Mammalian brains function through a constant balance of cooperation and competition between specialized circuits. While internal circuits cooperate, long-range competitive interactions manage limited resources and prevent excessive synchronization. This mechanism allows different brain systems to take turns shaping overall dynamics, facilitating complex cognitive processes like decision-making, attention, and memory.
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.
This study investigates the temporal dynamics of EEG power during breath-watching meditation, a focused-attention practice from the Isha Yoga tradition.
Analyzing 128-channel EEG data from meditation-naïve, novice, and advanced practitioners, researchers found that significant neurophysiological changes—including increased alpha, theta, and beta1 power—begin to emerge approximately 2 to 3 minutes after starting practice, peaking between 7 and 10 minutes.
Advanced meditators showed consistently higher theta and theta-alpha power throughout the session. This suggests that meditation has a rapid response influenced by experience level, implying that even short, digital sessions could provide scalable mental well-being benefits.
Analyzing 128-channel EEG data from meditation-naïve, novice, and advanced practitioners, researchers found that significant neurophysiological changes—including increased alpha, theta, and beta1 power—begin to emerge approximately 2 to 3 minutes after starting practice, peaking between 7 and 10 minutes.
Advanced meditators showed consistently higher theta and theta-alpha power throughout the session. This suggests that meditation has a rapid response influenced by experience level, implying that even short, digital sessions could provide scalable mental well-being benefits.
Researchers have identified a neural network associated with adaptive mentalization – the ability to adjust how we infer others’ intentions and beliefs based on their behavior. Using computational modeling and fMRI, they found activity and connectivity within brain regions (including the temporoparietal junction) tracked participants’ ability to update beliefs about opponents' strategic sophistication in a game setting. This neural signature could potentially be used to assess mentalization capabilities in both healthy individuals and those with brain disorders.
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.
A new study in twins suggests that daily protein and prebiotic supplements (inulin and FOS) can improve memory test scores in people over 60, potentially impacting early detection of Alzheimer's and offering new approaches to healthy aging.
This module uses NextBrain, a probabilistic atlas of the human brain, to segment ~300 distinct ROIs per hemisphere on in vivo or ex vivo scans. Segmentation relies on a Bayesian algorithm and is robust against changes in MRI pulse sequence.
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.
Scientists have mapped the activity that takes place across a mouse's entire brain as it decides how to complete a task - and the results could explain the origin of our gut feelings.
An international research team found that cats prefer to sleep on their left side, potentially as an evolutionary advantage for hunting and escape behavior. Sleeping on the left allows them to process threats with the right hemisphere of the brain, which specializes in spatial awareness and rapid movements.
