How Fast Our Brains Are At ‘Recording’ New Words? (Neuroscience)

How much time does a brain need to learn a new word? A team of Skoltech researchers and their colleagues monitored changes in brain activity associated with learning new words and found that cortical representations of the sound and meaning of these words may form in just one to two hours after exposure without any night’s sleep consolidation, as earlier research suggested. This research has implications for diagnosing speech disorders and improving the efficiency of learning. The paper was published in the journal Frontiers in Neuroscience.

Consider the word snollygoster, which means someone without principles, especially a politician. It is likely that you did not know this word before, but you do know now—repeat it several times, and you have learned it. This rather simple and everyday task of learning new words, however, is quite poorly understood in terms of neurocognitive mechanisms that ensure you will remember what snollygoster is days, weeks and years later.

“By nature, every word has two aspects: a particular phonetic pattern that is effectively detected by the brain and the semantics associated with the phonology (an object or an action). In order to dig into the word learning mechanism, one should provide word learning in both aspects: a pseudoword should have original phonetics, i.e. the word should not be constructed from the known roots or other morphemes, and it should acquire original meaning, i.e. not be a synonym for any known word. These restrictions are rather tough to satisfy and control in an experimental setting. The second difficulty is the separation of sematic and phonological processes as they overlap in time and brain localization. Also, the design of effective learning procedure that mobilizes the participant’s brain is challenging,” Alexandra Razorenova, a coauthor of the paper, explains.

Razorenova and Anna Butorina of the Skoltech Center for Computational and Data-Intensive Science and Engineering (CDISE) in collaboration with the Moscow Center for Neurocognitive Research (MEG Center) tried to look for evidence on how the brain learns both a phonological representation of a new word (how it sounds) and its meaning, or the semantic aspect of new word acquisition. They were also searching for what’s called rapid cortical plasticity, i.e. immediate changes in brain activity that follow the learning of a new word. Earlier studies of this particular design have been rare and inconclusive.

The team used magnetoencephalography (MEG) to observe how 24 participants in the experiment learned eight Russian pseudowords carefully designed for the study. A participant had to associate four particular pseudowords with hand and foot movements (so that these pseudowords would mean something). Unlike their colleagues in earlier studies, the researchers did not focus on any specific cortical regions or time intervals, performing an unbiased data search to find neural activity changes induced by word learning.

Not only were they able to observe immediate changes in cortical activity during the process of word learning, but the team also showed that these changes were significantly different for meaningful pseudowords compared to those that were not assigned any meaning.

“The contrast between neural responses elicited by action-associated, and ’empty’ pseudowords before and after learning procedure answers the question regarding the semantic network’ localization and the relation between sematic and phonological learning. Our findings present the evidence of short-term effortful semantization of word-form and suggest that this semantization facilitates or even triggers strengthening of the cortical network that underlies the phonological aspect of lexicality. That is, ‘meaningful’ pseudowords acquire priority to be recognized and remembered,” Razorenova says.

Some earlier electroencephalography and MEG studies also reported rapid cortical plasticity within short experiments; in these studies, repetition supp

ression was characteristic for real words, while for pseudowords repetition caused response enhancement. Razorenova’s group found the opposite to be true. The scientists hypothesize that this might be due to the fact that deep familiarization with word-forms during the experiment completely changed the repetition effect: instead of increasing neural responses to previously unfamiliar word-forms, it decreased them when the word-forms became well-recognized concatenations of phonemes. “The above considerations suggest that our findings most probably reflect a mechanism of familiarization memory that, once formed, lasts over days,” Razorenova notes.

The researchers believe their experimental paradigm and data analysis methods will be useful for diagnostics of speech disorders, as it will help differentiate the phonological processes disorders associated with Broca’s complex dysfunction from the sematic network failure.

“In a wider perspective, our results evidence the crucial role of interactive learning in contrast with passive learning procedures widely used in the literature. The key role of personal experience, or action or emotion association with the task, are consistent with the Pavlovian learning paradigm. However, this reinforcement method is still underestimated in linguistic methodology. The research may be used as experimental evidence for modification of foreign language learning programs for adults and in programs working with children with developmental disorders of speech and language. These programs should be realized in interactive way with wide usage of simulators of active search and reinforcement,” Alexandra Razorenova concludes.

References: Alexandra M. Razorenova et al. Rapid Cortical Plasticity Induced by Active Associative Learning of Novel Words in Human Adults, Frontiers in Neuroscience (2020). DOI: 10.3389/fnins.2020.00895 link: https://www.frontiersin.org/articles/10.3389/fnins.2020.00895/full

Scientists Discover What Happens In Our Brains When We Make Educated Guesses (Neuroscience)

Researchers have identified how cells in our brains work together to join up memories of separate experiences, allowing us to make educated guesses in everyday life. By studying both human and mouse brain activity, they report that this process happens in a region of the brain called the hippocampus.

The hippocampus is a region of the brain largely responsible for memory formation. Credit: Salk Institute

The study, published in the scientific journal Cell, also reveals that brain cells can link different memories while we are resting or sleeping, a process that may be important in creativity.

The research was funded by the Medical Research Council (MRC), part of UK Research and Innovation (UKRI), and Wellcome, and was carried out at the MRC Brain Network Dynamics Unit at the University of Oxford, by Dr. Helen Barron and Dr. David Dupret.

Dr. Barron said: “In everyday life we often infer connections or relationships between different things we see or hear. So even when we don’t know the full story, we can make an educated guess by joining-the-dots. For example, I’m looking for my friend Sam. Someone tells me that Ben is in the library. I know that Sam and Ben go everywhere together, so I guess that Sam is in the library too.

“Although this process is crucial to everyday life, until now, we didn’t know how the cells in our brains are able to form links between separate experiences.”

The researchers began by pinpointing this ability to an area of the brain called the hippocampus that is already known to play a role in learning and memory. They did this using MRI scans on people and by temporarily switching off the hippocampus in mice.

To discover precisely how brain cells enable us to make educated guesses, the researchers ran a set of very similar experiments in people and mice.

Human volunteers were asked to play a virtual reality game where hearing a sound, such as running water, signalled that the volunteers would also see a colourful picture appear on the wall.

They would then play another game where finding the colourful pictures would help them win money. The sound was never directly connected to winning money, yet the volunteers began to guess that the sound was linked to the prize and when they heard it, they would look for the reward.

The experiment was recreated in mice by playing a sound before showing a picture made from LED lights. Then, in a separate stage of the task, the mice could find a reward of sugar water if the lights were turned on. Like the people, the mice began connecting the sound with the reward.

Dr. Dupret said: “By carrying out similar experiments with both mice and people, this work shows that the process of establishing a link between separate events is common to both species. And by working with mice, it’s then possible to examine what’s going on in the brain of a mammal at the level of individual cells.”

In mouse brains, the researchers could record the activity of brain cells that individually represented sounds, lights or rewards. As the mice began to infer that a sound was logically linked to the reward via a light, they found that the cells began to fire in that order.

However, they kept monitoring the mice when they rested after completing the task and they saw that the mice’s brains began jumping over the intermediate ‘light’ step. The ‘sound’ brain cells became active with the ‘reward’ brain cells; joining the dots between different experiences.

Dr. Dupret added: “This suggests that while the mice are resting, their brains are making new links between things they have not directly experienced together, and we think it’s this process that will help them make useful decisions in the future.”

Dr. Barron said: “Our results suggest the process is very similar in people and that has important implications. It suggests that periods of rest and sleep play an important role in creativity, where we draw insight from previous experience to come up with original ideas.”

Dr. Simon Fisher, Programme Manager for the Neurosciences and Mental Health Board at the MRC, added: “Our ability to put individual memories together to form new links helps us make day-to-day decisions. This study provides insight into how and where in the brain this key process takes place. It also suggests that while we are sleeping or resting, our brains are actively making these links, a process that may form the basis of creative thinking.

“This strong approach, of working with mice alongside comparable experiments with people, allows findings from one species to inform studies in the other and enhances the translation of biological knowledge from animal models through to humans.

References: Helen C. Baron et al., “Neuronal Computation Underlying Inferential Reasoning in Humans and Mice”, Cell biology, 2020 DOI:https://doi.org/10.1016/j.cell.2020.08.035 link: https://www.cell.com/cell/fulltext/S0092-8674(20)31077-1?_returnURL=https%3A%2F%2Flinkinghub.elsevier.com%2Fretrieve%2Fpii%2FS0092867420310771%3Fshowall%3Dtrue

Plants Produce Nutrient-Rich Substances For Insects At Night (Botany)

A multidisciplinary team of researchers has just demonstrated that guttation, small watery drops exudated from the margins of plants leaves, is a nutrient-rich food source for beneficial insects (pollinators or those used for biological pest control).

Guttation is a common phenomenon in many plant species that occurs at night when soil moisture is high. Insects such as bees, parasitoids or dipterans drink from these small drops that for a long time had been considered only a source of water for them.

The new study, in which the UV and IVIA have participated through the Joint Research Unit on Biotechnological Control of Pests, and Rutgers University (U.S.), shows clear evidence that plant guttation is rich in carbohydrates but also contains proteins that can be essential for many insect species. Insects from three distinct families and feeding lifestyles (i.e., an herbivore, a parasitic wasp, and a predator) increased their survival and reproductive capacity when they fed on guttation droplets during their entire adult life, under controlled conditions, says Pablo Urbaneja Bernat, researcher at Rutgers University.

The study, says Joel González-Cabrera, Ramón y Cajal researcher from the Institute of Biotechnology and Biomedicine (BIOTECMED), from the University of Valencia, “has important agronomic implications because in the field trial we have evidenced that plants with guttation droplets doubled the abundance of beneficial insects such as parasitic wasps and predators, those that protect the plants from pests.”

“Therefore, the presence of guttation droplets might reduce the numerous problems caused by pests in crops, including invasive pests,” mentioned Alejandro Tena, researcher at IVIA, who also pointed out that this process could occur in numerous crops where guttation is common such as rice, wheat, barley, rye, oats, sorghum, corn, tobacco, tomato, strawberry and cucumber, among others.

Another novelty of the study is that contrary to what might be expected, guttation was present in blueberry fields throughout the season. “This finding can be crucial for the conservation of beneficial insects such as parasitic wasps, predators and pollinators, since they can find and feed on guttation droplets when pollen or nectar from flowers are scarce,” concludes Cesar Saona, who led the experiments at Rutgers University in the United States.

Overall, the data presented in the article provides the first evidence that plant guttation is an important but underexplored trait in plants with profound implications for their interactions with insects in managed and natural ecosystems. This research has been funded by the Ramón y Cajal program, as well as by several grants from the United States.

References: Pablo Urbaneja-Bernat et al. Plant guttation provides nutrient-rich food for insects, Proceedings of the Royal Society B: Biological Sciences (2020). DOI: 10.1098/rspb.2020.1080 link: https://royalsocietypublishing.org/doi/10.1098/rspb.2020.1080

This Device Could Help Detect Signs Of Extraterrestrial Life (Astronomy / Aliens)

Although Earth is uniquely situated in the solar system to support creatures that call it home, different forms of life could have once existed, or might still exist, on other planets. But finding traces of past or current lifeforms on other worlds is challenging. Now, researchers reporting in ACS’ Analytical Chemistry have developed a fully automated microchip electrophoresis analyzer that, when incorporated into a planetary rover, could someday detect organic biosignatures in extraterrestrial soil.

A fully automated microchip electrophoresis analyzer could someday be deployed in the search for life on other worlds. Credit: Adapted from Analytical Chemistry 2020, DOI: 10.1021/acs.analchem.0c01628

One critical piece of evidence for life beyond Earth is the presence of certain organic molecules. Previous missions to Mars have relied on gas chromatography coupled to mass spectrometry (GC-MS) to separate and detect compounds. However, the technique has limitations for the analysis of some molecules, such as organic acids, especially when water, minerals or salts are also in the sample. Microchip electrophoresis (ME)-based separations, followed by laser-induced fluorescence (LIF) detection, would be ideal, but current instruments are only partially automated, which wouldn’t work for interplanetary missions. Peter Willis and colleagues wanted to develop a portable, battery-powered ME-LIF instrument that could accept a sample and perform labeling, separation and detection of organic molecules, all in a fully automated fashion.

The researchers made a device that included two microchips—one for processing and labeling a liquid sample, and the other (the ME chip) for separating compounds—and an LIF detection system. After optimizing the device, the researchers put it to the test in a simulated Mars mission in a Chilean desert. The team coupled the analyzer to a portable subcritical water extractor on a remotely deployed rover system. The rover drilled into the soil to collect samples, which were delivered to the extractor. Then, water was added to the soil samples, and they were heated to extract compounds for analysis. The device detected parts per billion levels of amino acids in soil from three of four drilling locations. Importantly, the sensitivity was three orders of magnitude higher than that reported for GC-MS-based methods. Although more work is needed to ready the instrument for spaceflight and extraterrestrial conditions, this research lays the foundation for developing ME-LIF instruments for missions seeking signs of life beyond Earth.

This article is first published on science daily..

References: Maria F. Mora et al. Fully Automated Microchip Electrophoresis Analyzer for Potential Life Detection Missions, Analytical Chemistry (2020). DOI: 10.1021/acs.analchem.0c01628 link: https://pubs.acs.org/doi/10.1021/acs.analchem.0c01628

Does Death Of The Star Can Cause Any Impact On The Life? Webb Telescope Can Answer Us (Astronomy)

According to Lisa Kaltenegger and colleagues, a planet orbiting a white dwarf presents a promising opportunity to determine if life can survive the death of its star.

Jupiter sized planet, WD 1856+534b orbiting white dwarf

In a study, they showed how NASA’s upcoming James Webb Space Telescope could find signatures of life on Earth-like planets orbiting white dwarfs.

A planet orbiting a small star produces strong atmospheric signals when it passes in front, or “transits,” its host star. White dwarfs push this to the extreme: They are 100 times smaller than our sun, almost as small as Earth, affording astronomers a rare opportunity to characterize rocky planets.

If rocky planets exist around white dwarfs, we could spot signs of life on them in the next few years. James Webb Space Telescope, scheduled to launch in October 2021, is uniquely placed to find signatures of life on rocky exoplanets.

When observing Earth-like planets orbiting white dwarfs, the James Webb Space Telescope can detect robust >5σ (detections) of H2O and CO2 in a five-transit reconnaissance program (Few hours), while the biosignatures O3 + CH4 and CH4 + N2O can be detected to >4σ in as few as 25 transits (2days). N2 and O2 can be detected to >5σ within 100 transits. Given the short transit duration of white dwarf habitable zone planets (~2 minutes for WD 1856+534b), conclusive molecular detections can be achieved in a small or medium JWST transmission spectroscopy program.

WD 1856+534b planet is a gas giant and therefore not able to sustain life. But its existence suggests that smaller rocky planets, which could sustain life, could also exist in the habitable zones of white dwarfs.

The researchers combined state-of-the-art analysis techniques routinely used to detect gases in giant exoplanet atmospheres with the Hubble Space Telescope with model atmospheres of white dwarf planets from previous Cornell research.

NASA’s Transiting Exoplanet Survey Satellite is now looking for such rocky planets around white dwarfs. If and when one of these worlds is found, Kaltenegger and her team have developed the models and tools to identify signs of life in the planet’s atmosphere. The Webb telescope could soon begin this search.

The implications of finding signatures of life on a planet orbiting a white dwarf are profound. Most stars, including our sun, will one day end up as white dwarfs.

References: Lisa Kaltenegger et al. The White Dwarf Opportunity: Robust Detections of Molecules in Earth-like Exoplanet Atmospheres with the James Webb Space Telescope. The Astrophysical Journal Letters, Volume 901, Number 1. DOI: 10.3847/2041-8213/aba9d3 link: https://iopscience.iop.org/article/10.3847/2041-8213/aba9d3

“Cranian Pluvial Episode”, Is A Newly Discovered Mass Extinction Event (Paleontology)

In a new paper, published today in Science Advances, an international team has identified a major extinction of life 233 million years ago that triggered the dinosaur takeover of the world. The crisis has been called the Carnian Pluvial Episode (Late Triassic).

They reviewed all the geological and palaeontological evidence and determined what had happened and presented a meta-analysis of fossil data that suggests a substantial reduction in generic and species richness and the disappearance of 33% of marine genera. This crisis triggered major radiations. In the sea, the rise of the first scleractinian reefs and rock-forming calcareous nannofossils points to substantial changes in ocean chemistry.

The cause was most likely massive volcanic eruptions in the Wrangellia Province of western Canada, where huge volumes of volcanic basalt was poured out and forms much of the western coast of North America.

The eruptions were so huge that they pumped vast amounts of greenhouse gases like carbon dioxide, and there were spikes of global warming. The warming was associated with increased rainfall, and this had been detected back in the 1980s by geologists Mike Simms and Alastair Ruffell as a humid episode lasting about 1 million years in all. The climate change caused major biodiversity loss in the ocean and on land, but just after the extinction event new groups took over, forming more modern-like ecosystems. The shifts in climate encouraged growth of plant life, and the expansion of modern conifer forests.

The new floras probably provided slim pickings for the surviving herbivorous reptiles. They had noted a floral switch and ecological catastrophe among the herbivores back in 1983. They now know that dinosaurs originated some 20 million years before this event, but they remained quite rare and unimportant until the Carnian Pluvial Episode hit. It was the sudden arid conditions after the humid episode that gave dinosaurs their chance.”

It wasn’t just dinosaurs, but also many modern groups of plants and animals also appeared at this time, including some of the first turtles, crocodiles, lizards, and the first mammals.

The Carnian Pluvial Episode also had an impact on ocean life. It marks the start of modern-style coral reefs, as well as many of the modern groups of plankton, suggesting profound changes in the ocean chemistry and carbonate cycle.

So far, palaeontologists had identified five “big” mass extinctions in the past 500 million years of the history of life. Each of these had a profound effect on the evolution of the Earth and of life. They have identified another great extinction event, and it evidently had a major role in helping to reset life on land and in the oceans, marking the origins of modern ecosystems.

References: Jacopo Dal Corso, Massimo Bernardi, Yadong Sun, Haijun Song, Leyla J. Seyfullah, Nereo Preto, Piero Gianolla, Alastair Ruffell, Evelyn Kustatscher, Guido Roghi et al., “Extinction and dawn of the modern world in the Carnian (Late Triassic)”, Science Advances, 2020: Vol. 6, no. 38, eaba0099 DOI: 10.1126/sciadv.aba0099 link: https://advances.sciencemag.org/content/6/38/eaba0099

Th Afterburn Effect Makes You Burn Calories Even After A Workout Is Over (Fitness / Biology)

The adage “calories in, calories out” sounds simple enough: If your workout burns the same number of calories as you eat, you’ll maintain your weight. That’s true in theory, but tough in practice. How many calories does your workout burn? If you’re going by the number on the treadmill or your exercise watch, you’re probably getting it wrong. Exercise doesn’t just burn calories in the moment. The afterburn effect describes the way your body continues to burn calories after — sometimes long after — you’re done working out, and some exercises do it more than others.

Most people think of the human body like a car: while it’s running, it burns fuel in the form of calories, and while it’s at rest, it doesn’t. In reality, the human body is much more complex than that. Not only do you burn calories just by being alive, but exercise can also burn calories long after you’ve left the gym.

The scientific term for the afterburn effect is excess post-exercise oxygen consumption, or EPOC, and the research says the more intense the exercise, the more it kicks in. One study found that participants burned more calories in just the 14 hours after an intense workout than they did for an entire rest day. Another study showed that even though you burn more calories during cardio workouts than weight training, the calories you burn after each workout are roughly the same.

With the way people talk about diet and exercise, it seems like a good workout can be completely ruined by a single donut. The afterburn effect demonstrates how false this thinking is. Exercise has an impact that goes far beyond a few extra calories, which is why it’s important to make it a regular part of your life.

This Is How Often You Should Replace Your Toothbrush (Hygiene / Biology)

It’s not a great sign if you don’t remember the last time you replaced your toothbrush. But we’re not here to shame you; we’re here to help you. Just a heads-up: You’ll probably be pitching your current toothbrush before you finish reading this article.

Brushing your teeth has likely become a Pavlovian activity for you. Wake up, brush; get ready for bed, brush. You owe it to yourself to keep a closer eye on your teeth cleaning routine. Namely, the status of your toothbrush. If your brush isn’t clean, how can you expect it to polish your ivories effectively? According to the American Dental Association (ADA), you should swap out your toothbrush (or electric toothbrush head) every three to four months. That is, if you use it twice a day, which we hope you do. Think about your toothbrush as a seasonal item.

Dentist Keith Arbeitman tells Business Insider another key clue that your toothbrush needs to head to the trash: “Once the bristles start to bend, you’re not really cleaning as effectively.” Arbeitman also recommends just occasionally running your tongue across your teeth. If you don’t feel like your pearly whites are as slippery as usual, your brush probably isn’t doing the trick anymore.

You might think this seems all a little ridiculous. Three months is not a very long time, after all. What’s the worst that could happen if you ignore our advice? Some pretty nasty crap could get in those bristles. Literally. According to a 2015 study, toothbrushes in communal bathrooms can become contaminated with fecal matter. Having your toothbrush around other people’s contaminants is a dangerous thing, according to Lauren Aber, MHS, one of the study’s authors. Surprisingly, this isn’t such a big deal when you live alone. The trouble happens when the fecal matter is from someone else because it “contains bacteria, viruses or parasites that are not part of your normal flora.”

The most logical solution is a toothbrush cover, right? Well, they aren’t actually all that helpful. “Using a toothbrush cover doesn’t protect a toothbrush from bacterial growth, but actually creates an environment where bacteria are better suited to grow by keeping the bristles moist and not allowing the head of the toothbrush to dry out between uses,” Aber said. A 2007 study confirms this. Besides regular replacing, a good way to protect your uncovered toothbrush from unwanted germs is easy: Just stand it upright. “If you stand a toothbrush up and let it dry between uses,” Arbeitman told Business Insider, “the bacteria are pretty much going to die.”

If You Want To Live Longer, Become A Parent (Biology)

Among the top reasons for having kids, besides maintaining your family line and passing on your legacy, is to have someone to take care of you in old age. According to research, that is a very solid plan: people who have children live longer than people who don’t, and those benefits are even greater the older you get.

In 2017, Karin Modig of Sweden’s Karolinska Institute and her colleagues published a study in the Journal of Epidemiology & Community Health that looked at how having kids affected how long people live. As the Guardian reports, “While previous research has shown that adults with children live longer than those without, the new study [unpacks] how the effect plays out in older age.” The study used data from Sweden’s national registry to follow nearly 1.5 million men and women born between 1911 and 1925 from their 60th birthday until either their death, their emigration, or the end of the study in 2014, whichever came first.

Here’s what they found: at age 60, fathers had almost two years greater life expectancy than men without children, and mothers had a little over a year greater life expectancy than childless women. Once those people reached age 80, the differences were closer to a year for men and six months for women. But when it came to the overall risk of dying within a year, the differences were more pronounced the older the study subjects got. When adjusted for educational level and marital status, the difference in death risk between men with and without children went from 0.06 percent at age 60 to 1.47 percent at age 90.

The study also found that the benefits of having kids were even greater for unmarried men than for married men. According to the study, this may be because “marriage has sometimes been shown to be more beneficial to men’s survival than to women’s survival” — that is, marriage already helps men live longer, so any leg up unmarried men can get will have more of an impact. So if the parenting happiness gap has got you down, take comfort in the fact that you’ve got security in old age that the childless likely don’t.