This study investigates whether the human brain has an organized baseline state of function that is suspended during goal-directed tasks. Researchers used positron-emission tomography (PET) to measure the oxygen extraction fraction (OEF)—the ratio of oxygen used by the brain to oxygen delivered by blood—in resting adults.
Key findings include:
1. Uniformity at Rest: Despite significant differences in blood flow and oxygen consumption between gray and white matter, the OEF remains remarkably uniform across the brain during a resting state (eyes closed, awake).
2. Defining Baseline: The researchers propose that this uniform OEF represents an equilibrium state of local neuronal activity, serving as a true physiological baseline.
3. Deactivation Patterns: Many brain regions, particularly in the visual system, consistently show decreases in activity (deactivations) during cognitive tasks.
4. Validation: By measuring the OEF at rest, the study confirms that these task-induced decreases are not merely artifacts of an undefined control state but represent a genuine drop from a stable baseline level of brain function.
The results suggest the existence of a default mode of brain function that is active when specific goal-directed behaviors are not being performed.
Key findings include:
1. Uniformity at Rest: Despite significant differences in blood flow and oxygen consumption between gray and white matter, the OEF remains remarkably uniform across the brain during a resting state (eyes closed, awake).
2. Defining Baseline: The researchers propose that this uniform OEF represents an equilibrium state of local neuronal activity, serving as a true physiological baseline.
3. Deactivation Patterns: Many brain regions, particularly in the visual system, consistently show decreases in activity (deactivations) during cognitive tasks.
4. Validation: By measuring the OEF at rest, the study confirms that these task-induced decreases are not merely artifacts of an undefined control state but represent a genuine drop from a stable baseline level of brain function.
The results suggest the existence of a default mode of brain function that is active when specific goal-directed behaviors are not being performed.
Researchers from the Chinese Academy of Sciences have identified a new organizational principle within the default mode network (DMN) that explains how it supports both internal thoughts and external perceptions. The study reveals that the DMN is composed of distinct subregions acting as either senders or receivers of information, allowing the brain to flexibly shift between memory-driven thought and sensory perception.
Key findings include:
* Identification of receiver-like subregions that support information integration during perception through stronger connectivity with heteromodal association networks.
* Identification of sender-like subregions that guide memory-based behavior via coupling with sensorimotor systems.
* Evidence that these subdivisions correspond to specific cognitive modes, such as face recognition versus memory-guided decisions.
Key findings include:
* Identification of receiver-like subregions that support information integration during perception through stronger connectivity with heteromodal association networks.
* Identification of sender-like subregions that guide memory-based behavior via coupling with sensorimotor systems.
* Evidence that these subdivisions correspond to specific cognitive modes, such as face recognition versus memory-guided decisions.
Eon Systems has reportedly achieved a breakthrough in whole-brain emulation by simulating the 125,000 neurons and 50 million synaptic connections of an adult fruit fly's brain. This simulated brain was then integrated into a virtual environment, allowing the fly to interact with a digital world. The experiment utilized a pre-existing wiring diagram of the fruit fly brain and a physics-based simulation framework.
Researchers claim this is the first demonstration of a whole-brain emulation exhibiting multiple behaviors, paving the way for more complex simulations, potentially including mouse and eventually human brains.
Researchers claim this is the first demonstration of a whole-brain emulation exhibiting multiple behaviors, paving the way for more complex simulations, potentially including mouse and eventually human brains.
A study found that wild mice, and other animals like frogs, rats, and shrews, will voluntarily use a running wheel placed in their environment, suggesting play is an innate behavior, not just a result of captivity.
New experiments reveal how astrocytes tune neuronal activity to modulate our mental and emotional states, suggesting that neuron-only brain models are insufficient for understanding brain function.
NASA’s OSIRIS-REx mission has discovered tryptophan, an essential amino acid, on asteroid Bennu, providing further evidence that asteroids may have delivered building blocks for life to Earth.
Researchers from Japan and Seattle's Allen Institute have created a detailed supercomputer simulation of a mouse cortex, featuring nearly 10 million neurons and 26 billion synapses, using the world's fastest supercomputer Fugaku. This breakthrough could lead to new methods for studying brain diseases like Alzheimer's and epilepsy.
DeepScientist is a goal-oriented, fully autonomous scientific discovery system. It uses Bayesian Optimization and a hierarchical 'hypothesize, verify, and analyze' process with a Findings Memory to balance exploration and exploitation. It generated and validated thousands of scientific ideas, surpassing human SOTA on three AI tasks.
Large language models (LLMs) are rapidly being implemented in a wide range of disciplines, with the promise of unlocking new possibilities for scientific exploration. However, while the development of LLMs brings opportunities to science, it also comes with pressing challenges. This Focus discusses the current state of the art, highlights key obstacles, and examines some of the potential pitfalls and biases of implementing and using LLMs across different domains, including healthcare, urban planning, chemistry, linguistics, humanities, and computer science. In addition, the Focus explores emerging technologies – such as neuromorphic engineering – that show promise in enhancing the energy efficiency of LLM deployment on hardware platforms.
Neuroscience research suggests that scientists may have been undervaluing the most ancient regions of the human brain when studying consciousness. Evidence indicates that the subcortex and cerebellum may play a more significant role than previously thought, and could even be sufficient for basic forms of consciousness.
