bioRxiv Preprint Server
December 9, 2025
Tomas Berjaga-Buisan, Juan Manuel Monti, Martina Cortada et al.
preprint
The quest for reliable and objective measures of consciousness is critical in basic and clinical neuroscience. Across species, the Perturbational Complexity Index (PCI) has emerged as a robust empirical marker by directly perturbing the brain, yet its underlying principles of physics are not fully understood. Here, we bridge this gap by introducing a non-invasive framework based on generative...
arXiv Preprint Archive
October 7, 2025
Maria V. Sanchez-Vives, Arnau Manasanch, Andrea Pigorini et al.
The cerebral cortex spontaneously displays different patterns of activity that evolve over time according to the brain state. Sleep, wakefulness, resting states, and attention are examples of a wide spectrum of physiological states that can be sustained by the same structural network. Furthermore, additional states are generated by drugs (e.g., different levels of anesthesia) or by pathological...
PLoS Biology
October 1, 2025
Michele Angelo Colombo, Jacopo Favaro, Ezequiel Mikulan et al.
7 citations
Hemispherotomy is a neurosurgical procedure for treating refractory epilepsy, which entails disconnecting a significant portion of the cortex, potentially encompassing an entire hemisphere, from its cortical and subcortical connections. While this intervention prevents the spread of seizures, it raises important questions. Given the complete isolation from sensory-motor pathways, it remains...
Current biology : CB
June 9, 2025
Davide Albertini, Maria Del Vecchio, Ivana Sartori et al.
9 citations
Distilling the neural correlates of consciousness (NCCs) in humans is challenging due to limitations in the spatiotemporal resolution of recording techniques and confounds related to pre- and post-perceptual processes. In this study, we leveraged the detailed insights provided by human intracortical recordings to elucidate how somatosensory responses to simple tactile stimuli vary across...
Neuron
May 15, 2024
Johan F. Storm, P Christiaan Klink, Jaan Aru et al.
108 citations
How is conscious experience related to material brain processes? A variety of theories aiming to answer this age-old question have emerged from the recent surge in consciousness research, and some are now hotly debated. Although most researchers have so far focused on the development and validation of their preferred theory in relative isolation, this article, written by a group of scientists...
Trends in Cognitive Sciences
March 1, 2024
Tim Bayne, Anil K. Seth, Marcello Massimini et al.
Which systems/organisms are conscious? New tests for consciousness ('C-tests') are urgently needed. There is persisting uncertainty about when consciousness arises in human development, when it is lost due to neurological disorders and brain injury, and how it is distributed in nonhuman species. This need is amplified by recent and rapid developments in artificial intelligence (AI), neural...
bioRxiv Preprint Server
April 18, 2023
Martin Breyton, Jan Fousek, Giovanni Rabuffo et al.
preprint
Signatures of consciousness are found in spectral and temporal properties of neuronal activity. Among these, spatiotemporal complexity after a perturbation has recently emerged as a robust metric to infer levels of consciousness. Perturbation paradigms remain, however, difficult to perform routinely. To discover alternative paradigms and metrics, we systematically explore brain stimulation and...
Nature Communications
February 25, 2022
Minji Lee, Leandro R. D. Sanz, Alice Barra et al.
120 citations
Consciousness can be defined by two components: arousal (wakefulness) and awareness (subjective experience). However, neurophysiological consciousness metrics able to disentangle between these components have not been reported. Here, we propose an explainable consciousness indicator (ECI) using deep learning to disentangle the components of consciousness. We employ electroencephalographic (EEG)...
Neuroscience of Consciousness
2021
Simone Sarasso, Adenauer G. Casali, Silvia Casarotto et al.
183 citations
Abstract Over the last years, a surge of empirical studies converged on complexity-related measures as reliable markers of consciousness across many different conditions, such as sleep, anesthesia, hallucinatory states, coma, and related disorders. Most of these measures were independently proposed by researchers endorsing disparate frameworks and employing different methods and techniques....
Trends in Neurosciences
December 10, 2019
Tim Bayne, Anil K. Seth, Marcello Massimini
146 citations
Awareness may persist in fully disconnected cortical islands.We identify both natural and artificial examples of potential islands of awareness.Detecting islands of awareness poses difficult but often addressable challenges.The possibility of islands of awareness raises important ethical and legal issues.The discovery of islands of awareness would have important implications for debates about...
Comput. Methods Programs Biomed.
July 1, 2019
J. R. D. Miras, Fernando Soler-Toscano, Sergio Iglesias-Parro et al.
BACKGROUND AND OBJECTIVE Knowing whether a subject is conscious or not is a current challenge with a deep potential clinical impact. Recent theoretical considerations suggest that consciousness is linked to the complexity of distributed interactions within the corticothalamic system. The fractal dimension (FD) is a quantitative parameter that has been extensively used to analyse the complexity...
Neuroimage
January 11, 2019
Michele A. Colombo, Martino Napolitani, Melanie Boly et al.
359 citations
Despite the absence of responsiveness during anesthesia, conscious experience may persist. However, reliable, easily acquirable and interpretable neurophysiological markers of the presence of consciousness in unresponsive states are still missing. A promising marker is based on the decay-rate of the power spectral density (PSD) of the resting EEG. We acquired resting electroencephalogram (EEG)...
Brain Stimulation
November 1, 2018
Olivier Bodart, Matteo Fecchio, Marcello Massimini et al.
Meditation can be conceptualized as a family of complex emotional and attentional regulatory training regimes developed for various ends, including the cultivation of well-being and emotional balance. Previous studies have demonstrated that meditation may have positive effects on self-awareness, emotion regulation, attention processes, and also structural neuroplasticity [1]. However, the...
Journal of Medical Ethics
September 1, 2018
Andrea Lavazza, Marcello Massimini
Organoids are three-dimensional biological structures grown in vitro from different kinds of stem cells that self-organise mimicking real organs with organ-specific cell types. Recently, researchers have managed to produce human organoids which have structural and functional properties very similar to those of different organs, such as the retina, the intestines, the kidneys, the pancreas, the...
Oxford Scholarship Online
May 30, 2018
Marcello Massimini, Giulio Tononi
Sizing up Consciousness explores, at an introductory level, the potential practical, clinical, and ethical implications of a general principle about the nature of consciousness. Using information integration theory (IIT) as a guiding principle, the book takes the reader along a scientific trajectory to face fundamental questions about the relationships between matter and experience. What is so...
The Journal of neuroscience : the official journal of the Society for Neuroscience
November 8, 2017
Johan F. Storm, Melanie Boly, Adenauer G. Casali et al.
How consciousness (experience) arises from and relates to material brain processes (the "mind-body problem") has been pondered by thinkers for centuries, and is regarded as among the deepest unsolved problems in science, with wide-ranging theoretical, clinical, and ethical implications. Until the last few decades, this was largely seen as a philosophical topic, but not widely accepted in...
Journal of Neuroscience
October 4, 2017
Melanie Boly, Marcello Massimini, Naotsugu Tsuchiya et al.
591 citations
The role of the frontal cortex in consciousness remains a matter of debate. In this Perspective, we will critically review the clinical and neuroimaging evidence for the involvement of the front versus the back of the cortex in specifying conscious contents and discuss promising research avenues. Dual Perspectives Companion Paper: Should a Few Null Findings Falsify Prefrontal Theories of...
Neuroscience of Consciousness
January 27, 2017
Michael Schartner, Andrea Pigorini, Steve A. Gibbs et al.
158 citations
Key to understanding the neuronal basis of consciousness is the characterization of the neural signatures of changes in level of consciousness during sleep. Here we analysed three measures of dynamical complexity on spontaneous depth electrode recordings from 10 epilepsy patients during wakeful rest (WR) and different stages of sleep: (i) Lempel-Ziv complexity, which is derived from how...
Annals of Neurology
September 22, 2016
Silvia Casarotto, Angela Comanducci, Mario Rosanova et al.
504 citations
OBJECTIVE: Validating objective, brain-based indices of consciousness in behaviorally unresponsive patients represents a challenge due to the impossibility of obtaining independent evidence through subjective reports. Here we address this problem by first validating a promising metric of consciousness-the Perturbational Complexity Index (PCI)-in a benchmark population who could confirm the...
Scientific Reports
August 5, 2016
Jaakko O. Nieminen, Olivia Gosseries, Marcello Massimini et al.
60 citations
When subjects become unconscious, there is a characteristic change in the way the cerebral cortex responds to perturbations, as can be assessed using transcranial magnetic stimulation and electroencephalography (TMS-EEG). For instance, compared to wakefulness, during non-rapid eye movement (NREM) sleep TMS elicits a larger positive-negative wave, fewer phase-locked oscillations, and an overall...
Nature reviews. Neuroscience
April 20, 2016
Christof Koch, Marcello Massimini, Melanie Boly et al.
1,654 citations
There have been a number of advances in the search for the neural correlates of consciousness--the minimum neural mechanisms sufficient for any one specific conscious percept. In this Review, we describe recent findings showing that the anatomical neural correlates of consciousness are primarily localized to a posterior cortical hot zone that includes sensory areas, rather than to a...
PLoS One
May 13, 2015
Melanie Boly, Shuntaro Sasai, Olivia Gosseries et al.
69 citations
A meaningful set of stimuli, such as a sequence of frames from a movie, triggers a set of different experiences. By contrast, a meaningless set of stimuli, such as a sequence of 'TV noise' frames, triggers always the same experience--of seeing 'TV noise'--even though the stimuli themselves are as different from each other as the movie frames. We reasoned that the differentiation of cortical...
Brain Injury
August 1, 2014
Martino Napolitani, Olivier Bodart, Paola Canali et al.
44 citations
BACKGROUND: This review discusses the advantages of transcranial magnetic stimulation combined with high-density electroencephalography (TMS-hdEEG) over other current techniques of brain imaging. METHODS AND RESULTS: Its application was reviewed, focusing particularly on disorders of consciousness, in the perspective of recent theories of consciousness. Assessment of non-communicative patients...
Clinical EEG and Neuroscience
2014
Simone Sarasso, Mario Rosanova, Adenauer G. Casali et al.
164 citations
We normally assess another individual's level of consciousness based on her or his ability to interact with the surrounding environment and communicate. Usually, if we observe purposeful behavior, appropriate responses to sensory inputs, and, above all, appropriate answers to questions, we can be reasonably sure that the person is conscious. However, we know that consciousness can be entirely...
Science Translational Medicine
August 14, 2013
Adenauer G. Casali, Olivia Gosseries, Mario Rosanova et al.
1,299 citations
One challenging aspect of the clinical assessment of brain-injured, unresponsive patients is the lack of an objective measure of consciousness that is independent of the subject's ability to interact with the external environment. Theoretical considerations suggest that consciousness depends on the brain's ability to support complex activity patterns that are, at once, distributed among...