Neuroscience of Consciousness
January 1, 2019
Andrew Peterson, Enzo Tagliazucchi, Charles Weijer
25 citations
An ethical analysis of proposed psychedelic research with patients who have disorders of consciousness, using the Value-Validity Framework and Component Analysis, finds that the approach by Scott and Carhart-Harris is ethically permissible under certain conditions. The frameworks applied are also relevant for evaluating other novel consciousness research protocols.
Neuroscience of Consciousness
January 1, 2025
Michael C Wiest
22 citations
Recent experimental evidence indicates that inhalational anesthetics target intraneuronal microtubules, supporting the hypothesis that consciousness arises from a collective quantum state of microtubules, as predicted by the Orchestrated Objective Reduction theory. Evidence also shows functionally relevant quantum effects in microtubules at room temperature and a macroscopic quantum entangled state in the living human brain correlated with conscious state and working memory. The quantum model makes panprotopsychism a viable solution to the hard problem by solving the binding problem, but raises an epiphenomenalism problem. The author proposes the quantum approach can solve this, and the Orch OR theory accounts for nonalgorithmic understanding and the psychological arrow of time.
Neuroscience of Consciousness
January 1, 2023
Sidath Rankaduwa, Adrian M. Owen
21 citations
The entropic brain theory (EBT) explains how psychedelics alter brain activity by increasing brain entropy, offering insights into both normal and altered states of consciousness. This theory has implications for debates about whether consciousness exists in levels or dimensions, whether the psychedelic state represents a higher level of consciousness, and whether psychedelics could treat disorders of consciousness such as minimally conscious or vegetative states. The article summarizes EBT's core principles and their relevance to a theoretical model of consciousness, emphasizing that the therapeutic value of psychedelics for such patients depends on set and setting.
Neuroscience of Consciousness
January 1, 2021
Matteo Grasso, Andrew M. Haun, Giulio Tononi
20 citations
A grid-like neural network representing posterior cortical areas can perform the same fixation function as a map-like pretectal circuit, but only the grid-like network's cause-effect structure, as analyzed by Integrated Information Theory, accounts for the subjective experience of space as extended. Standard functional analysis explains what the model does—encoding, decoding, and triggering eye movements—but cannot explain why a human fixating a stimulus would also see it at a location. The map-like network, lacking lateral connections, is functionally equivalent yet cannot account for the phenomenal properties of space.
Neuroscience of Consciousness
January 1, 2025
Christopher Timmermann, James W. Sanders, David Reydellet et al.
19 citations
The psychedelic 5-MeO-DMT can, in its most extreme cases, produce a complete absence of self-experience and other perceptual content while preserving a quality of aroused, waking awareness. In an exploratory observational study in naturalistic ceremonial settings, micro-phenomenological interviews, questionnaires, and EEG recordings revealed a dynamic progression of effects, including variable disruptions of bodily and narrative self, reduced phenomenal distinctions, and visual imagery. EEG showed global alpha and posterior beta power reductions, suggesting inhibition of top-down brain models. The findings indicate 5-MeO-DMT's potential as a pharmacological model for deconstructed consciousness, though retrospective questionnaires have limitations.
Neuroscience of Consciousness
January 1, 2024
Niccolò Negro
19 citations
The neuroscience of consciousness is accelerating empirically through adversarial collaborations that test rival theories. This paper argues that consciousness science should be paired with confirmation theory, the philosophical study of evidence and hypotheses, to understand how experiments challenge or validate theories. Using Lakatos's philosophy of science, the author proposes a model of theory-appraisal built on three criteria: the distinction between prediction and accommodation, the structural relevance of predictions, and the boldness of predictions. This Lakatosian model offers both normative and descriptive advantages, advancing the debate by considering theories' diachronic development, logical structure, and relationship with background knowledge.
Neuroscience of Consciousness
January 1, 2020
Michael Schartner, Christopher Timmermann
17 citations
The serotonergic system regulates the balance between prior expectations and sensory information in shaping conscious visual perception. Psychedelic drugs like N,N-Dimethyltryptamine can perturb this system, altering how the brain gates internal and external inputs. Two generative deep neural networks are discussed as tools to both illustrate the visual effects of psychedelics and to model the biological mechanisms of sensory gating. This approach offers a new medium, alongside paintings and verbal reports, for understanding how the brain constructs conscious experience.
Neuroscience of Consciousness
January 1, 2019
Héléna Cassol, Arnaud D’Argembeau, Vanessa Charland-Verville et al.
16 citations
People who report near-death experiences (NDEs) often consider those memories central to their identity, regardless of whether the experience occurred during actual physical danger. Among 71 participants screened with the Greyson NDE scale, 48 had real NDEs and 23 had NDE-like experiences without life threat. Those who recalled their NDE (41 total) rated it as more central to their identity than other self-defining memories. Richer NDE memories were associated with greater centrality. The findings suggest that the self-defining nature of NDEs relates more to their phenomenological content than to the circumstances of occurrence, highlighting the importance of integrating these memories into personal identity.
Neuroscience of Consciousness
January 1, 2025
Adam Safron, Arthur Juliani, Nicco Reggente et al.
13 citations
Psychedelics profoundly impact brain and mind by altering belief systems. The REBUS model proposes that 5-HT2a receptor agonism relaxes prior expectations, enabling new perspectives. An alternative but compatible view, ALBUS (Altered Beliefs Under Psychedelics), suggests that at very high levels of 5-HT2a agonism, opposite effects may occur—synchronous neural activity becomes more powerful, leading to strengthened beliefs (SEBUS). These strengthened beliefs align with enhanced meaning-making in psychedelic therapy, hallucinations, and delusional thinking. ALBUS proposes that the balance between REBUS and SEBUS effects varies across the dose-response curve. Psychedelic experiences are described as waking dream states with varying lucidity, involving mechanisms of conscious perceptual synthesis, dreaming, and episodic memory.
Neuroscience of Consciousness
January 1, 2024
Xu Ji, Eric Elmoznino, George Deane et al.
13 citations
Conscious experiences feel rich and hard to fully describe or recall, a puzzle that partly motivates the explanatory gap—the belief that consciousness cannot be reduced to physical processes. This work offers an information-theoretic dynamical systems framework: richness corresponds to the amount of information in a conscious state, and ineffability to information lost during processing. Attractor dynamics in working memory cause impoverished recollections, language's discrete symbolic nature cannot capture high-dimensional experiential structure, and similar cognitive function between individuals improves communicability. The model advances a physicalist explanation of these puzzling aspects, though it may not settle all questions about the explanatory gap.
Neuroscience of Consciousness
January 1, 2023
Lena Lindström, Philippe R. Goldin, Johan Mårtensson et al.
12 citations
People who report a stronger sense of self-boundarylessness—feeling less distinct from the surrounding world—tend to endorse words related to fluidity more strongly and take longer on a math task. Brain imaging shows that during mind-wandering, boundarylessness is linked to less activity in the posterior cingulate cortex/precuneus. Interestingly, both low and high boundarylessness, compared to moderate levels, are associated with greater connectivity within the default mode network at rest, less activity in the medial prefrontal cortex when processing self-related words, and lower endorsement of words related to constancy. Directing attention to the center of experience activates brain regions similar to meditation onset, regardless of meditation experience.
Neuroscience of Consciousness
January 1, 2025
Lars Sandved-Smith, Juan Diego Bogotá, Jakob Hohwy et al.
10 citations
A computational formalism called deep parametric active inference, rooted in Bayesian mechanics, can bridge first-person phenomenological accounts of experience and third-person physiological measurements, fulfilling the neurophenomenology programme's goal of mutual constraints. The dual information geometry of Bayesian mechanics allows generative passage between lived experience and its neural instantiation under certain conditions. This paper argues that incorporating trained reflective awareness into empirical protocols yields incremental explanatory gains, shifting focus from the contents of experience to the how of experience—the activities of consciousness that constitute meaningful appearance. The resulting deep computational neurophenomenology gains explanatory power from disciplined circulation between perspectives, enabled by generative models that form beliefs about their own modelling parameters.
Neuroscience of Consciousness
January 1, 2025
Daniel A Atad, Pedro A. M. Mediano, Fernando E. Rosas et al.
10 citations
A scoping review of neural complexity in meditation finds that, during meditation, brain activity shows higher complexity compared to waking rest or mind-wandering, while regular meditation practice is associated with decreased baseline complexity as a long-term trait. The review disentangles different families of complexity measures, distinguishes short-term state effects from long-term trait effects, and considers differences among meditation styles. It provides a framework to guide debates and offers practical guidelines for future research on complexity and consciousness.
Neuroscience of Consciousness
January 1, 2025
Yair Dor-Ziderman, Yoav Schweitzer, Ohad Nave et al.
10 citations
Meditators' brains show acceptance rather than denial when processing death-related stimuli linked to the self, as measured by a magnetoencephalogram visual mismatch-response (vMMR) paradigm. This neural shift corresponds with increased self-reported well-being and is associated with positively valenced experiences of self-dissolution during meditation. The findings suggest that the brain's defensive response to mortality is not fixed but can be reduced through insight meditation grounded in mindful awareness, which trains acceptance of impermanence. The results also indicate that addressing mortality concerns is important when interventions may disrupt self-consciousness.
Neuroscience of Consciousness
January 1, 2024
Charlotte Grégoire, Corine Sombrun, Philippe Lenaif et al.
10 citations
Two Western trance practices, auto-induced cognitive trance (AICT) and Mahorikatan® trance (MT), both derived from traditional shamanic training, share core phenomenological features such as emotional expression, perceptual changes, a feeling of unicity, and expanded consciousness. AICT participants commonly reported body movements, vocalizations, increased creativity, visions of entities or places, and interaction with the environment, while MT participants commonly reported body dissolution. Most participants in both groups reported positive effects on personal life. The findings characterize the similarities and differences between these trance states and suggest further research into their potential clinical applications.
Neuroscience of Consciousness
January 1, 2024
André Sevenius Nilsen, Alessandro Arena, Johan F. Storm
10 citations
In rats under propofol, sevoflurane, and ketamine anesthesia, the perturbational complexity index (PCI) and two spontaneous EEG measures—Lempel-Ziv complexity (LZ) and geometric integrated information (ΦG)—best distinguished awake from anesthetized states for propofol and sevoflurane. However, PCI was anti-correlated with spontaneous measures of integrated information, which increased during propofol and sevoflurane anesthesia, contrary to expectations. The divergence suggests anesthesia disrupts global cortico-cortical information transfer, while spontaneous activity suggests the opposite, possibly due to suppressed encoding specificity or driving subcortical projections. Perturbation-based and spontaneous measures may be complementary for studying altered consciousness.
Neuroscience of Consciousness
January 1, 2024
Charlotte Martial, Robin Carhart-Harris, Christopher Timmermann
9 citations
People who have had both a near-death experience (NDE) and a psychedelic experience (PE) report overlapping mystical-like effects, such as feelings of unity and transcendence, and similar attributions of reality, psychological insights, and lasting changes. However, low-level sensory phenomena differ: NDEs involve stronger disembodiment, while psychedelics produce more visual imagery. The study used an online survey of 31 adults who had experienced both an NDE (scoring ≥27 on the NDE-C scale) and a PE with classic psychedelics. Bayesian and frequentist analyses confirmed these overlaps and differences, suggesting psychedelics can model the mystical aspects of NDEs but not their sensory features.
Neuroscience of Consciousness
January 1, 2024
Arthur Juliani, Adam Safron, Ryota Kanai
8 citations
Psychedelic therapy shows promise for treating mental disorders, and the "RElaxed Beliefs Under pSychedelics" (REBUS) model explains this by suggesting psychedelics loosen maladaptive high-level beliefs. The newer "CANAL" model proposes that overly rigid belief landscapes (canalization) contribute to psychopathology. This work uses deep neural network learning theory to refine the CANAL model, distinguishing two separate optimization landscapes for belief representation in the brain. Each can develop unique pathologies from either too much or too little canalization, indicating that canalization's link to psychopathology is not simply linear. The refined model makes novel predictions about which aspects of psychopathology psychedelic therapy may treat and which therapy forms might benefit a given individual.
Neuroscience of Consciousness
August 29, 2022
Camilo Miguel Signorelli, Ignacio Cea, Robert Prentner
8 citations
Integrated information theory (IIT) aims to explain consciousness by linking its subjective structure to physical systems without reducing it to neural activity alone. This article identifies ambiguities in IIT, particularly tensions between its claim that experience is ontologically and epistemologically primary and its goal of explaining consciousness in physical, operational terms. The authors propose ways to resolve these issues and suggest alternative explanatory approaches—mathematical, processual, and autonomy-based—that may better guide future models of consciousness. The goal is to clarify points of contention for both supporters and critics of IIT.
Neuroscience of Consciousness
January 1, 2020
Tehseen Noorani, Ben Alderson-Day
8 citations
Carhart-Harris and Friston's REBUS model applies predictive processing to explain how psychedelics alter brain function, offering a foundation for psychedelic psychiatry. The present authors commend this work but argue it underemphasizes contextual factors that shape extreme experiences and their outcomes. They also suggest that the comparisons made with certain non-psychedelic altered states miss more informative parallels elsewhere. Addressing these points would help identify the most relevant mechanisms of action in psychedelic experiences.
Neuroscience of Consciousness
January 1, 2019
Jennifer Windt
8 citations
A commentary on Nielsen's proposal that microdreams—experiences during the earliest stages of sleep onset—can reveal how dream imagery forms. The author examines microdreams through simulation views, which define dreaming as an immersive virtual-world experience centered on a virtual self, and evaluates expanding the oneiragogic spectrum to include kinesis. The conclusion is that although some microdreams may not qualify as minimal dreams, studying them can address key questions in dream research and may offer a distinct route to full dreaming.
Neuroscience of Consciousness
January 1, 2024
Audrey Vanhaudenhuyse, Marie-Carmen Castillo, Charlotte Martial et al.
7 citations
Auto-induced cognitive trance (AICT) produces richer and more distinct subjective experiences than ordinary rest, auditory stimulation, or imagination. In 27 trained participants, free recalls of experiences were longer during AICT than in other conditions. Text mining identified four distinct classes of discourse, with AICT forming its own class clearly separate from ordinary conscious states. Nine content categories emerged, including nature, animals, body modifications, and difficulty describing thoughts. AICT was specifically characterized by reports of nature, animals, body modifications, and difficulty describing thoughts. These findings indicate that AICT generates a unique and richer phenomenology compared to other conscious states.
Neuroscience of Consciousness
January 1, 2024
Justin Riddle, Jonathan W. Schooler
7 citations
Although we intuitively feel we have a single, unified conscious experience, we often face indecision, hold contradictory beliefs, or engage in internal debates. The Nested Observer Windows (NOW) Model proposes that consciousness is hierarchical: information processed across many spatiotemporal scales of the brain feeds into subjective experience. It likens the mind to a hierarchy of nested mosaic tiles, where each tile is itself an image made of smaller tiles. Unitary consciousness sits at the apex, where perceptual constructs become fully integrated and complex behaviors are initiated. The model defines observer windows as spatially and temporally constrained systems that integrate information.
Neuroscience of Consciousness
January 1, 2025
Chris Fields, Mahault Albarracin, Karl Friston et al.
6 citations
The free-energy principle (FEP) constrains possible models of consciousness, especially those of attentional control and imaginative experiences like episodic memory and planning. The paper first reviews classical and quantum formulations of the FEP, focusing on multi-component systems where only some parts interact directly with the environment. It discusses internal boundaries structured as Markov blankets, which act as classical information channels. The analysis shows how this framework supports models of attention and imagination, explaining how imaginative experience can use the same spatio-temporal and object-recognition frames as ordinary perception, and how it can be internally generated yet still surprising. The paper concludes with implications for implementation, phenomenology, phylogeny, and the large variability of imaginative experience in humans.
Neuroscience of Consciousness
January 1, 2024
Brian Key, Deborah J Brown
6 citations
Internal feeling states like pain, hunger, and thirst are often assumed to directly cause behaviors essential for survival, but this 'causal assumption' conflicts with the standard neuroscientific view of motor action. The authors argue that denying feelings cause behavior does not necessarily lead to epiphenomenalism, which would contradict evolutionary biology. Instead, they propose the 'sense making sense' hypothesis: the function of subjective experience is not to cause behavior but to explain it, in a restricted sense. This framework integrates neural computations for motor control, feelings, and explanatory processes to account for how feelings contribute to our understanding of why we act.