Journal of The Royal Society Interface
January 1, 2016
Enzo Tagliazucchi, Dante R. Chialvo, Michael Siniatchkin et al.
210 citations
Loss of consciousness from propofol sedation reduces long-range temporal correlations in frontothalamic brain activity and weakens the link between functional connectivity and anatomical structure. A model based on phase transitions in complex systems reproduces these patterns and also explains the cortex's reduced sensitivity to external stimuli during unconsciousness. The findings suggest that these neural changes are universal across different causes of unconsciousness.
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.
Scientific Reports
February 14, 2022
Johannes G. Ramaekers, Natasha L. Mason, Stefan W. Toennes et al.
26 citations
Acute cannabis intoxication and chronic cannabis use produce distinct patterns of altered connectivity across the whole brain, not just in isolated regions. Using ultra-high field (7T) resting state fMRI scans of 26 cannabis users under placebo and after vaporizing cannabis, two data-driven methods revealed that chronic users showed broad hyperconnectivity across major brain networks compared to occasional users, suggesting adaptive network reorganization from prolonged exposure. A separate spatial pattern—hypoconnectivity in dorsal attention, limbic, subcortical, and cerebellum networks combined with hyperconnectivity between the default mode and ventral attention network—was linked to the subjective feeling of being high during acute intoxication. These whole-brain approaches distinguish short- from long-term cannabis effects and may help probe the transition from occasional to chronic use.
Network Neuroscience
November 1, 2023
Juan Carlos Farah, Pablo Mallaroni, Enrico Amico et al.
21 citations
Functional connectomes become more idiosyncratic under psilocybin, with greater dissimilarity between individuals than under placebo. While idiosyncratic features in placebo subjects appear mainly in the frontoparietal network, under psilocybin they concentrate in the default mode network (DMN). A DMN-focused pattern predicts subjective psilocybin experience, marked by reduced within-DMN and DMN-limbic connectivity and increased connectivity between the DMN and attentional systems. These findings link psilocybin's brain effects to subjective experience and demonstrate the value of brain-fingerprinting in pharmacological neuroimaging.
NeuroImage
January 1, 2024
Pablo Mallaroni, Natasha L Mason, Lilian Kloft et al.
17 citations
Brain functional connectomes are unique fingerprints that persist across mental states, but their stability under altered states is unknown. After collective ayahuasca intake in 21 Santo Daime members, 7T fMRI showed reduced idiosyncrasy in static and dynamic functional connectivity, with a spatiotemporal reallocation of keypoint edges. Interindividual differences in higher-order connectivity motifs predicted perceptual drug effects, demonstrating that individualized connectivity markers can trace a subject's functional connectome across altered states of consciousness.
bioRxiv (Cold Spring Harbor Laboratory)
October 11, 2022
Pablo Mallaroni, Natasha L. Mason, Lilian Kloft et al.
4 citations
preprint
Brain functional connectomes are unique and reliable identifiers of individuals, but it was unknown whether these 'fingerprints' persist during altered states of consciousness. Ayahuasca, a serotonergic psychedelic, disrupts functional connectivity. In a within-subject study using 7T fMRI, 21 members of the Santo Daime church were scanned after collective ayahuasca intake. Connectome fingerprinting revealed a shared functional space and a spatiotemporal reallocation of key edges. Differences in higher-order functional connectivity motifs predicted perceptual drug effects, showing that individualized connectivity markers can trace a subject's functional connectome across altered states.
bioRxiv (Cold Spring Harbor Laboratory)
March 21, 2023
Hanna M. Tolle, Juan Carlos Farah, Pablo Mallaroni et al.
1 citation
preprint
Functional connectomes (FCs) become more idiosyncratic under the psychedelic psilocybin than under placebo, with idiosyncratic features concentrating in the default-mode network (DMN). An FC pattern predicting subjective psilocybin experience shows reduced within-DMN and DMN-limbic connectivity, alongside increased DMN-attentional system connectivity. These results bridge psilocybin's brain effects and behavior, demonstrating the value of brain-fingerprinting in pharmacological neuroimaging.
November 17, 2025
Krishna Prasad Bhavaraju, Natasha L. Mason, Pablo Mallaroni et al.
preprint
Psilocybin alters consciousness through multiple distinct neural processes rather than a single, uniform change in brain connectivity. Using a data-driven method called Connectome Independent Component Analysis on resting-state fMRI data from healthy volunteers, researchers identified separate functional connectivity traits. One trait was linked to the drug's physiological action, as its expression varied with plasma psilocin levels. A second, independent trait was associated with worse performance on a visual divergent thinking task. These results show the acute psilocybin state comprises co-occurring neural patterns, validating a decompositional approach to disentangle pharmacological and cognitive effects.
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.
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.