Around the Globe With Self-Care

Posted Posted in Jayne's blog

You’ve heard of armchair travel, right?

Well this is armchair travel with a twist. Cultures from around the world have cultivated well-being in many fascinating ways—and science agrees that they’re effective! Better yet? They won’t cost you a thing.

Self-care goes global!

  1. Spanish siesta

Let’s start with a bit of winter warmth. In Spain and other Mediterranean places, as well as Latin America and some places in Asia, it’s common practice to take an after-lunch nap, called a “siesta” in Spanish. This afternoon nap time is not just for kids—adults do it too! It’s taken so seriously that museums, shops, and churches usually close for a couple of hours, and everything shuts down.

Adult nap time isn’t just a nice treat to indulge in. Researchers have found that, among generally healthy Greeks, those who partake in regular napping had a 37% lower chance of dying from heart disease within a few years of enrolling in the study. So if you have the ability to take a short nap during the day, try it out! As long as it doesn’t mess up your nighttime sleep, it may be a great way to get an extra boost of well-being.

 

  1. Danish “hygge”

I love the cold. I love coming in after a walk feeling like an ice cube and then being welcomed (and defrosted) by my warm kitchen. And I love being able to curl up with a book on long winter nights. I  love hot baths.

But I know that there are many who definitely don’t share my love of freezing weather!

In 2016, Denmark ranked as the happiest nation in the world in the World Happiness Report. Then, Finland became number one for the next three years, with Norway and Sweden never far behind. Did you ever wonder at the fact that the five happiest countries in the world are almost always cold, Nordic countries. How do they do it?

Of course, there are likely many factors involved. These countries often have less income inequality, greater oil wealth, and breathtaking natural landscapes. But I wondered if there were any specific Nordic secrets to happiness and wellness—even during winter.

The Danish believe in hygge (pronounced “hoo-gah”), which loosely translates to “coziness” and sounds to me a lot like ‘hug’! The word originated from an Old Norwegian word meaning “well-being,” and it captures all that is cozy, warm, and enjoyable. Curling up under a soft blanket while holding a warm mug of cocoa is hygge. Chatting with friends and family around a fire is hygge. And simply enjoying the glow of a candle is hygge.

This concept of hygge not only gives practical inspiration for how to enjoy life—oversized scarves and hot drinks —but it also offers a philosophy for how to be with one’s environment instead of fighting against it. No wonder the Danes are happy in winter!

  1. Japanese forest bathing

On the subject of being with the environment, we’ll ‘travel’ now eastwards to Japan, to take a dip in the woods. Not an actual swim, but rather, an immersion in nature called “shinrin-yoku,” loosely translated to “forest bathing.”

Forest bathing is exactly what it sounds like—being immersed in nature. Importantly, it’s not about going camping, hiking, or doing any hardcore exercise in a forest. In fact, it’s not a goal-oriented activity at all. It’s simply being with nature, with your senses open and your body as your guide.

Health researcher Dr. Qing Li and his colleagues have found that forest bathing enhances the immune system and encourages the expression of anti-cancer proteins. They also found that it decreases depression, fatigue, anxiety, and unsurprisingly, heart rate.

To take a forest bath yourself, you don’t need to seek out special destinations. You can simply find a spot of nature, even if it’s just a group of trees or a garden, and walk through the area slowly and aimlessly. Turn off your mobile phone and simply let the forest in through your five senses.

 

  1. Indian laughter yoga

Who doesn’t enjoy a good belly laugh? But have you ever done it on purpose? The idea of (Indian) laughter yoga is that we don’t have to wait for something funny to happen in order to laugh. Instead, laughter can and should be practiced for its own sake.

Laughter yoga is often practiced in groups, where real playfulness and interaction between people can turn practiced laughs into real guffaws. And there seem to be real health benefits, even if the laughter is “fake.”

A recent meta-analysis found that simulated laughter may be even more effective than spontaneous, humorous laughter for improving mood. So why not give it a try—do a belly laugh like no one is watching. Or better yet, get together with others and laugh with them!

  1. South African Ubuntu philosophy

Speaking of being with others, perhaps nothing captures our social human nature better than the South African philosophy of Ubuntu. This term from the Zulu language can be translated as “humanity towards others,” and it’s part of a phrase that means “a person is a person through other people.” This idea has been spread, in part, by Archbishop Desmond Tutu, a South African theologian, and human rights activist.

The word Ubuntu can be translated as ‘humanity towards others,’ and is part of a phrase that means ‘a person is a person through other people.’

Ubuntu is different from the other items here because it’s not just a practice, but rather, a whole humanist philosophy that embraces diversity, compassion, warmth, and dignity for all.

This may be a philosophy we especially need right now, even if living by it might be a lifelong pursuit. We can begin by acknowledging the humanity of all people, being open to learning, and respecting all, even if we’re unfamiliar or in conflict with someone.

  1. Jewish Sabbath

Observing the Sabbath, the seventh day of the week, is a religious tradition in the practice of Judaism. The Shabbat—meaning “rest” or “cessation”—begins on Friday evening and ends on Saturday evening, during which people refrain from work. Instead, they honour the Sabbath with restful activities like meditation, contemplation, and having festive meals with family. This is what Christian cultures traditionally also do (or did) on  the Sunday – the day of rest.

Research has found that Sabbath-keeping is beneficial for physical and mental health. One Jewish writer, Menachem Kaiser, has referred to the Sabbath as “the only authentic form of leisure: the act and fulfillment of doing absolutely nothing productive” and “our best bet to enact lasting communities.” This sounds like a much-needed balm for our modern hurts.

Research has found that Sabbath-keeping is beneficial for physical and mental health. This is unsurprising, given that much research has established the benefits of rest, spirituality, and even simply eating meals together as a family. So even if you’re not religious, you can practice a secular version of Shabbat and let this weekly time out give you the chance to rest and connect with others. And if you manage to turn off your mobile phone for a day too then you’re really doing well!

Whether it’s through the quietness of forest bathing, or the exuberance of laughter yoga, so many wellness practices and philosophies from around the world get back to the basics—feeling connected to our bodies, our minds, and one another. None of the ideas require you to buy a single thing. All of them invite us to be mindful and connected. And that would be my Christmas and New Years wish for this year!

REFERENCES:

* Naska A, Oikonomou E, Trichopoulou A, Psaltopoulou T, Trichopoulos D. Siesta in Healthy Adults and Coronary Mortality in the General Population. Arch Intern Med. 2007, 167(3):296–301. doi:10.1001/archinte.167.3.296

*World Happiness Report. https://worldhappiness.report

* Li, Q et al. Forest bathing enhances human natural killer activity and expression of anti-cancer proteins. Int J Immunopathol Pharmacol, Apr-Jun 2007; 20(2 Suppl 2): pages 3-8.

* Li, Q et al. Effects of Forest Bathing on Cardiovascular and Metabolic Parameters in Middle-Aged Males. Evid Based Complement Alternat Med. 2016; 2016: 2587381

* Li, Q. Forest Bathing Is Great for Your Health. Here’s How To Do It. https://time.com/5259602/japanese-forest-bathing/

See also Dr Li’s book ‘Forest Bathing: How Trees Can Help You Find Health and Happiness’. Viking (Penguin Publishing Group), 2018.

* van der Wal, N.C and Kok, R.N. Laughter-inducing therapies: Systematic review and meta-analysis. Social Science & Medicine Volume 232, July 2019, Pages 473-488.

* Superville, D. J., Pargament, K. I., & Lee, J. W. (2014). Sabbath Keeping and Its Relationships to Health and Well-Being: A Mediational Analysis. The International Journal for the Psychology of Religion24(3), 241–256. https://doi.org/10.1080/10508619.2013.837655

* S. M. Fruh et al. The Surprising Benefits of the Family Meal. The Journal for Nurse Practitioners, Volume 7, Issue 1, 2011, Pages 18-22, https://doi.org/10.1016/j.nurpra.2010.04.017

The Surprising Benefits of Gossip

Posted Posted in Jayne's blog

Scientists have studied gossip for decades. That’s not surprising given how ‘normal’ it is in any social group, big or small.

It’s estimated that more than 90 percent of people in workplaces in Western Europe and North Americaindulge in such banter—defined as talking about someone not present. People in modern societies spend about an  hour a day in chin-wagging, one study reports. But investigators are now approaching this element of social life from a new perspective.

In past decades, researchers have focused primarily on the damage wrought by gossiping, and they zeroed in on either the gossip spreader or the target—the person being talked about. But currently they have changed course by looking more at the benefits of gossip and the dynamics of a three-part network that involves a gossiper, a listener and a target. This research is revealing the complex and diverse roles in shaping perceptions of self and others by looking at factors such as basic information, ego enhancement and social segregation within a group.

So what, if anything, can be good about gossip? Whenever someone confides something to you about someone you both know—whether the information is positive, negative or neutral—it brings the two of you closer, creating a social bond. According to one study, it even increases your liking for the spreader of the information. It helps you learn who to trust and who to avoid. It enforces group norms. For example, complaints about a co-worker who regularly leaves their lunch to rot in the fridge get back to them and let them know that doing so is not an office norm.

But gossip is a double-edged sword for each member of this equilateral triangle. Whether that sword aids or causes harm depends on a host of factors, including the relationships among gossiper, listener and target, the motives of each person and the trustworthiness of the imparted info.

The gossiper is the prime mover in this drama. So it’s not surprising that much of the social science research related to gossip has focused on why they do it, what they get out of it and what the attendant dangers are in doing it, if any. In its most benign form gossip creates a sense of connectedness and belonging. On the other hand, if what you’re sharing is injurious to the target, you may feel guilty. You may also feel anxious about repercussions, including retaliation. There’s the further risk that listeners may form unwelcome impressions about you.

Gossipers have been maligned from time immemorial as rumourmongers or talebearers, yet most of what they impart is actually true, research shows. Sociologist Francesca Giardini of the University of Groningen in the Netherlands and her colleagues found this to be the case in a lab experiment in which students played a series of ‘public goods’ games. In this type of game, players benefit from monetary contributions that they make to a common pool as long as people behave altruistically, but individual players can choose instead to maximize their payoff by acting in their own self-interest. In the study, four players had the opportunity to earn up to €21 from the experimenters depending on how the participants played. If they contributed to their private account, they got what they put in plus a share of the group pot. Everyone benefited more if they all contributed to that pot because its holdings were multiplied by 1.5.

Over several games, players recognised the behaviour of the others, and they were offered opportunities to confidentially warn other players about someone who didn’t contribute to the group. The experimenters learned that the biggest contributors were, on average, also more willing to pass on gossip, here defined as information about self-interested players, that was truthful.

Another lab experiment conducted by social psychologist Terence Dores Cruz, then at Free University Amsterdam, showed that the gossiper passed on true information when they had no conflict of interest with the target of the gossip. When they had a rivalry or other conflict with the target, however, they were likelier to pass on things that were self-serving or outright false. Like a villain in a melodrama, a gossiper can take down a rival, for instance, by manipulating people’s impressions of them. To figure out the gossiper’s motives, the research advises listeners, “ask yourself: Who gains?”

However…even being friends with anyone else in the gossip triangle affects the information’s truthfulness. For example, a friend of the target may not pass on something negative. In addition, a gossiper may say something positive—but false—about a friend.

Despite complex motivations, humans on average are quite good at sizing up the intentions of others with whom they interact. They usually know the person and their place in the network. One study shows that the determining factor of how people interpret gossip is whether they believe someone is passing on gossip to help out the listener or to benefit themselves. If they perceive it to be the former, they trust the gossiper more.

Gossip can be vital to those who listen to it. Learning that a colleague could be leaving their job, for example, could motivate a listener to take on challenging, promotion-worthy assignments. For someone new to a group, gossip can be invaluable. In any large organisation, there are always smaller cliques, in-groups and out-groups. If you are LGBTQ+, for example, gossip from your co-workers about company events or decisions that people have supported or opposed can inform your own decisions.

There has been little research on how gossip affects people in minority groups, but at least one study suggests that it can be helpful in certain cases. Between 2015 and 2020 investigators interviewed residents of Riace, a town in southern Italy that has hosted a variety of refugees and migrants more than 20 years. They found that much of the local gossip occurred between people of different ethnic groups and promoted strong community relationships. Race was not a factor in that research. A study done in 2016 using similar methods at a historically white South African university, however, found that gossip about Black employees not present at meetings undermined their work performance and morale.

There is a common assumption that being the target of gossip is a bad thing, but this is not always the case. Psychologist Elena Martinescu, then at the University of Groningen, and her colleagues found that targets of positive gossip experienced positive emotions such as pride, but negative gossip was sometimes beneficial by inspiring efforts to repair problematic behaviour. The good side is that you may become more aware of how you’re perceived by others. You may adjust your behaviour accordingly. But, in line with popular perception, if people are bad-mouthing about you, they can harm your reputation, your career prospects and your own mental health.

Most of the studies examined gossip in the workplace, but the actual research was conducted in the laboratory or online. Cruz has conducted one of the few studies of how gossip functions in real-life situations. He recruited more than 300 people in a community in the Netherlands and asked them to list 15 people with whom they had frequent contact. Four times each day for 10 days, the subjects were prompted to report on any information that someone in their social network told them—or that they told someone—about a third person. In this exchange, people passed on evaluations of many aspects of a target—qualities such as trustworthiness, warmth and competence. Listeners overwhelmingly believed the gossip to be true, and they updated their beliefs about the person being discussed and adjusted their behaviour toward them.

One of the most beneficial results of gossip is that it helps people better understand the behaviour of others. For example, Cruz found, someone might complain about a co-worker who shows up late every day, but if they learn through gossip that the offending colleague is in the middle of a divorce or that this person’s young son has cancer, they are less likely to complain. Perhaps more important, they sympathise with the co-worker who is suffering a crisis and feel motivated to be more helpful to them. Overall, Cruz and his colleagues found in their study that most gossip in real life was neither positive nor negative, just newsy: someone became a grandparent; someone got engaged. To avoid biasing their subjects, the investigators never used the term gossip.

Gossip may have a bad name, but science shows it’s often not a bad thing.

Enjoy the Office Christmas Party!

REFERENCES:

Robbins, M. L., & Karan, A. (2020). Who Gossips and How in Everyday Life? Social Psychological and Personality Science11(2), 185-195. https://doi.org/10.1177/1948550619837000

Tianjun Sun, Pauline Schilpzand, Yihao Liu (2023) .Workplace gossip: An integrative review of its antecedents, functions, and consequences. J. Organ. Behav. 44:311-334 https://doi.org/10.1002/job.2653

Terence D Dores Cruz et al. (2021). Gossip and reputation in everyday life. Phil. Trans. R. Soc. B376:20200301 https://doi.org/10.1098/rstb.2020.0301

Francesca Giardini et al. (2021). Gossip and competitive altruism support cooperation in a Public Good game. Phil. Trans. R. Soc. B376:20200303 http://doi.org/10.1098/rstb.2020.0303

D. Dores Cruz et al. (2024). Nasty and Noble Notes: Interdependence Structures Drive Self-Serving Gossip. Personality and Social Psychology Bulletin, 50(11), 1596-1612. https://doi.org/10.1177/01461672231171054

Martina Testori et al. Punishing or praising gossipers: How people interpret the motives driving negative gossip shapes its consequences (2024). Social and Personality Psycholoigy Compass Vol 18 (2), e12924. https://doi.org/10.1111/spc3.12924

Carrim, N.M.H. (2019). Minorities’ experiences of office gossip. SA Journal of Industrial Psychology/SA Tydskrif vir Bedryfsielkunde 45(0), a1562. https://doi.org/10.4102/sajip.v45i0.1562

Ester Driel and Maykel Verkuyten (2022). Gossip, diversity and community cohesion: the case of multi-ethnic Riace. Ethnic and Racial Studies Vol. 45, No. 16, 591-613. https://doi.org/10.1080/01419870.2022.2114806

Carrim, N. M. H. (2016). ‘Shh … quiet! Here they come.’ Black employees as targets of office gossip. Journal of Psychology in Africa, 26(2), 180–185. https://doi.org/10.1080/14330237.2016.1163912

Martinescu et al. (2019) Self-.Evaluative and Other-Directed Emotional and Behavioral Responses to Gossip About the Self. Front. Psychol., Sec. Organizational Psychology, Volume 9. https://doi.org/10.3389/fpsyg.2018.02603

Unveiling the Mystery of Pain in the Brain

Posted Posted in Jayne's blog

We’ve known for decades that the placebo effect is very real. This is seen in real-life observations and the best double-blinded randomised clinical trials researchers have devised for many diseases and conditions, especially pain. And yet, how and why the placebo effect occurs has remained a mystery. Now, neuroscientists have discovered a key piece of the placebo effect puzzle.

Publishing in Nature, researchers at the University of North Carolina School of Medicine, along with colleagues from Stanford University, discovered a pain control pathway that links the cingulate cortex in the front of the brain, through the pons region of the brainstem, to cerebellum in the back of the brain.

The researchers, led by Greg Scherrer, then showed that certain neurons and synapses along this pathway are highly activated when mice expect pain relief and experience pain relief, even when there is no medication involved.

That neurons in our cerebral cortex communicate with the pons and cerebellum to adjust pain thresholds based on our expectations is completely unexpected – given the previous /current understanding of the pain circuitry – and incredibly exciting. Scherrer’s results open the possibility to activate this pathway through other therapeutic means, such as drugs or neurostimulation methods to treat pain.

Scherrer and colleagues hope this new research provides a new framework for investigating the brain pathways underlying other mind-body interactions and placebo effects beyond the ones involved in pain.

The Placebo Paradox

It is the human experience, in the face of pain, to want to feel better. As a result — and in conjunction with millennia of evolution — our brains can search for ways to help us feel better. It releases chemicals, which can be measured. Positive thinking and even prayer have been shown to benefit some patients. And the placebo effect — feeling better even though there was no “real” treatment — has been documented as a very real phenomenon for decades.

In clinical research, the placebo effect is often seen in what we call the “sham” treatment group. That is, individuals in this group receive a fake pill or intervention that is supposed to be inert; no one in the control group is supposed to see a benefit. Except that the brain is so powerful and individuals so desire to feel better that some experience a marked improvement in their symptoms. Some placebo effects are so strong that individuals are convinced they received a real treatment meant to help them.

In fact, it’s thought that some individuals in the “actual” treatment group also derive benefit from the placebo effect. This is one of the reasons why clinical research of therapeutics is so difficult and demands as many volunteers as possible so scientists can parse the treatment benefit from the sham. One way to help scientists do this is to first understand what precisely is happening in the brain of someone experiencing the placebo effect.

Enter the Scherrer lab

The authors of the Nature paper knew that the scientific community’s understanding of the biological underpinnings of pain relief through placebo analgesia — when the positive expectation of pain relief is sufficient for patients to feel better — came from human brain imaging studies, which showed activity in certain brain regions. But those imaging studies did not have enough precision to show what was actually happening in those brain regions. So Scherrer’s team designed a set of meticulous, complementary, and time-consuming experiments to learn in more detail, with single nerve cell precision, what was happening in those regions.

First, the researchers created an assay (=test) that generates in mice the expectation of pain relief and then very real placebo effect of pain relief. Then the researchers used a series of experimental methods to study the intricacies of the anterior cingulate cortex (ACC), which had been previously associated with the pain placebo effect. While mice were experiencing the effect, the scientists used genetic tagging of neurons in the ACC, imaging of calcium in neurons of freely behaving mice, single-cell RNA sequencing techniques, electrophysiological recordings, and optogenetics — the use of light and fluorescent-tagged genes to manipulate cells.

These experiments helped them see and study the intricate neurobiology of the placebo effect down to the brain circuits, neurons, and synapses throughout the brain.

The scientists found that when mice expected pain relief, the rostral anterior cingulate cortex neurons projected their signals to the pontine nucleus, which had no previously established function in pain or pain relief. And they found that expectation of pain relief boosted signals along this pathway.

There is an abundance of opioid receptors in this pathway, which supports a role in pain modulation. When activity in this pathway was inhibited, the scientists realised that they were disrupting placebo analgesia and decreasing pain thresholds, giving rise to the experience of more pain. And then, in the absence of placebo conditioning, when we this pathway was activated, pain relief was produced/caused.

Lastly, the scientists found that Purkinje cells — a distinct class of large branch-like cells of the cerebellum — showed activity patterns similar to those of the ACC neurons during pain relief expectation. This is apparently cellular-level evidence for the cerebellum’s role in cognitive pain modulation.

In both the medical and para-medical work, it is widely known that we need better ways to treat chronic pain, particularly treatments without harmful side effects and addictive properties. Let’s hope that these newfindings open the door to targeting this novel neural pain pathway to treat people in a different but potentially more effective way.

 

REFERENCES:

Chen, C., Niehaus, J.K., Dinc, F. et al. Neural circuit basis of placebo pain relief. Nature, 632, 1092–1100 (2024). https://doi.org/10.1038/s41586-024-07816-z

University of North Carolina Health Care. Neuroscientists discover brain circuitry of placebo effect for pain relief. ScienceDaily. ScienceDaily, 24 July 2024.

Bingel, U. et al. The effect of treatment expectation on drug efficacy: imaging the analgesic benefit of the opioid remifentanil. Sci. Transl. Med. 3, 70ra14 (2011).

Fields, H. L. How expectations influence pain. Pain 159, S3–S10 (2018).

Chen, C. H. et al. A Purkinje cell to parabrachial nucleus pathway enables broad cerebellar influence over the forebrain. Nat. Neurosci. 26, 1929–1941 (2023).

Neuroscientists Discover Knowingly Taking Placebos Reduces Stress and Anxiety

Posted Posted in Jayne's blog

It is the human experience, in the face of pain, to want to feel better.

As a result – and in conjunction with millennia of evolution – our brains can search for ways to help us feel better. It releases chemicals, which can be measured. Positive thinking and even prayer have been shown to benefit some patients. And the placebo effect — feeling better even though there was no “real” treatment — has been documented as a very real phenomenon for decades.

The placebo effect is thus very real.

Despite the best double-blinded randomised clinical trials researchers have devised for many diseases and conditions the ‘how and why’ the placebo effect occurs has remained quite a mystery.

The Placebo Paradox

In clinical research, the placebo effect is often seen in what we call the “sham” treatment group. That is, individuals in this group receive a fake pill or intervention that is supposed to be inert; no one in the control group is supposed to see a benefit. Except that the brain is so powerful and individuals so desire to feel better that some experience a marked improvement in their symptoms. Some placebo effects are so strong that individuals are convinced they received a real treatment meant to help them.

In fact, it’s thought that some individuals in the “actual” treatment group also derive benefit from the placebo effect. This is one of the reasons why clinical research of therapeutics is so difficult and demands as many volunteers as possible so scientists can separate out the treatment benefit (i.e. what is the real effect of the pharmaceutical pill) from the sham.

New Nondeceptive Research

 A study out of Michigan State University found that nondeceptive placebos, or placebos given with people fully knowing they are placebos, effectively manage stress — even when the placebos are administered remotely.

Researchers recruited volunteers experiencing prolonged stress from the COVID-19 pandemic for a two-week randomised controlled trial. Half of the participants were randomly assigned to a nondeceptive placebo group and the other half to the control group that took no pills.

The participants interacted with a researcher online through four virtual sessions on Zoom. Those in the nondeceptive placebo group received information on the placebo effect and were sent placebo pills in the mail along with and instructions on taking the pills. COVID-related stress, overall stress, anxiety, and depression were assessed at the beginning, middle, and end of the study.

The study, published in Applied Psychology: Health and Well-Being, found that the nondeceptive group showed a significant decrease in stress, anxiety and depression in just two weeks compared to the no-treatment control group.

Participants also reported that the nondeceptive placebos were easy to use, not burdensome and appropriate for the situation. Compared with the control group, participants in the non-deceptive placebo group reported significant reductions from baseline in all primary affective outcomes after 2 weeks.

And now…

Exposure to long-term stress can impair a person’s ability to manage emotions and cause significant mental health problems long-term. It’s exciting to see that an intervention that takes minimal effort can still lead to significant benefits. This minimal burden makes nondeceptive placebos an attractive intervention for those with significant stress, anxiety and depression.

The researchers are particularly hopeful in the ability to remotely administer the nondeceptive placebos by health care providers. It increases scalability potential dramatically. Remotely administered nondeceptive placebos have the potential to help individuals struggling with mental health concerns who otherwise would not have access to traditional mental health services.

Future large-scale studies are needed to determine if non-deceptive placebos can be effective across different prolonged stress situations and for clinical populations.

REFERENCES:

J. Moser et al. Remotely administered non-deceptive placebos reduce COVID-related stress, anxiety, and depression. Applied Psychology Health and Well-Being. 14th August 2024, Open Access. https://doi.org/10.1111/aphw.12583

Babies Smell Sweet but Teenagers Stink: Is Evolution to Blame?

Posted Posted in Jayne's blog

Teenagers have a reputation for smelling, well, just a bit ‘strong’. According to the latest research, that stereotype might be more than standard adult bias against teenagers in general—it could actually be rooted in solid science.

In a study published on 21st March in the journal Communications Chemistry, researchers characterised the chemical makeup of ‘Essence of Teen’ and compared it with the smell composition of infants and toddlers. They found that, from both a qualitative and quantitative standpoint, children’s body odour takes a dramatically smelly turn after the onset of puberty. And there may be a good evolutionary reason for this shift.

Helene Loos, an aroma researcher at the Friedrich-Alexander University of Erlangen-Nuremberg in Germany and senior author of that new research paper, began this research by attempting to pinpoint the cause of that fragrance change. She and her team first collected body odour samples from 18 infants and toddlers and 18 teenaged children. Then they analysed the samples in the lab to determine what scent chemicals were present in each sample. They also combined their findings with a previous survey of 270 families that had indicated that parents found babies’ body odour much more agreeable than that of teenagers.

The researchers discovered pleasant citrusy and soapy-smelling aldehydes in the body odour samples from both age groups. In the underarm sweat of teens, however, Loos and her colleagues found a higher concentration of carboxylic acids—compounds that are associated with sharp, funky scents such as cut grass, cheese and goat musk. This chemical cocktail was much less pronounced in the infants’ samples. Additionally, two naturally occurring steroids with musk-like odours were only found in the teens’ sweat.

The source of these stinky compounds is complex, but it starts with the activity of the sebaceous glands, which secrete sebum, an oily substance that helps protect your skin and keep your hair shiny and hydrated. The glands are active just before birth and then mostly go dormant for years, but they get very active again around puberty.

When the sebaceous glands ‘reactivate’, they encounter all sorts of bacteria and bodily substances—think sweat—that weren’t around during the infant and toddler years. These additional agents help break down sebum into the kind of smelly molecules that make up the characteristic teenage musksmell. Without much sebum, such compounds simply don’t form in high concentrations on a baby’s skin. Instead that sweet, milky scent that parents find very pleasant lingers.

Evolutionarily this makes a lot of sense: baby odour facilitates bonding between parents and children. But that doesn’t last forever. Once children become teens and are no longer as reliant on their parents, becoming smellier to mum and dad can help them foster a degree of independence as they begin to strike out on their own.

However, other scientists caution that the research might be too preliminary to jump to any firm evolutionary conclusions. Bodily smells change over time,  but  it could be that they have no communicative purpose. For example, imagine a “new car smell.” Most people have a positive association with this scent, even though there isn’t any good evolutionary reason for it. New cars are filled with volatile chemicals that don’t smell particularly nice on their own and might even be hazardous in high concentrations. Yet many people learn to perceive this smell as “good” because it represents the exciting, high-status act of buying a new car. This association is so strong that you can purchase air fresheners designed to make your old car smell like you just drove it from the showroom/car dealer.

Similarly, it’s possible that babies aren’t hardwired to smell nice to their parents. Infants certainly don’t consciously control their body odour in order to manipulate adults into feeding and pampering them. Through repeated exposure, however, parents might come to associate their child’s smell with the dopamine rush produced by caring for them. But just because the association is below the level of conscious awareness doesn’t mean parents aren’t evolutionarily predisposed to find baby scents pleasant and teenage scents repellant. There is previous research on stickleback fish (yes, honestly) that has shown that closely related individual sticklebacks dislike one another’s smell once they reach sexual maturity. Scientists hypothesize that this helps the fish avoid inbreeding when it comes time to choose a mate. A similar mechanism may be at play in humans, with infant smells provoking a deep-seated nurturing response in parents that later turns to avoidance once puberty begins. In other words it could be the receptors of the person who’s perceiving the body odour that  have changed.

Looking ahead, the researchers hope to pair their molecular odour data with magnetic resonance imaging scans of parents’ brain as they sniff their children’s body odour to determine whether a specific brain region is activated by the smell. The researchers also hope to identify whether some odour molecules stay consistent over the course of a person’s lifetime, the scent equivalent of an individual’s unique fingerprint.

But for now, they’re happy to be able to pinpoint some of the molecules behind teens’ unique ‘aroma’. You can’t spell adolescent without “scent,” after all….🤣🤣🤣

REFERENCES:

Owsienko, D., Goppelt, L., Hierl, K. et al. Body odor samples from infants and post-pubertal children differ in their volatile profiles. Commun Chem 7, 53 (2024). https://doi.org/10.1038/s42004-024-01131-4

Croy, I., Frackowiak, T., Hummel, T. et al. Babies Smell Wonderful to Their Parents, Teenagers Do Not: an Exploratory Questionnaire Study on Children’s Age and Personal Odor Ratings in a Polish Sample. Chem. Percept. 10, 81–87 (2017). https://doi.org/10.1007/s12078-017-9230-x

Lundström J. N., Mathe A. et al. Maternal status regulates cortical responses to the body odor of newborns. Frontiers in Psychology, 4 (2013). DOI=10.3389/fpsyg.2013.00597

Milinski M, Griffiths S, Wegner KM et al. Mate choice decisions of stickleback females predictably modified by MHC peptide ligands. Proc Natl Acad Sci USA. 2005 Mar 22;102(12):4414-8. doi: 10.1073/pnas.0408264102.

Lifting the Veil on Human Consciousness via Near-Death Experiences

Posted Posted in Jayne's blog

Near-death experiences (NDE) have been long reported across time and cultures. An astounding 5 to 10 percent of the general population is estimated to have memories of an NDE, including somewhere between 10 and 23 percent of heart attack survivors. A growing number of scholars now accept NDEs as a unique mental state that can offer novel insights into the nature of consciousness. Neuroscientists no longer question anymore the reality of near-death experience: People who report an experience really did experience something.

Those who undergo an NDE also return with a quality from the experience, which very often changes their life.

A handful of researchers, mostly emergency room doctors, began collecting qualitative data about NDEs after the 1975 publication of psychiatrist and physician Raymond A. Moody’s book Life after Life, which detailed patients’ accounts of near-death experiences. Since then, only a few research teams have attempted to empirically investigate the neurobiology of NDEs. But their findings are already challenging long-held beliefs about the dying brain, including that consciousness ceases almost immediately after the heart stops beating. This discovery has important implications for current resuscitation practices. If we understand the mechanisms of death, then this could lead to new ways of saving lives.

Like psychedelic drugs and other means of altering consciousness, NDEs could also serve as probes for revealing fundamental truths about the mind and brain. Such states are disturbances to the system of consciousness and when you disturb a system, you understand better how it works. If we want to understand the nature of experience, we have to take into account what’s happening at the margins of nonordinary states.

Moreover, there are important existential implications, although exactly what those might be continues to be debated in the scientific literature and at conferences, including at a 2023 meeting held by the New York Academy of Sciences. It explored consciousness through the lens of death, psychedelics and mysticism. Since these transcendent experiences are found in the major world religions and traditions scientists are curious as to if they have some greater purpose for helping humanity cultivate understanding and awareness of consciousness. The weightiness of threse sort of questions makes careful study of NDEs and their rigorous interpretation all the more critical, in order to disentangle empirical findings from beliefs.

Many people who had an NDE describe one or more of a specific set of characteristics. They may recall separating from their body and viewing it in real time from above. They may pass through tunnels and see light, encounter deceased relatives or compassionate entities, and have a sense of vastness and deep insight. People may undergo a life review and morally evaluate the choices they have made, including by experiencing the joy or pain their actions caused others. What’s intriguing is that when people die, they don’t evaluate themselves based on their own standards of morals, they evaluate themselves based on a universal standard.

Although most people describe their NDE in glowing terms, a minority recount visits to hell-like regions, encounters with demonic beings or terrifying voids. In a 2019 study, Charlotte Martial, a neuroscientist at the University of Liège in Belgium and her colleagues found that among 123 people who reported an NDE, 14 percent classified it as negative—a proportion Martial says she’s “sure” is an underestimate because of how disturbing these memories can be.

Somewhat surprisingly, religious people don’t seem to be more inclined toward NDEs. There is, however, preliminary evidence of another group being more likely to have NDEs: those who are prone to REM sleep intrusion, a condition that occurs when rapid eye movement (REM) sleep intrudes into wakefulness and blends elements of dreaming and waking. During the seconds or minutes it lasts for, people may have an out-of-body experience, sense that someone or something is in the room with them, or want to move but find that they can’t. In 2019 Daniel Kondziella, a neurologist at the Copenhagen University Hospital and his colleagues recruited a sample of 1,034 adults from the general population in 35 countries. Ten percent of the study participants had experienced an NDE, and of those, 47 percent also reported REM sleep intrusion—a statistically significant association. Among the people who had not had NDEs, just 14 percent reported REM sleep intrusion.

Still, little is known about the neurobiology of NDEs. Open questions include whether they are driven by a single, core mechanism or are a more variable response to understanding somehow that death is near. A few researchers, including Martial, are peering into the brains of people who are approaching or undergoing death, in the hope of understanding what is going on.

In 2023 Jimo Borjigin of the University of Michigan Medical School and her colleagues published what they suspect could be a signature of NDEs in the dying brain. The researchers analysed EEG data from four comatose patients before and after their ventilators were removed. As their brains became deprived of oxygen, two of the dying patients exhibited a paradoxical surge of gamma activity, a type of high-frequency brain wave linked to the formation of memory and the integration of information.

Borjigin had seen the same upwelling of activity in previous studies of the brains of healthy rats during induced cardiac arrest. In the rodents, the surge occurred across the entire brain. In humans, though, it was confined primarily to the junction of the brain’s temporal, parietal and occipital lobes, a region involved in multiple features of consciousness, including visual, auditory and motion processing. Past research has also associated the region with out-of-body sensations, as well as with altruism and empathy. Although these are all regular components of NDEs, Borjigin says, it’s impossible to know whether the two patients actually experienced an NDE because they did not live to tell about it.

A 2023 study led by Sam Parnia, director of critical care and resuscitation research at the N.Y.U. Grossman School of Medicine and detailed in his forthcoming 2024 book, Lucid Dying, provides further evidence of brain activity after patients’ hearts have stopped. Parnia and his colleagues worked with 25 hospitals in the U.S., the U.K. and Bulgaria to review EEG and brain-oxygen data from 567 people who experienced an in-hospital cardiac arrest. Medical staff managed to collect interpretable EEG data from 53 of these patients. Most showed an electrical flatline during the crisis, but in around 40 percent of those cases, neurological activity consistent with that of conscious brains transiently reemerged—in some instances up to an hour into CPR.

A different subset of 53 patients from the study survived. Doctors collected EEG and brain-oxygen levels for too few of these people to draw a correlation between any potential memory they had of the event and their brain activity. The authors were able to interview 28 of the survivors, and six had a NDE.

Parnia and his colleagues also sought to test conscious and unconscious awareness, including reports of out-of-body experiences, by projecting a series of 10 random images on a tablet placed near patients’ heads and by playing a repeated recording of the names of three fruits—apple, pear, banana—to them through headphones every minute for five minutes while they were unconscious. None of the survivors could remember the images that had been projected. One person who had a recalled experience of death correctly named the fruits in order, although this could have been by chance, Parnia says.

According to Parnia, this study presents a coherent, mechanistic explanation for how and why people have recalled experiences of death. When someone starts dying, Parnia says, the brain becomes dysfunctional. Some actions are immediately lost, such as brain stem reflexes, but others that are normally suppressed to optimise performance for ordinary life suddenly become disinhibited because the brain’s natural braking systems are no longer working. As a result, your entire consciousness comes to the fore. The purpose of this change, he suggests, is to prepare the person “for a new reality”—the transition from life to death, a condition in which, Parnia believes, consciousness endures.

Other scientists flatly disagree. Kondziella suggests that when you have an NDE, you must have a functioning brain to store the memory. And you have to survive with an intact brain so you can retrieve that memory and be able to tell about it. A functioningg brain is necessary for that, so “all those arguments that NDEs prove that there’s consciousness outside the brain are simply nonsense”.

Kondziella, Martial, and others instead theorise that NDEs might be part of a last-ditch survival tactic. Species across the animal kingdom “play dead”—a behaviour technically called thanatosis—when they perceive a mortal threat, typically from an attacking predator. If fight-or-flight fails, the instinct to feign death kicks in as an attempt to forestall the danger. The animal becomes immobilised and unresponsive to external stimuli—but with continued awareness so that, given a chance, it can escape. Kondziella believes the evolutionary aspect really is the key to understanding what NDEs are and how they came about. For him there is a perfectly valid biological explanation.

In their latest study, Martial and her colleagues plan to use the most rigorous approach to date to collect both subjective and objective data from around 100 patients, including EEG and brain-oxygen readings, plus information from several rounds of interviews and surveys with survivors in the group. The University of Liège team is also trying to more thoroughly evaluate claims about out-of-body experiences. Around 79 percent of people who have an NDE report leaving their body, and some wake up knowing facts about their environment that they seemingly should not know. That’s something she wants to test objectively.

To this end, she and her colleagues have decorated the hospital resuscitation room with unexpected objects and images, some of which are hidden in places that could be viewed only from the vantage point of someone near the ceiling. While a patient is in the resuscitation room, including while they are conscious, the team plays an audio clip of various words and animal sounds once every minute. They will test for recollections of any images or sounds in follow-ups with surviving participants, and they will also use video recordings to compare people’s memories with reality.

An easier approach to studying NDEs is via safe proxies such as hypnosis, induced fainting and psychedelic drugs. None of these methods produce true NDEs, but the states they trigger may have some overlap with the dying brain. In 2018 Timmermann, Martial and their colleagues published a study comparing NDEs with the effects of N,N-dimethyltryptamine (DMT), a mind-altering component of ayahuasca, a South American plant-derived psychedelic brew. Trace amounts of DMT also occur endogenously in humans. There’s speculation that that’s somehow underlying NDEs.

In the study, 13 volunteers received intravenous DMT in a lab setting and rated their experience on a scale commonly used to measure NDEs, developed by psychiatrist Bruce Greyson in 1983. The researchers compared the DMT group’s scores and subjective accounts with other people’s taken from an NDE database that Martial and her colleagues have been compiling since 2016. (The database includes around 2,000 accounts, accepted from anyone who contacts the Liège team claiming to have had an NDE and then fills out a lengthy questionnaire.)

They found “striking overlap” between the DMT and NDE groups with people in both describing a sense of entering into an unearthly realm, separating from their body, encountering mystical beings and seeing a bright light. People in both groups also reported feelings of peace, unity and joy. There was just one significant difference: those in the NDE group more frequently experienced reaching a border demarcating a point of no return.

Roland Griffiths, a psychiatrist at Johns Hopkins University who pioneered studies of psilocybin and who died last October, reported similar findings with his colleagues in 2022. The authors compared 3,192 people who had undergone an NDE, a psychedelic drug trip or a non-drug-induced mystical experience. The team found remarkably similar long-term outcomes across subjects in all three groups, including a reduced fear of death and lasting positive effects of insights they had gained.

In another study currently undergoing peerreview, Martial, Timmermann and their colleagues interviewed 31 people who had experienced an NDE and had also tried a psychedelic drug—LSD, psilocybin, ayahuasca, DMT or mescaline—to see what they had to say about the similarities and differences between the events. Participants reported stronger sensory effects during their NDE, including the sensation of being disembodied, but stronger visual imagery during their drug trip. They reported feelings of spirituality, connectedness and deeper meaning across both.

In comparisons of these mystical experiences, Bossis has found that the common ground is in things like a profound, deep sense of love—that all is love and that consciousness is love. He studies the effects of psilocybin in people with terminal cancer, focusing on relieving end-of-life distress, enhancing spirituality, and providing a greater sense of meaning and fulfillment in life. There’s also a sense of transcending time and a greater acceptance of the mystery of life and death.

Regardless of how people interpret NDEs, studying them may provide a better understanding of mind and brain, and hopefully further illuminate some of the deepest mysteries of existence.

REFERENCES:

S. Parnia et al. Guidelines and standards for the study of death and recalled experiences of death––a multidisciplinary consensus statement and proposed future directions (2022). Ann. N.Y. Acad. Sci., 1511: 5-21. https://doi.org/10.1111/nyas.14740

H. Cassolet al. A systematic analysis of distressing near-death experience accounts (2019). Memory Sep 27 (8), pages 1122-1129. https://doi.org/10.1080/09658211.2019.1626438

D. Kondziella et al . Prevalence of near-death experiences in people with and without REM sleep intrusion(2019). PeerJ 7:e7585 https://doi.org/10.7717/peerj.7585

G. Xu et al. Surge of neurophysiological coupling and connectivity of gamma oscillations in the dying human brain (2023). PNAS, Vol. 120, nr. 19 e2216268120 https://doi.org/10.1073/pnas.2216268120

J. Borjigin et al. Surge of neurophysiological coherence and connectivity in the dying brain (2013). PNAS, Vol. 110, nr. 35 e14432-14437 https://doi.org/10.1073/pnas.1308285110

S. Parnia et al. Awareness during Resuscitation – II: A multi-center study of consciousness and awareness in cardiac arrest (2023). Resuscitation vol. 191, 109903. DOI:https://doi.org/10.1016/j.resuscitation.2023.109903

R. Nuwer. Lifting the Veil on Near-Death Experiences. Scientific American Mind (2024).

C. Peinkhofer et al.. The evolutionary origin of near-death experiences: a systematic investigation (2021). Brain Commun. Jun 22;3(3):fcab132.doi: 10.1093/braincomms/fcab132. Erratum in: Brain Commun. 2021 Sep 06;3(3):fcab181. PMID: 34240053; PMCID: PMC8260963.

C. Timmermann et al. DMT Models the Near-Death Experience (2018). Front. Psychol., Sec. Consciousness Research. Vol. 9. https://doi.org/10.3389/fpsyg.2018.01424

M.M. Sweeney et al. Comparison of psychedelic and near-death or other non-ordinary experiences in changing attitudes about death and dying (2022). PLoS ONE 17(8): e0271926. https://doi.org/10.1371/journal.pone.0271926

How Can Nature Help Us Heal Our Frantic Sense of Time?

Posted Posted in Jayne's blog

In an increasingly competitive world, time is of the essence. Notions of productivity and timeliness have accelerated contemporary lifestyles to a dizzying, sometimes overwhelming pace, and our dependence on technology is doing little to help. As the clock grows to dominate the tempo of life, time itself seems to be increasingly fleeting. This is particularly true in large cities, where hours, days, and even weeks can sometimes seem to fly by in an instant.

Indeed, an increasing number of people report constantly feeling short of time. Such feelings of “time scarcity” emerge from how time is both used and perceived by people. Long working hours inevitably limit the time that people have available for other activities, but leading fast-paced lifestyles while packed into noisy, dynamic and crowded urban environments is mentally exhausting, and this can also influence how we perceive time.

In a recent publication, research was published that nature experiences offer a potential solution to the increasingly widespread feelings of time scarcity caused by contemporary urban lifestyles. This emerges from the unique nature of human time perception, which is highly subjective, and moulded by the experiences and environments in which we immerse ourselves.

Human sense of time

Human time perception — our sense of time — is made up of three key dimensions. One of these is temporal succession, meaning the way we perceive the order and overlap of different events. For instance, pressing a light switch and the light turning on may seem like simultaneous events, but we have the capacity to perceive the order in which they happen, and this helps us to make sense of the world around us.

Another dimension is temporal duration, or how we perceive and estimate the duration of an event. An afternoon spent with your accountant, for example, can seem to last forever, while the same amount of time spent in the company of friends can seem short and swift. Popular expressions such as “time stood still” or “time flies when you’re having fun” reflect our perception of temporal duration.

The third dimension is called temporal perspective, and it refers to the way we regard the past, present and future. Humans have a unique capacity to mentally “time travel” and focus on representations of the past, present and future. Most people have a natural tendency towards certain perspectives, either dwelling on the past or focusing on the future, but maintaining a balanced and dynamic time perspective is a sign of psychological wellbeing.

Together, these dimensions help humans make sense of time. However, the way we perceive them can be profoundly influenced by our own characteristics, what goes on around us, and what we do during a given period of time. Our perception of time changes hugely when, for example, work captures our attention, when we are stuck in traffic, or when we find ourselves in the dentist’s chair undergoing a painful procedure.

In contrast, nature experiences can be mentally, physically and emotionally restorative, and this is reflected in our perception of time.

How nature experiences help regulate human time perception

Evidence from psychological experiments suggests that there are at least two ways natural surroundings can have a positive impact on human time perception.

One of these is expanding our perception of temporal duration. For example, one study reports that when people are inquired how long they have been walking in natural or urban settings, they tend to overestimate the time spent strolling in nature, but not in the city. In other words, time feels longer when we are immersed in natural settings in comparison to urban environments. Ha! My experience, exactly!

The other way nature experiences can influence our time perception is by promoting a shift in perspective. In one experiment, participants spent a short period of silence either indoors or outdoors, and were later asked how this experience influenced their temporal orientation towards the past, present and future. People who experienced the natural setting reported feeling more focused on the present, and less on the past.

Other studies have provided similar evidence suggesting nature experiences can help us shift our perspective on time, and induce a more positive outlook of the present moment.

While there is plenty of evidence that nature experiences have various physical and mental benefits, the idea that such experiences can help people uplift their relationship with time is new, and provides a unique perspective on the importance of nature for human well-being.

REFERENCES:

Ogden et al. Technology Is Stealing Your Timehttps://theconversation.com/technology-is-stealing-your-time-in-ways-you-may-not-realise-heres-what-you-can-do-about-it-216863

Rudd, Feeling short on time: trends, consequences, and possible remedies. Current Opinion in Psychology, 2019, Volume 26, Pages 5-10,https://doi.org/10.1016/j.copsyc.2018.04.007.

A. Correia. Acknowledging and understanding the contributions of nature to human sense of time. People & Nature 2024, Volume6, Issue2, April 2024, Pages 358-366

F. Cunningham et al. Time Perspectives and Subjective Well-Being: A Dual-Pathway Framework. In: Stolarski, M., Fieulaine, N., van Beek, W. (eds) Time Perspective Theory; Review, Research and Application. (2015) Springer, Cham. https://doi.org/10.1007/978-3-319-07368-2_26.

Davydenko & J. Peetz. Time grows on trees: The effect of nature settings on time perception. Journal of Environmental Psychology, 2017, Volume 54, Pages 20-26. https://doi.org/10.1016/j.jenvp.2017.09.003

E. Pfeifer et al. Increased relaxation and present orientation after a period of silence in a natural surrounding. Nordic Journal of Music Therapy 2020

Is Writing by Hand Better for Memory and Learning?

Posted Posted in Jayne's blog

Handwriting notes in class might seem unnecessary as smartphones and other digital technology take over every aspect of learning across schools and universities. But a steady stream of research continues to suggest that taking notes the traditional way—with pen and paper or even stylus and tablet—is still the best way to learn, especially for young children. And now scientists are finally zeroing in on why.

A recent study in Frontiers in Psychology monitored brain activity in students taking notes and found that those writing by hand had higher levels of electrical activity across a wide range of interconnected brain regions responsible for movement, vision, sensory processing and memory. The findings add to a growing body of evidence that has many experts speaking up about the importance of teaching children to handwrite words and draw pictures.

DIFFERENCES IN BRAIN ACTIVITY

The new research, by Audrey van der Meer and Ruud van der Weel at the Norwegian University of Science and Technology (NTNU), builds on a foundational 2014 study. That work suggested that people taking notes by computer were typing without thinking. It appears to be very tempting to type down everything that the lecturer is saying since it goes in through your ears and comes out through your fingertips. But you apparently don’t process the incoming information. But when taking notes by hand, it’s often impossible to write everything down; students have to actively pay attention to the incoming information and process it—prioritise it, consolidate it and try to relate it to things they’ve learned before. This conscious action of building onto existing knowledge can make it easier to stay engaged and grasp new concepts.

To understand specific brain activity differences during the two note-taking approaches, the NTNU researchers tweaked the 2014 study’s basic setup. They sewed electrodes into a hairnet with 256 sensors that recorded the brain activity of 36 students as they wrote or typed 15 words from the game Pictionary that were displayed on a screen.

When students wrote the words by hand, the sensors picked up widespread connectivity across many brain regions. Typing, however, led to minimal activity, if any, in the same areas. Handwriting activated connection patterns spanning visual regions, regions that receive and process sensory information and the motor cortex. The latter handles body movement and sensorimotor integration, which helps the brain use environmental inputs to inform a person’s next action.

When you are typing, the same simple movement of your fingers is involved in producing every letter, whereas when you’re writing by hand, you immediately feel that the bodily feeling of producing A is entirely different from producing a B. It  seems that children who have learned to read and write by tapping on a digital tablet often have difficulty distinguishing letters that look a lot like each other or that are mirror images of each other, like the b and the p.

REINFORCING MEMORY AND LEARNING PATHWAYS

The findings in the new study are exciting and consistent with past research. With tasks that lock the motor and sensory systems together, such as in handwriting, there is a clear tie between the motor action being accomplished and the visual and conceptual recognition being created. As you’re drawing a letter or writing a word, you’re taking a perceptual understanding of something and using your motor system to create it. That creation is then fed back into the visual system, where it’s processed again—strengthening the connection between an action and the images or words associated with it. It’s similar to imagining something and then creating it: when you materialise something from your imagination (by writing it, drawing it or building it), this reinforces the imagined concept and helps it stick in your memory.

The phenomenon of boosting memory by producing something tangible has been well studied. Previous research has found that when people are asked to write, draw or act out a word that they’re reading, they have to focus more on what they’re doing with the received information. Transferring verbal information to a different form, such as a written format, also involves activating motor programs in the brain to create a specific sequence of hand motions. But handwriting requires more of the brain’s motor programs than typing. When you’re writing the word ‘the,’ the actual movements of the hand relate to the structures of the word to some extent.

For example, participants in a 2021 study by memorised a list of action verbs more accurately if they performed the corresponding action than if they performed an unrelated action or none at all. Drawing information and enacting information is helpful because you have to think about information and you have to produce something that’s meaningful. And by transforming the information, you pave and deepen these interconnections across the brain’s vast neural networks, making it much easier to access that information.

THE IMPORTANCE OF HANDWRITING LESSONS FOR KIDS

Across many contexts, studies have shown that kids appear to learn better when they’re asked to produce letters or other visual items using their fingers and hands in a coordinated way—one that can’t be replicated by clicking a mouse or tapping buttons on a screen or keyboard. Research has also found that the action of handwriting appears to engage different brain regions at different levels than other standard learning experiences, such as reading or observing. Her work has also shown that handwriting improves letter recognition in preschool children, and the effects of learning through writing last longer than other learning experiences that might engage attention at a similar level. Additionally, she thinks it’s possible that engaging the motor system is how children learn how to break “mirror invariance” (registering mirror images as identical) and begin to decipher things such as the difference between the lowercase b and p.

The new study opens up bigger questions about the way we learn, such as how brain region connections change over time and when these connections are most important in learning. These new findings don’t mean technology is a disadvantage in the classroom. Laptops, smartphones and other such devices can be more efficient for writing essays or conducting research and can offer more equitable access to educational resources. Problems occur when people rely on technology too much. People are increasingly delegating thought processes to digital devices, an act called “cognitive offloading”—using smartphones to remember tasks, taking a photo instead of memorising information or depending on a GPS to navigate. Scientists think it’s helpful, but the constant offloading means we’re not actively using those memory or motor areas in  the brain,…that can lead to deterioration over time.

Van der Meer says some officials in Norway are inching toward implementing completely digital schools. She claims first grade teachers there have told her their incoming students barely know how to hold a pencil now—which suggests they weren’t colouring pictures or assembling puzzles in nursery school. Van der Meer says they’re missing out on opportunities that can help stimulate their growing brains. Scientists are discovering that there is a very strong case for engaging children in drawing and handwriting activities, especially in preschool and kindergarten when they’re first learning about letters. Engaging the fine motor system and production activities that impacts learning and is vitally important!

REFERENCES:

R. van der Weel and A. L. H.Van der Meer. Handwriting but not typewriting leads to widespread brain connectivity: a high-density EEG study with implications for the classroom. Frontiers in Psychology. 2024, vol 14. DOI=10.3389/fpsyg.2023.1219945

Mueller, P. A., & Oppenheimer, D. M. (2014). The Pen Is Mightier Than the Keyboard: Advantages of Longhand Over Laptop Note Taking. Psychological Science25(6), 1159-1168. https://doi.org/10.1177/0956797614524581

Dong , M.S -Y. Jong and R. B. King. How Does Prior Knowledge Influence Learning Engagement? The Mediating Roles of Cognitive Load and Help-Seeking. Frontiers in Psychology. 2020, vol 11. DOI=10.3389/fpsyg.2020.591203

Roberts, B.R., Wammes, J.D. Drawing and memory: Using visual production to alleviate concreteness effects. Psychon Bull Rev 28, 259–267 (2021). https://doi.org/10.3758/s13423-020-01804-w

Y. Sivashankar & M. Fernandes (2022) Enhancing memory using enactment: does meaning matter in action production?, Memory, 30:2, 147-160, DOI: 10.1080/09658211.2021.1995877.

Adoniou (2013) Drawing to support writing development in English language learners, Language and Education, 27:3, 261-277, DOI: 10.1080/09500782.2012.704047.

Vinci-Booher S, James KH. Protracted Neural Development of Dorsal Motor Systems During Handwriting and the Relation to Early Literacy Skills. Front Psychol. 2021 Nov 19;12:750559. doi: 10.3389/fpsyg.2021.750559. PMID: 34867637; PMCID: PMC8639586.

Wiley RW, Rapp B. The Effects of Handwriting Experience on Literacy Learning. Psychol Sci. 2021 Jul;32(7):1086-1103. doi: 10.1177/0956797621993111. Epub 2021 Jun 29. PMID: 34184564; PMCID: PMC8641140.

Pegado F, Nakamura K, Hannagan T. How does literacy break mirror invariance in the visual system? Front Psychol. 2014 Jul 10;5:703. doi: 10.3389/fpsyg.2014.00703. PMID: 25071669; PMCID: PMC4091125.

Gilbert, S.J., Boldt, A., Sachdeva, C. et al. Outsourcing Memory to External Tools: A Review of ‘Intention Offloading’. Psychon Bull Rev 30, 60–76 (2023). https://doi.org/10.3758/s13423-022-02139-4.

Soares, J.S., Storm, B.C. Does taking multiple photos lead to a photo-taking-impairment effect?. Psychon Bull Rev 29, 2211–2218 (2022). https://doi.org/10.3758/s13423-022-02149-2.

Brügger A, Richter KF, Fabrikant SI. How does navigation system behavior influence human behavior? Cogn Res Princ Implic. 2019 Feb 13;4(1):5. doi: 10.1186/s41235-019-0156-5. PMID: 30758681; PMCID: PMC6374493.

E. Tømte and J. H. Smedsrud. Governance and digital transformation in schools with 1:1 tablet coverage. Frontiers in Education. 2023, vol. 8. DOI=10.3389/feduc.2023.1164856

Can You Smell What I’m Feeling?

Posted Posted in Jayne's blog

If you’ve ever (even for a short while) lost your sense of smell – it may have been with early covid, but it could have been due to a heavy cold – then you’ll understand how disorienting it can be.

We know that smell is deeply embedded in our brains and linked inextricably to memory. But it now appears that smell forms an intrinsic part of a person’s identity: scents are not only important in our relationship to food and the natural world but they also play a role in how we communicate with people we know.

A 2023 study from European researchers found that not only can we pick up the scent of other people’s fear or anxiety, but such emotions affect how we feel, too. Another study from China showed that people with better olfaction have more friends.

Humans have a long history of disregarding our noses—even Darwin claimed that the sense of smell is of “extremely slight service” to people. It appears that ‘social olfaction’ happens outside of our conscious attentionand the only thing you pick up on is that your body feeling changes. But you can’t quite put your finger on what it is…Yet humans seem quite able to pick out someone else’s body odour. One study found that after shaking hands with people of the same gender, people reflexively sniffed their right hand more than twice as often as they did before the greeting.

We pick up quite a lot of information from sniffing the body odour of people around us: we can recognise our relatives, tell who is genetically related and pinpoint potential friends (apparently we tend to choose friends who are genetically similar to us and have similar body odour). In one study, most new mothers were able to identify their baby by its smell after spending as little as 10 minutes together, and newborns can recognise their mother, too.

Adult human sniffers, meanwhile, can match pairs of identical twins by their body odour, even if the siblings live apart. In a 2022 study, researchers at the Weizmann Institute of Science managed to predict which volunteers would bond together simply by comparing their body odour—a task performed both by human smellers and an electronic nose (a device that looks like an old CB radio with a hose). The scientists discovered that people who smelled similar to each other were more likely to enjoy chatting and report that they felt instant chemistry. This goes along with earlier research showing that we subconsciously choose friends who share some of the same genes.

What’s more, if we were to chat with someone feeling happy, chances are we would detect their current emotional state through smells that reach the nose. In one experiment conducted in the Netherlands, volunteers watched cheerful videos while holding absorbent pads in their armpits. Later, when another group sniffed the pads, measurements of their facial muscles’ activity revealed that their mood improved, too: their smile muscles moved more.

Yet it’s not only happy feelings that can be communicated through body odour. A 2020 study by Pause and colleagues showed that women’s brains reacted more strongly when they smelled the sweat of men who had played an aggressively competitive game compared with the odours of men who had just enjoyed a calm construction game. It turns out that women also proved to be particularly sensitive to odours that signaled male anxiety. On picking up such odours, they became more risk-avoidant and less trusting. Anxiety is a signal of, ‘Please, I need help.” This may explain why women appear more attuned to the smell of anxiety—historically, in distressing situations, it was women that cared for the young and the feeble. Such evolutionary links could also explain why women with more discerning noses perform better at tests of empathy, as revealed in a small 2022 study carried out by Pause and her colleagues.

In general, a sensitive nose seems to be an asset that enhances our deeply social life. Those who could better tell apart everyday odours also reported less loneliness, a 2020 study of 221 volunteers concluded. In other experiments, people with a better sense of smell had a larger social network and more friends, and they met with those friends more often. Functional magnetic resonance imaging of the brain, meanwhile, revealed that the same brain circuits may be involved in both our sense of smell and the size of our social circle.

For now, however, the mechanisms of how exactly humans pick up body odours and translate them into changes in our behaviours remain largely a mystery. Scientists are also just beginning to pinpoint which chemicals in body odour may be responsible for influencing social connections. One such molecule may be hexanal, which gives off a pleasant whiff of freshly cut grass—and appears to boost trust in people. Yet we still don’t know if those who have more hexanal in their body odour are perceived as more trustworthy, says Monique Smeets, a social psychologist at Utrecht University in the Netherlands.

More research will likely follow because, the covid pandemic really put a spotlight on the sense of smell. Even though Omicron appears to be less damaging to our noses than previous COVID variants were, a 2023 study estimated that 11.7 percent of adults of European ancestry who have been infected with Omicron have had some amount of olfactory dysfunction. People with smell loss may end up missing out on important but subconscious ways of communicating with others. And smell should be valued because olfaction is the most honest of our senses—something that, unlike our words or facial expressions, we just can’t fake. We can laugh even though we’re sad or aggressive, but we cannot intentionally change our chemical messages. It’s information which you can really trust!

REFERENCES:

Nuno Gomes, Bettina M Pause et al. Comparing fear and anxiety chemosignals: Do they modulate facial muscle activity and facilitate identifying facial expressions?, Chemical Senses, Volume 48, 2023, bjad016, https://doi.org/10.1093/chemse/bjad016

Zou, Lq., Yang, Zy., Wang, Y. et al. What does the nose know? Olfactory function predicts social network size in human. Sci Rep 6, 25026 (2016). https://doi.org/10.1038/srep25026

Idan Frumin, Ofer Perl et al. A social chemosignaling function for human handshaking. eLife 2015;4:e05154. DOI: 10.7554/eLife.05154

Nicholas A. Christakis and James H. Fowler. Friendship and natural selection. PNAS, 2014, Volume  111 (supplement_3) 10796-10801. https://doi.org/10.1073/pnas.1400825111

Kaitz M, Good A, Rokem AM, Eidelman AI. Mothers’ recognition of their newborns by olfactory cues. Dev Psychobiol. 1987 Nov;20(6):587-91. doi: 10.1002/dev.420200604. PMID: 3691966.

Craig Roberts, L. Morris Gosling et al., Body Odor Similarity in Noncohabiting Twins, Chemical Senses, Volume 30, Issue 8, October 2005, Pages 651–656, https://doi.org/10.1093/chemse/bji058

Lübke KT, Blum TC, Pause BM. Reading the Mind through the Nose: Mentalizing Skills Predict Olfactory Performance. Brain Sciences. 2022; 12(5):644. https://doi.org/10.3390/brainsci12050644

de Groot, J. H. B., Smeets, M. A. M., Rowson, M. J., Bulsing, P. J., Blonk, C. G., Wilkinson, J. E., & Semin, G. R. (2015). A Sniff of Happiness. Psychological Science, 26(6), 684-700. https://doi.org/10.1177/0956797614566318

Pause BM, Storch D, Lübke KT. 2020 Chemosensory communication of aggression: women’s fine-tuned neural processing of male aggression signals. Phil. Trans. R. Soc. B 375: 20190270. http://dx.doi.org/10.1098/rstb.2019.0270

Lukas Meister & Bettina M. Pause, It’s trust or risk? Chemosensory anxiety signals affect bargaining in women. Biological Psychology, Volume 162, 2021, 108114. https://doi.org/10.1016/j.biopsycho.2021.108114

Lübke KT, Blum TC, Pause BM. Reading the Mind through the Nose: Mentalizing Skills Predict Olfactory Performance. Brain Sciences. 2022; 12(5):644. https://doi.org/10.3390/brainsci12050644

Desiato VM, Soler ZM, Nguyen SA, et al. Evaluating the Relationship Between Olfactory Function and Loneliness in Community-Dwelling Individuals: A Cross-sectional Study. American Journal of Rhinology & Allergy. 2021;35(3):334-340. https://doi.org/10.1177/19458924209583

Boesveldt, S., Yee, J., McClintock, M. et al. Olfactory function and the social lives of older adults: a matter of sex. Sci Rep 7, 45118 (2017). https://doi.org/10.1038/srep45118

Daan van Nieuwenburg,  Jasper H. B. de Groot and Monique A. M. Smeets. The Subtle Signaling Strength of Smells: A Masked Odor Enhances Interpersonal Trust. Front. Psychol., Sec. Cognition. Volume 10, 2019.https://doi.org/10.3389/fpsyg.2019.01890

von Bartheld CS, Wang L. Prevalence of Olfactory Dysfunction with the Omicron Variant of SARS-CoV-2: A Systematic Review and Meta-Analysis. Cells. 2023 Jan 28;12(3):430. doi: 10.3390/cells12030430.

Do You Eat With Your Eyes, Your Gut Or Your Brain?

Posted Posted in Jayne's blog

The holiday season is upon us, and with it, opportunities to indulge in festive treats. The proverbial saying “you eat with your eyes first” seems particularly relevant at this time of year.

The science behind eating behaviour, however, reveals that the process of deciding what, when and how much to eat is far more complex than just consuming calories when your body needs fuel. Hunger cues are only part of why people choose to eat.

So how do people decide when to eat?

 

Eating With Your Eyes

Food-related visual cues can shape feeding behaviours in both people and animals. For example, wrapping food in McDonald’s packaging is sufficient to enhance taste preferences across a range of foods – from chicken nuggets to carrots – in young children. Visual food-related cues, such as presenting a light when food is delivered, can also promote overeating behaviours in animals by overriding energy needs.

In fact, a whole host of sensory stimuli – noises, smells and textures – can be associated with the pleasurable consequences of eating and influence food-related decisions. This is why hearing a catchy radio jingle for a food brand, seeing a television ad for a restaurant or walking by your favourite restaurant can shape your decision to consume and sometimes overindulge.

However, your capacity to learn about food-related cues extends beyond just stimuli from the outside world and includes the internal signals from your body. In other words, you also tend to eat with your stomach in mind, and you do so by using the same learning and brain mechanisms involved in processing food-related stimuli from the outside world. These internal signals, also called interoceptive cues, include feelings of hunger and fullness emanating from your gastrointestinal tract.

It’s no surprise that the signals from your gut help set the stage for when to eat, but the role these signals play is more profound than you might expect.

Trust Your Gut

Feelings of hunger or fullness act as important interoceptive cues influencing your decision-making around food.

To examine how interoceptive states shape eating behaviours, researchers trained laboratory rats to associate feelings of hunger or fullness with whether they receive food or not. They did this by giving rats food only when they were hungry or full, such that the rats were forced to recognize those internal cues to calculate whether food would be available or not. If a rat is trained to expect food only when hungry, it would generally avoid the area where food is available when it feels full because it does not expect to be fed.

However, when rats were injected with a hormone that triggers hunger called ghrelin, they approached the food delivery location more frequently. This suggests that the rats used this artificial state of hunger as an interoceptive cue to predict food delivery and subsequently behaved like they expected food.

Interoceptive states are sufficient to shape feeding behaviours even in the absence of external sensory cues. One particularly striking example comes from mice that have been genetically engineered to be unable to taste food but nevertheless show preferences for specific foods solely by caloric content. In other words, rodents can use internal cues to shape their food-related decision-making, including when and where to eat and which foods they prefer.

These findings also suggest that feelings of hunger and the detection of nutrients is not restricted to the stomach. They also involve areas of the brain important for regulation and homeostasis, such as the lateral hypothalamus, as well as centers of the brain involved in learning and memory, such as the hippocampus.

What Happens in the Vagus

The gut-brain axis, or the biochemical connection between your gut and your brain, shapes feeding behaviours in many ways. One of them involves the vagus nerve, a cranial nerve that helps control the digestive tract, among other things.

The vagus nerve rapidly communicates nutrient information to the brain. Activating the vagus nerve can induce a pleasurable state, such that mice will voluntarily perform a behaviour, such as poking their nose through an open port, to stimulate their vagus nerve. Importantly, mice also learn to prefer foods and places where vagal nerve stimulation occurred.

The vagus nerve plays an essential role in not only communicating digestive signals but also an array of other interoceptive signals that can affect how you feel and behave. In people, vagal nerve stimulation can improve learning and memory and can be used to treat major depression.

Benefits of Interoceptive Awareness

Your body’s capacity to use both external and internal cues to regulate how you learn and make decisions about food highlights the impressive processes involved in how you regulate your energy needs.

Poor interoceptive awareness is associated with a range of dysfunctional feeding behaviours, such as eating disorders. For instance, anorexia may result when interoceptive signals, such as feelings of hunger, are unable to trigger the motivation to eat. Alternatively, the inability to use the feeling of fullness to dampen the rewarding and pleasurable consequences of eating palatable food could result in binge eating.

Your interoceptive signals play an important role in regulating your daily eating patterns. During the holidays, many stressors from the outside world surround eating, such as packed social calendars, pressures to conform and feelings of guilt when overindulging. At this time, it is particularly important to cultivate a strong connection to your interoceptive signals (though this may be more difficult than you think – or maybe much easier!). This can help promote intuitive eating and a more holistic approach to your dietary habits. Rather than fixating on external factors and placing conditions on your eating behaviour, enjoy the moment, deliberately savour each bite and provide time for your interoceptive signals to function in the role they are designed to play.

Your brain evolved to sense your current energy needs. By integrating these signals with your experience of your food environment, you can both optimize your energetic needs and enjoy the season!

Happy holidays and see you again in the New Year.

Is Hitting the Snooze Button Good or Bad for Your Health?

Posted Posted in Jayne's blog

When the alarm goes off in the early morning, it’s tempting to hit the snooze button and curl back under the warm covers for a few more minutes of slumber. This repeated postponing of the buzzer is often thought of as a bad habit—one that creates not only a lazy start to a day but also a fragmented sleep pattern that’s detrimental to health. Now, however, a growing body of recent research is contradicting this notion.

A new study published in the Journal of Sleep Research found that people who regularly press the snooze button lost only about six minutes of sleep per night—and that it didn’t affect their morning sleepiness or mood. In fact, tests showed that it actually improved cognition. This adds to research in 2022 that also found chronic snoozers generally felt no sleepier than nonsnoozers.

Tina Sundelin, a sleep researcher at Stockholm University, says that her new snooze study is one of few that have directly tested snoozing’s effect on sleep health, and it supplies evidence that snoozing doesn’t break up sleep in a harmful way.

 

The Potential Benefits of Snoozing

According to Sundelin’s research, snoozing does shorten sleep but it’s not as bad as scientists once thought. Past research has suggested that the extra minutes snoozers get don’t really help them feel more rested—and repeatedly waking up and trying to sleep again has been thought to prevent the restorative stages of sleep, including rapid-eye movement (REM). Other research has suggested that waking someone in the middle of their sleep cycle causes them to feel sleepier throughout the day. But this idea is based on a whole night of sleep fragmentation. And apparently many of the theories about snoozing are inferred – based more on what is known about sleep in general – than actually what has been measured,

In the new study, Sundelin found that snoozing the alarm for a half hour benefited chronic snoozers—people who delay the alarm two or more times a week and almost always fall back asleep between alarms. Thirty-one such chronic snoozers who were observed in the study slept well throughout the night and only showed signs of fragmented sleep in the last 30 minutes before getting up, which is typically around the time that people first hit the snooze button. But this fragmented sleep did apparently not have a big enough impact to make them tired throughout the rest of the day.

Sundelin’s research also suggests that snoozing may help people shake off morning drowsiness by easing the transition from deep sleep to a lighter stage. A good night’s rest typically involves four to five sleep cycles, each made up of four stages. Light sleep happens in the first two stages of nonrapid eye movement (NREM). This is when muscles start to relax, and brain activity slows, along with breathing and heart rate—but a person can still be easily woken. As the night goes on, people progressively reach deeper stages. It gets harder to wake up during the third and final stage of NREM and the first stage of REM. A person who receives a phone call during these stages, for example, may be less likely to hear it or remember answering.

Abruptly waking up, especially amid deep sleep, can prolong sleep inertia—a drowsy state of transition to wakefulness in which one may feel disoriented or struggle with adjusting to being awake. This is where snoozing may help, Sundelin has found thay people who squeeze little naps between alarms can more effectively shift out of deep sleep and wake up during lighter sleep. This may help them decrease sleep inertia and feel more alert and energetic in the morning.

Sundelin’s results show that the additional light slumber may also aid cognition. Even with their last half hour of sleep fragmented, snoozers didn’t feel more tired during the day. They were also alert enough to perform well on cognitive tests of processing speed, episodic memory and executive functioning, as well as simple arithmetic. A second cognitive test showed these benefits continued for at least 40 minutes after waking up.

Sundelin hypothesizes that snoozing prevented people’s brain from quickly reverting to deeper sleep stages. Snoozers also showed higher levels of cortisol, a hormone involved in wakefulness, compared with people who slept uninterrupted throughout the whole night.

Snoozing Impacts Peoples Differently

Young adults typically press snooze more often than older ones. Thomas Kilkenny, director of the Institute of Sleep Medicine at Staten Island University Hospital, says that adults in their early to mid-20s tend to stay up late and get less sleep overall. Some people’s biological clock—a built-in 24-hour cycle that helps the body regulate processes including wakefulness and sleep—tends to shift toward a “night owl” chronotype during adolescence, reaching a peak “lateness” around age 20. The body just doesn’t want to go to sleep until one o’clock in the morning, even if you have to get up at six to go to school/class!

Night owl–types, regardless of age, are also more likely to hit snooze. Those with late chronotypes often feel their best in the evening and prefer going to bed closer to midnight. Given that school and work typically start early, however, night owls often have to wake up when they are least alert compared to “morning larks” (people with an early chronotype). She adds that sleep inertia can be worse when waking up closer to one’s circadian low, a time when alertness is bottoming out. Therefore, later chronotypes may find it harder to wake up for early classes and workdays given the increased sleep inertia during this time.

How to Get the Most Out of Snoozing

The optimal period to spend snoozing is somewhere between 20 to 30 minutes. This is then charaterized as “refreshing but not too much.” This is equivalent to hitting the snooze button every five to 10 minutes for a total of three or four times. This is likely enough to overcome sleep inertia, which usually lasts 30 minutes or less for someone who isn’t sleep-deprived. Additionally, snoozing for more than half an hour can inch a person closer to the deeper phases of sleep from which it’s harder to get up. This is why people who say they’ve “overslept” sometimes feel so groggy or disoriented.

So snoozing can give the body some time to adjust and prepare to get out of bed. This may come in handy for things such as adjusting to the beginning of daylight saving time, when many people lose an hour of sleep when the clocks go forward an hour. But people who regularly wake up without an alarm or who get up the first time it goes off may not get those same benefits if they snooze. This is because the body has already had enough time to fully rest.

There is one caveat: snoozing can never replace a good night’s sleep. People who feel they need to snooze for more than 30 minutes and who have difficulty waking up after that may be showing signs of sleep deprivation. If that’s the case, the problem won’t be solved with the touch of a button—and snoozing might, in fact, make things worse. Waking tactics such as the slow-to-rise method (gradually shifting wake-up time 10 to 15 minutes earlier every few days) could help some people—but only those who are already getting enough sleep.

There is still much to learn about snoozing’s long-term impact on cognition and the brain. But the new research is a helpful step toward dispelling some of the “lazy” stereotypes often associated with this common morning ritual. So regular snoozers can feel less guilty for catching some extra z’s while hitting the alarm button tomorrow morning. Hooray! I know what I’m doing tomorrow morning when my alarm goes off in the dark early hours…

REFERENCES:

Sundelin, S. Landry &  J. Axelsson (2023).  Is snoozing losing? Why intermittent morning alarms are used and how they affect sleep, cognition, cortisol, and mood. Journal of Sleep Research, e14054. https://doi.org/10.1111/jsr.14054

Simon Makin. Deep Sleep Gives Your Brain a Deep Clean. https://www.scientificamerican.com/article/deep-sleep-gives-your-brain-a-deep-clean1/

Tassi & A. Muzet (2000). Sleep inertia. Sleep Medicine Reviews Volume 4, Issue 4, Pages 341-353. https://doi.org/10.1053/smrv.2000.0098

Pappas. Are Naps Good For You? https://www.scientificamerican.com/article/are-naps-good-for-you/

Fries, L. Dettenborn & C. Kirschbaum (2009). The cortisol awakening response (CAR): Facts and future directions. International Journal of Psychophysiology. Volume 72, Issue 1, Pages 67-73. https://doi.org/10.1016/j.ijpsycho.2008.03.014.

Roenneberg et al. (2004). A marker for the end of adolescence. Current Biology. Volume 14, Issue 24, PR 1038-R1039. https://doi.org/10.1016/j.cub.2004.11.039

The National Institute for Occupational Safety and Health (NIOSH). Training for Nurses on Shift Work and Long Work Hours. https://www.cdc.gov/niosh/work-hour-training-for-nurses/longhours/mod7/03.html

New Evidence – Food Can Be Addictive

Posted Posted in Jayne's blog

When I was doing my neuroscience degree, I always found it astonishing that, given the option, most rats will choose sugar instead of cocaine.

Their lust for sugar is so intense that they will go as far as to self-administer electric shocks in their desperation to consume it.

Rats aren’t alone in this drive. Humans, it seems, do something similar.

People who’ve had bariatric surgery (gastric band) sometimes continue to overindulge in highly processed foods, those made from white flour, sugar, butter, and the like, even if it means later enduring vomiting and diarrhea. Daily snacking on processed foods, recent studies show, rewires the brain’s reward circuits. Cravings for tasty meals light up the brain just like cravings for cocaine do, prompting some researchers to ask whether products such as chips (fries) or biscuits can trigger addiction akin to that associated with drugs or alcohol.

Yet the issue is by no means settled. An ongoing debate persists over whether these foods are truly addictive. Processed foods might provoke compulsive behaviours that reinforce the need to consume more, but do they really have mood-altering effects, another criterion used to define an addiction?

Answers to these questions are complicated by the enormous variety of foods we consume. There is no single opiate-like substance that can be identified as leading someone to become a food addict. Arguments in favour of food addiction suggest that if carbohydrates and fats are mixed together in unnaturally large doses, this creates a rapid “delivery system” for nutrients that results in physiological effects on the brain’s reward system that resemble those produced by cocaine or nicotine.

To examine how this affects actual behaviours, researchers developed a measurement to examine the strong pull that highly processed food exerts on humans. In 2009 the Yale Food Addiction Scale emerged. It is used to assess whether a person displays behavioural patterns that would merit fries, shakes and other palatable foods being classified as addictive substances.

Using this measurement technique, a 2022 meta-analysis suggested that a whopping 20 percent of adults are addicted to food! People in this group go out of their way to obtain their favourite foods and often eat to the point of feeling physically ill. They experience withdrawal, fail to quit eating certain foods and continue their consumption pattern despite adverse consequences, such as disruptions to their daily routines and social activities. These are all criteria set out by the Yale Food Addiction Scale, which is adapted from measures used to gauge substance use disorders. The definition of food addiction is separable from obesity. Surprisingly, many people who tick the boxes for food addiction maintain a typical weight. If anything, food addiction is the closest cousin to binge eating disorder. Both cause people to exhibit a lack of control in the way food is consumed, but the definition for a substance use disorder also includes cravings, withdrawal symptoms and continued use despite negative consequences.

Critics of this research suggest that you can’t get addicted to something that’s essential to life. What’s more, while science has pinpointed nicotine in cigarettes and ethanol in wine or beer as the substances responsible for keeping people hooked, no such clear-cut equivalent exists for food. It’s apparently very difficult to prove that there are nutrients in food that directly cause addiction.

Yet Ashley Gearhardt, a clinical psychologist at the University of Michigan, argues that highly processed foods are vastly different from what our ancestors used to consume. Foods that are very high in fat and carbohydrate in an approxiamtely equal ratio don’t exist naturally. Those ratios and foods are designed by food scientists in a laboratory to look a certain way, feel a certain way in your mouth and smell a certain way when you open the package. A 2021 study showed, for example, that people with binge eating disorder exclusively overeat ultraprocessed foods.

Early research on rats suggested that sucrose keeps animals hooked. They want more and more and more. And each day, they’ll show signs of craving. Sugars are present in many natural foods, from bananas to beetroot. Yetit’s all about packaging. For example, a piece of fruit has the appropriate amount of sugar in it, based on how much fibre it contains. Also, it has other nutrients that are going to minimise or mitigate the effects that that sugar might have on our brain.

What matters, the scientists argue, is the dosage and the speed of absorption of a substance. Most people don’t consume pure ethanol, for example. Instead they opt for wine or beer, which contain a small amount of the addictive substance. (Most beer is more than 90 percent water.) Similarly, few of us indulge in sucrose by the spoonful. Nicotine also mixes with other ingredients and is carefully dosed. It’s naturally present in eggplants and tomatoes, but you won’t become an addict by indulging in vegetables.

When it comes to ultraprocessed snacks, sugar often goes together with fat—a combination that could make such foods even more addictive. A 2018 study by DeFeliceantonio and her colleagues showed that, compared with equally caloric foods containing only fat or only a carbohydrate, those made with both ingredients are far more efficient at activating the striatum, a part of the brain’s reward centre that is implicated in addictions.

For a 2023 study, DeFeliceantonio and her colleagues randomly assigned 82 people to snack on either high-fat, high-sugar yogurts or low-sugar, low-fat ones for eight weeks. The scientists discovered not only that the first group’s preference for the healthier yogurts decreased after the trial but that their brain activation patterns changed, too. When they tasted fatty, sugary milkshakes, those who had been indulging in high-fat, high-sugar snacks had an increased response in their reward circuits, including the striatum. Ultraprocessed foods seem to be hijacking the brain in a way you’d see with addiction to drugs.

One of the hallmarks of drug addiction is the release of dopamine in the brain’s reward regions. The potency of a fatty, sugary treat in triggering this release was highlighted by a 2023 study in which scientists used positron-emission tomography (PET scans) on a small sample of volunteers. The results showed that indulging in a milkshake leads to a significant release of dopamine in healthy people that can be about one third of what is usually seen with amphetamines—a group of highly addictive stimulant drugs, such as “speed.”

The addictive potential of ultraprocessed foods may not relate just to dopamine, however. A 2023 study revealed the importance of the cannabinoid receptor 2 (CB2) in getting hooked on certain foods (in this particular case, chocolate-flavored pellets, because the subjects were mice). Rodents lacking these receptors in the brain are not only less likely to become addicted to cocaine or alcohol, the research showed, but also less prone to food addiction—a finding that may open new paths for treatment of binge eating.

Research on weight-loss drugs provides further evidence that overeating and substance misuse may share common brain processes. Semaglutide (sold under the brand names Ozempic and Wegovy) induces weight loss by mimicking the insulin-increasing gut hormone glucagonlike peptide-1 (GLP-1), and it could potentially aid those struggling with various addictions, too. Animal experiments suggest, for example, that it can reduce dependence on cocaine and opioids. This supports the argument that foods and drugs, in many ways, can act on the same brain systems.

What’s more, both illegal drugs and processed foods can induce cravings in the same reward areas of the brain—as demonstrated by a 2023 functional magnetic resonance imaging (fMRI) study. When researchers showed pictures of cocaine to drug addicts or photographs of donuts to healthy people, the same brain regions—ranging from the ventral striatum and amygdala to the cerebellum—lit up in both groups. And the stronger the volunteers’ reported craving was, the more intense their neural response was as well.

Withdrawal symptoms, another classic feature of addiction, also seem to be present in connection with ultraprocessed foods. While it’s unlikely that anyone experiences physical shakes from quitting biscuits, parents who attempt to restrict their children’s intake of sugar-sweetened drinks have reported symptoms such as headaches, irritability and social withdrawal in their kids. Similarly, adolescents instructed to abstain from their high intake of sodas for three days complained of decreased motivation and ability to concentrate—along with increased headaches.

Critics of the idea that certain foods may be addictive point out that treats such as burgers don’t induce the same kind of “high” that one might experience with opioids or alcohol. That data is not included or measured in food addiction studies.

In 2022 Gearhardt and DiFeliceantonio published an opinion piece in the journal Addiction arguing that highly processed foods should be classified as addictive based on a 1988 Surgeon General report on tobacco products. That document outlined scientific evidence behind cigarettes’ addictive nature, including their psychoactive effects and potential to trigger compulsive use. Similar evidence, the scientists argue, already exists for ultraprocessed foods. If we apply that same criteria to this specific class of foods, it apparently meets every single checkbox….

REFERENCES:

M. Lenoir  et al. Intense Sweetness Surpasses Cocaine Reward. PLOS ONE 2007, 2(8): e698. https://doi.org/10.1371/journal.pone.0000698

D. Oswald et al.. Motivation for palatable food despite consequences in an animal model of binge eating. Int J Eat Disord. 2011 Apr;44(3):203-11. doi: 10.1002/eat.20808. PMID: 20186718; PMCID: PMC2941549.

N. Gearhardt and A. G. DiFeliceantonio. Highly processed foods can be considered addictive substances based on established scientific criteria. Addiction. 2023; 118:589–598. DOI: 10.1111/add.16065.

E. Thanarajah et al. Habitual daily intake of a sweet and fatty snack modulates reward processing in humans. 2023, Cell Metabolism 35, 571–584 April 4, 2023 a 2023. https://doi.org/10.1016/j.cmet.2023.02.015

Yale Food Addiction Scale https://sites.lsa.umich.edu/fastlab/yale-food-addiction-scale/

R. S. Praxedes et al. Prevalence of food addiction determined by the Yale Food Addiction Scale and associated factors: A systematic review with meta-analysis. European Eating Disorders Review, 2022, 30(2), 85–95. https://doi.org/10.1002/erv.2878

C. Fletcher and P. J. Kenny. Food addiction: a valid concept? Neuropsychopharmacol 43, 2506–2513 (2018). https://doi.org/10.1038/s41386-018-0203-9

Ayton et al. Ultra-processed foods and binge eating: A retrospective observational study. Nutrition, 2021, Volume 84, 111023. https://doi.org/10.1016/j.nut.2020.111023.

D. Oswald et al.. Motivation for palatable food despite consequences in an animal model of binge eating. Int J Eat Disord. 2011 Apr;44(3):203-11. doi: 10.1002/eat.20808

G. DiFeliceantonio et al. Supra-Additive Effects of Combining Fat and Carbohydrate on Food Reward. Cell Metabolism. VOLUME 28, ISSUE 1, P33-44.E3, JULY 03, 2018. https://doi.org/10.1016/j.cmet.2018.05.018

Carnell et al.. Milkshake Acutely Stimulates Dopamine Release in Ventral and Dorsal Striatum in Healthy-Weight Individuals and Patients with Severe Obesity Undergoing Bariatric Surgery: A Pilot Study. Nutrients 2023, 15, 2671. https://doi.org/10.3390/nu15122671

García-Blancoet al.. Role of CB2 cannabinoid receptor in the development of food addiction in male mice. Neurobiol Dis. 2023 Apr;179:106034. doi: 10.1016/j.nbd.2023.106034.

Shevchouk Olesya et al. An Overview of Appetite-Regulatory Peptides in Addiction Processes; From Bench to Bed Side. Frontiers in Neuroscience, 2021, volume 15. DOI=10.3389/fnins.2021.774050

Koban et al. A neuromarker for drug and food craving distinguishes drug users from non-users. Nat Neurosci 26, 316–325 (2023). https://doi.org/10.1038/s41593-022-01228-w

Falbe et al. Potentially addictive properties of sugar-sweetened beverages among adolescents. Appetite. 2019 Feb 1;133:130-137. doi: 10.1016/j.appet.2018.10.032.

N. Gearhardt and A. G. DiFeliceantonio. Highly processed foods can be considered addictive substances based on established scientific criteria. Addiction. 2023; 118(4): 589–598. https://doi.org/10.1111/add.16065

Benton. The plausibility of sugar addiction and its role in obesity and eating disorders. Clinical Nutrition,2010, Volume 29, Issue 3,Pages 288-303. https://doi.org/10.1016/j.clnu.2009.12.001.