brain health, according to a study published in the July 5, 2023, online issue of Neurology®, the medical journal of the American Academy of Neurology. The study found that gum disease and tooth loss were linked to brain shrinkage in the hippocampus, which plays a role in memory and Alzheimer's disease. The study does not prove that gum disease or tooth loss causes Alzheimer's disease; it only shows an association.

"Tooth loss and gum disease, which is inflammation of the tissue around the teeth that can cause shrinkage of the gums and loosening of the teeth, are very common, so evaluating a potential link with dementia is incredibly important," said study author Satoshi Yamaguchi, PhD, DDS, of Tohoku University in Sendai, Japan. "Our study found that these conditions may play a role in the health of the brain area that controls thinking and memory, giving people another reason to take better care of their teeth."

The study involved 172 people with an average age of 67 who did not have memory problems at the beginning of the study.

Participants had dental exams and took memory tests at the beginning of the study. They also had brain scans to measure volume of the hippocampus at the beginning of the study and again four years later.

For each participant, researchers counted the number of teeth and checked for gum disease by looking at periodontal probing depth, a measurement of the gum tissue. Healthy readings are from one to three millimeters.

Mild gum disease involves probing depths of three or four millimeters in several areas, while severe gum disease involves probing depths of five or six millimeters in several areas as well as more bone loss and can cause teeth to become loose and eventually fall out.

Researchers found that the number of teeth and amount of gum disease was linked to changes in the left hippocampus of the brain.

For people with mild gum disease having fewer teeth was associated with a faster rate of brain shrinkage in the left hippocampus.

However, for people with severe gum disease having more teeth was associated with a faster rate of brain shrinkage in the same area of the brain.

After adjusting for age, researchers found that for people with mild gum disease, the increase in the rate of brain shrinkage due to one less tooth was equivalent to nearly one year of brain aging. Conversely, for people with severe gum disease the increase in brain shrinkage due to one more tooth was equivalent to 1.3 years of brain aging.

"These results highlight the importance of preserving the health of the teeth and not just retaining the teeth," Yamaguchi said. "The findings suggest that retaining teeth with severe gum disease is associated with brain atrophy. Controlling the progression of gum disease through regular dental visits is crucial, and teeth with severe gum disease may need to be extracted and replaced with appropriate prosthetic devices."

Yamaguchi said future studies are needed with larger groups of people. Another limitation of the study is that it was conducted in one region of Japan, so the results may not be generalizable to other locations.

https://www.sciencedaily.com/releases/2023/07/230705171101.htm

Taking higher-than-recommended doses of vitamin D for five years reduced the risk of atrial fibrillation

June 27, 2023

Science Daily/University of Eastern Finland

Taking higher-than-recommended doses of vitamin D for five years reduced the risk of atrial fibrillation in older men and women, according to a new study from the University of Eastern Finland.

Atrial fibrillation is the most common arrhythmia, the risk of which increases with age, and which is associated with an increased risk of stroke, heart failure and mortality. Vitamin D has been shown to have an effect, for example, on the atrial structure and the electrical function of the heart, suggesting that vitamin D might prevent atrial fibrillation.

Conducted at the University of Eastern Finland in 2012-2018, the main objective of the Finnish Vitamin D Trial, FIND, was to explore the associations of vitamin D supplementation with the incidence of cardiovascular diseases and cancers. The five-year study involved 2,495 participants, 60-year-old or older men and 65-year-old or older women, who were randomised into three groups: one placebo group and two vitamin D3 supplementation groups, with one of the groups taking a supplement of 40 micrograms (1600 IU) per day, and the other a supplement of 80 micrograms (3200 IU) per day. All participants were also allowed to take their personal vitamin D supplement, up to 20 micrograms (800 IU) per day, which at the beginning of the study was the recommended dose for this age group. At baseline, study participants had not been diagnosed with cardiovascular disease or cancer, and they completed comprehensive questionnaires, both at the beginning and throughout the study, on their lifestyles and nutrition, as well as on risk factors of diseases and disease occurrence. Data on the occurrence of diseases and deaths were also obtained from Finnish nationwide health registers. Approximately 20 % of participants were randomly selected for more detailed examinations and blood samples.

During the five-year study, 190 participants were diagnosed with atrial fibrillation: 76 in the placebo group, 59 in the 40 micrograms group, and 55 in the 80 micrograms group. The risk of atrial fibrillation was 27% lower in the 40 micrograms group, and 32% lower in the 80 micrograms group, when compared to the placebo group. In the sub-cohort selected for more detailed examinations, the mean baseline serum calcidiol concentration, which is a marker of the body's vitamin D concentration, was relatively high, 75 nmol/l. After one year, the mean calcidiol concentration was 100 nmol/l in the 40 micrograms group, and 120 nmol/l in the 80 micrograms group. No significant change in the calcidiol concentration was observed in the placebo group.

FIND is the first randomized controlled trial to observe that vitamin D supplementation reduces the risk of atrial fibrillation in generally healthy men and women. Previous research is limited to only two randomized trials, which did not observe an effect when using doses of 10 micrograms (400 IU) or 50 micrograms (2000 IU) per day. Further confirmation of the present results from the FIND study is therefore needed before doses of vitamin D that significantly exceed current recommendations can be recommended for preventing atrial fibrillation. The FIND study has previously published findings showing no association with the incidence of other cardiovascular events or cancers.

https://www.sciencedaily.com/releases/2023/06/230627225210.htm

Fighting loneliness by finding purpose

June 26, 2023

Science Daily/Washington University in St. Louis

A sense of purpose in life -- whether it's a high-minded quest to make a difference or a simple hobby with personal meaning -- can offer potent protection against loneliness, according to new research.

A new study co-authored by Patrick Hill, associate professor of psychological and brain sciences, offers an important message for our times: A sense of purpose in life -- whether it's a high-minded quest to make a difference or a simple hobby with personal meaning -- can offer potent protection against loneliness.

"Loneliness is known to be one of the biggest psychological predictors for health problems, cognitive decline, and early mortality," Hill said. "Studies show that it can be as harmful for health as smoking or having a poor diet."

The new study, based on surveys of more than 2,300 adults in Switzerland, found that feelings of loneliness were less common in people who reported a purposeful life, regardless of their age. It was co-authored by Mathias Allemand of the University of Zurich in Switzerland and Gabriel Olaru of Tilburg University in the Netherlands.

Respondents were asked to score their feelings on a lack of companionship, isolation from other people, and a sense of being "left out or passed over" during a four-week period. Participants also filled out the six-item Life Engagement Test, which asked them to rate statements such as "there is not enough purpose in my life" and "I value my activities a lot."

"A sense of purpose is this general perception that you have something leading and directing you from one day to the next," Hill said. "It can be something like gardening, supporting your family, or achieving success at work."

Many of the activities that can provide a sense of purpose -- joining a club, volunteering at a school, playing in a sports league -- involve interaction with others, which is one reason why a purpose-filled life tends to be less lonely. In the study, people who said they received or provided social support were especially likely to report feelings of purpose.

But Hill noted that there's more to fighting loneliness than simply being around others. "We've all had time in our lives when we've felt lonely even though we weren't actually alone." There's something about having a sense of purpose that seems to fight loneliness regardless of how many other people are involved, he said.

The study found a slight uptick in reports of loneliness for people in their 70s and beyond, an age when a sense of purpose can be especially important. "We're trying to dispel the myth from previous generations that this is simply a time for retiring and resting," Hill said. "There are no downsides to finding something meaningful later in life."

Still, it's important to keep in mind that a quest for purpose can be somewhat self-defeating if taken too seriously. "Feeling like you need to save the world can lead to existential dread and distress," Hill said. When it comes to purpose and meaning, even small things can matter. "It's OK if someone else thinks that your purpose is trivial, as long as it's meaningful to you."

https://www.sciencedaily.com/releases/2023/06/230626164203.htm

Unraveling the connections between the brain and gut

MIT engineers' new technology can probe the neural circuits that influence hunger, mood, and a variety of diseases

June 22, 2023

Science Daily/Massachusetts Institute of Technology

Engineers designed a technology to probe connections between the brain and the digestive tract. Using fibers embedded with a variety of sensors, as well as optogenetic stimulation, the researchers could control neural circuits connecting the gut and the brain, in mice.

The brain and the digestive tract are in constant communication, relaying signals that help to control feeding and other behaviors. This extensive communication network also influences our mental state and has been implicated in many neurological disorders.

MIT engineers have now designed a new technology that can be used to probe those connections. Using fibers embedded with a variety of sensors, as well as light sources for optogenetic stimulation, the researchers have shown that they can control neural circuits connecting the gut and the brain, in mice.

In a new study, the researchers demonstrated that they could induce feelings of fullness or reward-seeking behavior in mice by manipulating cells of the intestine. In future work, they hope to explore some of the correlations that have been observed between digestive health and neurological conditions such as autism and Parkinson's disease.

"The exciting thing here is that we now have technology that can drive gut function and behaviors such as feeding. More importantly, we have the ability to start accessing the crosstalk between the gut and the brain with the millisecond precision of optogenetics, and we can do it in behaving animals," says Polina Anikeeva, the Matoula S. Salapatas Professor in Materials Science and Engineering, a professor of brain and cognitive sciences, associate director of MIT's Research Laboratory of Electronics, and a member of MIT's McGovern Institute for Brain Research.

Anikeeva is the senior author of the new study, which appears today in Nature Biotechnology. The paper's lead authors are MIT graduate student Atharva Sahasrabudhe, Duke University postdoc Laura Rupprecht, MIT postdoc Sirma Orguc, and former MIT postdoc Tural Khudiyev.

The brain-body connection

Last year, the McGovern Institute launched the K. Lisa Yang Brain-Body Center to study the interplay between the brain and other organs of the body. Research at the center focuses on illuminating how these interactions help to shape behavior and overall health, with a goal of developing future therapies for a variety of diseases.

"There's continuous, bidirectional crosstalk between the body and the brain," Anikeeva says. "For a long time, we thought that the brain is a tyrant that sends output into the organs and controls everything. But now we know that there's a lot of feedback back into the brain, and this feedback potentially controls some of the functions that we have previously attributed exclusively to the central neural control."

Anikeeva, who directs the new center, was interested in probing the signals that pass between the brain and the nervous system of the gut, also called the enteric nervous system. Sensory cells in the gut influence hunger and satiety via both the neuronal communication and hormone release.

Untangling those hormonal and neural effects has been difficult because there hasn't been a good way to rapidly measure the neuronal signals, which occur within milliseconds.

"To be able to perform gut optogenetics and then measure the effects on brain function and behavior, which requires millisecond precision, we needed a device that didn't exist. So, we decided to make it," says Sahasrabudhe, who led the development of the gut and brain probes.

The electronic interface that the researchers designed consists of flexible fibers that can carry out a variety of functions and can be inserted into the organs of interest. To create the fibers, Sahasrabudhe used a technique called thermal drawing, which allowed him to create polymer filaments, about as thin as a human hair, that can be embedded with electrodes and temperature sensors.

The filaments also carry microscale light-emitting devices that can be used to optogenetically stimulate cells, and microfluidic channels that can be used to deliver drugs.

The mechanical properties of the fibers can be tailored for use in different parts of the body. For the brain, the researchers created stiffer fibers that could be threaded deep into the brain. For digestive organs such as the intestine, they designed more delicate rubbery fibers that do not damage the lining of the organs but are still sturdy enough to withstand the harsh environment of the digestive tract.

"To study the interaction between the brain and the body, it is necessary to develop technologies that can interface with organs of interest as well as the brain at the same time, while recording physiological signals with high signal-to-noise ratio," Sahasrabudhe says. "We also need to be able to selectively stimulate different cell types in both organs in mice so that we can test their behaviors and perform causal analyses of these circuits."

The fibers are also designed so that they can be controlled wirelessly, using an external control circuit that can be temporarily affixed to the animal during an experiment. This wireless control circuit was developed by Orguc, a Schmidt Science Fellow, and Harrison Allen '20, MEng '22, who were co-advised between the Anikeeva lab and the lab of Anantha Chandrakasan, dean of MIT's School of Engineering and the Vannevar Bush Professor of Electrical Engineering and Computer Science.

Driving behavior

Using this interface, the researchers performed a series of experiments to show that they could influence behavior through manipulation of the gut as well as the brain.

First, they used the fibers to deliver optogenetic stimulation to a part of the brain called the ventral tegmental area (VTA), which releases dopamine. They placed mice in a cage with three chambers, and when the mice entered one particular chamber, the researchers activated the dopamine neurons. The resulting dopamine burst made the mice more likely to return to that chamber in search of the dopamine reward.

Then, the researchers tried to see if they could also induce that reward-seeking behavior by influencing the gut. To do that, they used fibers in the gut to release sucrose, which also activated dopamine release in the brain and prompted the animals to seek out the chamber they were in when sucrose was delivered.

Next, working with colleagues from Duke University, the researchers found they could induce the same reward-seeking behavior by skipping the sucrose and optogenetically stimulating nerve endings in the gut that provide input to the vagus nerve, which controls digestion and other bodily functions.

"Again, we got this place preference behavior that people have previously seen with stimulation in the brain, but now we are not touching the brain. We are just stimulating the gut, and we are observing control of central function from the periphery," Anikeeva says.

Sahasrabudhe worked closely with Rupprecht, a postdoc in Professor Diego Bohorquez' group at Duke, to test the fibers' ability to control feeding behaviors. They found that the devices could optogenetically stimulate cells that produce cholecystokinin, a hormone that promotes satiety. When this hormone release was activated, the animals' appetites were suppressed, even though they had been fasting for several hours. The researchers also demonstrated a similar effect when they stimulated cells that produce a peptide called PYY, which normally curbs appetite after very rich foods are consumed.

The researchers now plan to use this interface to study neurological conditions that are believed to have a gut-brain connection. For instance, studies have shown that children with autism are far more likely than their peers to be diagnosed with GI dysfunction, while anxiety and irritable bowel syndrome share genetic risks.

"We can now begin asking, are those coincidences, or is there a connection between the gut and the brain? And maybe there is an opportunity for us to tap into those gut-brain circuits to begin managing some of those conditions by manipulating the peripheral circuits in a way that does not directly 'touch' the brain and is less invasive," Anikeeva says.

https://www.sciencedaily.com/releases/2023/06/230622120236.htm

Everyone's brain has a pain fingerprint -- new research has revealed for the first time

June 20, 2023

Science Daily/University of Essex

 New research has revealed everyone's brain has a 'pain fingerprint' that varies from person to person.

The University of Essex-led study, in collaboration with the neuroscience of pain group at the Ludwig Maximilians University of Munich, found fast-oscillating brain waves linked to brief pain and touch can differ widely in scans.

These waves, called gamma oscillations, were previously thought to represent pain perception in the brain -- with past research focussing on group data and overlooking individual differences, even discarding them as 'noise' in scans.

The Department of Psychology's Dr Elia Valentini found major differences in timing, frequency and location of the gamma oscillations and incredibly some people showed no waves at all.

Dr Valentini said: "Not only, for the first time, can we pinpoint the extreme variability in the gamma response across individuals, but we also show that the individual response pattern is stable across time."

"This pattern of group variability and individual stability may apply to other brain responses, and characterising it may allow us to identify individual pain fingerprints in the activity of the brain."

The study, published in the Journal of Neurophysiology, was able to map patterns in participants from another lab, suggesting a replicable phenomenon.

In total, data from 70 people were examined. The experiments were split into two studies with a laser used to generate pain.

Overall, it was discovered that the subject's gamma waves were "remarkably stable" and created similar individual patterns when stimulated.

Interestingly, some recorded feeling pain and having no gamma response, whilst others had a large response.

At this stage, it is not known why there is such variation -- but it is hoped this will be a springboard for future research.

Dr Valentini added: "I think we need to go back to square one because past findings on the relationship between pain and gamma oscillations do not represent all the participants.

"Unfortunately, this minority can drive the research results and lead to misleading conclusions about the functional significance of these responses.

"We don't mean for gamma oscillations not to have a role in pain perception, but we certainly won't find its true role if we keep quantifying it as we did thus far."

Dr Valentini hopes this study will also change the way gamma oscillations are measured in other sensory domains.

https://www.sciencedaily.com/releases/2023/06/230620113739.htm

Walkable neighborhoods help adults socialize, increase community

June 20, 2023

Science Daily/University of California - San Diego

Adults who live in walkable neighborhoods are more likely to interact with their neighbors and have a stronger sense of community than people who live in car-dependent communities, report researchers at the Herbert Wertheim School of Public Health and Human Longevity Science at University of California San Diego.

The findings of the study, published online in the journal Health & Place, support one of six foundational pillars suggested by United States Surgeon General Vivek Murthy as part of a national strategy to address a public health crisis caused by loneliness, isolation and lack of connection in this country.

In May 2023, the Surgeon General Advisory stated that loneliness and isolation can lead to a 29% increased risk of heart disease, a 32% increased risk of stroke, a 50% increased risk of developing dementia among older adults, and increases risk of premature death by more than 60%.

To address this public health crisis, the Surgeon General recommends strengthening social infrastructure by designing environments that promote connection.

"Our built environments create or deny long-lasting opportunities for socialization, physical activity, contact with nature, and other experiences that affect public health," said James F. Sallis, Ph.D., Distinguished Professor at the Herbert Wertheim School of Public Health and senior author of the UC San Diego study.

"Transportation and land use policies across the U.S. have strongly prioritized car travel and suburban development, so millions of Americans live in neighborhoods where they must drive everywhere, usually alone, and have little or no chance to interact with their neighbors."

Walkable neighborhoods promote active behaviors like walking for leisure or transportation to school, work, shopping or home.

The study analyzed data from the Neighborhood Quality of Life Study, which included 1,745 adults ages 20 to 66 living in 32 neighborhoods located in and around Seattle, Baltimore and Washington, D.C.

Neighborhood walkability may promote social interactions with neighbors -- like waving hello, asking for help or socializing in their homes, said the first author, Jacob R. Carson, M.P.H., a student in the UC San Diego -- San Diego State University Joint Doctoral Program in Public Health. Carson began the research while a Master of Public Health student at the Herbert Wertheim School of Public Health.

Neighborhoods where people must drive in and out, and where there is an absence of gathering places, may have the opposite effect, preventing neighbors from socializing.

"Promoting social interaction is an important public health goal. Understanding the role of neighborhood design bolsters our ability to advocate for the health of our communities and the individuals who reside in them," said Carson.

"Fewer traffic incidents, increases in physical activity, and better neighborhood social health outcomes are just a few of the results of designing walkable neighborhoods that can enrich our lives."

https://www.sciencedaily.com/releases/2023/06/230620113745.htm

New research reveals the impact of different species and their traits on human wellbeing

June 20, 2023

Science Daily/University of Kent

New research has revealed for the first time that well-functioning ecosystems are crucial to human health and wellbeing, with human-biodiversity interactions delivering wellbeing gains equating to substantial healthcare cost-savings, when scaled-up across populations.

The University of Kent-led study, which is part of the European Research Council-funded project 'Relating Subjective Wellbeing to Biodiversity' (RELATE), set out to understand which components of nature and biodiversity played a particular role in human wellbeing.

The team, which was led by Kent's Professor Zoe Davies, analysed the effects of species' traits, based on people's feedback following a series of workshops, to identify those that generate different types of wellbeing e.g., physical, emotional, cognitive, social, spiritual, and 'global', the latter being akin to 'whole-person health'.

The team found that, in general, the vast majority of species and traits are beneficial to human wellbeing. They also discovered that each species may support multiple traits, potentially with different impacts. For example, the colours of brambles (black, pink, red) are linked to multiple positive physical, emotional and social wellbeing types, but their prickly texture generated negative emotional wellbeing. The numerous traits from across an ecological community can elicit a multitude of wellbeing responses, illustrating the true complexity of how people relate to biodiversity.

Professor Davies, a biodiversity conservationist at Kent's Durrell Institute of Conservation and Ecology (DICE), said: 'While we know that spending time in natural environments can improve our health and wellbeing, we still need to know more about which species, or traits of species (such as colours, sounds, smells, textures and behaviours), deliver these benefits -- and how people's relationships with biodiversity are both contextually and culturally specific. Understanding how people experience biodiversity is therefore key to successfully managing biodiversity to facilitate human wellbeing.'

Study co-author, Professor Martin Dallimer, from the School of Earth and Environment, University of Leeds, said: 'For the first time, through analysing people's own words and reflections, we are able to explicitly link that feeling of wellbeing with species and their traits. How people respond to biodiversity is hugely varied and if we want people's wellbeing to benefit from spending time in nature, then it is essential to make sure we are maintaining and restoring high quality biodiverse spaces for wildlife and for people. Our aim is that these findings really drive home how important biodiversity is in underpinning wellbeing benefits, particularly to healthcare and public sectors who include 'spending time in nature' as an element of mental health and wellbeing.'

Dr Jessica Fisher, also from DICE, added: 'By starting to comprehend how people experience biodiversity, we can begin to manage our natural environments for both biodiversity conservation and human health. Even small improvements in wellbeing at an individual level could scale up to substantial healthcare cost savings across an entire country. Our approach can be used to create better-tailored public health interventions or architectural/landscape designs by, for example, maximising the likelihood of people having interactions with certain species and their traits. Critically, as each additional species in an ecological community supports additional traits, maintaining or enhancing biodiversity will be key to delivering human wellbeing.'

https://www.sciencedaily.com/releases/2023/06/230620113805.htm

Regular napping linked to larger brain volume

Daytime napping may help to preserve brain health by slowing the rate at which our brains shrink as we age

June 20, 2023

Science Daily/University College London

A study analyzed data from people aged 40 to 69 and found a causal link between habitual napping and larger total brain volume -- a marker of good brain health linked to a lower risk of dementia and other diseases.

Daytime napping may help to preserve brain health by slowing the rate at which our brains shrink as we age, suggests a new study led by researchers at UCL and the University of the Republic in Uruguay.

The study, published in the journal Sleep Health, analysed data from people aged 40 to 69 and found a causal link between habitual napping and larger total brain volume -- a marker of good brain health linked to a lower risk of dementia and other diseases.

Senior author Dr Victoria Garfield (MRC Unit for Lifelong Health & Ageing at UCL) said: "Our findings suggest that, for some people, short daytime naps may be a part of the puzzle that could help preserve the health of the brain as we get older."

Previous research has shown that napping has cognitive benefits, with people who have had a short nap performing better in cognitive tests in the hours afterwards than counterparts who did not nap.

The new study aimed to establish if there was a causal relationship between daytime napping and brain health.

Using a technique called Mendelian randomisation, they looked at 97 snippets of DNA thought to determine people's likelihood of habitual napping. They compared measures of brain health and cognition of people who are more genetically "programmed" to nap with counterparts who did not have these genetic variants, using data from 378,932 people from the UK Biobank study, and found that, overall, people predetermined to nap had a larger total brain volume.

The research team estimated that the average difference in brain volume between people programmed to be habitual nappers and those who were not was equivalent to 2.6 to 6.5 years of ageing.

But the researchers did not find a difference in how well those programmed to be habitual nappers performed on three other measures of brain health and cognitive function -- hippocampal volume, reaction time and visual processing.

Lead author and PhD candidate Valentina Paz (University of the Republic (Uruguay) and MRC Unit for Lifelong Health & Ageing at UCL) said: "This is the first study to attempt to untangle the causal relationship between habitual daytime napping and cognitive and structural brain outcomes. By looking at genes set at birth, Mendelian randomisation avoids confounding factors occurring throughout life that may influence associations between napping and health outcomes. Our study points to a causal link between habitual napping and larger total brain volume."

Dr Garfield added: "I hope studies such as this one showing the health benefits of short naps can help to reduce any stigma that still exists around daytime napping."

The genetic variants influencing our likelihood to nap were identified in an earlier study looking at data from 452,633 UK Biobank participants. The study, led by Dr Hassan Dashti (Harvard University and Massachusetts General Hospital), also an author on the new study, identified the variants on the basis of self-reported napping, and this was supported by objective measurements of physical activity recorded by a wrist-worn accelerometer.

In the new study, researchers analysed health and cognition outcomes for people with these genetic variants as well as several different subsets of these variants, adjusted to avoid potential bias, for instance avoiding variants linked to excessive daytime sleepiness.

Genetic data and magnetic resonance imaging (MRI) scans of the brain were available for 35,080 individuals drawn from the larger UK Biobank sample.

In terms of study limitations, the authors noted that all of the participants were of white European ancestry, so the findings might not be immediately generalisable to other ethnicities.

While the researchers did not have information on nap duration, earlier studies suggest that naps of 30 minutes or less provide the best short-term cognitive benefits, and napping earlier in the day is less likely to disrupt night-time sleep.

Previous research looking at the UK and the Netherlands found that nearly a third of adults aged 65 or over had a regular nap.

https://www.sciencedaily.com/releases/2023/06/230620113759.htm

Study finds combustion from gas stoves can raise indoor levels of chemical linked to a higher risk of blood cell cancers

June 16, 2023

Science Daily/Stanford University

About 47 million homes use natural gas or propane-burning cooktops and ovens. Researchers found that cooking with gas stoves can raise indoor levels of the carcinogen benzene above those found in secondhand smoke.

A chemical linked to a higher risk of leukemia and other blood cell cancers creeps into millions of homes whenever residents light their gas stoves. A new Stanford-led analysis finds that a single gas cooktop burner on high or a gas oven set to 350 degrees Fahrenheit can raise indoor levels of the carcinogen benzene above those in secondhand tobacco smoke. Benzene also drifts throughout a home and lingers for hours in home air, according to the paper published June 22 in Environmental Science & Technology.

"Benzene forms in flames and other high-temperature environments, such as the flares found in oil fields and refineries. We now know that benzene also forms in the flames of gas stoves in our homes," said study senior author Rob Jackson, the Michelle and Kevin Douglas Provostial Professor and professor of Earth system science at the Stanford Doerr School of Sustainability. "Good ventilation helps reduce pollutant concentrations, but we found that exhaust fans were often ineffective at eliminating benzene exposure."

Worse than secondhand smoke

Overall, the researchers found that indoor concentrations of benzene formed in the flames of gas stoves can be worse than average concentrations from secondhand smoke, that benzene can migrate into other rooms far from the kitchen, and that concentrations measured in bedrooms can exceed national and international health benchmarks. They also found residential range hoods are not always effective at reducing concentrations of benzene and other pollutants, even when the hoods vent outdoors.

The new paper is the first to analyze benzene emissions when a stove or oven is in use. Previous studies focused on leaks from stoves when they are off, and did not directly measure resulting benzene concentrations. The researchers found gas and propane burners and ovens emitted 10 to 50 times more benzene than electric stoves. Induction cooktops emitted no detectable benzene whatsoever. The rates of benzene emitted during combustion were hundreds of times higher than benzene emission rates identified in other recent studies from unburned gas leaking into homes.

The researchers also tested whether foods being cooked emit benzene and found zero benzene emissions from pan-frying salmon or bacon. All benzene emissions the investigators measured came from the fuel used rather than any food cooked.

A previous Stanford-led study showed that gas-burning stoves inside U.S. homes leak methane with a climate impact comparable to the carbon dioxide emissions from about 500,000 gasoline-powered cars. They also expose users to pollutants, such as nitrogen dioxide, which can trigger respiratory diseases. A 2013 meta-analysis concluded that children who live in homes with gas stoves had a 42% greater risk of asthma than children living in homes without gas stoves, and a 2022 analysis calculated that 12.7% of childhood asthma in the U.S. is attributable to gas stoves.

"I'm renting an apartment that happens to have an electric stove," said study lead Yannai Kashtan, a graduate student in Earth system science. "Before starting this research, I never thought about it twice, but the more we learn about pollution from gas stoves, the more relieved I am to be living without a gas stove."

Jackson is also a senior fellow at the Stanford Woods Institute for the Environment and the Precourt Institute for Energy. Study co-authors also include Metta Nicholson and Colin Finnegan, environmental science research professionals in Stanford's Earth System Science Department; Zutao Ouyang, a physical science research associate in Stanford's Earth System Science Department; and researchers at PSE Healthy Energy, the University of California, Berkeley, and Lawrence Berkeley National Lab.

The study was funded by the High Tide Foundation.

How to reduce exposure to pollutants from gas stoves

Beyond ensuring proper ventilation with a range hood or open window, relatively low-cost approaches to reducing exposure to pollutants from gas stoves include:

• Use portable induction cooktops, which can be found for less than $50 new.

• Use electric kitchenware, such as tea kettles, toaster ovens, and slow cookers.

• Where available, take advantage of state and local rebates as well as low- or no-interest loans (such as these programs for California and the San Francisco Bay Area) to offset the cost of replacing gas appliances.

• Federal tax credits are available now, and federal rebates should be available later this year or sometime in 2024 to help offset the cost of replacing gas appliances.

https://www.sciencedaily.com/releases/2023/06/230616161910.htm

Cutting back on social media reduces anxiety, depression, loneliness

June 14, 2023

Science Daily/Iowa State University

Researchers found college students who tried to cut their social media use to 30 minutes per day scored significantly lower for anxiety, depression, loneliness and fear of missing out at the end of the two-week experiment and when compared to the control group.

Last month, the American Psychological Association and the U.S. Surgeon General both issued health advisories. Their concerns and recommendations for teens, parents and policymakers addressed a mounting body of research that shows two trends are intertwined.

Young people are using social media more, and their mental health is suffering.

Researchers at Iowa State University found a simple intervention could help. During a two-week experiment with 230 college students, half were asked to limit their social media usage to 30 minutes a day and received automated, daily reminders. They scored significantly lower for anxiety, depression, loneliness and fear of missing out at the end of the experiment compared to the control group.

They also scored higher for "positive affect," which the researchers describe as "the tendency to experience positive emotions described with words such as 'excited' and 'proud.'" Essentially, they had a brighter outlook on life.

"It surprised me to find that participants' well-being did not only improve in one dimension but in all of them. I was excited to learn that such a simple intervention of sending a daily reminder can motivate people to change their behavior and improve their social media habits." says Ella Faulhaber, a Ph.D. student in human-computer interaction and lead author of the paper.

The researchers found the psychological benefits from cutting back on social media extended to participants who sometimes exceeded the 30-minute time limit.

"The lesson here is, it's not about being perfect but putting in effort, which makes a difference. I think self-limiting and paying attention are the secret ingredients, more so than the 30-minute benchmark," Faulhaber states.

Douglas A. Gentile, co-author and distinguished professor of psychology, says their results fit with other research that's grown out of kinesiology and health fields.

"Knowing how much time we spend on activities each day and making something countable makes it easier for people to change their behaviors," he says, giving Fitbits and daily steps as an example.

Many of the participants in the ISU study commented that the first few days of cutting back were challenging. But after the initial push, one said they felt more productive and in tune with their lives. Others shared that they were getting better sleep or spending more time with people in person.

Self-limiting may be more practical

Gentile and Faulhaber point out other studies have investigated the effects of limiting or abstaining from social media. But many of the interventions require heavy supervision and deleting apps or using a special application to block or limit social media. Like rehab for someone who's addicted to drugs, external accountability can help some users. But it also carries a higher risk of backfiring.

"When a perceived freedom is taken away, we start resisting," says Gentile. He adds that eliminating social media also means losing some of the benefits it can bring, like connecting with friends and family.

Faulhaber says their study extends the current research on social media and provides a practical way for people to limit their use. For anyone looking to cut back, she recommends:

1. Create awareness. Set a timer or use a built-in wellness app to see how much time you spend on social media.

2. Give yourself grace. Recognize that it's not easy to stick to a time limit. Social media apps are designed to keep you engaged.

3. Don't give up. Limiting social media use over time has real benefits for your daily life.

The researchers say it's also important to be mindful of how and when we use these platforms. Future research could further explore this, along with the long-term effects from limiting social media and what people do with the time they gain.

"We live in an age of anxiety. Lots of indicators show that anxiety, depression, loneliness are all getting worse, and that can make us feel helpless. But there are things we can do to manage our mental health and well-being," says Gentile.

Paying more attention to how much time we spend on social media and setting measurable goals can help.

https://www.sciencedaily.com/releases/2023/06/230614220707.htm

Reduced Stress-Related Neural Network Activity Mediates the Effect of Alcohol on Cardiovascular Risk

The findings could help in identifying new interventions that reduce the brain's stress activity without the negative health effects of alcohol

June 12, 2023

Science Daily/Massachusetts General Hospital

A new study led by investigators from Massachusetts General Hospital, a founding member of the Mass General Brigham healthcare system, offers an explanation for why light-to-moderate alcohol consumption may be associated with lower risk of heart disease. For the first time, researchers found that alcohol, in light to moderate quantities, was associated with long-term reductions in stress signaling in the brain. This impact on the brain's stress systems appeared to significantly account for the reductions in cardiovascular events seen in light to moderate drinkers participating in the study. Findings are published in the Journal of the American College of Cardiology.

"We are not advocating the use of alcohol to reduce the risk of heart attacks or strokes because of other concerning effects of alcohol on health," says senior author and cardiologist Ahmed Tawakol, MD, co-director of the Cardiovascular Imaging Research Center at Massachusetts General Hospital. "We wanted to understand how light to moderate drinking reduces cardiovascular disease, as demonstrated by multiple other studies. And if we could find the mechanism, the goal would be to find other approaches that could replicate or induce alcohol's protective cardiac effects without the adverse impacts of alcohol."

Previous epidemiological studies have suggested that light to moderate alcohol consumption (1 drink per day for women and 1 to 2 drinks per day for men) is associated with a lower risk of cardiovascular disease. But it was unknown whether alcohol was inducing cardiovascular benefits, or whether light/moderate drinkers' health behaviors, socioeconomic status, or other factors protected their hearts.

The study, led by K Mezue and M Osborne, included more than 50,000 individuals enrolled in the Mass General Brigham Biobank. The first part of the study evaluated the relationship between light/moderate alcohol consumption and major adverse cardiovascular events after adjusting for a range of genetic, clinical, lifestyle, and socioeconomic confounders. The researchers found that light/moderate alcohol consumption was associated with a substantial reduction in the risk of cardiovascular disease events, even after accounting for those other factors.

Next, they studied a subset of 754 individuals who had undergone previous PET/CT brain imaging (primarily for cancer surveillance) to determine the effect of light/moderate alcohol consumption on resting stress-related neural network activity.

The brain imaging showed reduced stress signaling in the amygdala, the brain region associated with stress responses, in individuals who were light to moderate drinkers compared to those who abstained from alcohol or who drank little. And when the investigators looked at these individuals' history of cardiovascular events, they found fewer heart attacks and strokes in light to moderate drinkers. "We found that the brain changes in light to moderate drinkers explained a significant portion of the protective cardiac effects," says Tawakol.

It's long been known that alcohol reduces the amygdala's reactivity to threatening stimuli while individuals are drinking. The current study is the first to indicate that light to moderate alcohol consumption has longer-term neurobiological effects in dampening activity in the amygdala, which may have a significant downstream impact on the cardiovascular system.

"When the amygdala is too alert and vigilant, the sympathetic nervous system is heightened, which drives up blood pressure and increases heart rate, and triggers the release of inflammatory cells," explains Tawakol. "If the stress is chronic, the result is hypertension, increased inflammation, and a substantial risk of obesity, diabetes, and cardiovascular disease."

Finally, the investigators examined whether light/moderate alcohol would be even more effective at reducing heart attacks and strokes in people who are prone to a chronically higher stress response, such as those with a history of significant anxiety. They found that, within the 50,000-patient sample, light to moderate drinking was associated with nearly double the cardiac-protective effect in individuals with a history of anxiety compared with others.

Yet while light/moderate drinkers lowered their risk for cardiovascular disease, the study also showed that any amount of alcohol increases the risk of cancer. And at higher amounts of alcohol consumption -- more than 14 drinks a week -- heart attack risk started to increase while overall brain activity started to decrease (which may be associated with adverse cognitive health).

The authors concluded that research should focus on finding new interventions that reduce the brain's stress activity without the deleterious effects of alcohol. The research team is currently studying the effect of exercise, stress-reduction interventions such as meditation, and pharmacological therapies on stress-associated neural networks and how they might induce cardiovascular benefits.

Co-authors include Kenechukwu Mezue and Michael T. Osborne.

This study was supported by the National Institutes of Health.

https://www.sciencedaily.com/releases/2023/06/230612200347.htm

New research identifies cells linking chronic psychological stress to inflammatory bowel disease

June 8, 2023

Science Daily/University of Pennsylvania School of Medicine

For the first time, cells involved with the communication between stress responses in the brain and inflammation in the gastrointestinal (GI) tract have been identified in animal models, according to findings from the Perelman School of Medicine at the University of Pennsylvania, published recently in Cell. Glial cells, which support neurons, communicate stress signals from the central nervous system (CNS) to the semi-autonomous nervous system within the gastrointestinal (GI) tract, called the enteric nervous system (ENS). These psychological stress signals can cause inflammation and exacerbate symptoms of inflammatory bowel disease (IBD).

An estimated 1.6 million Americans currently have IBD, which refers to two conditions -- Crohn's disease and ulcerative colitis -- characterized by inflammation of the GI tract, and can cause symptoms like persistent diarrhea, abdominal pain, and bloody stools. Prolonged inflammation can also lead to permanent damage to the GI tract. Current treatments consist of anti-inflammatory drugs, immune suppressants, dietary changes, and steroids.

"Clinicians have long observed that chronic stress can worsen IBD symptoms, but until now, no biological connection has been identified to explain how the digestive system knows when someone is stressed," said senior author Christoph Thaiss, PhD, an assistant professor of Microbiology.

In the study, researchers found that, like humans, mice with IBD developed severe symptoms when stressed. They traced the initial stress response signals to the adrenal cortex, which releases glucocorticoids -- steroid hormones that activate the physiological responses to stress throughout the body. The researchers found that neurons and glia in the ENS responded to chronically elevated glucocorticoid levels, suggesting that they are the link between stress perception by the brain and intestinal inflammation.

While glucocorticoids typically have an anti-inflammatory effect in the body, the researchers found that when glia in the ENS were exposed to the steroid hormones for a prolonged period, such as during chronic stress, they attract white blood cells to the GI tract that increase inflammation. The researchers also found that when exposed to chronic stress, the neurons in the ENS in the GI tract stop functioning as they normally do, which can lead to impaired bowel movements and exacerbated IBD symptoms.

Thaiss and collaborators verified the connection between psychological stress and IBD symptoms in humans using the UK Biobank and a patient cohort from the IBD Immunology Initiative at Penn Medicine. They found that the in patients with an IBD diagnosis, the level of reported stress correlated with an increased severity of IBD symptoms.

"This finding highlights the importance of psychological evaluations in patients being treated for IBD, as well as to inform treatment protocols," said Maayan Levy, PhD, an assistant professor of Microbiology and co-senior author of the study. "One of the most common treatments for IBD flare-ups is steroids, and our research indicates that in patients with IBD who experience chronic stress, the efficiency of this treatment could be impaired."

Researchers underscore the opportunity for more research into the biology of enteric glial cells, and the role they play in many regulatory systems within the body, including the communication between the nervous system and the immune system.

https://www.sciencedaily.com/releases/2023/06/230608195659.htm

Life before air conditioning: Curly hair kept early humans cool

Tightly curled scalp hair protected early humans from the sun's radiative heat, allowing their brains to grow to sizes comparable to those of modern humans.

June 7, 2023

Science Daily/Penn State

Curly hair does more than simply look good -- it may explain how early humans stayed cool while conserving water, according to researchers who studied the role human hair textures play in regulating body temperature. The findings can shed light on an evolutionary adaptation that enabled the human brain to grow to modern-day sizes.

"Humans evolved in equatorial Africa, where the sun is overhead for much of the day, year in and year out," said Nina Jablonski, Evan Pugh University Professor of Anthropology at Penn State. "Here the scalp and top of the head receive far more constant levels of intense solar radiation as heat. We wanted to understand how that affected the evolution of our hair. We found that tightly curled hair allowed humans to stay cool and actually conserve water."

The researchers used a thermal manikin -- a human-shaped model that uses electric power to simulate body heat and allows scientists to study heat transfer between human skin and the environment -- and human-hair wigs to examine how diverse hair textures affect heat gain from solar radiation. The scientists programmed the manikin to maintain a constant surface temperature of 95 degrees Fahrenheit (35 degrees Celsius), similar to the average surface temperature of skin, and set it in a climate-controlled wind tunnel.

The team took base measurements of body heat loss by monitoring the amount of electricity required by the manikin to maintain a constant temperature. Then they shined lamps on the manikin's head to mimic solar radiation under four scalp hair conditions -- none, straight, moderately curled and tightly curled.

The scientists calculated the difference in total heat loss between the lamp measurements and the base measurements to determine the influx of solar radiation to the head, explained George Havenith, director of the Environmental Ergonomics Research Centre at Loughborough University, U.K., who led the manikin experiments. They also calculated heat loss at different windspeeds and after wetting the scalp to simulate sweating. They ran their results through a model to study how the diverse hair textures would affect heat gain in 86-degree Fahrenheit (30 degrees Celsius) heat and 60% relative humidity, like environments in equatorial Africa.

The researchers found that all hair reduced solar radiation to the scalp, but tightly curled hair provided the best protection from the sun's radiative heat while minimizing the need to sweat to stay cool. They reported their findings yesterday (June 6) in the Proceedings of the National Academy of Sciences.

"Walking upright is the setup and brain growth is the payoff of scalp hair," said Tina Lasisi, who conducted the study as part of her doctoral dissertation at Penn State. Lasisi will start as an assistant professor of anthropology at the University of Michigan in the fall.

As early humans evolved to walk upright in equatorial Africa, the tops of their heads increasingly took the brunt of solar radiation, explained Lasisi. The brain is sensitive to heat, and it generates heat, especially the larger it grows. Too much heat can lead to dangerous conditions like heat stroke. As humans lost much of their body hair, they developed efficient sweat glands to keep cool, but sweating comes at a cost in lost water and electrolytes. Scalp hair likely evolved as a way to reduce the amount of heat gain from solar radiation, thereby keeping humans cool without the body having to expend extra resources, said Lasisi.

"Around 2 million years ago we see Homo erectus, which had the same physical build as us but a smaller brain size," she said. "And by 1 million years ago, we're basically at modern-day brain sizes, give or take. Something released a physical constraint that allowed our brains to grow. We think scalp hair provided a passive mechanism to reduce the amount of heat gained from solar radiation that our sweat glands couldn't."

The multidisciplinary research provides important preliminary results for bettering our understanding of how human hair evolved without putting humans in potentially dangerous situations, said Jablonski.

The study also shows that evolutionary anthropologists have an extra tool in the thermal manikin -- normally used for testing the functionality of protective clothing -- for quantifying human data that is otherwise very difficult to capture, added Havenith.

"The work that's been done on skin color and how melanin protects us from solar radiation can shape some of the decisions that a person makes in terms of the amount of sunscreen needed in certain environments," said Lasisi. "I imagine that similar decision making can occur with hair. When you think about the military or different athletes exercising in diverse environments, our findings give you a moment to reflect and think: is this hairstyle going to make me overheat more easily? Is this the way that I should optimally wear my hair?"

https://www.sciencedaily.com/releases/2023/06/230607215834.htm

Junk food may impair our deep sleep

May 30, 2023

Science Daily/Uppsala University

In a new study, researchers at Uppsala University have investigated how junk food affects sleep. Healthy participants consumed an unhealthier as well as a healthier diet in a randomised order. After the unhealthier diet, the quality of the participants' deep sleep had deteriorated, compared with those who had followed the healthier diet. The results have been published in the journal Obesity.

Several epidemiological studies have shown that what we eat is associated with changes in our sleep. However, few studies have investigated how diet itself directly affects sleep. One way to do that is to have the same participant consume different diets in a randomised order.

"Both poor diet and poor sleep increase the risk of several public health conditions. As what we eat is so important for our health, we thought it would be interesting to investigate whether some of the health effects of different diets could involve changes to our sleep. In this context, so-called intervention studies have so far been lacking; studies designed to allow the mechanistic effect of different diets on sleep to be isolated," says Jonathan Cedernaes, Physician and Associate Professor in Medical Cell Biology at Uppsala University.

Previous epidemiological studies have shown that diets with greater sugar content, for example, are linked to poorer sleep. Yet sleep is an interplay of different physiological states, as Cedernaes explains:

"For example, deep sleep can be affected by what we eat. But no study had previously investigated what happens if we consume an unhealthy diet and then compared it to quality of sleep after that same person follows a healthy diet. What is exciting in this context is that sleep is very dynamic. Our sleep consists of different stages with different functions, such as deep sleep which regulates hormonal release, for example. Furthermore, each sleep stage is hallmarked by different types of electrical activity in the brain. This regulates aspects such as how restorative sleep is, and differs across different brain regions. But the depth or integrity of the sleep stages can also be negatively affected by factors such as insomnia and ageing. Previously, it has not been investigated whether similar changes in our sleep stages can occur after exposure to different diets."

Each study session involved several days of monitoring in a sleep laboratory. Therefore, only 15 individuals were included in the study. A total of 15 healthy normal-weight young men participated in two sessions. Participants were first screened for aspects such as their sleep habits, which had to be normal and within the recommended range (an average of seven to nine hours of sleep per night).

In random order, the participants were given both a healthier diet and an unhealthier diet. The two diets contained the same number of calories, adjusted to each individual's daily requirements. Among other things, the unhealthier diet contained a higher content of sugar and saturated fat and more processed food items. The meals of each diet had to be consumed at individually adjusted times, which were matched across the two dietary conditions. Each diet was consumed for a week, while the participants' sleep, activity and meal schedules were monitored at an individual level.

After each diet, the participants were examined in a sleep laboratory. There, they were first allowed to sleep a normal night, while their brain activity was measured to monitor their sleep. The participants were then kept awake in the sleep laboratory, before being allowed to catch up on sleep. Their sleep was recorded in this case, too.

"What we saw was that the participants slept for the same amount of time when they consumed the two diets. This was the case both while they were following the diets, as well as after they had switched to another, identical diet. In addition, across the two diets, the participants spent the same amount of time in the different sleep stages. But we were particularly interested in investigating the properties of their deep sleep. Specifically, we looked at slow-wave activity, a measure that can reflect how restorative deep sleep is. Intriguingly, we saw that deep sleep exhibited less slow-wave activity when the participants had eaten junk food, compared with consumption of healthier food. This effect also lasted into a second night, once we had switched the participants to an identical diet. Essentially, the unhealthy diet resulted in shallower deep sleep. Of note, similar changes in sleep occur with ageing and in conditions such as insomnia. It can be hypothesised, from a sleep perspective, that greater importance should potentially be attached to diet in such conditions," explains Cedernaes.

The researchers do not currently know how long-lasting the sleep effects of the unhealthier diet may be. The study did not investigate whether the shallower deep sleep may alter functions that are regulated by deep sleep, for example.

"It would also be interesting to conduct functional tests, for example to see whether memory function can be affected. This is regulated to a large extent by sleep. And it would be equally interesting to understand how long-lasting the observed effects may be. Currently, we do not know which substances in the unhealthier diet worsened the depth of deep sleep. As in our case, unhealthy diets often contain both higher proportions of saturated fat and sugar and a lower proportion of dietary fibre. It would be interesting to investigate whether there is a particular molecular factor that plays a greater role. Our dietary intervention was also quite short, and both the sugar and fat content could have been higher. It is possible that an even unhealthier diet would have had more pronounced effects on sleep," notes Cedernaes.

https://www.sciencedaily.com/releases/2023/05/230530125400.htm

Keeping time: Understanding the master clock in the brain

Researchers find a molecular pathway that controls sleep rhythms and homeostasis

May 25, 2023

Science Daily/University of Tsukuba

Researchers found that, in neurons that produced the neuropeptide NMS, the interaction between molecules SIK3 and HDAC4 has a critical role in sleep regulation through both the length of the circadian period and sleep homoeostasis. Given the similarities among different mammals, new information about how the circadian system works in mice could lead to new treatments for sleep and circadian rhythm disorders in humans.

Most living creatures exhibit a circadian rhythm, an internal clock that repeats around every 24 hours. Now, researchers from Japan have found new details about the molecular processes that govern sleep/wake rhythms in mice.

In a recently published study, researchers from the University of Tsukuba have revealed that a key molecule involved in sleep homeostasis (called SIK3 or salt-inducible kinase 3) also plays a critical role in circadian behavior.

Animals are able to adapt to the 24-hour cycle of light and dark in terms of both behavior and physiology via changes in the suprachiasmatic nucleus (SCN), which is the brain's master clock that synchronizes the various rhythms in the body. However, the biological activities within the SCN that induce time-specific wakefulness have not been fully characterized; the research team aimed to address this.

"Most animals show a peak in activity at a specific point in the circadian cycle," explains lead author of the study Professor Masashi Yanagisawa. "Because the SCN has been found to regulate sleep and wakefulness at certain times of the day, we wanted to investigate the distinct neurons that control this process."

To do this, the research team genetically manipulated levels of SIK3 in specific neuron groups in the SCN of mice. Then, they examined sleep and circadian behaviors in the mice, such as when and for how long the mice exhibited activity with respect to the light-dark cycle.

"We found that SIK3 in the SCN can influence circadian cycle length and the timing of peak arousal activity, without changing the daily sleep amount," says Professor Yanagisawa.

The research team previously reported that SIK3 interacts with LKB1 (an upstream molecule of SIK3) and HDAC4 (an important target of SIK3) in glutamatergic neurons to regulate the amount and depth of sleep. Now, they have found that the SIK3-HDAC4 pathway modulates the length of the circadian period through NMS-producing neurons, and contributes to the sleep/wake rhythm.

The length of the behavioral period and the timing of peak activity are important components of the circadian rhythm. Given the similarities between the circadian systems of different mammals, new information about how this system works in mice could lead to new treatments for sleep and circadian rhythm disorders in humans.

https://www.sciencedaily.com/releases/2023/05/230525141332.htm