Brain activity in the resting state shows scale-free, critical dynamics balanced between order and disorder, but a direct link to cognition has been missing. Using MEG recordings during mindfulness meditation, the authors found that scale-free near-critical dynamics originated only from broad-band high-frequency activity above 100 Hz, which is associated with action potential firing. During meditation, avalanche dynamics shifted toward a critical point by reducing neural noise, and the topography of avalanches differed from rest. Self-regulated attention during meditation can serve as a control parameter for criticality in scale-free brain dynamics.
Integrated Information Theory (IIT) starts from five axioms about conscious experience—existence, composition, information, integration, and exclusion—to derive physical postulates that specify which systems can be conscious and what their experience is like. IIT provides a calculus to measure both the quantity and quality of experience, explains clinical and laboratory findings, and makes testable predictions. It holds that consciousness is graded, common among biological organisms, and present even in some simple systems, but not in everything: groups of individuals or feedforward networks lack it. Crucially, IIT implies that digital computers, even those that perfectly simulate human behavior or brain function, would experience next to nothing, contradicting functionalist views.
Having a conscious experience with recall during N2 sleep is linked to increased beta/gamma brain activity across widespread cortical areas, with peak activity in posterior occipital-temporal regions in the 30-second window before awakening and in parietal regions in the 20-second window. This effect was significant for high-perceptual dreams but not for low-perceptual dreams, suggesting that the neural activity is driven by sensory experiences such as vision and audition. The findings emphasize the need to distinguish content-specific neural correlates of dreaming and to study their temporal dynamics.