bioRxiv
November 26, 2020
Andrea I. Luppi, Pedro A.M. Mediano, Fernando E. Rosas et al.
49 citations
preprint
The brain coordinates information from many sources to create a unified conscious experience. Combining network science and information theory, the authors identify a “synergistic global workspace” where gateway regions gather synergistic information from specialized brain modules, integrate it, and then broadcast it widely via broadcaster regions. Functional MRI shows that gateway regions correspond to the default mode network and broadcasters to the executive control network. Loss of consciousness from general anesthesia or disorders of consciousness reduces the workspace’s ability to integrate information, which is restored upon recovery. This work reconciles aspects of the Global Neuronal Workspace and Integrated Information Theory.
bioRxiv Preprint Server
April 12, 2021
Peter Coppola, Lennart R.b. Spindler, Andrea I. Luppi et al.
preprint
The diversity of brain dynamics within small-world network topology, measured as sample entropy (dSW-E), consistently predicts levels of awareness across sedation and disorders of consciousness, even after accounting for underlying functional connectivity dynamics. Both subcortical and cortical areas show predictive value, but subcortical regions exhibit higher and more robust effect sizes. The dynamic reorganization of the functional information architecture, especially in the subcortex, emerges with awareness and offers explanatory power beyond the complexity of dynamic functional connectivity alone.
bioRxiv Preprint Server
June 7, 2026
Andrea I. Luppi, Dragana Manasova, Justine Y. Hansen et al.
preprint
Functional connectivity in the awake human brain is shaped primarily by cognitive co-activation—the tendency of brain regions to work together during mental tasks—more than by structural or molecular constraints. This predominance is systematically lost across five datasets involving pharmacological and pathological perturbations of consciousness (chronic disorders of consciousness; anesthesia with sevoflurane, propofol, or ketamine), when cognition is disconnected from the environment or abolished. During such states, the predictors of functional architecture shift away from cognitive co-activation and toward anatomical and molecular constraints.
NeuroImage
February 11, 2023
Andrea I. Luppi, Pedro A.M. Mediano, Fernando E. Rosas et al.
High-level brain functions are thought to arise from coordinated activity across neural systems, but this has been hard to test empirically. Using a framework called Integrated Information Decomposition, which quantifies emergence in dynamical systems, the authors analyzed functional MRI data and found that emergent and hierarchical neural dynamics are significantly reduced in chronically unresponsive patients with severe brain injury. Emergence capacity was positively correlated with hierarchical organization in brain activity. Combining network control theory and whole-brain modeling, the authors show that reduced emergent and hierarchical dynamics in these patients can be explained by disruptions in the structural connectome. The results suggest that chronic unresponsiveness after severe brain injury may stem from structural damage to neural infrastructure needed for emergent brain dynamics.
Proceedings of the National Academy of Sciences of the United States of America
July 23, 2021
L. R. Spindler, A. Luppi, R. Adapa et al.
A network of brain regions called the default mode network breaks down during anesthesia and after brain damage causing disorders of consciousness. The neurochemical reasons for this breakdown were unclear. Using functional MRI, researchers found that the ventral tegmental area, a dopamine-producing brainstem region, disconnects from key default mode network nodes (precuneus and posterior cingulate) during both propofol sedation and disorders of consciousness. Stronger connectivity between the ventral tegmental area and these nodes was associated with a more awake-like configuration of the default mode network. In patients with disorders of consciousness who later improved behaviorally, this connectivity increased toward healthy levels. In a separate group of traumatic brain injury patients, the drug methylphenidate significantly strengthened this connection. The findings suggest that dopamine modulation may be central to maintaining consciousness.
PLoS ONE
February 13, 2020
Thomas F. Varley, Michael M. Craig, R. Adapa et al.
Fractal dimension of brain activity—a measure of complexity beyond simple randomness—is lower in patients with disorders of consciousness than in healthy volunteers. Using fMRI data, fractal dimension was computed for cortical functional connectivity networks, adjacency matrices, and BOLD time-series. Healthy volunteers (n=15) had the highest fractal dimensions, followed by patients in a minimally conscious state (n=10), and patients in a vegetative state (n=8). Decreases in fractal dimension correlated with decreasing level of consciousness regardless of injury mechanism. The findings support the hypothesis that consciousness is associated with brain complexity and that fractal structures may indicate proximity to a critical point between low- and high-entropy states.
Nature Communications
October 10, 2019
A. Luppi, Michael M. Craig, I. Pappas et al.
Consciousness relies on spatio-temporal interactions between brain integration and functional diversity. Combining graph theory and dynamic functional connectivity, resting-state fMRI data from awake volunteers, propofol-anaesthetised volunteers, and patients with disorders of consciousness showed that cortical networks are especially affected during loss of consciousness in temporal states of high integration, exhibiting reduced functional diversity and compromised informational capacity, while thalamo-cortical functional disconnections emerge during states of higher segregation. Posterior regions of the brain's default mode network show reductions in both functional diversity and integration during unconsciousness. These overlapping reductions in diversity and integration may represent a generalisable biomarker of loss of consciousness.