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I ain’t afraid of no ghosts: People with mind-blindness not so easily spooked: The link between mental imagery and emotions may be closer than we thought

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I ain’t afraid of no ghosts: People with mind-blindness not so easily spooked: The link between mental imagery and emotions may be closer than we thought

People with aphantasia — that is, the inability to visualise mental images — are harder to spook with scary stories, a new UNSW Sydney study shows.

The study, published today in Proceedings of the Royal Society B, tested how aphantasic people reacted to reading distressing scenarios, like being chased by a shark, falling off a cliff, or being in a plane that’s about to crash.The researchers were able to physically measure each participant’s fear response by monitoring changing skin conductivity levels — in other words, how much the story made a person sweat. This type of test is commonly used in psychology research to measure the body’s physical expression of emotion.According to the findings, scary stories lost their fear factor when the readers couldn’t visually imagine the scene — suggesting imagery may have a closer link to emotions than scientists previously thought.

“”We found the strongest evidence yet that mental imagery plays a key role in linking thoughts and emotions,” says Professor Joel Pearson, senior author on the paper and Director of UNSW Science’s Future Minds Lab.

“In all of our research to date, this is by far the biggest difference we’ve found between people with aphantasia and the general population.”

To test the role of visual imagery in fear, the researchers guided 46 study participants (22 with aphantasia, and 24 with imagery) to a blackened room before attaching several electrodes to their skin. Skin is known to become a better conductor of electricity when a person feels strong emotions, like fear.

The scientists then left the room and turned the light off, leaving the participants alone as a story started to appear in the screen in front of them.At first, the stories started innocuously — for example, ‘You are at the beach, in the water’ or ‘You’re on a plane, by the window’. But as the stories continued, the suspense slowly built, whether it was a dark flash in the distant waves and people on the beach pointing, or the cabin lights dimming as the plane starts to shake.

“Skin conductivity levels quickly started to grow for people who were able to visualise the stories,” says Prof Pearson. “The more the stories went on, the more their skin reacted.”But for people with aphantasia, the skin conductivity levels pretty much flatlined.”To check that differences in fear thresholds didn’t cause the response, the experiment was repeated using a series of scary images instead of text, like a photo of a cadaver or a snake bearing its fangs.But this time, the pictures made the skin crawl equally in both groups of people.

“These two sets of results suggest that aphantasia isn’t linked to reduced emotion in general, but is specific to participants reading scary stories,” says Prof. Pearson. “The emotional fear response was present when participants actually saw the scary material play out in front of them.

“The findings suggest that imagery is an emotional thought amplifier. We can think all kind of things, but without imagery, the thoughts aren’t going to have that emotional ‘boom’.”

Living with aphantasia

Aphantasia affects 2-5 per cent of the population, but there is still very little known about the condition.

A UNSW study published last year found that aphantasia is linked to a widespread pattern of changes to other cognitive processes, like remembering, dreaming and imagining.

But while most previous aphantasia research focused on behavioural studies, this study used an objective measure of skin conductance.

“This evidence further supports aphantasia as a unique, verifiable phenomenon,” says study co-author Dr Rebecca Keogh, a postdoctoral fellow formerly of UNSW and now based at Macquarie University.

“”This work may provide a potential new objective tool which could be used to help to confirm and diagnose aphantasia in the future.””

The idea for this experiment came after the research team noticed a recurring sentiment on aphantasia discussion boards that many people with the condition didn’t enjoy reading fiction.

While the findings suggest that reading may not be as emotionally impactful for people with aphantasia, Prof. Pearson says it’s important to note that the findings are based on averages, and not everyone with aphantasia will have the same reading experience.

The study was also focused on fear, and other emotional responses to fiction could be different.

“Aphantasia comes in different shapes and sizes,” he says. “Some people have no visual imagery, while other people have no imagery in one or all of their other senses. Some people dream while others don’t.

“So don’t be concerned if you have aphantasia and don’t fit this mould. There are all kinds of variations to aphantasia that we’re only just discovering.”

Next, Prof. Pearson and his team at the Future Minds Lab plan to investigate how disorders like anxiety and Post Traumatic Stress Disorder might be experienced differently by people with aphantasia.

“Aphantasia is neural diversity,” says Prof. Pearson. “It’s an amazing example of how different our brain and minds can be.”

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Early dark energy could resolve cosmology’s two biggest puzzles

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I ain’t afraid of no ghosts: People with mind-blindness not so easily spooked: The link between mental imagery and emotions may be closer than we thought


A new study by MIT physicists proposes that a mysterious force known as early dark energy could solve two of the biggest puzzles in cosmology and fill in some major gaps in our understanding of how the early universe evolved.

One puzzle in question is the “Hubble tension,” which refers to a mismatch in measurements of how fast the universe is expanding. The other involves observations of numerous early, bright galaxies that existed at a time when the early universe should have been much less populated.

Now, the MIT team has found that both puzzles could be resolved if the early universe had one extra, fleeting ingredient: early dark energy. Dark energy is an unknown form of energy that physicists suspect is driving the expansion of the universe today. Early dark energy is a similar, hypothetical phenomenon that may have made only a brief appearance, influencing the expansion of the universe in its first moments before disappearing entirely.

Some physicists have suspected that early dark energy could be the key to solving the Hubble tension, as the mysterious force could accelerate the early expansion of the universe by an amount that would resolve the measurement mismatch.

The MIT researchers have now found that early dark energy could also explain the baffling number of bright galaxies that astronomers have observed in the early universe. In their new study, reported in the Monthly Notices of the Royal Astronomical Society, the team modeled the formation of galaxies in the universe’s first few hundred million years. When they incorporated a dark energy component only in that earliest sliver of time, they found the number of galaxies that arose from the primordial environment bloomed to fit astronomers’ observations.

You have these two looming open-ended puzzles,” says study co-author Rohan Naidu, a postdoc in MIT’s Kavli Institute for Astrophysics and Space Research. “We find that in fact, early dark energy is a very elegant and sparse solution to two of the most pressing problems in cosmology.”

The study’s co-authors include lead author and Kavli postdoc Xuejian (Jacob) Shen, and MIT professor of physics Mark Vogelsberger, along with Michael Boylan-Kolchin at the University of Texas at Austin, and Sandro Tacchella at the University of Cambridge.

Big city lights

Based on standard cosmological and galaxy formation models, the universe should have taken its time spinning up the first galaxies. It would have taken billions of years for primordial gas to coalesce into galaxies as large and bright as the Milky Way.

But in 2023, NASA’s James Webb Space Telescope (JWST) made a startling observation. With an ability to peer farther back in time than any observatory to date, the telescope uncovered a surprising number of bright galaxies as large as the modern Milky Way within the first 500 million years, when the universe was just 3 percent of its current age.

“The bright galaxies that JWST saw would be like seeing a clustering of lights around big cities, whereas theory predicts something like the light around more rural settings like Yellowstone National Park,” Shen says. “And we don’t expect that clustering of light so early on.”

For physicists, the observations imply that there is either something fundamentally wrong with the physics underlying the models or a missing ingredient in the early universe that scientists have not accounted for. The MIT team explored the possibility of the latter, and whether the missing ingredient might be early dark energy.

Physicists have proposed that early dark energy is a sort of antigravitational force that is turned on only at very early times. This force would counteract gravity’s inward pull and accelerate the early expansion of the universe, in a way that would resolve the mismatch in measurements. Early dark energy, therefore, is considered the most likely solution to the Hubble tension.

Galaxy skeleton

The MIT team explored whether early dark energy could also be the key to explaining the unexpected population of large, bright galaxies detected by JWST. In their new study, the physicists considered how early dark energy might affect the early structure of the universe that gave rise to the first galaxies. They focused on the formation of dark matter halos — regions of space where gravity happens to be stronger, and where matter begins to accumulate.

“We believe that dark matter halos are the invisible skeleton of the universe,” Shen explains. “Dark matter structures form first, and then galaxies form within these structures. So, we expect the number of bright galaxies should be proportional to the number of big dark matter halos.”

The team developed an empirical framework for early galaxy formation, which predicts the number, luminosity, and size of galaxies that should form in the early universe, given some measures of “cosmological parameters.” Cosmological parameters are the basic ingredients, or mathematical terms, that describe the evolution of the universe.

Physicists have determined that there are at least six main cosmological parameters, one of which is the Hubble constant — a term that describes the universe’s rate of expansion. Other parameters describe density fluctuations in the primordial soup, immediately after the Big Bang, from which dark matter halos eventually form.

The MIT team reasoned that if early dark energy affects the universe’s early expansion rate, in a way that resolves the Hubble tension, then it could affect the balance of the other cosmological parameters, in a way that might increase the number of bright galaxies that appear at early times. To test their theory, they incorporated a model of early dark energy (the same one that happens to resolve the Hubble tension) into an empirical galaxy formation framework to see how the earliest dark matter structures evolve and give rise to the first galaxies.

“What we show is, the skeletal structure of the early universe is altered in a subtle way where the amplitude of fluctuations goes up, and you get bigger halos, and brighter galaxies that are in place at earlier times, more so than in our more vanilla models,” Naidu says. “It means things were more abundant, and more clustered in the early universe.”

“A priori, I would not have expected the abundance of JWST’s early bright galaxies to have anything to do with early dark energy, but their observation that EDE pushes cosmological parameters in a direction that boosts the early-galaxy abundance is interesting,” says Marc Kamionkowski, professor of theoretical physics at Johns Hopkins University, who was not involved with the study. “I think more work will need to be done to establish a link between early galaxies and EDE, but regardless of how things turn out, it’s a clever — and hopefully ultimately fruitful — thing to try.”

We demonstrated the potential of early dark energy as a unified solution to the two major issues faced by cosmology. This might be an evidence for its existence if the observational findings of JWST get further consolidated,” Vogelsberger concludes. “In the future, we can incorporate this into large cosmological simulations to see what detailed predictions we get.”

This research was supported, in part, by NASA and the National Science Foundation.



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Plant-derived secondary organic aerosols can act as mediators of plant-plant interactions

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I ain’t afraid of no ghosts: People with mind-blindness not so easily spooked: The link between mental imagery and emotions may be closer than we thought


A new study published in Science reveals that plant-derived secondary organic aerosols (SOAs) can act as mediators of plant-plant interactions. This research was conducted through the cooperation of chemical ecologists, plant ecophysiologists and atmospheric physicists at the University of Eastern Finland.

It is well known that plants release volatile organic compounds (VOCs) into the atmosphere when damaged by herbivores. These VOCs play a crucial role in plant-plant interactions, whereby undamaged plants may detect warning signals from their damaged neighbours and prepare their defences. “Reactive plant VOCs undergo oxidative chemical reactions, resulting in the formation of secondary organic aerosols (SOAs). We wondered whether the ecological functions mediated by VOCs persist after they are oxidated to form SOAs,” said Dr. Hao Yu, formerly a PhD student at UEF, but now at the University of Bern.

The study showed that Scots pine seedlings, when damaged by large pine weevils, release VOCs that activate defences in nearby plants of the same species. Interestingly, the biological activity persisted after VOCs were oxidized to form SOAs. The results indicated that the elemental composition and quantity of SOAs likely determines their biological functions.

“A key novelty of the study is the finding that plants adopt subtly different defence strategies when receiving signals as VOCs or as SOAs, yet they exhibit similar degrees of resistance to herbivore feeding,” said Professor James Blande, head of the Environmental Ecology Research Group. This observation opens up the possibility that plants have sophisticated sensing systems that enable them to tailor their defences to information derived from different types of chemical cue.

“Considering the formation rate of SOAs from their precursor VOCs, their longer lifetime compared to VOCs, and the atmospheric air mass transport, we expect that the ecologically effective distance for interactions mediated by SOAs is longer than that for plant interactions mediated by VOCs,” said Professor Annele Virtanen, head of the Aerosol Physics Research Group. This could be interpreted as plants being able to detect cues representing close versus distant threats from herbivores.

The study is expected to open up a whole new complex research area to environmental ecologists and their collaborators, which could lead to new insights on the chemical cues structuring interactions between plants.



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Folded or cut, this lithium-sulfur battery keeps going

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I ain’t afraid of no ghosts: People with mind-blindness not so easily spooked: The link between mental imagery and emotions may be closer than we thought


Most rechargeable batteries that power portable devices, such as toys, handheld vacuums and e-bikes, use lithium-ion technology. But these batteries can have short lifetimes and may catch fire when damaged. To address stability and safety issues, researchers reporting in ACS Energy Letters have designed a lithium-sulfur (Li-S) battery that features an improved iron sulfide cathode. One prototype remains highly stable over 300 charge-discharge cycles, and another provides power even after being folded or cut.

Sulfur has been suggested as a material for lithium-ion batteries because of its low cost and potential to hold more energy than lithium-metal oxides and other materials used in traditional ion-based versions. To make Li-S batteries stable at high temperatures, researchers have previously proposed using a carbonate-based electrolyte to separate the two electrodes (an iron sulfide cathode and a lithium metal-containing anode). However, as the sulfide in the cathode dissolves into the electrolyte, it forms an impenetrable precipitate, causing the cell to quickly lose capacity. Liping Wang and colleagues wondered if they could add a layer between the cathode and electrolyte to reduce this corrosion without reducing functionality and rechargeability.

The team coated iron sulfide cathodes in different polymers and found in initial electrochemical performance tests that polyacrylic acid (PAA) performed best, retaining the electrode’s discharge capacity after 300 charge-discharge cycles. Next, the researchers incorporated a PAA-coated iron sulfide cathode into a prototype battery design, which also included a carbonate-based electrolyte, a lithium metal foil as an ion source, and a graphite-based anode. They produced and then tested both pouch cell and coin cell battery prototypes.

After more than 100 charge-discharge cycles, Wang and colleagues observed no substantial capacity decay in the pouch cell. Additional experiments showed that the pouch cell still worked after being folded and cut in half. The coin cell retained 72% of its capacity after 300 charge-discharge cycles. They next applied the polymer coating to cathodes made from other metals, creating lithium-molybdenum and lithium-vanadium batteries. These cells also had stable capacity over 300 charge-discharge cycles. Overall, the results indicate that coated cathodes could produce not only safer Li-S batteries with long lifespans, but also efficient batteries with other metal sulfides, according to Wang’s team.

The authors acknowledge funding from the National Natural Science Foundation of China; the Natural Science Foundation of Sichuan, China; and the Beijing National Laboratory for Condensed Matter Physics.



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