New evidence confirms a long-held theory that people with schizophrenia hear 'voices' in their heads by misattributing inner speech as external.

"This idea's been around for 50 years, but it's been very difficult to test because inner speech is inherently private," says Thomas Whitford, a psychology researcher at the University of New South Wales.

Using EEG (electroencephalography) to measure brainwaves, Whitford and his colleagues tested the way that the brain reacts to inner speech, and, in people with schizophrenia, the way their brains react to auditory hallucinations.

"When we speak – even just in our heads – the part of the brain that processes sounds from the outside world becomes less active," Whitford explains. "This is because the brain predicts the sound of our own voice. But in people who hear voices, this prediction seems to go wrong, and the brain reacts as if the voice is coming from someone else."

The Solar System ☀️🪐🌎

Vascular dementia is caused by blood flow issues in the brain: it's one of the most common types of dementia, but not as well researched or understood as others.

Neuropathologist Elaine Bearer from the University of New Mexico is trying to change that.

In a recent review, she has suggested new categorizations for vascular dementia, each with unique pathologies – the actual biological changes in tissues and organs.

She highlights some significant overlap with Alzheimer's disease, and she says her team's novel microscopy method sheds light on how microplastics that have seeped into the body could be triggering or exacerbating cases of vascular dementia.

"We have been flying blind," says Bearer. "The various vascular pathologies have not been comprehensively defined, so we haven't known what we're treating."

"And we didn't know that nano- and microplastics were in the picture, because we couldn't see them."

Climate projections have long indicated that global warming might weaken the Southern Ocean’s capacity to absorb carbon dioxide (CO2). Yet, long-term measurements reveal that this crucial ability has remained largely unchanged in recent decades. A new study by scientists at the Alfred Wegener Institute (AWI) offers insight into why this might be the case.

For many years, low-salinity water near the ocean’s surface has helped trap carbon in the deep sea, preventing it from escaping back into the atmosphere. However, climate change is now disrupting this balance and altering how effectively the Southern Ocean functions as a carbon sink. The findings are detailed in the journal Nature Climate Change.

Oceans collectively take up about one quarter of the CO2 produced by human activity. Of that amount, the Southern Ocean alone accounts for roughly 40 percent, making it one of the planet’s most important regions for slowing global warming.

Its powerful influence stems from the region’s unique circulation patterns. Deep waters rise to the surface, exchange gases with the atmosphere, and then sink again, carrying newly absorbed CO2 into the depths.

“Previous studies suggested that global climate change would strengthen the westerly winds over the Southern Ocean, and with that, the overturning circulation too,” says Léa Olivier. “However, that would transport more carbon-rich water from the deep ocean to the surface, which would consequently reduce the Southern Ocean’s ability to store CO₂.” Although strengthening winds have already been observed and attributed to human-made change in recent modeling and observational studies, there is no evidence pointing to the Southern Ocean absorbing less CO₂ – at least at this point.

Long-term observations by the AWI and other international research institutes suggest that climate change may be affecting the properties of surface and deep water masses.

The Southern Ocean’s surface water salinity has reduced as a result of increased input of freshwater caused by precipitation and melting glaciers and sea ice. This “freshening” reinforces the density stratification between the two water masses, which in turn keeps the CO₂-rich deep water trapped in the lower layer and prevents it from breaking through the barrier between the two layers.

The team found that a normally inactive gene, WUSCHEL-D1, becomes active early in flower development, causing the plant to form extra ovaries that can each grow into a grain. This discovery could allow breeders to develop new, higher-yielding wheat varieties without needing more land or resources, offering a major step toward meeting global food demands in a changing climate.

A tiny chip implanted into the eyes of people suffering vision loss from irreversible age-related macular degeneration has restored central sight in a dazzling first.

It's called the PRIMA system, tested across 17 European hospitals, and it restored central vision in 26 of 32 patients who used it for 12 months – many of whom could even read again. The result, developed by a large international team of doctors and scientists over many years, represents a massive breakthrough in treatments for vision loss.

"It's the first time that any attempt at vision restoration has achieved such results in a large number of patients," says ophthamologist José-Alain Sahel of the University of Pittsburgh School of Medicine, co-senior author on a paper describing the results.

"More than 80 percent of the patients were able to read letters and words, and some of them are reading pages in a book. This is really something we couldn't have dreamt of when we started on this journey, together with Daniel Palanker, 15 years ago."

Poisoning is a term most often associated with the human body and natural environments.

But it is also a growing problem in the world of artificial intelligence (AI) – in particular, for large language models such as ChatGPT and Claude.

In fact, a joint study by the UK AI Security Institute, Alan Turing Institute and Anthropic, published earlier this month, found that inserting as few as 250 malicious files into the millions in a model's training data can secretly "poison" it.

So what exactly is AI poisoning? And what risks does it pose?

What is AI poisoning?
Generally speaking, AI poisoning refers to the process of teaching an AI model wrong lessons on purpose. The goal is to corrupt the model's knowledge or behavior, causing it to perform poorly, produce specific errors, or exhibit hidden, malicious functions.

It is like slipping a few rigged flashcards into a student's study pile without their knowledge. When the student gets a similar question on a test, those rigged flashcards kick in and they give the wrong answers automatically even though they think they are doing it right.

The results of the first clinical trial of “enteral ventilation” have been published, and are considered a success, a step along the road to a treatment that could save many lives and prevent even more injuries. Such events happen every day as medicine progresses, but this one stands out because “enteral ventilation” is more popularly known as “butt-breathing” or a few other names you can probably fill in for yourself.

Several Australian turtle species have found a way to delay the dangers of coming to the surface to breathe by extracting oxygen dissolved in water using their cloaca. In other words, they have gill-like features in their bums that supplement their oxygen intake. Dragonfly nymphs do something similar, and even expel the water afterwards as a form of jet propulsion. This, however, is Australia, and you can probably find seventeen weirder animal behaviors within a stone’s throw of a butt-breathing turtle (arguably including their headwear). 

Medical applications were probably not the first thing on the mind of those who discovered the trait. However, sick of watching patients struggle for breath with various lung conditions, and inspired by loaches (fish that process air through their stomachs), Dr Takanori Takebe of the Institute of Science, Tokyo, proposed to take an algal leaf out of the turtles’ book. Inevitably, the work was awarded the 2024 Ig Nobel physiology prize for demonstrating the viability of mammals being able to breathe through their butts on some no doubt surprised pigs.

Undeterred by the challenges of getting taken seriously, Takebe has ploughed ahead, and the first results are promising. 

"This is the first human data, and the results are limited solely to demonstrating the safety of the procedure and not its effectiveness,” Takebe stressed in a statement. “But now that we have established tolerance, the next step will be to evaluate how effective the process is for delivering oxygen to the bloodstream."

It’s always a good day to celebrate vaccines. As one of the all-time great achievements in medicine, vaccines are the reason humanity has been able to eradicate smallpox, end the “summer plagues” of polio, and slash the incidence of cervical cancer, to name just a few. But there’s one disease that gets a bit less publicity, despite it being a significant cause of serious childhood infections before a vaccine was introduced in the 1980s: Hib.

Hib disease is caused by a bacterium called Haemophilus influenzae type B. First described in 1892 by Richard Pfeiffer, it was thought at the time to be the cause of influenza, as the bacteria were found in sputum samples from influenza patients. It was a good thought, but now we know that the flu is caused by a virus. 

H. influenzae was later understood to be a secondary infection in these patients. In fact, the bacterium can sometimes sit harmlessly inside the nose. But when it does cause disease, it can quickly get very serious. 

Hib used to be the most common cause of bacterial meningitis in children, with symptoms including fever, headache, stiff neck, and vomiting. In more severe cases, this could progress to seizures and coma. Case fatality rates vary depending on access to prompt medical care and antibiotics, but can be as high as 40 percent, according to the European Centre for Disease Prevention and Control (ECDC). 

Even with recovery, meningitis carries the risk of lifelong complications, including vision and hearing loss. Other presentations of Hib disease include epiglottitis, a potentially deadly swelling of the throat, cellulitis, pneumonia, and septicemia. 

Scientists may be closer to understanding why time seems to pass more quickly as we age — and brain scans of people watching an old Alfred Hitchcock show helped them address this enduring question.

In a study published Sept. 30 in the journal Communications Biology, scientists pulled data from the Cambridge Centre for Ageing and Neuroscience (Cam-CAN), a long-term brain-aging research project. In total, 577 people had previously watched an excerpt from the old television series "Alfred Hitchcock Presents" — specifically, eight minutes of an episode called "Bang! You're Dead." As the study participants watched the clip, functional MRI (fMRI) scans were recorded; these scans would provide a measure of how the participants' brain activity changed over time.

This particular clip was chosen because previous research showed that, compared with other video clips, it elicits the most synchronous patterns of brain activity in a wide variety of viewers. That makes it ideal for studying how the brain divides and tracks unfolding events.

At the time the brain scans were taken, the participants were between 18 and 88 years old. The researchers got access to these existing fMRI recordings and used the so-called Greedy State Boundary Search (GSBS) to analyze them.

As the name suggests, this computer algorithm detects transitions between stable patterns of brain activity. It does so "greedily" — that is, it identifies these shifts moment by moment, without taking into account the overall structure of the narrative on a longer time scale.

During the eight-minute clip, the brains of older participants shifted to new activity states less frequently, and those brain states lasted longer for them than they did for younger participants. This pattern was consistent across the full age range of 18 to 88 years.

"This suggests that longer [and, therefore, fewer] neural states within the same period may contribute to older adults experiencing time as passing more quickly," the researchers wrote in their report. This aligns with an idea of time that dates back to Aristotle: The more notable events occur in a given time period, the longer it subjectively seems. The new results raise the possibility that if older adults' brains are logging fewer "events" in a given time frame, maybe that's why time seems to fly by.

Using supercomputers, researchers recreated the galaxy’s history and mapped where dark matter should gather and collide. The results matched real gamma-ray observations, suggesting the mysterious light could be produced by dark matter particles colliding rather than by dying stars.

Clues in the Cosmic Mystery of Dark Matter
Scientists may have uncovered one of the most promising hints yet in the search to confirm the existence of dark matter.

At the heart of the Milky Way, a faint and widespread glow of gamma rays has puzzled astronomers for decades. The light could be the result of dark matter particles colliding, or it might come from fast-spinning neutron stars known as millisecond pulsars.

According to a new study published October 16 in Physical Review Letters, both explanations currently appear equally possible. If the gamma-ray glow is not produced by dying stars, it could mark the first real evidence that dark matter exists.

Scientists on the Hunt for Hidden Matter
“Dark matter dominates the universe and holds galaxies together. It’s extremely consequential and we’re desperately thinking all the time of ideas as to how we could detect it,” said co-author Joseph Silk, a professor of physics and astronomy at Johns Hopkins and a researcher at the Institute of Astrophysics, Sorbonne University, and CNRS. “Gamma rays, and specifically the excess light we’re observing at the center of our galaxy, could be our first clue.”

Silk and an international team of researchers, led by Moorits Muru with the Leibniz Institute for Astrophysics Potsdam (AIP), used supercomputers to create maps of where dark matter should be located in the Milky Way, taking into account for the first time the history of how the galaxy formed.

Galactic Collisions and a Cosmic Match
Today, the Milky Way is a relatively closed system, without materials coming in or going out of it. But this hasn’t always been the case. During the first billion years, many smaller galaxy-like systems made of dark matter and other materials entered and became the building blocks of the young Milky Way. As dark matter particles gravitated toward the center of the galaxy and clustered, the number of dark matter collisions increased.

When the researchers factored in more realistic collisions, their simulated maps matched actual gamma-ray maps taken by the Fermi Gamma-ray Space Telescope.

These matching maps round out a triad of evidence that suggests excess gamma rays in the center of the Milky Way could originate from dark matter. Gamma rays coming from dark matter particle collisions would produce the same signal and have the same properties as those observed in the real world, the researchers said—though it’s not definitive proof.

Using cutting-edge computational modeling, scientists from the University of Oxford, in collaboration with the Instituto Superior Técnico at the University of Lisbon, have successfully produced the first real-time, three-dimensional simulations showing how powerful laser beams can modify the “quantum vacuum.”

Once thought to be completely empty, this vacuum is now understood through quantum physics to be filled with fleeting pairs of virtual electrons and positrons.

The team’s simulations vividly capture a strange and long-theorized effect in quantum physics called vacuum four-wave mixing. According to this phenomenon, when three laser pulses are precisely focused, their combined electromagnetic fields can polarize the virtual particles within the vacuum.

This interaction causes photons to scatter off one another like billiard balls, resulting in the creation of a fourth beam of light in what researchers describe as a “light from darkness” process. These simulated events may provide a new way to explore untested areas of physics at extremely high energy levels.

“This is not just an academic curiosity—it is a major step toward experimental confirmation of quantum effects that until now have been mostly theoretical,” said study co-author Professor Peter Norreys, Department of Physics, University of Oxford.

A New Era of Ultra-Intense Lasers
The work arrives just in time as a new generation of ultra-powerful lasers starts to come online. Facilities such as the UK’s Vulcan 20-20, the European ‘Extreme Light Infrastructure (ELI)’ project, and China’s Station for Extreme Light (SEL) and SHINE facilities are set to deliver power levels high enough to potentially confirm photon-photon scattering in the lab for the first time. Photon-photon scattering has already been selected as one of three flagship experiments at the University of Rochester’s OPAL dual-beam 25 PW laser facility in the United States.

The simulations were carried out using an advanced version of OSIRIS, a simulation software package that models interactions between laser beams and matter or plasma.

In research published on October 23 in Science, the team precisely measured the energy of electrons orbiting a radium atom that was chemically bound to a fluoride atom, forming radium monofluoride. By using the molecular environment as a microscopic stand-in for a particle collider, they confined the radium atom's electrons and increased the likelihood that some would briefly pass through the nucleus.

Traditional experiments that investigate nuclear interiors depend on kilometer-scale accelerators that speed up electron beams to smash into and fragment nuclei. The new molecule-centered approach provides a compact, table-top way to directly probe the inside of a nucleus.

Table-Top Method Detects Nuclear "Messages"
Working with radium monofluoride, the researchers tracked the energies of the radium atom's electrons as they moved within the molecule. They observed a small shift in energy and concluded that some electrons must have briefly entered the nucleus and interacted with what lies inside. As those electrons left, they retained the energy change, effectively carrying a nuclear "message" that reveals features of the nucleus's interior.

The method opens a path to measuring the nuclear "magnetic distribution." Inside a nucleus, each proton and neutron behaves like a tiny magnet, and their orientations depend on how these particles are arranged. The team plans to use the technique to map this property in radium for the first time, a step that could inform one of cosmology's central puzzles: why the universe contains far more matter than antimatter.

"Our results lay the groundwork for subsequent studies aiming to measure violations of fundamental symmetries at the nuclear level," says study co-author Ronald Fernando Garcia Ruiz, who is the Thomas A. Franck Associate Professor of Physics at MIT. "This could provide answers to some of the most pressing questions in modern physics."

This July, astronomers were left reeling by an event unlike anything seen before: a gamma-ray burst (GRB) that repeated four times in a day, instead of lasting a few minutes as is usually the case. The JWST has examined the source of this event and a paper undergoing peer-review claims the total energy released probably exceeded anything previously witnessed, including events that were brighter but much briefer. The work only helps a little in trying to get to the bottom of what could cause such a prodigious event.

The universe keeps raising the bar on us in terms of how energetic events can be. We have only understood the power of GRBs since the 1990s, but recently we have discovered there are specific examples of this phenomenon that involve almost unimaginably more energy than the ordinary ones.

One such example, GRB 221009A, has been dubbed the BOAT (Brightest Of All Time) for being so far off the range predicted by other GRBs that we should only see something like it every thousand years. GRB 250702B proved there is more than one way for such events to be extraordinary, in the form of rapidly repeating explosions.

Some GRB-like events, known as soft gamma repeaters, come from within our galaxy and are suspected to be produced by magnetars. Others are extragalactic. The two can look similar at first, but the vastly greater distances to those in other galaxies mean the energy released must have been millions or billions of times greater, implying a different cause.

Consequently, when GRB 250702B was detected the most urgent question was its distance, which would indicate how much energy had been emitted. The Very Large Telescope and Hubble provided evidence it was from beyond the Milky Way, although the suspected source galaxy identification was tentative.

The JWST, however, has detected hydrogen emission lines in the afterglow, and these are red-shifted enough to confirm that the explosion took place billions of light-years away. Using that distance, a team of astronomers across 23 departments and institutions concluded the event released at least 2 x 1054 ergs in the course of the later three bursts. For comparison, the Sun emits about 1041 ergs a year, so at its current rate it would take about 20 trillion years to release that much energy. 

Supernovae are sometimes measured in “foes”, where a foe is 1051 ergs because that is the energy released by a run-of-the-mill supernova, if there is such a thing (the name "foe" comes from [ten to the power of] Fifty-One Ergs). This is 2,000 times greater, and in a day, rather than the months over which supernovae emit most of their energy.

People recalling a familiar image use different brain mechanisms to focus on a component than those who are viewing the situation live, a new study indicates. The reasons why the brain has evolved a different process for this task are not known, but might hold the key to understanding why some people have this capacity and others do not.

A few years ago, many frequent Internet users were astonished to discover that some people have no “mind’s eye”, the capacity to visualize things that they cannot see at the time, also known as aphantasia. A smaller group were at least as amazed to learn that other people can, and that references to such capacities were not merely metaphorical. 

Possibly influenced by these exchanges, research into the working of the mind’s eye, where it exists, has picked up, for example finding that psychedelics may switch it on. The most recent example investigated how the brain responds when challenged to focus on part of a remembered map, in contrast to a scene laid out before it, revealing crucial differences.

Some think it's a no brainer: Scattering microscopic particles of sulfur into Earth's atmosphere would reduce the amount of sunlight that reaches the ground, thereby cooling the planet. Indeed, this cooling might temporarily offset the progressing climate change — but a new study claims this type of intervention is likely to have several more unwanted side effects than previously thought.

The concept of geoengineering, or human-induced alteration of the planet's climate, by stratospheric sulfur injections (SAI) is backed by nature's own phenomena. The 1991 eruption of the Philippine stratovolcano Mount Pinatubo injected nearly 20 million tons of sulfur dioxide in the stratosphere, the layer of Earth's atmosphere between altitudes of 7.6 and 31 miles (12 and 50 kilometers). The presence of the sulfur particles in the atmosphere led to a global mean temperature drop of about 1 degree Fahrenheit (0.5 degree Celsius), according to the U.S. Geological Survey.

But that cooling, measurable for two years after the eruption, also disrupted the Indian monsoon system, causing a drought across South Asia, according to the new research paper. Plus, although the sulfur aerosol cooled Earth's surface, it warmed the stratosphere, speeding up ozone destruction.

"There are a range of things that might happen if you try to do this — and we're arguing that the range of possible outcomes is a lot wider than anybody has appreciated until now," Faye McNeill, an atmospheric chemist and aerosol scientist at Columbia’s Climate School and Columbia Engineering and one of the authors of the paper said in a statement.

Researchers are using sophisticated computer models to understand the effects of geoengineering interventions. But McNeill and her colleagues warn that no simulation is perfect and that, in the real world, surprises would be inevitable.

The impact of physical activity continues long after the workout ends.

A new study published in the Proceedings of the National Academy of Sciences by researchers from Virginia Tech, the University of Aberdeen, and Shenzhen University found that being active increases the total amount of energy the body uses each day without prompting it to cut back elsewhere.

While the health advantages of regular exercise are well established, scientists know less about how physical activity influences the body’s overall “energy budget,” meaning how energy is distributed among different biological processes.

For years, researchers have debated whether this energy budget works like a fixed income, where energy for movement is taken from other functions, or like a flexible system that expands to support more activity. The study aimed to identify which of these models best reflects how the human body manages energy at varying levels of physical activity.

To do this, researchers evaluated the total energy expenditure, or the total calories burned in a day, in participants across a wide spectrum of physical activity.

Biologists have long been fascinated by the ability of salamanders to regrow entire limbs. Now Harvard researchers have solved part of the mystery of how they accomplish this feat—by activating stem cells throughout the body, not just at the injury site.

In a paper published in the journal Cell, researchers documented how this body-wide response in axolotl salamanders is triggered by the sympathetic nervous system—the iconic "fight or flight" network. The study raises the possibility that these mechanisms might one day be manipulated to regenerate human limbs and organs.

"We've shown the importance of the adrenaline stress signaling hormone in getting cells ready for regeneration," said Duygu Payzin-Dogru, lead author of the new study and a postdoctoral researcher in the Department of Stem Cell and Regenerative Biology (SCRB).

"Because adrenaline exists in humans, this tells us we can co-opt some of the things we found in the axolotl to perhaps improve regenerative outcomes in humans. We have some of the same components and just have to figure out the right way to implement them."

The new study culminates several years of research by the lab of Jessica Whited, associate professor in SCRB, who studies limb regeneration in axolotls, a species native to Mexico. Axolotls are often examined as model organisms of limb regeneration because they are among the fastest-breeding species of salamanders.

Some invertebrates such as planarian flatworms can regrow entire bodies from small bits of tissue. But salamanders are the only vertebrates that can regenerate full limbs.