Craving snacks after a meal? It might be food-seeking neurons, not an overactive appetite

The discovery of a circuit in the brain of mice that makes them seek fatty food, even when they are not hungry, could have implications for future understanding of and treatment for human eating disorders.
Photo Credit: Annie Spratt

People who find themselves rummaging around in the refrigerator for a snack not long after they’ve eaten a filling meal might have overactive food-seeking neurons, not an overactive appetite.

UCLA psychologists have discovered a circuit in the brain of mice that makes them crave food and seek it out, even when they are not hungry. When stimulated, this cluster of cells propels mice to forage vigorously and to prefer fatty and pleasurable foods like chocolate over healthier foods like carrots.

People possess the same kinds of cells, and if confirmed in humans, the finding could offer new ways of understanding eating disorders.

The report, published in the journal Nature Communications, is the first to find cells dedicated to food-seeking in a part of the mouse brainstem usually associated with panic, but not with feeding.

“This region we’re studying is called the periaqueductal gray (PAG), and it is in the brainstem, which is very old in evolutionary history and because of that, it is functionally similar between humans and mice,” said corresponding author Avishek Adhikari, a UCLA associate professor of psychology. “Although our findings were a surprise, it makes sense that food-seeking would be rooted in such an ancient part of the brain, since foraging is something all animals need to do.”

New research deepens our understanding of pescatarians

(L-R)
Postgraduate researcher Maja Cullen, teaching assistant and researcher Devon Docherty, and Dr Carol Jasper
Photo Credit: Courtesy of University of Stirling

New research has deepened our understanding of why pescatarians choose to eat fish but not the meat of land animals.

The perceived distance between marine life and participants in the study was a key factor, researchers in the University of Stirling’s Division of Psychology found.

The team, consisting of Maja Cullen, Devon Docherty and Dr Carol Jasper, used the construal-level theory of psychological distance to investigate further how this distance is created and how this might be experienced.

The theory argues that we interpret people, animals, objects or situations differently depending on how much we know about them.

Dr Carol Jasper, co-author of the study, said: “When we do not know much about someone or something we think of it in more abstract and general terms because we lack information.

“For our sample of pescatarians, this meant that they felt less emotionally connected to marine animals than they felt to land animals with whom we share some more obvious similarities.

Researchers identify distinct sleep types and their impact on long-term health

Photo Credit: Sam Moghadam Khamseh

Poor sleep habits are strongly associated with long-term chronic health conditions, according to decades of research. To better understand this relationship, a team led by researchers in Penn State’s College of Health and Human Development identified four distinct patterns that characterize how most people sleep. These patterns are also predictive of long-term health, the researchers said.

Soomi Lee, associate professor of human development and family studies at Penn State, led a team in identifying these sleep patterns and their correlation to overall health. Their results were published in Psychosomatic Medicine.

Using a national sample of adults from the Midlife in the United States study, the team gathered data on approximately 3,700 participants’ sleep habits and their chronic health conditions across two time points 10 years apart. The data included self-reported sleep habits, including sleep regularity and duration, perceived sleep satisfaction and daytime alertness, as well as the number and type of chronic conditions.

The brain is 'programmed' for learning from people we like

Image Credit: Gemini Advance AI

Our brains are "programmed" to learn more from people we like – and less from those we dislike. This has been shown by researchers in cognitive neuroscience in a series of experiments.

Memory serves a vital function, enabling us to learn from new experiences and update existing knowledge. We learn both from individual experiences and from connecting them to draw new conclusions about the world. This way, we can make inferences about things that we don't necessarily have direct experience of. This is called memory integration and makes learning quick and flexible.

Inês Bramão, associate professor of psychology at Lund University, provides an example of memory integration: Say you're walking in a park. You see a man with a dog. A few hours later, you see the dog in the city with a woman. Your brain quickly makes the connection that the man and woman are a couple even though you have never seen them together. 

“Making such inferences is adaptive and helpful. But of course, there's a risk that our brain draws incorrect conclusions or remembers selectively”, says Inês Bramão.

Study finds childhood bullying linked to distrust and mental health problems in adolescence

Photo Credit: Mikhail Nilov

A new study, co-led by UCLA Health and the University of Glasgow, found that young teenagers who develop a strong distrust of other people as a result of childhood bullying are substantially more likely to have significant mental health problems as they enter adulthood compared to those who do not develop interpersonal trust issues.

The study, published in the journal Nature Mental Health on Feb. 13, is believed to be the first to examine the link between peer bullying, interpersonal distrust, and the subsequent development of mental health problems, such as anxiety, depression, hyperactivity and anger. 

Researchers used data from 10,000 children in the United Kingdom who were studied for nearly two decades as part of the Millennium Cohort Study. From these data, the researchers found that adolescents who were bullied at age 11 and in turn developed greater interpersonal distrust by age 14 were around 3.5 times more likely to experience clinically significant mental health problems at age 17 compared to those who developed less distrust.

Can we decode the language of our primate cousins?

The UNIGE team wanted to find out whether the frontal and orbitofrontal regions of our brain activate in the same way when faced with human and simian vocalizations.
Image Credit: © Leonardo Ceravolo

Are we able to differentiate between the vocal emissions of certain primates? A team from the University of Geneva (UNIGE) asked volunteers to categorize the vocalizations of three species of great apes (Hominidae) and humans. During each exposure to these "onomatopoeia", brain activity was measured. Unlike previous studies, the scientists reveal that phylogenetic proximity - or kinship - is not the only factor influencing our ability to identify these sounds. Acoustic proximity - the type of frequencies emitted - is also a determining factor. These results show how the human brain has evolved to process the vocal emissions of some of our closest cousins more efficiently. Find out more in the journal Cerebral Cortex Communications.

Our ability to process verbal language is not based solely on semantics, i.e. the meaning and combination of linguistic units. Other parameters come into play, such as prosody, which includes pauses, accentuation and intonation. Affective bursts - "Aaaah!" or ‘‘Oh!’’ for example - are also part of this, and we share these with our primate cousins. They contribute to the meaning and understanding of our vocal communications.

When such a vocal message is emitted, these sounds are processed by the frontal and orbitofrontal regions of our brain. The function of these two areas is, among other things, to integrate sensory and contextual information leading to a decision. Are they activated in the same way when we are exposed to the emotional vocalizations of our close cousins, the chimpanzees, macaques and bonobos? Are we able to differentiate between them?

VR users need an emotional connection to virtual worlds, not better graphics

Realistic graphics are only important when the virtual world triggers a sense of threat
Image Credit: Sara Kurig

Being wowed by powerful graphics is not enough for a person to feel fully immersed in a virtual-reality (VR) world – a strong emotional response to the simulated environment is essential too, according to a new study from the University of Bath.

Indeed, field of view and visual realism – achieved through cutting-edge graphics and usually powered by high-end headsets – can be relatively unimportant in creating a believable VR experience. Far more important is the way a user is made to feel (e.g. happy or scared) within the virtual environment, the study found.

Dr Crescent Jicol, principal investigator of the study, said: “A lot of money goes into making headsets and screens better and into rendering virtual worlds more realistic, but more effort needs to be centered on improving the user’s emotional experience.”

Though the findings of this Bath study may ultimately reduce the pressure on gamers to overspend on high-end VR equipment, the implications of this work extend beyond entertainment: in the years ahead, VR is expected to play an ever-growing role in many areas of life, from workplace training to medical rehabilitation programs.

A good night’s sleep may help to generate false memories, a new study reveals

Sleep may play a key role in distorting memories
Photo Credit: Vlada Karpovich
Edited: Scientific Frontline 

From misremembering that movie quote to forgetting that vital ingredient from the shops for the evening dinner, the human memory is not always reliable. Now, researchers have discovered that sleep may play a key role in distorting memories, but perhaps in a good way.

In psychological experiments, false memories often arise when people are given a list of related words to memorize, and falsely remember a word being there that would have fit the category but in fact was missing.

Lure words

As part of this study, published in the journal Royal Society Open Science, researchers from the University of York’s Department of Psychology tested 488 participants on their ability to recall a list of words 12 hours after seeing them, with some of the participants being allowed to sleep in the 12-hour interim.

They found that those who had slept remembered more of the words on the list than those who had not, but they were also more likely to give words that weren't on the list, but were related. 

The related incorrect words are known as "lure words". If a list contained words like nurse, hospital and sick, the false memories may include lure words like doctor.

What’s the story behind ASMR clips?

Quiet noises such as touching a microphone with your fingertips trigger a pleasant feeling in some people.
Photo Credit: © RUB, Marquard

Researchers at Ruhr University Bochum have published the first systematic review of Autonomous Sensory Meridian Response (ASMR).

Millions of people watch content creators on YouTube and social media platforms such as TikTok as they whisper soothing words, perform simulated role plays such as a visit to the hairdresser, or interact with certain objects such as the keyboard of a computer in a specific rhythm. About 25 to 30 percent of the viewers experience the Autonomous Sensory Meridian Response (ASMR) associated with well-being, a characteristic tingling sensation on the scalp and neck. Tobias Lohaus of Ruhr University Bochum, Germany, together with Professor Patrizia Thoma (also Ruhr University) and Professor Silja Bellingrath (University of Duisburg-Essen), published the first systematic review on this topic. This systematic review reveals that, among other things, this phenomenon is associated with short-term positive effects on mental health. The research team published their findings in the journal Psychology of Consciousness: Theory, Research, and Practice.

Brain health in over 50s deteriorated more rapidly during the pandemic

Photo Credit: Gabriel Porras

Brain health in over 50s deteriorated more rapidly during the pandemic, even if they didn’t have COVID-19, according to major new research linking the pandemic to sustained cognitive decline.

Researchers looked at results from computerized brain function tests from more than 3,000 participants of the online PROTECT study, who were aged between 50 and 90 and based in the UK. The remote study, led by teams at the University of Exeter and the Institute of Psychiatry, Psychology & Neuroscience (IoPPN) at King’s College London, and part-funded by NIHR Maudsley BRC, tested participants’ short-term memory and ability to complete complex tasks.

Through analyzing the results from this big dataset, researchers found that cognitive decline quickened significantly in the first year of the pandemic, when they found a 50 per cent change to the rate of decline across the study group. This figure was higher in those who already had mild cognitive decline before the pandemic, according to the research published in The Lancet Healthy Longevity.

Stunting in infancy linked to differences in cognitive and brain function

Photo Credit: bethL

Children who are too short for their age can suffer reduced cognitive ability arising from differences in brain function as early as six months of age, according to new research.

Researchers from the University of Nottingham were part of a team led by the University of East Anglia who compared the ‘visual working memory’ – the memory capacity that holds visual cues for processing – in children who had stunted growth with those having typical growth.

Published today in the journal Nature Human Behavior, the study found that the visual working memory of infants with poor physical growth was disrupted, making them more easily distracted and setting the stage for poorer cognitive ability one year later.

Stunted growth had previously been linked with poor cognitive outcomes later in life, but this is the first time that this association has been found in infancy. It is also the first time stunted growth has been linked to functional differences in how the brain works in early development.

New Research Suggests Why Males and Females Respond Differently to Social Stress

Emily Wright, researcher, in a UC Davis lab.
Photo Credit: Jerry Tsai

Women are nearly twice as likely as men to be diagnosed with an anxiety disorder, but among boys and girls the likelihood is the same. New University of California, Davis, research has identified changes in the brain during puberty that may account for differences in how women and men respond to stress.

A team of psychologists has found that testosterone is the key hormone that drives gender-based differences in responses to social stress. The study encompassed six separate experiments with mice to isolate what changes in the brain drive these differences between males and females. The study was published in the Proceedings of the National Academy of Sciences, or PNAS, today.

“This research shows how the body’s hormones shape the complex interplay between the brain’s circuitry and behavioral responses to stress,” said Brian Trainor, a professor of psychology in the College of Letters and Science at UC Davis and the study’s corresponding author.

Sexism and poorer parenting: Auckland study suggests a link

Professor Nickola Overall (top left) with researchers Dr Annette Henderson, Dr Rachel Low, Dr Valerie Chang, Dr Caitlin McRae and Dr Nina Waddell.
Photo Credit: Courtesy of University of Auckland

Fathers and mothers who believe men should hold the power and authority in society and the family were less responsive to their children during family interactions, according to University of Auckland research.

The study was the first of its type.

“For decades, sexism has been known to predict negative behaviors toward women, from discrimination to violence,” says lead author Professor Nickola Overall, of Waipapa Taumata Rau, University of Auckland. “Our study suggests the effects flow through to poorer parenting.”

Video-recording family groups in the laboratory, researchers assessed parents’ responsiveness, including warmth, involvement, engagement, and sensitivity toward their children.

The less responsive parents – both mothers and fathers – had disclosed higher levels of “hostile sexism,” an academic term for attitudes favoring male authority and antagonism toward women who challenge men’s social power.

Cannabis intoxication triggers cognitive mechanism of addiction

Photo Credit: Matthew Brodeur

New research from the Institute of Psychiatry, Psychology & Neuroscience (IoPPN) at King’s College London and the University of Oxford has found that the main component of cannabis, delta-9-tetrahydrocannabinol (THC), leads to people’s attention being more drawn to other cannabis stimuli when using the drug, which researchers suggest could underpin the cognitive mechanisms behind cannabis use disorder (CUD).

The research, published in Addiction, also found that levels of cannabidiol (CBD) typically found in cannabis had no modulating effects on the participants, despite many users believing this to be the case.

Over the course of four sessions, researchers asked 46 infrequent cannabis users (using cannabis less than once a week) to inhale a cannabis vapour containing 10mg of THC, and either 0, 10, 20, or 30mg of CBD. They were then given a task designed to measure what they focused on more when given the choice between options of images (cannabis stimuli vs neutral and food stimuli vs neutral).

Researchers found that the acute inhalation of THC resulted in people being more drawn to cannabis-related cues without explicitly liking it more.

Post-traumatic stress affects more than one in 10 cardiac device patients

Image Credit: Joshua Chehov

Nearly one-third of patients with an implanted device to prevent sudden death have anxiety in the first year, while depression affects one in five. That’s the finding of a study published this week in EP Europace, a journal of the European Society of Cardiology (ESC).

Lead author Professor Hannah Keage from the University of South Australia says implantable cardioverter defibrillators (ICDs) are effective at extending patients’ lives, “but we need to make sure that is a good quality life”.

“Rates of mood disorders in people with an ICD are much higher than in the general population, suggesting that psychological assessment and therapy should be integrated into the routine care of these patients,” Prof Keage says.

An ICD is recommended for people at high risk of a life-threatening heart rhythm and those who have had a cardiac arrest. Anxiety and depression are associated with a higher likelihood of premature death in patients with an ICD.

The study compiled the best available evidence to determine levels of depression, anxiety, and post-traumatic stress disorder (PTSD) in patients with an ICD.

Alcohol harm reduction can also reduce other substance use

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Quitting alcohol or drugs was not a top priority for people experiencing homelessness in a harm reduction treatment study, yet participants still reduced their use of both.

A different approach than traditional abstinence-based programs, harm reduction treatment for alcohol use disorder, also called HaRT-A, has patients set their own goals. In a study of 308 people experiencing homelessness, the participants receiving harm reduction treatment set goals of meeting basic needs and improving quality of life well above quitting alcohol and other substances.

Yet harm reduction treatment still led to more reduced use compared to a control group who received regular services. The findings are detailed in the Journal of Addiction Medicine.

“It’s a good reminder that all people have the same basic goals: we all want to be safer, healthier and happier, and when we help people experiencing homelessness achieve those goals, they might end up doing the things that treatment providers want them to do anyway,” said Susan Collins, a Washington State University psychology professor and the study’s senior author. “They might end up cutting down their use; they might end up quitting, but it’s on their own terms and their own timeline, so it’s more sustainable.”

Collins and first author Nicki Mostofi analyzed data from an earlier clinical study focused on harm reduction and alcohol use. That study involved people with alcohol use disorder from three Seattle homeless shelters who were divided into different groups: one received harm reduction treatment alone, another treatment with naltrexone which reduces alcohol cravings, and a third group had the treatment and a placebo. A fourth control group received traditional services.

Reindeer can show great performance at following human-given indications

Photo Credit: Courtesy of University of Turku

An international team of researchers from the University of Turku, Finland, and the INRAE of Nouzilly, France, explored the ability of sledging reindeer to follow directional indications from humans. Their results highlight that reindeer, which are well habituated to humans, can make use of gestural cues very well with minimal training.

Working animals, such as equines, shepherd dogs, and logging elephants, spend a significant amount of time interacting closely with humans to fulfil specific tasks. Effective communication plays a crucial role in their working relationship. Animals' understanding of human cues, particularly manual pointing gestures, is an important aspect of this communication. 

The use of pointing gestures to communicate with others and to show them where to look or to go is very natural for humans. For other animals that do not use this means of communication, the gesture may not always be easy to understand. For this reason, the pointing gesture is often used in experiments to see if animals can understand cues that are specific to humans. 

“Many species, such as dogs, primates, horses, goats or elephants, have already shown great potential at following human gestures, but this has never been investigated in any deer species. “, says the lead author of the study, Doctoral Researcher Océane Liehrmann from the Department of Biology at the University of Turku, Finland. 

Women feel the pain of losses more than men when faced with risky choices

Evaluating risk - are women more risk averse than men?
Photo Credit: Oleksandr Pidvalnyi

Women are less willing to take risks than men because they are more sensitive to the pain of any losses, they might incur than any gains they might make, new research from the University of Bath School of Management shows.

Published in the British Psychological Society’s British Journal of Psychology, the study – “Gender differences in optimism, loss aversion and attitudes toward risk" - also finds that men are ‘significantly’ more optimistic than women, making them more willing to take risks.

Researcher Dr Chris Dawson, associate professor in business economics at the University of Bath School of Management, said the findings were significant and could help explain sex-specific outcomes in different employment sectors, and in financial markets.

‘It is widely acknowledged that men, across many domains, take more risks than women. These differences in how the sexes view risk can have significant effects,” Dr Dawson says.

‘For instance, differences between the sexes in risk taking can explain why women are less likely to be entrepreneurs, are underrepresented in high-paying jobs and upper management, and less likely to invest their wealth in equities markets than men. Despite these important implications, we still know very little about why women take fewer risks than men.

Neurotic people are more likely to suffer from mood swings

Neurotic people experience negative emotions more intensely and have more mood swings than others.
Photo Credit: Gerd Altmann

In everyday life, our emotions often change from moment to moment, and people experience these fluctuations to varying degrees. Psychologists at Leipzig University have studied the relationship between the personality trait neuroticism – a potential risk factor for mental health – and emotional experiences. They found that neurotic people experience negative emotions not only more intensely, but also with more mood swings than others. They have just published their findings in the Proceedings of the National Academy of Sciences (PNAS).

“Previous studies are in agreement that neurotic people experience stronger negative emotions in everyday life. Because of new, contradictory studies, there has been disagreement about whether this is also associated with increased variability in emotional experiences, i.e. mood swings,” says the study’s first author, Nina Mader from the Wilhelm Wundt Institute of Psychology at Leipzig University. Personality psychologists at Leipzig University have developed a new approach to modelling data that solves previous methodological problems. “We use an approach from Bayesian statistics that allows additional flexibility in data modelling. We first successfully tested this approach in simulations and then re-examined 13 longitudinal data sets. The results suggest that neurotic people do indeed experience greater variability in negative emotions,” explains Mader. A total of 2,518 people were asked about their emotions.

New insights into teen sleep

Dr Serena Bauducco with a sleep monitor at the Flinders University Sleep and Psychology Lab.
Photo Credit: Courtesy of Flinders University

Parents setting bedtime rules can be “protective” of their teenage children’s health and wellbeing, helping them to establish good sleep routines as young adults and in the future, say Flinders University researchers.  

Using feedback from 2500 students aged from 12 to 14 between 2019-2020, the national study found adolescents whose parents set bedtimes had at least 20 minutes more sleep on average which can make “all the difference” to next-day performance – including reaching the recommended 8-10 hours of sleep a night.  

The adolescent sleep researchers at Flinders University are now seeking 30 participants for a new study in Adelaide to record their self-monitored sleep overnight, using electronic devices and other factors to find out more about teen sleep habits.  

“Most young people tend to stay up later and have less sleep when they are left to set their own bedtimes, but qualitative research is finding that adolescents are open to parental guidance to improve their sleep patterns,” says psychology researcher Dr Serena Bauducco, a visiting scholar from Sweden.