Criticality Creates a Functional Platform for Network Transitions Between Internal and External Processing Modes in...

Area of Science:

• Neuroscience
• Computational Neuroscience
• Cognitive Science

Background:

• The brain continuously switches between internal and external processing modes, essential for self and world modeling.
• The neural mechanisms underlying these transitions, particularly how the brain shifts between integrating internal information and processing external stimuli, remain poorly understood.

Purpose of the Study:

• To investigate how the brain transitions between internal and external information processing modes.
• To explore the role of brain network dynamics, particularly near criticality, in facilitating these switches.
• To examine how these dynamics are altered across different states of consciousness.

Main Methods:

• Development of a computational model simulating brain network synchronization.
• Analysis of electroencephalography (EEG) data during altered states of consciousness.
• Analysis of functional magnetic resonance imaging (fMRI) data during altered states of consciousness.

Main Results:

• Brain networks near criticality exhibit fluctuations that create temporal windows favoring either internal or external information processing.
• Synchronized networks bias towards internal information, while incoherent networks bias towards external stimuli.
• These network preferences are most pronounced at criticality and in conscious states (4-12 Hz bandwidth), with specific functional network configurations.
• Network configurations and preferences are disrupted in various altered states of consciousness (anesthesia, psychedelic, minimally conscious, unresponsive wakefulness syndrome).
• Internal information integration preference is present in conscious and psychedelic states but absent in unconscious states, highlighting its role in consciousness.

Conclusions:

• Criticality in brain networks provides a dynamic platform for switching between internal and external processing, vital for consciousness.
• Disruption of these critical dynamics underlies altered states of consciousness.
• Internal information processing is a key neural correlate of conscious states.