PLoS One
June 30, 2014
Enrico Amico, Francisco Gómez, Carol di Perri et al.
115 citations
Functional connectivity of brain areas fluctuates over time, even during anesthesia. By applying point process analysis to resting-state fMRI data from 18 healthy subjects during propofol-induced wakefulness, sedation, unconsciousness, and recovery, the study identified eight distinct co-activation patterns centered on the posterior cingulate cortex (PCC). The core of these patterns remained stable across consciousness levels, but propofol caused region-specific reductions in co-activation, including disconnections of the prefrontal cortex, thalamus, auditory cortex, motor cortex, and visual area. The methodology helps refine characterization of local functional brain changes associated with propofol-induced modulation of consciousness.
Neuroimage
February 9, 2021
Riku Ihalainen, Olivia Gosseries, Frederik van de Steen et al.
30 citations
Using dynamic causal modelling of high-density EEG recordings from 10 people during propofol anaesthesia, the study evaluated how three resting state networks—the default mode network, the salience network, and the central executive network—contribute to consciousness. Loss of consciousness reduced inter-network connectivity in the parietal cortex, especially feed-forward frontoparietal and parietal connections at the precuneus node within the default mode network. Within the salience and central executive networks, unconsciousness generated small increases in bidirectional connectivity. The most consistent predictions of consciousness came from a key set of frontoparietal connections, supporting the importance of the posterior hot zone in explaining loss of consciousness.
arXiv Preprint Archive
February 6, 2020
Marco Alberto Javarone, Olivia Gosseries, Daniele Marinazzo et al.
A mean-field model inspired by Integrated Information Theory and Tegmark's representation of consciousness analyzes order-disorder phase transitions on Curie-Weiss models generated from EEG signals recorded on healthy individuals undergoing deep sedation. A machine learning tool classifies mental states using critical temperatures computed from these models. The method discriminates between states of awareness and deep sedation. A state space representing the path between mental states is identified, with dimensions corresponding to critical temperatures over different EEG frequency bands. The method may have clinical applications.
Neuroimage
October 15, 2019
Guo-Rong Wu, Carol Di Perri, Vanessa Charland-Verville et al.
Changes in the brain's hemodynamic response in the precuneus and posterior cingulate are a common principle underlying loss of consciousness under Propofol anesthesia and in unresponsive wakefulness syndrome. The thalamus is less obviously modulated by Propofol compared with frontoparietal regions, but patients with unresponsive wakefulness syndrome show a significant increase in spontaneous thalamic hemodynamic response compared with healthy controls. The results indicate that anesthesia- or pathology-induced neurovascular coupling can be tracked by modulated spontaneous hemodynamic response derived from resting state fMRI.
arXiv Preprint Archive
May 10, 2016
Enrico Amico, Daniele Marinazzo, Carol DiPerri et al.
A new data-driven method, connICA, extracts independent functional connectivity patterns (FC-traits) from brain scans of patients with disorders of consciousness after severe brain damage. Three main FC-traits emerged. The first relates to sedation, overall pathology, and level of arousal. The second reflects disconnection of visual and sensory-motor networks, time since injury, and ability to communicate. The third involves fronto-parietal and default-mode networks and interhemispheric interaction, associated with self-awareness and awareness of surroundings. Each trait represents a distinct functional process linked to degradation of conscious states, clarifying which neural subcircuits are disrupted in severe brain injury.