Science Advances
February 1, 2019
Athena Demertzi, Enzo Tagliazucchi, Stanislas Dehaene et al.
545 citations
Consciousness depends on the brain's ability to sustain rich, dynamic patterns of signal coordination. Using functional magnetic resonance imaging, a complex pattern of coordinated and anticoordinated signals characterized healthy individuals and minimally conscious patients. Unresponsive patients showed low interareal phase coherence mainly mediated by structural connectivity, with fewer transitions between patterns. This complex pattern was also seen in patients with covert cognition who could perform mental imagery tasks, validating its link to consciousness. Anesthesia increased the probability of the less complex pattern to levels seen in unresponsive patients, confirming its role in unconsciousness. These results establish generalizable fingerprints of conscious and unconscious states after brain damage.
PLoS One
February 10, 2023
Lucia Melloni, Liad Mudrik, Michael Pitts et al.
106 citations
An adversarial collaboration between proponents of Global Neuronal Workspace and Integrated Information Theory devised and preregistered two experiments that test contrasting predictions about the location and timing of correlates of visual consciousness. Six theory-impartial laboratories will follow the study protocol using fMRI, M-EEG, and intracranial EEG, with built-in replications between labs and within datasets. The project aims to provide decisive evidence for or against the two theories and clarify the neural footprints of conscious visual perception, while modeling large-scale, collaborative, and open science practice.
Nature
June 1, 2025
Oscar Ferrante, Urszula Gorska-Klimowska, Simon Henin et al.
94 citations
Different theories explain how subjective experience arises from brain activity. An open science adversarial collaboration directly juxtaposed integrated information theory (IIT) and global neuronal workspace theory (GNWT). Human participants (n = 256) viewed suprathreshold stimuli for variable durations while neural activity was measured with fMRI, MEG, and intracranial EEG. Information about conscious content was found in visual, ventrotemporal, and inferior frontal cortex, with sustained responses in occipital and lateral temporal cortex reflecting stimulus duration, and content-specific synchronization between frontal and early visual areas. These results align with some predictions of IIT and GNWT but substantially challenge key tenets of both theories, including a lack of sustained posterior cortex synchronization for IIT and a lack of ignition at stimulus offset and limited prefrontal representation for GNWT.
Neuroscience and Biobehavioral Reviews
March 1, 2025
Liad Mudrik, Melanie Boly, Stanislas Dehaene et al.
68 citations
In a structured public debate at the 2022 meeting of the Association for the Scientific Study of Consciousness, proponents of five major theories—Global Neuronal Workspace Theory, Higher-Order Theories, Integrated Information Theory, Recurrent Processing Theory, and Predictive Processing—clarified their theories' core mechanisms, foundational premises, and what each theory aims to explain. The discussion revealed more controversy than agreement, particularly on the most basic questions: what consciousness is, how to identify conscious states, and what any adequate theory must account for. Addressing these foundational disagreements is essential for advancing the field and enabling meaningful comparison of competing theories.
Neuroscience of Consciousness
January 1, 2022
Joachim Bellet, Marion Gay, Abhilash Dwarakanath et al.
57 citations
Neuronal populations in the macaque prefrontal cortex (PFC) reliably encode visual stimuli even under conditions that challenge conscious perception and reduce post-perceptual processing. Recordings from the ventrolateral PFC during isolated trials and rapid serial visual presentation (RSVP) showed that stimulus identity could be decoded from population activity, with first signals at 60 ms and peak information at 150 ms. In RSVP, decoding accuracy dropped to chance by 200 ms as the next stimulus became decodable. Decoding in ventrolateral PFC was stronger than in posterior parietal cortex. The findings indicate PFC encodes visual information under conditions that limit conscious access and post-perceptual elaboration, raising questions about whether this reflects conscious access, phenomenal consciousness, or preconscious bottom-up processing.
bioRxiv Preprint Server
December 14, 2016
Darinka Trübutschek, Sebastien Marti, Andrés Ojeda et al.
47 citations
preprint
Working memory and conscious perception are often thought to rely on the same brain mechanisms, but recent evidence suggests non-conscious working memory exists. Using visual masking and magnetoencephalography in a spatial delayed-response task, participants reported the location of a subjectively unseen target above chance after a long delay. Conscious perception and conscious working memory showed sustained alpha/beta desynchronization over frontal cortex and decodable target location in posterior sensors. During non-conscious working memory, these signals vanished, contradicting models equating working memory with sustained neural firing. The findings support 'activity-silent' working memory, where slowly decaying synaptic changes allow cell assemblies to go dormant during the delay yet be retrieved above chance after seconds.
Cell Reports
March 25, 2025
Ulysse Klatzmann, Sean Froudist-Walsh, Daniel P Bliss et al.
14 citations
Conscious access involves 'ignition,' an all-or-none activation across cortical areas. Computer simulations of a detection task using a mesoscale connectome-based model of the macaque cortex reveal a dynamic bifurcation mechanism that produces ignition in a network of associative regions. A hierarchical NMDA/AMPA receptor gradient is critical: fast AMPA receptors drive feedforward signal propagation, while slow NMDA receptors in feedback pathways shape and sustain the ignited network. The model suggests higher NMDA-to-AMPA receptor ratios in sensory areas compared to association areas, a prediction supported by in vitro autoradiography data. The model accounts for diverse behavioral and physiological phenomena linked to consciousness.
Neuron
May 15, 2024
Stanislas Dehaene
1 citation
Stanislas Dehaene, a cognitive neuroscientist, discusses his research into the biological basis of perception and cognition, his ongoing interest in consciousness, the importance of theory in neuroscience, and his current work on education and the science of learning.
bioRxiv : the preprint server for biology
November 8, 2025
Lucie Berkovitch, Alexandre Salvador, Thomas Andrillon et al.
preprint
Low doses of ketamine, an NMDA-receptor antagonist, disrupt the ability to consciously perceive visual information in healthy people. In a double-blind, placebo-controlled experiment with 21 volunteers, ketamine increased visual masking and reduced conscious perception of a digit. The N1 component of brain activity, an early marker of visual processing, was significantly reduced under ketamine and correlated with conscious access. Ketamine also induced psychotic-like and manic-like symptoms, but only the psychotic-like dimension was linked to impairments in conscious access. These findings suggest ketamine attenuates early visual brain responses, impairing conscious access, and that this mechanism differs in some ways from that seen in schizophrenia.
bioRxiv Preprint Server
June 23, 2023
Oscar Ferrante, Urszula Gorska-Klimowska, Simon Henin et al.
preprint
An open science adversarial collaboration directly juxtaposed Integrated Information Theory (IIT) and Global Neuronal Workspace Theory (GNWT) by investigating neural correlates of visual experience. 256 human subjects viewed suprathreshold stimuli for variable durations while neural activity was measured with fMRI, MEG, and ECoG. Information about conscious content was found in visual, ventro-temporal, and inferior frontal cortex, with sustained responses in occipital and lateral temporal cortex reflecting stimulus duration, and content-specific synchronization between frontal and early visual areas.
Elife
May 5, 2021
Moti Salti, Simo Monto, Lucie Charles et al.
Conscious perception of a stimulus is linked to a specific sequence of brain processes that unfold after about 270 milliseconds, involving superior parietal and superior frontal regions. Using EEG and MEG recordings during a task where participants reported the location and visibility of a brief visual target, multivariate pattern analysis showed that information about stimulus location is still processed in the cortex even when the stimulus is not consciously seen (blindsight). However, only consciously perceived stimuli trigger additional, time-limited neural activity in higher-order brain areas, whereas unconscious processing decays slowly without this chain of activity.
Neuroimage
January 1, 2017
Lucie Charles, Raphaël Gaillard, Isabelle Amado et al.
Error detection relies on two distinct brain systems: one tied to conscious awareness and another that operates without it. In people with schizophrenia, the conscious error-detection system is impaired, as shown by a reduced Error-Related Negativity (ERN) in EEG and MEG recordings during a speeded number comparison task. However, on trials where stimuli were presented unconsciously, both schizophrenia patients and healthy controls could still evaluate their own errors above chance levels. This dissociation indicates that non-conscious performance monitoring remains intact in schizophrenia, while conscious metacognition is specifically altered.
PLoS Biology
June 15, 2016
Stanislas Dehaene, Jean-Pierre Changeux
Even without sensory input, cortical and thalamic neurons exhibit structured spontaneous activity whose origins and functions are unclear. Computer simulations of a simplified model with multiple interconnected thalamocortical columns and long-range excitatory axons reveal two main activity states: spontaneous gamma-band oscillations emerge at a precise threshold controlled by neuromodulator systems, and within a spontaneously active network, sudden "ignition" of one of many possible coherent high-level activity states occurs among cortical neurons with long-distance projections. During ignition, spontaneous activity can block external sensory processing, relating to inattentional blindness, where intensely engaged subjects fail to notice salient but irrelevant stimuli. The minimal network's generic properties may clarify basic cerebral phenomena underlying consciousness's autonomy.
Proceedings of the National Academy of Sciences of the United States of America
April 21, 2015
Aaron Schurger, Ioannis Sarigiannidis, Lionel Naccache et al.
Conscious perception may involve the transient stabilization of distributed cortical networks, corresponding to a global brain-scale decision. Pattern-similarity analyses of MEG/EEG data from participants viewing threshold-level visual stimuli showed a decrease in variability across trials after stimulus onset, followed by a divergence in variability based on subjective report (seen/unseen), with seen trials exhibiting less variability. Within-trial stability alone could classify individual trials as seen or unseen. In patients with disorders of consciousness exposed to auditory stimuli, stability metrics diverged according to clinically diagnosed level of consciousness. Differences in signal strength could not account for these results.
Neuroimage
February 1, 2012
Sebastien Marti, Mariano Sigman, Stanislas Dehaene
The psychological refractory period (PRP) and attentional blink (AB) are two well-known phenomena that limit the ability to process two successive tasks or stimuli. A neuromimetic model proposed they might share a common bottleneck—a serial stage where stimuli gain access to consciousness. Using magneto-encephalography (MEG) in a cross-modal paradigm with an auditory first target and a visual second target, the authors observed both PRP (delayed processing) and AB (missed detection) on different trials with identical stimuli. Brain recordings showed identical early sensory processing in visual cortices for both trial types, but later frontal activations (>350 ms) were delayed in PRP trials and absent in blinked trials. The results indicate that both phenomena arise from the same cortical stages and are distinguished by trial-by-trial fluctuations in task processing.
Frontiers in Human Neuroscience
December 16, 2011
Valentin Wyart, Stanislas Dehaene, Catherine Tallon-Baudry
Spatial attention amplifies early visual brain responses around 100 milliseconds after a stimulus appears, but this amplification does not determine whether the stimulus is consciously detected. In a magnetoencephalography experiment, participants attended toward or away from masked stimuli that were physically identical yet detected half the time. Attention increased occipital responses equally for detected and missed stimuli and did not increase detection rates. The earliest neural correlate of conscious detection occurred around 120 milliseconds over contralateral temporal cortex, independent of attention. A later correlate of conscious reportability appeared from 220 milliseconds over temporal and frontal cortex, coinciding with attentional reorienting triggered by masks at uncued locations. Conscious detection of a masked stimulus at an unexpected location captures spatial attention, supporting a double dissociation between endogenous spatial attention and perceptual awareness.