Annals of Neurology
September 22, 2016
Silvia Casarotto, Angela Comanducci, Mario Rosanova et al.
504 citations
A brain-based measure called the Perturbational Complexity Index (PCI) can reliably distinguish conscious from unconscious individuals, even when they cannot speak or move. The index was first validated in 150 healthy and brain-injured people who could report their conscious state, achieving perfect accuracy in separating conscious from unconscious conditions. Applied to 81 noncommunicative patients, PCI correctly identified 94.7% of those in a minimally conscious state and revealed that 9 of 43 patients diagnosed as vegetative had PCI values overlapping with conscious individuals. These findings suggest that some behaviorally unresponsive patients may retain hidden conscious capacity.
Neuroscience of Consciousness
January 27, 2017
Michael Schartner, Andrea Pigorini, Steve A. Gibbs et al.
158 citations
During non-rapid eye movement (NREM) sleep, neural dynamical complexity—measured by Lempel-Ziv complexity, amplitude coalition entropy, and synchrony coalition entropy—decreased substantially across broadly distributed brain regions in ten epilepsy patients. This decrease partially reversed during late-night NREM sleep and returned to wakeful rest levels during rapid eye movement (REM) sleep. Local brain regions mirrored this global pattern. The frontal lobe showed elevated signal complexity. These changes were not solely due to spectral power differences. The findings suggest that level of consciousness correlates with neural dynamical complexity.
Neuron
May 15, 2024
Johan F Storm, P Christiaan Klink, Jaan Aru et al.
108 citations
Consciousness may be explained by multiple, partly compatible theories rather than a single winner. A group of scientists representing different theories argue that various accounts often address different aspects or mechanistic levels of conscious experience, so they do not necessarily contradict each other. Instead, several theories may converge on fundamental neuronal mechanisms and be complementary, allowing multiple perspectives to simultaneously advance understanding. The authors advocate for unifying, integration-oriented approaches that combine valuable elements from diverse theories, an approach that has so far been largely neglected.
Current biology : CB
June 9, 2025
Davide Albertini, Maria Del Vecchio, Ivana Sartori et al.
9 citations
Conscious perception of simple touch depends on sustained neural activity in higher-order somatosensory regions, specifically the posterior perisylvian areas. Using human intracortical recordings, tonic responses in these regions showed all-or-nothing patterns at the sensory threshold, remained unchanged whether or not participants reported the stimulus, and most clearly distinguished perceived from non-perceived stimuli. These dynamics may serve as an organizational principle of somatosensory awareness.
PLoS biology
October 1, 2025
Michele Angelo Colombo, Jacopo Favaro, Ezequiel Mikulan et al.
7 citations
After hemispherotomy surgery for epilepsy, which disconnects an entire brain hemisphere, the isolated cortex shows brainwave patterns typical of deep sleep or anesthesia, not wakefulness. In 10 pediatric patients, EEG recordings revealed prominent slow oscillations and a steeper spectral decay in the disconnected hemisphere, while the connected hemisphere maintained normal waking patterns. These sleep-like patterns persisted years after surgery, suggesting the isolated cortex likely lacks awareness.
bioRxiv
December 7, 2023
Joseph Starkey, Robin L. Carhart-Harris, Andrea Pigorini et al.
preprint
A measure of 'statistical complexity' that calculates the diversity of statistical interactions in neural activity, removing randomness, was tested on human brain data from different sleep stages and from people under ketamine, LSD, and psilocybin. Statistical complexity differentiated sleep stages similarly to the standard Lempel-Ziv complexity measure and increased relative to placebo for all three psychedelic substances. The measure is a useful alternative for investigating neural activity complexity across states of consciousness.