Sense of Agency (SoA), the subjective experience of initiating and controlling one's actions, is a critical component of self-perception and consciousness, and is often degraded in different psychopathologies. Individuals with dissociation seem to have diminished SoA, but it is yet unknown whether this affects communication with their surroundings. This study employs Natural Language Processing (NLP) to examine linguistic markers of SoA in dissociation, focusing on passive voice usage as an indicator of diminished agency. A dataset of 26 017 posts was extracted from 'Reddit' forums concerning dissociation and maladaptive daydreaming (a suggested dissociative disorder), and for comparison, depression, anxiety, and social anxiety. Passive voice usage was measured using spaCy's NLP framework, and verb tense distributions were analysed to explore additional potential linguistic markers of agency. Negative binomial regression models were used to compare passive voice usage across groups, controlling for word count. The dissociation group, but not the maladaptive daydreaming group, exhibited significantly greater use of passive voice compared to the general psychopathology control group (IRR = 1.10, P < .001). Additionally, when examining the three psychopathology control subgroups separately (depression, anxiety, and social anxiety), no significant difference was found between the depression and dissociation groups in passive voice usage. These findings suggest that diminished SoA is a core feature of dissociation, reflected in linguistic patterns. The results highlight the usefulness of language-based big data investigations in understanding the self-experience in psychopathology research.
The ability to imagine scenarios decoupled from the immediate environment supports a wide range of cognitive functions, such as planning, memory, and decision making. However, this increase in cognitive sophistication comes with a potential cost of mistaking simulation for reality. Here, we provide a functional analysis of the imagination-reality problem and argue that the specific way that imagination is used to guide behaviour puts unique constraints on the ability to distinguish it from reality. Our analysis illuminates the space of possible solutions supporting the ability to separate imagination from reality and offers a roadmap for future empirical research.
Theoretical models and empirical evidence suggest that psychedelics alter contextual influences on perception. To test this, we examined contrast surround suppression, a visual illusion in which a grating appears lower in contrast when embedded in a high-contrast surround. While psilocybin has been reported to enhance this and related illusions at moderate-to-high doses, it is unknown whether low-dose Lysergic Acid Diethylamide (LSD) produces similar effects. In a randomized, double-blind, within-subjects crossover study, N = 30 healthy participants received placebo, 10, and 20 μg of LSD (base-equivalent). In each session, participants performed a contrast discrimination task and rated subjective drug effects. LSD did not measurably influence contrast surround suppression. However, participants reported subjective visual changes, including blurrier, more saturated, and more dynamical visual perception. These subjective alterations did not correlate with individual differences in contrast-surround suppression. Our findings indicate a dissociation between subjective experience and early visual contextual processing, suggesting that subjective visual effects of low-dose LSD may arise through mechanisms distinct from those mediating contrast surround suppression. Future research should test whether higher doses of LSD affect contrast surround suppression.
Gender identity plays a crucial role in how we come to feel our bodies as our own. When the inner sense of gender does not align with bodily appearance, the resulting tension can shape both conscious and pre-reflective aspects of embodiment. In this study, we examined how gendered self-representations influence bodily self-consciousness using the Full-Body Illusion in immersive virtual reality. Eleven transgender and eleven cisgender participants embodied both gender-congruent and gender-incongruent avatars viewed from a first-person perspective under visuomotor synchrony. Participants rated their sense of ownership and agency using the Avatar Embodiment Questionnaire, and completed the Utrecht Gender Dysphoria Scale-Gender Spectrum to assess dysphoria and affirmation. All participants experienced a convincing illusion of embodiment. Yet, only transgender participants showed a clear difference between conditions, with stronger embodiment for gender-congruent avatars. Bootstrapped analyses confirmed higher ownership and mirror-ownership scores in the congruent condition, and correlations revealed that dysphoria was positively associated with mirror-based embodiment, whereas affirmation was negatively associated with agency. These findings suggest that the sense of owning and controlling one's body may be influenced not only by multisensory integration but also by its alignment with one's affirmed gender. Gender identity thus may emerge as a deeply embodied and dynamically instantiated dimension of minimal selfhood, bridging the sensorimotor and the phenomenological layers of bodily consciousness.
This study aimed to explore whether spontaneous eye blinking features from a brief vertical electro-oculogram recording can distinguish patients with severe acquired brain injury from healthy volunteers. Given evidence for shared neurobiological substrates in blinking control and attention, we expected altered blinking features in patients. In this observational cross-sectional study we extracted eye blink rate, amplitude, rise time, fall time, duration, and blink-blink interval variability from electro-oculography in 19 patients with severe acquired brain injury and 21 healthy controls during resting state and an auditory oddball task. We tested group differences with Kruskal-Wallis and Conover-Iman post-hoc comparisons. Differences covarying age and sex were assessed with Wald tests for odds ratios from logistic regression. Univariate Kruskal-Wallis testing showed longer rise time and duration and smaller amplitude in patients relative to healthy controls. When considering demographics as covariate, we show that amplitude is strongly confounded by demographics whereas rise time, duration and, to a lesser extent, fall time, are associated to the brain injury condition regardless of age or sex. Eye blink rate and blink-blink interval variability did not show statistically significant differences. Condition moderated effects: group contrasts were strongest at rest and attenuated during oddball. We found preliminary evidence that rise time and total duration are prolonged in patients independently of demographic factors, although with no difference between different levels of consciousness. Our results suggest a general slowing of blink dynamics consistent with altered basal ganglia dopaminergic activity, contributing physiological information relevant for monitoring and rehabilitation planning in brain injury.
Integrated information theory (IIT) makes two predictions about the role of inactive neurons in consciousness. According to the silent brain (SB) prediction, rendering all active neurons inactive ("silent") in the physical substrate of consciousness (the "main complex") does not eliminate the presence of consciousness, because the neurons are still able to spike. According to the disabled neuron (DN) prediction, rendering a subset of silent neurons in the main complex no longer able to spike ("disabled") can impact the qualitative character of experiences "nonconventionally" associated with those neurons. Bartlett (2022) argues that these predictions are untestable, because evidence for either prediction would imply that the testing conditions were not met. In this paper, we provide a detailed analysis of both silent neuron predictions, showing how they can in fact be tested. For the SB case, we clarify how a neural mechanism outside of the main complex can yield the required report of consciousness while maintaining the SB state. For the DN case, we distinguish between two ways of explaining how a neural mechanism could casually interact with the main complex: an IIT-inspired "dispositionalist" explanation, and a more conventional "actualist" explanation. Drawing on the work of Imre Lakatos, we conclude with a discussion of how the distinction between the two explanations sheds light on why it is so difficult to resolve theoretical disputes about consciousness. Despite these difficulties, we provide a framework that can lead to concrete progress for consciousness science.
In this study, the Consciousness States Comparison Scale: REM Version (CSCS-REM) was developed as a self-report instrument to assess dream consciousness during REM sleep in comparison with waking consciousness. Existing instruments capture only limited aspects of phenomenology and provide few opportunities for systematic cross-state evaluation. By anchoring waking consciousness as a reference point, the CSCS-REM quantifies relative differences in phenomenological experience and serves as a tool for empirically testing the predictions of the continuity and discontinuity hypotheses in consciousness research. The item pool was derived from a systematic review, expert evaluations, and preliminary studies, with content validity ensured through expert panels. After pilot testing, the 63-item draft was administered online, and data from 432 participants were analyzed using exploratory factor analysis. The final version consisted of 35 items across eight subscales: Metacognitive Awareness, Cognitive Fluency, Memory, Temporal Awareness, Spatial Awareness, Emotional Awareness, Perceptual and Bodily Senses, and Interoceptive and Chemical Senses. This structure accounted for 56.04% of the variance, with Cronbach's α ranging from .736 to .915 and McDonald's ω from .639 to .901. Confirmatory factor analysis in an independent sample (n = 211) demonstrated excellent fit indices (Comparative Fit Index = .986, Tucker-Lewis Index = .984, Root Mean Square Error of Approximation = .059). Subscales of the CSCS-REM showed small to moderate, yet significant, correlations with the Bodily Self-Consciousness in Dreams Questionnaire and the Dream Reflective Awareness Questionnaire, supporting convergent validity. In conclusion, while subject to some limitations, the CSCS-REM is a psychometrically reliable and valid instrument that enables systematic comparison of REM dream consciousness and waking consciousness across shared phenomenological dimensions.
Psychedelic compound N,N-Dimethyltryptamine (DMT) is renowned for inducing highly immersive experiences, often including encounters with seemingly sentient presences. While such phenomena are well documented, immersion under psychedelics remains conceptually underdefined and phenomenologically underexplored. Here we apply micro-phenomenology to characterize immersion under DMT as a structured continuum from subtle to gross forms of immersion, and to examine how perceived presences arise within this continuum. Twenty-three participants received 20 mg intravenous DMT during simultaneous fMRI-EEG acquisition, followed by detailed micro-phenomenological interviews focused on the temporal unfolding of experience. Micro-phenomenological analysis methods yielded 125 phenomenological categories describing structural dimensions, including sensory and amodal faculties, spatial organisation, self-world configuration, and modes of social relatedness. Dynamic analysis revealed reliable developmental patterns, with bodily effects typically preceding visual and auditory ones, and perceived presences emerging only after multisensory integration and 3D spatial characteristics had developed, illustrating a hierarchical relationship between subtle and gross forms of immersion. Perceived presences varied widely in sensory modality, semantic complexity, and relational mode. These findings show immersion under DMT as a dynamic, constructive process, providing precise structural features for future neurophenomenological modelling, and supporting the view that DMT research may inform our understanding of immersive experience across other aetiologies, including ordinary experience of the world.
Perceptual learning can occur without external feedback, raising questions about what internal signals might guide this learning. Here, we test the hypothesis that confidence, namely the observer's subjective sense of decision accuracy, is this internal teaching signal. In the present study, participants performed a visual motion discrimination task across 5 days without feedback. After every two trials, they indicated which decision they were more confident in, using a confidence forced-choice paradigm. In addition, following previous literature, we attempted to manipulate confidence independently of accuracy by varying dot density while holding signal-to-noise ratio constant (overall-strength manipulation), however, this manipulation did not consistently separate confidence from performance. In our study without feedback, we found that some participants improved their performance in the visual task, but other participants failed to become better. Those participants who improved their perceptual thresholds over time ("learners") also exhibited systematic changes in their confidence computations: not only sensory noise decreased, but confidence efficiency declined due to increases in confidence-specific noise. Learners also showed an increased reliance on additional evidence not used in the perceptual decision itself (confidence boost). Non-learners showed no comparable changes. These results suggest that confidence judgments evolve during perceptual learning and may serve as an index of how internal monitoring adapts during feedback-free training.
Consciousness is often treated as a property of the brain alone, yet accumulating evidence suggests that it is shaped by a recurrent dialogue between the brain and body. In this review, we discuss how cognition associated with consciousness-processes that define the observer, their observations, and arising qualia-depend on structured rhythmic correspondences between bodily rhythms and brain signals. We first review how cardiac, respiratory, and gastric rhythms modulate neuroelectric and neurovascular fluctuations in support of interoception-perception of the bodily state-and functionally related faculties such as emotion and selfhood, which draw upon interoceptive representations. We then discuss how clinical and subclinical conditions are associated with dysrhythmia in underlying bodily rhythms and atypical increases or decreases in a bodily rhythm's modulation of brain processes. Across bodily systems, an emergent pattern suggests both an optimal window of brain-body synchrony, beyond which adverse effects are likely to occur, and that non-clinical, stress-related increases in brain-body synchrony may promote the utility of bodily rhythms for coordinating disparate entrained cognitive systems to facilitate functions such as multisensory integration. We conclude that these converging lines of research support a categorical difference between an embodied agent and the proverbial brain-in-a-vat because disturbing bodily rhythms or their coupling to the brain alters phenomenological experience-at times to such a degree as to warrant labeling the resulting states as meeting clinical criteria.
Patients with severe anterograde amnesia have been described as "stuck in time"; their mental time travel abilities are altered, and they seem to live in the present. Here, we examine an unusual phenomenon in which severely amnesic patients recurrently report the belief that they have just awakened from an unconscious state. A famous case illustrating this phenomenon was that of Clive Wearing who repeatedly wrote “I am now awake” in his diary. This unique cognitive phenomenon has not been specifically studied until now. We report three new patients who described similar subjective experiences. All three patients suffered from autoimmune encephalitis and showed massive bilateral hippocampal inflammation causing severe anterograde amnesia. We propose to call this phenomenon “Stream of Consciousness Impairment”, a reference to William James’s theory according to which, normally, we experience an uninterrupted flow of consciousness. This condition should be added to the spectrum of neurological symptoms that contribute to the study of memory and consciousness in humans.
This paper explores the fundamental challenges of machine consciousness in the era of Physical AI, where Large Language Models (LLMs) are integrated with humanoid platforms. While current systems like 'Ameca' exhibit sophisticated conversational abilities, they remain ungrounded discursive constructs operating within the realm of 'spoken speech' (parole parlée)-linguistic patterns detached from lived experience. Drawing on phenomenology and developmental psychology, this study argues that authentic self-consciousness is not an internal property of an isolated agent but a relational quality emerging from the Aida (a Japanese concept referring to the relational 'in-between' that emerges between interacting agents). To address the symbol grounding problem, this research proposes the paradigm of 'Aidification.' Through a phenomenological analysis of bodily origins, we trace the constitution of the 'Me' through a developmental trajectory from the hands-initially experienced as visible instruments of action-to the face, which remains phenomenologically inaccessible to the self and thus requires the 'gaze of the Other' as the essential catalyst for self-objectification. Within this framework, language is reconceptualized as a 'cane for thought' that enables 'speaking speech' (parole parlante)-a creative act of meaning-generation anchored in the human 'felt sense.' Ultimately, Aidification reconceptualizes the AI robot as a dynamic participant in a shared intersubjective world rather than a solitary processor. By shifting the locus of cognition to the interactional field, we envision a 'symbiotic intelligence' that flourishes between humans and machines. This grounded intelligence does not merely simulate life but actively participates in the continuous co-creation of a shared reality, ensuring that the future of robotics is deeply rooted in the intersubjective fabric of human existence.
Schizophrenia is characterized by widespread neural dysconnectivity and impaired temporal coordination. Despite these pervasive disruptions, patients often maintain coherent perception and sense of agency, particularly during remission. This paradox remains underexplored, as research has mainly focused on symptom emergence rather than the mechanisms supporting preserved conscious experience. We propose a dual-role hypothesis of sensorimotor temporal recalibration, a process of adaptation to temporal asynchronies in sensorimotor integration. Temporal recalibration may serve both as a compensatory mechanism mitigating neural incoherence and, under certain conditions, as a trigger for positive symptoms. We compared clinically stable schizophrenia patients with healthy controls using a visuomotor temporal-order-judgement task following adaptation to sensorimotor asynchronies (0, 150, 300 ms). Patients exhibited significantly greater temporal recalibration than controls. When they experienced asynchrony between their actions and visual outcomes, they adjusted their point of subjective simultaneity more strongly, indicating enhanced adaptation to new temporal relationships. Consequently, after adaptation, patients were more likely to perceive outcomes as occurring before their actions when the adapted asynchrony was transiently reduced, whereas without adaptation they perceived them as following the action. No group differences emerged in just noticeable differences, indicating comparable temporal precision and task difficulty. These findings suggest that patients not only possess an intact recalibration mechanism but may engage it more to counteract neural delays and preserve temporal coherence. Overreliance on this adaptive process, however, may distort the perceived order of actions and outcomes, especially under transient temporal instability in information processing, and contribute to disrupted causality and agency in schizophrenia.
Breathing, beyond its metabolic role, has been increasingly implicated in shaping perception, attention, and aspects of cognitive processing. Here, we propose the Rhythmic Embodied Perception (REP) Framework, a multi-level framework linking body and brain to explain how respiration structures conscious experience. At the neurophysiological level, slow respiratory cycles modulate cortical oscillations via cross-frequency coupling, biasing excitability patterns across frontoparietal and occipital networks. At the perceptual-phenomenological level, these oscillatory dynamics create transient pause states-low-excitability phases of alpha/theta activity-during which sensory input is most likely to reach awareness. Respiration rhythmically gates these windows, coordinating perceptual clarity and attentional receptivity. At the regulatory-attentional level, volitional breath control stabilizes oscillatory and perceptual dynamics by entraining neuromodulatory networks such as the locus coeruleus-noradrenaline system, extending pause duration, and enhancing attentional stability. The REP Framework yields concrete, testable predictions: for example, respiratory phase should modulate phase-dependent sensory detection, and slow-paced breathing should strengthen respiration-cortex coupling and improve attentional continuity. Conceptually, this framework unifies evidence from neuroscience, theories of discrete perception, and yogic models of prana, grounding ancient accounts of pulsative attention in contemporary neural dynamics. Practically, it positions respiration as a trainable lever for shaping perceptual and attentional rhythms, offering an experimentally tractable route to probe the embodied mechanisms of consciousness. By highlighting the rhythmic interplay of breath, brain, and perception, the REP Framework provides a novel, integrative perspective on how bodily rhythms structure conscious experience, with implications for cognitive neuroscience, contemplative practice, and therapeutic interventions.
Prior research on confidence in perceptual decision making has almost exclusively used simple, static stimuli. While this work has led to many insights, it remains unclear how complex, real-world factors affect confidence judgments. To address this question, we developed a new task where participants watched short video clips and answered questions about their content by typing their answers and providing confidence on a 0-100 scale. We manipulated five variables related to the video clips-affective states induced by the clips (valence and arousal), prior information about the clips (contextual information coming from prior clips from the same movie and whether those clips were in correct or reverse chronological order), and heuristic cues about task difficulty (group size, quantified as the number of people shown). We found that arousal had a U-shaped effect on accuracy but an inverted-U-shaped effect on confidence. In addition, group size, event chronology, and the number of prior clips from the same movie affected confidence, but not accuracy. A second experiment, in which participants chose among a fixed set of options, replicated all these effects except for the effect of event chronology on confidence. These findings demonstrate that a range of factors- including affect, priors, and heuristic information- contribute selectively to confidence under natural viewing conditions. More broadly, these results highlight major differences in how decisions and confidence incorporate information and begin to reveal the possible sources of metacognitive inefficiency.
The unfolding argument in the neuroscience of consciousness posits that causal structure cannot account for consciousness because any recurrent neural network (RNN) can be "unfolded" into a functionally equivalent feedforward neural network (FNN) with identical input-output behavior. Subsequent debate has focused on dynamical properties and philosophy of science critiques. We examine a boundary condition on the unfolding argument for RNN systems with rapid plasticity in their connection weights. We demonstrate through rigorous mathematical proofs that rapid plasticity negates the functional equivalence between the RNN and the FNN. Our proofs address history-dependent plasticity, dynamical systems analysis, information-theoretic considerations, perturbational stability, complexity growth, and resource limitations. We demonstrate that neuronal systems that possess properties such as plasticity, history dependence, and complex temporal information encoding have features that cannot be captured by a static FNN. We show that plasticity is a concrete instance of lenient dependency between behavioral and internal observables, restoring empirical testability to theories that incorporate plasticity on perception-relevant timescales. Our results do not establish that recurrence, plasticity, or process are necessary for consciousness; they establish that the unfolding argument does not preclude empirical investigation of whether these properties matter.
A predictive coding (PC) framework assumes that the visual cortex generates and tests hypotheses about the likely causes of retinal stimulation. In doing so, it requires computation of the error between the predicted model and the sensory data. By contrast, a representational framework assumes that the visual cortex builds a surface representation by engaging horizontal and feedback connections that form excitatory feedback loops between cortical areas, without requiring error computation. I review studies on contour integration, illusory contours (ICs), figure-ground segregation, temporal and spatial predictability, and attentional modulation that involve single- and multi-unit recordings of neural activity in the early stages of visual processing, specifically to search for evidence of error computation. In agreement with the representational framework, many studies revealed that the V1-V4 complex forms an excitatory feedback loop that enhances the representation of the global contour or figure and suppresses the background across multiple levels of the visual hierarchy. By contrast, several studies on ICs and figure-ground segregation revealed evidence for error computation as hypothesized by PC. Taken together, the available neuronal data associated with visual processing and attentional modulation do not unequivocally support either of the proposed frameworks.
Under the influence of psychedelics, people often report encountering "entities" who seem to have their own autonomous agency. Depending on the cultural milieu, these entities are reported to take a variety of forms, including spirits, elves, ancestors, or fragments of the self. Encounters with such beings hold a central place in many traditions of psychedelic practice around the world. And yet, mechanistic accounts of these experiences are scarce in the neuroscientific literature. Here, we propose a neurocomputational model to account for experiences of entities, focusing primarily on those occasioned by the serotonergic psychedelic N,N-dimethyltryptamine. Our model builds on earlier theoretical accounts, including the entropic brain model of psychedelics, computational accounts of the felt presence of other minds, and theories of self-other discrimination based on sensory attenuation. We synthesize and expand on these perspectives through an overarching physics-based approach to cognition and brain function-the active inference framework. We propose that the general effects of psychedelics on large-scale neural dynamics may shape the way the brain comes to infer and interpret agentic presences. In particular, the reduction in the predictability of sensory perceptions during the psychedelic state may incline the brain to interpret perceptions, both internal and external, as resulting from non-self-agentic sources. In specifying the neurocomputational mechanisms, our model aims to explain how the brain supports entity encounters while also accounting for the diversity (and similarity) of these experiences across cultural contexts.
We surveyed attendees at two leading conferences on consciousness, asking for their views on central issues concerning infant consciousness. These include questions about whether newborns are conscious, when consciousness and self-consciousness emerge, where in the brain the neural basis of infant consciousness is found, what sorts of consciousness infants may have, and how best to study infant consciousness, as well as questions about which creatures are conscious and which theories of consciousness are preferred. A majority of respondents favoured the view that newborns are conscious. Pluralities favored the view that consciousness emerges prenatally after 24 weeks of gestation and the view that self-consciousness emerges postnatally after 6 months of age. Large majorities favoured the views that infants have sensory and affective consciousness (with fewer favouring cognitive and agentive consciousness). A plurality favored the view that the neural basis of infant consciousness is in sensory cortex. Majorities favored behavioural and neural markers (but not theories of consciousness) as a guide to infant consciousness.
The pursuit of a scientific theory of consciousness has gained momentum in neuroscience over the past 25 years. While much research has centered on perceptual consciousness, the dynamic experience of the stream of thought, proposed by William James over a century ago, has remained relatively underexplored. The Dynamic Framework of Thought (DFT) introduced a taxonomy of thought dynamics, emphasizing their role in shaping conscious experiences. The present study explores the introspective accessibility and distinctiveness of two dynamic dimensions of thought, freely moving and deliberately directed, derived from the taxonomy of the DFT. To investigate these dynamics, four experiments were conducted, including laboratory-based and online experiments as well as an fMRI-based experiment, to assess the consistency of the relationship between these thought dynamics across various experimental contexts. In all experiments, participants reported the dynamics of their thoughts during a probed resting period in which they sat quietly with eyes open, viewing a blank screen. Using a mixed-methods approach combining qualitative and quantitative assessments, this study suggests that individuals can have some introspective access to their thought dynamics. Freely moving and deliberately directed thoughts were distinguishable and negatively correlated but not anticorrelated across participants and experimental contexts. These findings suggest that the stream of thought can be characterized by at least two distinct dynamic dimensions-freely moving and deliberately directed-offering valuable insights for future neurophenomenological research aimed at bridging first-person reports of thought dynamics with third-person data on brain processes.
