Introduction: Transcranial direct current stimulation (tDCS) has shown encouraging results in patients with Disorders of Consciousness (DoC), yet its efficacy and mechanisms remain unclear. This study aimed to evaluate the effects of left dorsolateral prefrontal cortex (DLPFC) tDCS on Coma Recovery Scale-Revised (CRS-R) scores and EEG activity in severely brain-injured DoC patients. Methods: In...
PNAS NexusMarch 1, 2026Lina Jeantin, Pierre Bourdillon, Marc Guenot et al.
Electroencephalography (EEG) signal complexity reflects the richness of brain activity and is considered a marker of consciousness. However, its normative values across physiological conscious states using intracranial EEG (iEEG) across cortical areas remain poorly defined. We aimed at referencing iEEG complexity in the human brain and its links with global states of consciousness. We analyzed...
Sleep has traditionally been conceptualized as a state of cognitive disconnection, yet emerging evidence indicates that decision-making capacities persist across sleep stages. Here, we elucidate the computational mechanisms underlying real-time lexical decision-making during polysomnographically-verified sleep, using facial electromyography and hierarchical drift diffusion modeling in both...
PLoS One2026Matilda Gibbons, Ethan G McBride, Raghuram Holenarasipura Venkatasubbaiah et al.
Identifying the neural correlates of consciousness (NCC) is widely regarded as imperative to our understanding of consciousness. Although several scientific theories of consciousness make predictions about the NCC, they often differ in their level of detail, making direct comparison through experimental findings difficult. Here, we report an adversarial collaboration protocol in which unbiased...
Does being awake necessarily mean being conscious of something? This study investigates the phenomenon of mind blanking (MB), characterized by an "emptiness of mind," comparing it with mind wandering (MW) and on-task (ON) states. Using a sustained attention task and electroencephalogram monitoring, behavioral, and neurophysiological signatures of MB were examined in 62 participants. MB...
2025) aimed at enriching the progressive build-up of a valid theory of conscious processing using valuable multicentric experimentation and massive data-sharing open to new analyses (Bryant and Whyte 2025).
Retinal illumination primarily determines pupil size, yet extra-retinal factors like subjective brightness also influence pupillary responses. Previous works reported that in healthy individuals, stimuli whose semantic content evokes brightness cause greater pupillary constriction than control stimuli of similar luminance. This study adapted this approach and tested a passive task to assess...
Attention shapes our consciousness content and perception by increasing the probability of becoming aware and/or better encoding a selection of the incoming inner or outer sensory world. Engaging interoceptive and exteroceptive attention should elicit distinctive neural responses to visceral and external stimuli and could be useful in detecting covert command-following in unresponsive patients....
Disorders of consciousness (DoC) represent a challenging and complex group of neurological conditions characterised by profound disturbances in consciousness. The current range of treatments for DoC is limited. This has sparked growing interest in developing new treatments, including the use of psychedelic drugs. Nevertheless, clinical investigations and the mechanisms behind them are...
Abstract Identifying the neuronal markers of consciousness is key to supporting the different scientific theories of consciousness. Neuronal markers of consciousness can be defined to reflect either the brain signatures underlying specific conscious content or those supporting different states of consciousness, two aspects traditionally studied separately. In this paper, we introduce a...
Abstract We introduce here a general model of Functional Neurological Disorders based on the following hypothesis: a Functional Neurological Disorder could correspond to a consciously initiated voluntary top-down process causing involuntary lasting consequences that are consciously experienced and subjectively interpreted by the patient as involuntary. We develop this central hypothesis...
Disorders of consciousness (DoC) are a challenging and complex group of neurological conditions characterised by absent or impaired awareness. The current range of therapeutic options for DoC patients is limited, offering few non-invasive pharmacological alternatives. This situation has sprung a growing interest in the development of novel treatments, such as the proposal to study the efficacy...
Identifying the neural correlates of consciousness (NCCs) is key to support the different scientific theories of consciousness. NCCs can be defined to reflect either the brain signatures underlying specific conscious content or those supporting different states of consciousness, two aspects traditionally studied separately. In this paper, we introduce a framework to characterize NCCs according...
Significant advances have been made by identifying the levels of synchrony of the underlying dynamics of a given brain state. This research has demonstrated that non-conscious dynamics tend to be more synchronous than in conscious states, which are more asynchronous. Here we go beyond this dichotomy to demonstrate that different brain states are underpinned by dissociable spatiotemporal...
Hypnosis can be conceived as a unique opportunity to explore how top-down effects can influence various conscious and non-conscious processes. In the field of perception, such modulatory effects have been described in distinct sensory modalities. In the present study we focused on the auditory channel and aimed at creating a radical deafness to elementary sounds by a specific hypnotic...
Abstract The clinical and fundamental exploration of patients suffering from disorders of consciousness (DoC) is commonly used by researchers both to test some of their key theoretical predictions and to serve as a unique source of empirical knowledge about possible dissociations between consciousness and cognitive and/or neural processes. For instance, the existence of states of vigilance free...
In this commentary, I discuss my main points of convergence and divergence with Mark Solms' conception of consciousness presented in his very stimulating opus, The Hidden Spring, and then frame two proposals to integrate some of his key concepts into the global neuronal workspace theory (GNWT) of consciousness.
Adopting the framework of brain dynamics as a cornerstone of human consciousness, we determined whether dynamic signal coordination provides specific and generalizable patterns pertaining to conscious and unconscious states after brain damage. A dynamic pattern of coordinated and anticoordinated functional magnetic resonance imaging signals characterized healthy individuals and minimally...
Scientific research on consciousness is critical to multiple scientific, clinical, and ethical issues. The growth of the field could also be beneficial to several areas including neurology and mental health research. To achieve this goal, we need to set funding priorities carefully and address problems such as job creation and potential media misrepresentation.
Pupil dilation has been reliably identified as a physiological marker of consciously reportable mental effort. This classical finding raises the question of whether or not pupil dilation could be a specific somatic signature of conscious processing. In order to explore this possibility, we engaged healthy volunteers in the 'local global' auditory paradigm we previously designed to disentangle...
According to a popular distinction proposed by the philosopher Ned Block in 1995, our conscious experience would overflow the very limited set of what we can consciously report to ourselves and to others. He proposed to coin this limited consciousness 'Access Consciousness' (A-Cs) and to define 'Phenomenal Consciousness' as a much richer subjective experience that is not accessed but that would...
By looking for properties of consciousness, cognitive neuroscience studies have dramatically enlarged the scope of unconscious cognitive processing. This emerging knowledge inspired the development of new approaches allowing clinicians to probe and disentangle conscious from unconscious cognitive processes in non-communicating brain-injured patients both in terms of behaviour and brain...
According to recent evidence, stimulus-tuned neurons in the cerebral cortex exhibit reduced variability in firing rate across trials, after the onset of a stimulus. However, in order for a reduction in variability to be directly relevant to perception and behavior, it must be realized within trial--the pattern of activity must be relatively stable. Stability is characteristic of decision states...
Casali et al. recently showed that the complexity of the electrophysiological brain response to a transcranial magnetic stimulation pulse distinguishes conscious from unconscious humans in a variety of conditions. In addition to its theoretical implications, this novel method paves the way to a quantitative assessment of the states of consciousness.
Neuronal theories of conscious access tentatively relate conscious perception to the integration and global broadcasting of information across distant cortical and thalamic areas. Experiments contrasting visible and invisible stimuli support this view and suggest that global neuronal communication may be detectable using scalp electroencephalography (EEG). However, whether global information...