By Frontiers’ science writers
As part of Frontiers’ passion to make science available to all, we highlight just a small selection of the most fascinating research published with us each month to help inspire current and future researchers to achieve their research dreams.
2022 was no different, and saw many game-changing discoveries contribute to the world’s breadth of knowledge on topics ranging from the climate crisis to robotics, and exercise to the lives of our ancestors.
So to round of the year, here are 10 Frontiers articles from this year that got the world’s top media talking.
1. This illusion, new to science, is strong enough to trick our reflexes
Have a look at the image below. Do you perceive that the central black hole is expanding, as if you’re moving into a dark environment, or falling into a hole? If so, you’re not alone: a study published to Frontiers in Human Neuroscience showed that this ‘expanding hole’ illusion, which is new to science, is perceived by approximately 86% of people.
The researchers don’t yet know why a minority seem unsusceptible to the ‘expanding hole’ illusion. Nor do they know whether other vertebrate species, or even nonvertebrate animals with camera eyes such as octopuses, might perceive the same illusion as we do.
“Our results show that pupils’ dilation or contraction reflex is not a closed-loop mechanism, like a photocell opening a door, impervious to any other information than the actual amount of light stimulating the photoreceptor,” said Dr Bruno Laeng, a professor at the Department of Psychology of the University of Oslo and the study’s first author.
“Rather, the eye adjusts to perceived and even imagined light, not simply to physical energy. Future studies could reveal other types of physiological or bodily changes that can ‘throw light’ onto how illusions work.”
2. A replay of life: What happens in our brain when we die?
Imagine reliving your entire life in the space of seconds. Like a flash of lightning, you are outside of your body, watching memorable moments you lived through. This process, known as ‘life recall’, can be similar to what it’s like to have a near-death experience. What happens inside your brain during these experiences and after death are questions that have puzzled neuroscientists for centuries. However, a study published to Frontiers in Aging Neuroscience suggested that your brain may remain active and coordinated during and even after the transition to death, and be programmed to orchestrate the whole ordeal.
When an 87-year-old patient developed epilepsy, Dr Raul Vicente of the University of Tartu, Estonia and colleagues used continuous electroencephalography (EEG) to detect the seizures and treat the patient. During these recordings, the patient had a heart attack and passed away. This unexpected event allowed the scientists to record the activity of a dying human brain for the first time ever.
3. Eating vegetables does not protect against cardiovascular disease, finds large-scale study
A sufficient intake of vegetables is important for maintaining a balanced diet and avoiding a wide range of diseases. But might a diet rich in vegetables also lower the risk of cardiovascular disease (CVD)? Unfortunately, researchers from the Nuffield Department of Population Health at the University of Oxford, the Chinese University of Hong Kong, and the University of Bristol found earlier this year no evidence for this.
That the consumption of vegetables might lower the risk of CVD might at first sight seem plausible, as their ingredients such as carotenoids and alpha-tocopherol have properties that could protect against CVD. But so far, the evidence from previous studies for an overall effect of vegetable consumption on CVD has been inconsistent.
Results from a powerful, large-scale new study in Frontiers in Nutrition showed that a higher consumption of cooked or uncooked vegetables is unlikely to affect the risk of CVD. They also explain how confounding factors might explain previous spurious, positive findings.
4. Having good friendships may make for a healthier gut microbiome
Social connections are essential for good health and wellbeing in social animals, such as ourselves and other primates. There is also increasing evidence that the gut microbiome – through the so-called ‘gut-brain axis’ – plays a key role in our physical and mental health and that bacteria can be transmitted socially, for example through touch. So how does social connectedness translate into the composition and diversity of the gut microbiome? That’s the topic of a study in Frontiers in Microbiology on rhesus macaques, Macaca mulatta.
The scientists focused on a single social group (with 22 males and 16 females between the ages of six and 20 years) of rhesus macaques on the island of Cayo Santiago, off the eastern coast of Puerto Rico. Macaques originally only lived in North Africa and Asia. But in 1938, a founder population of 409 rhesus macaques was moved from India to Cayo Santiago. Today, more than 1,000 macaques live on the 15.2 hectare island, divided into several social groups. They range and forage freely, although their diet gets supplemented daily with monkey chow. Researchers do behavioral observations on the monkeys each year.
Lead author Dr Katerina Johnson, a research associate at the Department of Experimental Psychology and the Department of Psychiatry of the University of Oxford, said: “Here we show that more sociable monkeys have a higher abundance of beneficial gut bacteria, and a lower abundance of potentially disease-causing bacteria.”
5. Robotic arms connected directly to brain of partially paralyzed man allows him to feed himself
Two robotic arms – a fork in one hand, a knife in the other – flank a seated man, who sits in front of a table, with a piece of cake on a plate. A computerized voice announces each action: “moving fork to food” and “retracting knife.” Partially paralyzed, the man makes subtle motions with his right and left fists at certain prompts, such as “select cut location”, so that the machine slices off a bite-sized piece. Now: “moving food to mouth” and another subtle gesture to align the fork with his mouth.
In less than 90 seconds, a person with very limited upper body mobility who hasn’t been able to use his fingers in about 30 years, just fed himself dessert using his mind and some smart robotic hands.
A team led by researchers at the Johns Hopkins Applied Physics Laboratory (APL), in Laurel, Maryland, and the Department of Physical Medicine and Rehabilitation (PMR) in the Johns Hopkins School of Medicine, published a paper in Frontiers in Neurorobotics that described this latest feat using a brain-machine interface (BMI) and a pair of modular prosthetic limbs.
6. Excessive blue light from our gadgets may accelerate the aging process
Too much screen use has been linked to obesity and psychological problems. Now a study has identified a new problem – a study in fruit flies suggests our basic cellular functions could be impacted by the blue light emitted by these devices. These results are published in Frontiers in Aging.
“Excessive exposure to blue light from everyday devices, such as TVs, laptops and phones, may have detrimental effects on a wide range of cells in our body, from skin and fat cells, to sensory neurons,“ said Dr Jadwiga Giebultowicz, a professor at the Department of Integrative Biology at Oregon State University and senior author of this study. “We are the first to show that the levels of specific metabolites – chemicals that are essential for cells to function correctly – are altered in fruit flies exposed to blue light.“
“Our study suggests that avoidance of excessive blue light exposure may be a good anti-aging strategy,“ said Giebultowicz.
The researchers at Oregon State University have previously shown that fruit flies exposed to light ‘turn on‘ stress protective genes, and that those kept in constant darkness lived longer.
“To understand why high-energy blue light is responsible for accelerating aging in flies, we compared the levels of metabolites in flies exposed to blue light for two weeks to those kept in complete darkness,“ explained Giebultowicz. Blue light exposure caused significant differences in the levels of metabolites measured by the researchers in the cells of fly heads. In particular, they found that the levels of the metabolite succinate were increased, but glutamate levels were lowered.
7. Scientific ‘detective work’ reveals South American mummies were brutally murdered
How frequent was violence in prehistoric human societies? One way to measure this is to look for trauma in prehistoric human remains. For example, a recent review of pre-Columbian remains found evidence of trauma from violence in 21% of males. So far, most studies of this kind focused on skulls and other parts of the skeleton, but a potentially richer source of information are mummies, with their preserved soft tissues.
Now in a study in Frontiers in Medicine, researchers used 3D computed tomography (3D CT) to examine three mummies from pre-Columbian South America, conserved since the late 19th century in European museums.
“Here we show lethal trauma in two out of three South American mummies that we investigated with 3D CT. The types of trauma we found would not have been detectable if these human remains had been mere skeletons,” said Dr Andreas G Nerlich, a professor at the Department of Pathology of Munich Clinic Bogenhausen in Germany, the study’s corresponding author.
Nerlich and colleagues studied a male mummy at the ‘Museum Anatomicum’ of the Philipps University Marburg, Germany, as well as a female and a male mummy at the Art and History Museum of Delémont, Switzerland. Mummies can form naturally when dry environments, for example in deserts, soak up fluids from a decomposing body faster than the decay can proceed – conditions common in the southern zones of South America.
8. WWII shipwreck has leaked many pollutants into the sea, changing the ocean floor around it
Researchers have discovered that an 80 year old historic World War II shipwreck is still influencing the microbiology and geochemistry of the ocean floor where it rests. In Frontiers in Marine Science, they showed how the wreck is leaking hazardous pollutants, such as explosives and heavy metals, into the ocean floor sediment of the North Sea, influencing the marine microbiology around it.
The seabed of the North Sea is covered in thousands of ship and aircraft wrecks, warfare agents, and millions of tons of conventional munition such as shells and bombs. Wrecks contain hazardous substances (such as petroleum and explosives) that may harm the marine environment. Yet, there is a lack of information about the location of the wrecks, and the effect they might have on the environment.
“The general public is often quite interested in shipwrecks because of their historical value, but the potential environmental impact of these wrecks is often overlooked,” said PhD candidate Josefien Van Landuyt, of Ghent University. For example, it is estimated that World War I and II shipwrecks around the world collectively contain between 2.5m and 20.4m tons of petroleum products.
As part of the North Sea Wrecks project, Van Landuyt and her colleagues investigated how the World War II shipwreck V-1302 John Mahn in the Belgian part of the North Sea is impacting the microbiome and geochemistry in its surrounding seabed.
“We wanted to see if old shipwrecks in our part of the sea (Belgium) were still shaping the local microbial communities and if they were still affecting the surrounding sediment. This microbial analysis is unique within the project,” explained Van Landuyt.
9. Verbal insults trigger a ‘mini slap to the face’, finds new research
Humans are a highly social species. We rely on ever-changing cooperation dynamics and interpersonal relations to survive and thrive. Words have a big role to play in these relations, as they are tools used to understand interpersonal behavior. As such, words can hurt, but we know little about how the impact of words comes about as someone processes an insult.
“The exact way in which words can deliver their offensive, emotionally negative payload at the moment these words are being read or heard is not yet well-understood,” said corresponding author of a Frontiers in Communication study, Dr Marijn Struiksma, of Utrecht University.
Because insults pose a threat against our reputation and against our ‘self’, they provide a unique opportunity to research the interface between language and emotion. Struiksma continued:
“Understanding what an insulting expression does to people as it unfolds, and why, is of considerable importance to psycholinguists interested in how language moves people, but also to others who wish to understand the details of social behavior.”
10. When should I schedule my exercise? The question is more important than you think
When should I fit exercise within my daily schedule? For most, the answer depends on our family’s schedule and working hours, and perhaps on whether we’re ‘larks’ or ‘night owls’. But over the past decade, researchers have found that much more hangs on this question than these constraints. That’s because recent findings suggest that the effectiveness of exercise depends on the time of day (Exercise Time Of Day, ETOD).
Now, a randomized controlled trial not only confirms convincingly that ETOD affects the effectiveness of exercise, but also shows that these effects differ between types of exercise, and between women and men. The results are published in Frontiers in Physiology.
Principal investigator Dr Paul J Arciero, a professor at the Health and Human Physiological Sciences Department of Skidmore College in Saratoga Springs, NY, US, said: “Here we show for the first time that for women, exercise during the morning reduces belly fat and blood pressure, whereas evening exercise in women increases upper body muscular strength, power, and endurance, and improves overall mood and nutritional satiety.”
“We also show that for men, evening exercise lowers blood pressure, the risk of heart disease, and feelings of fatigue, and burns more fat, compared to morning exercise.”
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