Psychedelics profoundly alter subjective experience and brain dynamics. Brain oscillations express signatures of near-critical dynamics, relevant for healthy function. Alterations in the proximity to criticality have been suggested to underlie the experiential and neurological effects of psychedelics. Here, we investigate the effects of a psychedelic substance (DMT) on the criticality of brain oscillations, and in relation to subjective experience, in humans of either sex. We find that DMT shifts the dynamics of brain oscillations away from criticality in alpha and adjacent frequency bands. In this context, entropy is increased while complexity is reduced. We find that the criticality-shifts observed in alpha and theta bands correlate with the intensity ratings of self-dissolution, a hallmark of psychedelic experience. Finally, using a recently developed metric, the functional excitatory-inhibitory ratio, we find that the DMT-induced criticality-shift in brain oscillations is toward subcritical regimes. These findings have major implications for the neuronal understanding of the self and psychedelics, as well as for the neurological basis of altered states of consciousness.
Keywords: DMT; EEG; brain oscillations; criticality; self-dissolution.
Copyright © 2025 Irrmischer et al.
Artificial neural networks have become powerful tools for finding patterns in complex data, from classifying images to predicting protein structures and assisting mathematical discovery. Yet their success has so far relied almost entirely on classical hardware. Recent developments in quantum-computing technologies make it timely to ask whether trainable models can also make use of quantum effects such as superposition and the intrinsic uncertainty associated with quantum measurements. What’s more, running neural networks on real quantum processors could potentially turn these networks into probes, revealing how different hardware architectures shape networks’ behaviors.
One of the goals of spintronics is to flip the magnetization of ferromagnetic domains solely via an electrically controlled spin current flowing in a layer underneath. The antiferromagnet manganese germanide (Mn3Ge) is a prime candidate for providing that control thanks to the out-of-plane polarization of its spin currents. Now Mingxing Wu of the University of Tokyo and his colleagues have identified which of two mechanisms proposed by theorists is responsible for the polarization [1]. The answer is both.
The triangular lattice of Mn3Ge causes groups of three adjacent spins to orient themselves at 120° with respect to each other. That noncolinear arrangement engenders so-called Weyl points in the crystal’s band structure. Thanks to a quantum geometry property called Berry curvature, Weyl points act like internal magnetic fields that deflect electrons in a spin-dependent way.
Until the work of Wu and his colleagues, just how the deflection leads to out-of-plane polarization was unclear. It could conceivably arise either via a mechanism called spin swapping (SSW) or via the magnetic spin Hall effect (MSHE). To settle the question, the researchers subjected single-crystal strips of Mn3Ge topped with layers of permalloy (a nickel–iron alloy) to a technique called spin-torque ferromagnetic resonance (ST-FMR). The ST-FMR signal from MSHE depends on the orientation of the Mn3Ge lattice with respect to the spin current, whereas the signal from SSW does not. By creating differently oriented samples, Wu and his colleagues found that both mechanisms contribute to the out-of-plane spin polarization with comparable magnitudes. Now that the mystery has been solved, the next step is to harness both mechanisms for the magnetic-field-free switching of magnetization.
Many modern technologies, from optical communications and artificial intelligence (AI) hardware to advanced sensors and medical imaging, depend on photonic and semiconductor devices that precisely control the interaction between light and electrons. Designing these devices, however, remains a major challenge because existing simulation tools often require researchers to choose between modeling an entire device or capturing the detailed behavior of electrons. Few can do both within the same model.
Researchers from the Singapore University of Technology and Design (SUTD) and National University of Singapore (NUS) have developed a new computational approach that extends the widely used open-source particle-in-cell (PIC) method with condensed-matter physics. The result is a single platform that can simulate a much broader range of light-matter interactions in metals, semiconductors and emerging quantum materials.
Published in Computer Physics Communications, the research, “Particle-in-cell simulations of quantum plasmas,” demonstrates how an established plasma physics tool can be adapted to study condensed-matter systems, opening new possibilities for designing photonic and quantum technologies.
A biotech company called Revel Pharmaceuticals is looking into ways to reverse aging, and the company’s science team, along with researchers from the company Calico and the University of Colorado, may be a step closer to realizing the so-called fountain of youth. The team recently published their study in Nature Communications detailing how they engineered an enzyme capable of reversing a particular form of age-related damage and demonstrated its competence with test results.
One common sign of aging in the cells of living organisms is a type of protein damage called Nε-carboxymethyl-lysine (CML). CML is part of a group of harmful compounds aptly named “AGEs” (or advanced glycation and lipoxidation end products). Oddly enough, it is also part of the Maillard reaction, known for causing the browning in cooked food that creates rich, savory flavors, complex aromas and golden-brown crusts. In living organisms, CML builds up on long-lived proteins, like those in skin, blood vessels and the eye. This stiffens tissues and can fuel chronic inflammation through an immune-signaling receptor called “RAGE.”
“The engagement of the CML-RAGE axis triggers a signaling cascade that activates NF-κB and stimulates the release of pro-inflammatory cytokines and profibrotic growth factors. In the context of the central nervous system, CML accumulation has been linked to oxidative stress and mitochondrial damage in microglia, further disrupting brain homeostasis during aging,” the authors of the new study explain.