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Why you hardly notice your blind spot: New tests pit three theories of consciousness

Although humans’ visual perception of the world appears complete, our eyes contain a visual blind spot where the optic nerve connects to the retina. Scientists are still uncertain whether the brain fully compensates for the blind spot or if it causes perceptual distortions in spatial experience. A new study protocol, published in PLOS One, seeks to compare different theoretical predictions on how we perceive space from three leading theories of consciousness using carefully controlled experiments.

The new protocol focuses on three contrasting theories of consciousness: Integrated Information Theory (IIT), Predictive Processing Active Inference (AI), and Predictive Processing Neurorepresentationalism (NREP). Each of the theories have different predictions about the effects that the blind spot’s structural features have on the conscious perception of space, compared to non-blind spot regions.

IIT argues that the quality of spatial consciousness is determined by the composition of a cause-effect structure, and that the perception of space involving the blind spot is altered. On the other hand, AI and NREP argue that perception relies on internal models that reduce prediction errors and that these models adapt to accommodate for the structural deviations resulting from the blind spot. Essentially, this means that perceptual distortions should either appear small or nonexistent in both theories. However, AI and NREP differ in some ways.

Redesigned electrolyte helps lithium-metal batteries safely reach full charge in 15 minutes

Lithium-metal batteries (LMBs) are rechargeable batteries that contain an anode (i.e., the electrode through which current flows and a loss of electrons occurs) made of lithium metal. Compared to conventional lithium-ion batteries (LIBs), which power most electronic devices on the market today, LMBs could store more energy, charge faster and operate in extreme environments.

Despite their advantages, these batteries have not yet achieved their full potential and recharging them safely in short periods of time has proved challenging. In particular, enabling the fast and efficient movement of electrons and ions across the boundary between electrodes and the electrolyte, a process known as charge transfer, has proved difficult.

If charge transfer is slow, chemical reactions become sluggish, which can also lead to undesirable side reactions and prompt the formation of Li dendrites. These are essentially needle-like extensions that can adversely impact a battery’s performance, lead to its sudden failure and, in most extreme cases, result in fires or explosions.

Lithium alternatives? Calcium-ion batteries show strong 1,000-cycle performance in new test

Researchers at The Hong Kong University of Science and Technology (HKUST) have achieved a breakthrough in calcium-ion battery (CIB) technology, which could transform energy storage solutions in everyday life. Utilizing quasi-solid-state electrolytes (QSSEs), these innovative CIBs promise to enhance the efficiency and sustainability of energy storage, impacting a wide range of applications from renewable energy systems to electric vehicles.

The findings, titled “High-Performance Quasi-Solid-State Calcium-Ion Batteries from Redox-Active Covalent Organic Framework Electrolytes,” are published in the journal Advanced Science.

The urgency for sustainable energy storage solutions is growing critical worldwide. As the world accelerates its shift to green energy, the demand for efficient and stable battery systems has never been more pressing. Today’s mainstream lithium-ion batteries (LIBs) face challenges due to resource scarcity and near-limited energy density, making the exploration of alternatives like CIBs essential for a sustainable future.

Rule-breaking discovery reveals new way to strengthen metal in extreme conditions

There’s a reason why blacksmiths fire metals before hammering them. Heat always softens metal, making it more malleable and easier to reshape. Or does it? In a surprising new study, Northwestern University engineers discovered that, in extreme conditions, heat doesn’t soften pure metals—it strengthens them.

Not only does this new finding challenge long-held assumptions of how metals behave, it also could provide new insights for designing metals for futuristic applications in extreme conditions, such as hypersonic flight, extraterrestrial construction and advanced manufacturing.

The study will be published Tuesday (Feb. 17) in Physical Review Letters.

Midair haptics and levitation may get steadier with predictable ultrasonic airflow

Acoustic streaming generated by airborne ultrasonic phased arrays plays a critical role in the performance of advanced ultrasonic technologies, including midair haptic feedback, odor delivery, and acoustic levitation. Researchers at University of Tsukuba have developed a predictive model for acoustic streaming in phased arrays by integrating three-dimensional acoustic and fluid simulations.

Airborne ultrasonic phased arrays focus ultrasonic waves at prescribed locations in space and dynamically steer them, enabling applications such as noncontact tactile feedback, odor transport, and the levitation of small objects.

Despite the nonnegligible influence of acoustic streaming—steady airflow induced by high-intensity sound fields—on tactile perception and the stability of levitated objects, reliable prediction and modeling of this phenomenon have remained challenging.

How did humans develop sharp vision? Lab-grown retinas show likely answer

Humans develop sharp vision during early fetal development thanks to an interplay between a vitamin A derivative and thyroid hormones in the retina, Johns Hopkins University scientists have found. The findings could upend decades of conventional understanding of how the eye grows light-sensing cells and could inform new research into treatments for macular degeneration, glaucoma, and other age-related vision disorders. Details of the study, which used lab-grown retinal tissue, are published today in Proceedings of the National Academy of Sciences.

“This is a key step toward understanding the inner workings of the center of the retina, a critical part of the eye and the first to fail in people with macular degeneration,” said Robert J. Johnston Jr., an associate professor of biology at Johns Hopkins who led the research. “By better understanding this region and developing organoids that mimic its function, we hope to one day grow and transplant these tissues to restore vision.”

A microfluidic chip for one-step detection of PFAS and other pollutants

Environmental pollutant analysis typically requires complex sample pretreatment steps such as filtration, separation, and preconcentration. When solid materials such as sand, soil, or food residues are present in water samples, analytical accuracy often decreases, and filtration can unintentionally remove trace-level target pollutants along with the solids.

To address this challenge, a joint research team led by Dr. Ju Hyeon Kim at the Korea Research Institute of Chemical Technology (KRICT), in collaboration with Professor Jae Bem You’s group at Chungnam National University, has developed a microfluidic-based analytical device that enables direct extraction and analysis of pollutants from solid-containing samples without any pretreatment. The study was published in ACS Sensors

Water, food, and environmental samples encountered in daily life may contain trace amounts of hazardous contaminants that are invisible to the naked eye.

Hologram processing method boosts 3D image depth of focus fivefold

Researchers from the University of Tartu Institute of Physics have developed a novel method for enhancing the quality of three-dimensional images by increasing the depth of focus in holograms fivefold after recording, using computational imaging techniques. The technology enables improved performance of 3D holographic microscopy under challenging imaging conditions and facilitates the study of complex biological structures.

The research results were published in the Journal of Physics: Photonics in the article “Axial resolution post-processing engineering in Fresnel incoherent correlation holography.”

One of the main limitations of conventional microscopes and 3D imaging systems is that, once an image or hologram has been recorded, its imaging properties cannot be altered. To overcome this limitation, Shivasubramanian Gopinath, a Junior Research Fellow at the University of Tartu Institute of Physics, and his colleagues have developed a new method that enables to capture a set of holograms with different focal distances at the time of acquisition, instead of a single image. These can then be computationally combined to produce a synthetic hologram that offers a much greater depth of focus than conventional approaches, and allows for post-processing of the recorded image.

Electrically controllable 3D magnetic hopfions realized in chiral magnets

A research team from the High Magnetic Field Laboratory of the Hefei Institutes of Physical Science of the Chinese Academy of Sciences, together with collaborators from Anhui University, ShanghaiTech University, and the University of New Hampshire, has demonstrated the first electrically controllable generation of hopfions—three-dimensional topological solitons—in a solid-state magnetic system. The results are published online in Nature Materials.

Proposed in 1975, hopfions are three-dimensional topological structures characterized by a Hopf charge and capable of forming rings, links, and knots. Although they are predicted to exist in a wide range of physical systems—from magnetic materials and plasmas to the early universe—their complexity has kept hopfions largely confined to theory, with only limited experimental realization and control.

In this study, the researchers used a chiral magnet as a laboratory test bed. By applying spin-transfer torque together with thermal excitation, they successfully generated magnetic hopfions in the chiral magnet FeGe.

Shaping carbon fiber with electricity: Wireless voltage pulses drive reversible bending

Controlled manipulation of fibers that are as thin as or even thinner than human hair is a real challenge. Despite technological development, the precise and reversible change of the microfibers’ orientation is not easy. The interdisciplinary team of researchers from the Institute of Physical Chemistry, Polish Academy of Sciences, has recently developed a way to control the shape of microfibers with electricity. This brings us closer to a novel technical solution in micromechanics and soft robotics.

Their recent work, published in the Nature Communications journal, demonstrates the first proof-of-concept results on the motion of pristine carbon fibers caused by asymmetric electrochemical processes occurring in the material.

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