Fact-checked by Grok 2 weeks ago

Models of consciousness

Models of consciousness refer to theoretical frameworks in cognitive science, neuroscience, and philosophy that seek to explain the mechanisms underlying subjective experience, awareness, and the distinction between conscious and unconscious mental processes.^[1] These models address both the "easy problems" of consciousness—such as how the brain enables reportability, attention, and integration of information—and the "hard problem" of why and how physical processes give rise to phenomenal experience, or qualia.^[1] Prominent among these are higher-order theories (HOTs), which posit that a mental state becomes conscious when it is the subject of a higher-order representation, such as metacognitive monitoring in the prefrontal cortex; this approach, advanced by philosophers like David Rosenthal since the late 20th century, emphasizes self-awareness and cognitive access as central to consciousness.^[1] In contrast, global workspace theories (GWTs), originally proposed by Bernard Baars in 1988 and refined by neuroscientists like Stanislas Dehaene, describe consciousness as arising from the global broadcasting of selected information across distributed brain networks, enabling widespread access for cognitive control and reportability; empirical support comes from neuroimaging studies showing ignition-like neural activity during conscious perception.^[1]^[2] Re-entry and predictive processing theories highlight recurrent, feedback-driven neural dynamics as the basis for consciousness, drawing on ideas from Hermann von Helmholtz's 19th-century work on unconscious inference and modern frameworks like Karl Friston's predictive coding; proponents such as Victor Lamme and Anil Seth argue that consciousness emerges from iterative top-down predictions and error minimization, particularly in sensory and interoceptive processing, with evidence from studies on visual awareness and perceptual illusions.^[1] Finally, integrated information theory (IIT), developed by Giulio Tononi since 2004, quantifies consciousness as the degree of irreducible, integrated information (measured by Φ) generated by a system's causal interactions; this mathematical approach, supported by Christof Koch, applies beyond biology to any complex system and predicts consciousness in posterior "hot zones" of the brain, backed by perturbation analyses in disorders of consciousness.^[1]^[3] These models, while overlapping in emphasizing neural integration and information processing, differ in their focus—functional versus structural, access versus phenomenal—and continue to guide empirical research through adversarial collaborations and targeted experiments, such as those distinguishing neural signatures of consciousness.^[1] A notable example is the 2025 adversarial collaboration that directly tested predictions of GWT and IIT using neuroimaging and behavioral paradigms, advancing efforts toward convergence.^[4] Ongoing debates center on their ability to bridge the explanatory gap between brain activity and subjective experience, with advances in neuroimaging and computational modeling fostering greater convergence.^[1]

Neuroscientific Models

Neural Correlates of Consciousness

The neural correlates of consciousness (NCCs) refer to the minimal set of neuronal events and mechanisms sufficient, when they occur, for a specific conscious percept, and necessary if they are absent for the absence of that percept.^[5] This concept was introduced by Francis Crick and Christof Koch in their 1990 paper, which proposed focusing on visual consciousness to identify these correlates through empirical neuroscience, emphasizing the need to distinguish conscious from unconscious processing.^[5] NCCs do not explain why neural activity gives rise to subjective experience but provide a foundational empirical target for understanding the brain basis of consciousness.^[6] The historical pursuit of NCCs draws from earlier cognitive models, such as Bernard Baars' 1988 theater metaphor, which likened consciousness to a spotlight on a stage amid parallel unconscious processes, inspiring searches for neural mechanisms that amplify select information for global access. This evolved into targeted empirical investigations in the 1990s and 2000s, with modern efforts including adversarial collaborations between competing theories to rigorously test predictions about NCC localization and dynamics.^[4] A 2025 open-science adversarial collaboration involving 256 participants using fMRI, MEG, and iEEG tested predictions of global neuronal workspace theory (GNWT) and integrated information theory (IIT 4.0); results showed partial support for IIT, with sustained posterior cortical activity maintaining conscious content and posterior regions enabling content decoding, while challenging GNWT by finding no prefrontal ignition for maintenance and no decoding improvement from prefrontal inclusion. Neither theory was fully supported on interareal connectivity predictions.^[4] Key methodologies for identifying NCCs include neuroimaging techniques like functional magnetic resonance imaging (fMRI) to measure blood-oxygen-level-dependent signals correlated with awareness, electroencephalography (EEG) for temporal dynamics of neural activity, lesion studies assessing deficits in conscious perception following brain damage, and psychophysical paradigms such as binocular rivalry, where conflicting stimuli presented to each eye alternate in conscious dominance despite constant input.^[7]^[8] These approaches dissociate conscious from unconscious processing by contrasting conditions where stimuli are identical but awareness varies.^[9] Empirical findings highlight the involvement of prefrontal and parietal cortices in aspects of visual awareness, such as sustaining attention and integrating sensory information, as evidenced by increased activation during conscious detection tasks in fMRI studies.^[10] For content-specific consciousness, the posterior cortical hot zone—encompassing occipital, temporal, and parietal regions—emerges as a critical area, where local neural activity patterns directly support the phenomenal qualities of experience, as shown in lesion and stimulation studies sparing frontal regions yet disrupting sensory awareness.^[11] These results frame NCCs within broader neuroscientific models, such as the Global Neuronal Workspace Theory, which interprets them as signals achieving widespread broadcast.^[4]

Global Neuronal Workspace Theory

The Global Neuronal Workspace Theory (GNWT) posits that consciousness emerges when sensory information competes for access to a centralized "workspace" in the brain, where select representations are amplified and broadcast globally to enable widespread cognitive processing and reportability.^[12] Originally proposed by Bernard Baars in 1988 as a psychological framework for understanding conscious cognition, the theory draws an analogy to a theater where unconscious processes vie for the spotlight of a global workspace, allowing winning contents to influence multiple brain systems simultaneously. This core concept was later refined into a neurocomputational model by Stanislas Dehaene and Jean-Pierre Changeux in the early 2000s, integrating neural mechanisms to explain how unconscious processing transitions to conscious awareness through ignition in prefrontal and parietal regions.^[13] At the neural level, the workspace is formed by a distributed network of pyramidal neurons with long-range axons, particularly in prefrontal, cingulate, and parietal cortices, which facilitate bidirectional communication across brain areas.^[14] Unconscious stimuli undergo initial feedforward processing in sensory cortices, but only those reaching an ignition threshold—modulated by attentional and vigilance signals from subcortical structures like the brainstem—trigger a nonlinear amplification via recurrent loops, sustaining activity and enabling global broadcasting.^[15] This ignition process is electrophysiologically marked by the P3b wave in EEG recordings, a late positivity around 300 ms post-stimulus that correlates with conscious access and contrasts with the earlier, unconscious feedforward sweep occurring within 100-200 ms.^[16] Empirical support for GNWT comes from attentional blink and masking paradigms, where briefly presented stimuli below awareness thresholds fail to elicit late amplification, as evidenced by absent sustained neural firing beyond 200 ms and lack of prefrontal activation on fMRI.^[14] In contrast, consciously perceived stimuli show widespread cortical activation and behavioral reportability, with masking experiments demonstrating that interrupting recurrent processing prevents the transition to consciousness, highlighting the theory's distinction from purely feedforward models.^[15] However, a 2025 adversarial collaboration testing GNWT against IIT found challenges to the theory, including lack of prefrontal ignition for maintaining conscious content after stimulus offset and no improvement in decoding accuracy when including prefrontal regions, though both theories predict posterior involvement in content decoding.^[4] GNWT predicts that consciousness requires sustained recurrent processing within the global workspace for broadcasting, but not merely local recurrences in sensory areas, which suffice for unconscious perception; this is supported by findings of prefrontal-parietal correlates enabling reportability without quantum or integrated information mechanisms, though recent tests indicate limitations in explaining content maintenance.^[12]^[4]

Integrated Information Theory

Integrated Information Theory (IIT), developed by neuroscientist Giulio Tononi beginning in 2004 and refined through versions up to IIT 4.0 in 2023, posits that consciousness corresponds to the capacity of a system to integrate information, quantified by a measure denoted as Φ (phi), which captures the irreducible causal interactions generated by the system's whole beyond its parts.^[17]^[18] The theory frames consciousness as an intrinsic property of any physical system that possesses sufficient integrated information, regardless of its biological or artificial nature.^[17] This approach emphasizes the quality and quantity of causal power within a system, distinguishing conscious experiences by their specificity and unity.^[19] The foundational axioms of IIT derive from phenomenological properties of conscious experience: intrinsic existence, which asserts that experience is directly available only to the subject; composition, meaning experiences are structured from multiple components; information, indicating that experiences are specific and differentiated from other possibilities; integration, requiring experiences to be unified and irreducible; and exclusion, stipulating that each experience has definite boundaries and a maximum level of irreducibility.^[19] These axioms translate into postulates about the physical mechanisms supporting consciousness, such as cause-effect power, specificity, compositionality, irreducibility, and definiteness, which guide the identification of substrates capable of generating conscious states.^[19] Applying these postulates yields cause-effect structures—conceptual representations of all possible past states that could influence the current state and future states that could be influenced by it—revealing the informational profile of the system. In IIT 4.0, Φ is calculated using normalized distances (e.g., Earth Mover's Distance) between the cause-effect repertoire of the whole system and those of its partitioned parts, minimizing over all minimum-information partitions to quantify irreducibility. Earlier versions approximated this via effective information, defined as the mutual information between past and future states of a mechanism under maximum-entropy input distributions, minimized over bipartitions: Φ ≈ min EI(past → future).^[18]^[17] In biological systems, high values of Φ are associated with the thalamocortical complex, where dense reciprocal connections enable extensive causal interactions that support unified conscious experiences.^[17] Unlike theories emphasizing functional access or reportability, IIT focuses on the intrinsic causal structure, implying that consciousness arises from integration independent of external broadcasting. IIT's implications extend to panpsychism, suggesting that any system with non-zero Φ possesses some degree of consciousness, as integration is a fundamental property not limited to brains.^[20] This leads to predictions that simple systems like photodiodes may have minimal conscious experiences, while complex ones like the human brain exhibit rich phenomenology.^[20] However, the theory faces critiques regarding its computational feasibility, as calculating Φ involves a combinatorial explosion that renders exact computation intractable for systems beyond a few elements, necessitating approximations that may undermine precision.^[21] Additionally, some argue that IIT's reliance on abstract cause-effect structures lacks direct empirical testability, potentially conflating theoretical elegance with verifiable predictions.^[22] Empirically, IIT has inspired the perturbational complexity index (PCI), which measures the complexity of brain responses to transcranial magnetic stimulation (TMS) as a proxy for integrated information.^[23] In clinical studies, PCI distinguishes levels of consciousness across states such as wakefulness (high PCI), non-rapid eye movement sleep and anesthesia (low PCI), and disorders of consciousness like vegetative and minimally conscious states (intermediate PCI), correlating with recovery trajectories in unresponsive patients.^[23] For instance, PCI values above 0.31 indicate potential awareness in disorders, aiding diagnosis where behavioral assessments fail.^[23] Regions of high Φ, such as the posterior cortex, align with neural correlates of consciousness identified through lesion and imaging studies. A 2025 adversarial test provided partial empirical support for IIT, demonstrating sustained posterior activity for conscious content maintenance and effective posterior decoding, though interareal connectivity predictions were not fully confirmed.^[4]

Electromagnetic Theories

Electromagnetic theories of consciousness posit that conscious experience arises from the brain's endogenous electromagnetic (EM) fields generated by synchronized neuronal firing, rather than solely from synaptic or structural neural processes. In this framework, these fields serve as the physical substrate for integrating distributed neural information into unified conscious percepts. A seminal proposal is Johnjoe McFadden's conscious electromagnetic information (CEMI) field theory, introduced in 2002, which argues that consciousness is identical to the brain's EM field component that influences neuronal firing and enables volitional control over behavior.^[24] This theory emphasizes that EM fields provide a holistic medium for information processing, distinct from the slower, point-to-point synaptic transmission. The core mechanisms involve the superposition and integration of EM fields produced by action potentials and synaptic currents, allowing for rapid binding of disparate neural activities across brain regions. Unlike synaptic delays, which operate on millisecond timescales limited by chemical diffusion, EM fields propagate at the speed of light, facilitating near-instantaneous information exchange and resolving the binding problem by unifying sensory inputs into coherent experiences, such as perceiving a complete visual scene.^[25] McFadden proposes that these fields interact back on neurons via voltage-gated ion channels, effectively "downloading" conscious content to motor systems for action.^[24] This classical EM approach relates briefly to neural correlates of consciousness observed in oscillatory patterns, where synchronized brain waves generate measurable field coherence underlying awareness.^[26] Supporting evidence includes EEG studies showing increased gamma-band coherence (30-90 Hz) during conscious perception compared to unconscious processing, interpreted as reflecting unified EM field dynamics that bind neural ensembles.^[25] Additionally, transcranial magnetic stimulation (TMS), which induces external EM fields, disrupts endogenous brain fields and alters conscious states, such as inducing perceptual illusions or modulating awareness in clinical settings, suggesting a causal role for EM interactions in consciousness.^[24] A variant is Susan Pockett's electromagnetic field theory from 2000, which identifies consciousness with specific spatiotemporal EM patterns in the neocortex, particularly those featuring a "neutral area" in lamina 4 of pyramidal cells that distinguishes conscious from non-conscious fields.^[27] Pockett's model highlights how synchronous synaptic firing generates these patterns, capable of influencing neuronal activity at a distance.^[28] Critiques of these theories center on the perceived weakness of brain-generated EM fields, estimated at microtesla levels, questioning their ability to significantly influence neuronal firing amid thermal noise.^[24] Proponents counter that even weak fields can modulate ion channels effectively over short distances, as demonstrated in vitro studies.^[25] Another concern involves rapid decoherence in biological environments, potentially disrupting field coherence, though classical EM models like CEMI avoid quantum dependencies and emphasize macroscopic field stability.^[27] Pockett has addressed measurement challenges, noting that EEG captures only the electrical component while magnetoencephalography (MEG) detects magnetic aspects, supporting the fields' role in conscious integration.^[28]

Quantum and Physical Models

Orchestrated Objective Reduction

Orchestrated Objective Reduction (Orch OR) is a quantum theory of consciousness proposed by physicist Roger Penrose and anesthesiologist Stuart Hameroff in the mid-1990s, suggesting that consciousness arises from non-computable quantum processes within neuronal microtubules rather than classical neural firing alone.^[29] The model posits that these processes enable the subjective experience of qualia by linking quantum superpositions in the brain to fundamental spacetime geometry, addressing limitations of algorithmic computation in explaining conscious moments.^[29] In Orch OR, the basic units of quantum computation are tubulin dimers, protein structures within microtubules that function as qubits capable of existing in superposed states.^[29] These superpositions are "orchestrated" by biological mechanisms, such as actin gels and MAPs (microtubule-associated proteins), to maintain coherence long enough for computations relevant to neural function.^[30] The process culminates in objective reduction (OR), a proposed non-computable collapse of the quantum wavefunction triggered by gravitational effects, distinct from environmentally induced decoherence.^[29] This collapse selects specific microtubule states that influence synaptic firing and broader brain activity, with each OR event corresponding to a discrete conscious experience occurring roughly 40 times per second.^[29] The timing of OR is governed by the equation for the collapse timescale:

t \approx \frac{\hbar}{\Delta E}

where t is the time until objective reduction, \hbar is the reduced Planck's constant, and \Delta E is the gravitational self-energy difference between the superposed spacetime geometries of the tubulin states.^[29] For neuronal scales, \Delta E arises from mass-energy differences in superposed tubulin conformations, leading to collapse probabilities that align with observed conscious event rates.^[29] Supporting evidence includes the action of general anesthetics, which selectively bind to hydrophobic pockets in microtubules, disrupting quantum dipole oscillations and vibrations without affecting classical ion channels, thereby erasing consciousness.^[31] A key critique came from physicist Max Tegmark in 2000, who calculated decoherence times in microtubules at brain temperature (37°C) as approximately $10^{-13} seconds due to environmental interactions like water collisions, far shorter than the $10^{-4} to $10^{-2} seconds required for Orch OR computations.^[32] Proponents counter that ordered water layers and actin shielding around microtubules extend coherence, and Tegmark's model overlooked these protective structures.^[29] Recent experiments in the 2020s have bolstered Orch OR by detecting coherent quantum vibrations in microtubules under physiological conditions. For instance, studies have identified megahertz and gigahertz dipole oscillations in tubulin, along with superradiant excitonic states that could sustain entanglement across multiple subunits.^[30] Additionally, anesthetic molecules have been shown to dampen these vibrations, providing direct tests of the model's predictions for consciousness suppression.^[33] Further 2023–2025 research, including evidence of microtubule quantum superradiance (Babcock et al., 2023) and brain entanglement (Kerskens, 2024), suggests sustained quantum effects resilient to decoherence, though full validation requires additional nanoscale measurements.^[34]^[35] These findings suggest microtubules may indeed support quantum effects resilient to the brain's warm, wet environment, though full validation requires further nanoscale measurements.^[36]

Holographic Models

Holographic models of consciousness propose that the brain functions as a holographic processor, where information is encoded through interference patterns analogous to those in optical holograms, enabling distributed storage and reconstruction of perceptual and cognitive experiences. Developed primarily by neuroscientist Karl Pribram from the 1960s through the 1990s, the holonomic brain theory draws inspiration from the principles of holography discovered by Dennis Gabor in 1946, which utilize Fourier transforms to record and reconstruct three-dimensional images from interference patterns of light. In this framework, neural activity does not rely on localized point-to-point connections but instead distributes information across the brain in a manner that allows partial damage to still permit recovery of the whole, much like a hologram where any fragment contains the full image.^[37] The core mechanisms involve dendritic waves and electromagnetic (EM) fields within fine-fibered neural webs, particularly in the dendritic arbors of cortical neurons, which generate local field potentials described mathematically by windowed Fourier transforms or Gabor functions. These transforms convert spatial-temporal patterns of neural activity into frequency domains, facilitating holographic encoding where interference patterns store information holonomically—spread across receptive fields rather than in discrete locations. Pribram posited that eye movements and other scanning processes invert these transforms, allowing the brain to "read out" perceptual images from the spectral representations. This process underscores the theory's emphasis on patch holography, where localized dendritic patches assemble into coherent wholes through axonal integrations.^[37] Supporting evidence emerges from studies on memory engrams, which reveal distributed storage across cortical areas rather than localized sites, aligning with principles of equipotentiality and mass action observed in lesion experiments where broad cortical removal impairs but does not erase specific memories. For instance, Pribram's research demonstrated that memories persist despite significant tissue loss, suggesting holographic distribution enhances robustness and enables content-addressable recall. This distributed encoding also addresses the binding problem in consciousness—integrating disparate sensory features into unified percepts—through interference patterns that superimpose information without requiring precise synchronization, as seen in the superposition of neural waves.^[38]^[37] Variants of holographic models extend into quantum holography, incorporating physicist David Bohm's concept of the implicate order, where reality unfolds from an underlying holistic, non-local structure enfolding all information. Pribram collaborated with Bohm to propose that brain processes reflect this implicate order, with neural holography manifesting explicate perceptions from deeper quantum interferences, though classical mechanisms remain central. These extensions overlap briefly with quantum models like Orchestrated Objective Reduction in suggesting non-local quantum effects but emphasize holographic interference over microtubule-specific collapses.^[37]

Philosophical Models

Higher-Order Thought Theories

Higher-order thought (HOT) theories posit that a mental state becomes conscious only when it is accompanied by a higher-order thought about that state, distinguishing conscious from unconscious mental processes. Developed primarily by David Rosenthal in the 1980s and 1990s, these theories argue that phenomenal consciousness arises not from the first-order state itself—such as a perception or sensation—but from its disposition to be the object of a metacognitive higher-order representation.^[39] In Rosenthal's framework, a state is conscious if the individual is disposed to form a thought that one is in that state, emphasizing that consciousness involves transitive awareness: being aware of being aware.^[40] HOT theories come in two main variants: actualist and dispositionalist. Actualist versions, championed by Rosenthal, require an actual occurrent higher-order thought to render the first-order state conscious, ensuring that consciousness involves real-time metacognitive monitoring.^[41] Dispositionalist variants, advanced by philosophers like Peter Carruthers and David Armstrong, hold that a mere disposition or potential for such a higher-order thought suffices for consciousness, avoiding the need for constant higher-order activity and accommodating cases where awareness is latent.^[41] A related approach is the inner sense model, proposed by William Lycan, which conceives higher-order awareness as a perceptual-like scanning mechanism akin to an internal sensory faculty that detects first-order states. Mechanistically, HOT theories link consciousness to metacognitive processes often associated with the prefrontal cortex, where higher-order representations monitor and integrate first-order sensory inputs.^[42] This framework explains phenomena like blindsight, in which patients with visual cortex damage exhibit unconscious visual discrimination without subjective experience; here, first-order visual processing occurs, but the absence of a higher-order thought about it prevents conscious awareness.^[41] Empirically, HOT theories find support in studies of confidence judgments, where metacognitive accuracy—such as calibrating reported confidence to perceptual evidence—correlates with higher-order representations, distinguishing conscious from subliminal stimuli. For instance, participants show heightened metacognitive sensitivity for consciously perceived signals, aligning with the theory's emphasis on higher-order monitoring.^[43] Critics argue that HOT theories face an infinite regress problem, as each higher-order thought seemingly requires its own higher-order awareness to be conscious, potentially leading to an unending chain without explanatory power.^[41] Proponents counter that only the first-order state needs the higher-order thought for consciousness, with the higher-order thought itself potentially unconscious.^[44] Another challenge concerns animal consciousness: if HOTs demand sophisticated metacognition, many animals may lack phenomenal experience despite evident perceptual behaviors, raising ethical and empirical concerns about their subjective lives.^[45] HOT theories align with functionalism by specifying a particular functional role for consciousness—higher-order access and monitoring—while allowing diverse neural implementations.^[41]

Multiple Drafts Model

The Multiple Drafts Model of consciousness, proposed by philosopher Daniel C. Dennett (1942–2024) in his 1991 book Consciousness Explained, posits that consciousness emerges from multiple parallel neural processes distributed throughout the brain, rather than a centralized or unified representation.^[46] In this framework, sensory inputs and cognitive contents are continually revised and edited in various "drafts" across different brain regions, with no single draft achieving final authority or privileged status. Dennett argued this model escapes the pitfalls of Cartesian dualism by eliminating the need for a metaphorical "Cartesian theater"—a central stage where experiences are projected and observed—thus avoiding infinite regress in explaining awareness.^[46] Central to the model are mechanisms of competition and dissemination, often described as "fame in the brain," where neural contents vie for influence through their connections and effects on behavior and further processing, rather than being stamped with a precise moment of conscious onset.^[46] These drafts are dynamic and overlapping, subject to ongoing editing over time, which accounts for phenomena like the subjective sense of a "specious present" without invoking a fixed "now." Illusions of seamlessness or immediacy in experience arise from retrospective reconstruction, as the brain integrates disparate processes into coherent narratives only when probed, such as during verbal reports or actions. This distributed approach shares a brief overlap with the Global Neuronal Workspace Theory in emphasizing competitive dynamics for content prominence, though it rejects any singular broadcasting mechanism.^[46] The model's implications extend to methodology and ontology in consciousness studies, advocating heterophenomenology—a third-person approach that treats subjects' introspective reports as data to be interpreted without assuming privileged access to inner qualia.^[46] Dennett contended that qualia, often conceived as ineffable subjective properties, are illusions generated by this competitive editing process, reducing consciousness to functional, observable patterns rather than mysterious essences. This challenges traditional views by framing consciousness as a gradual, probabilistic phenomenon akin to biological speciation, with no sharp boundary between conscious and unconscious states.^[46] Critiques of the Multiple Drafts Model often center on its handling of experiential unity, with philosopher David Chalmers arguing that it equivocates on the phenomenal cohesiveness of consciousness, failing to explain how disparate drafts cohere into a singular, integrated "what it is like" for an experience at a given moment.^[47] Similarly, Thomas Metzinger contends that the absence of a central integrator risks portraying consciousness as chaotic, undermining the first-person perspective's apparent stability and self-modeling.^[47] Other challenges include the model's potential to underplay the subjective seamlessness of experience, treating it as mere narrative construction rather than a robust phenomenal fact.^[47]

Functionalism

Functionalism in the philosophy of mind posits that mental states, including those constitutive of consciousness, are defined by their causal roles in relation to sensory inputs, behavioral outputs, and other mental states, rather than by their specific physical composition. This view emerged in the 1960s, primarily through the work of Hilary Putnam, who argued against both behaviorism and the type-identity theory by proposing that mental states are like states in a finite automaton or Turing machine, analogous to software running on hardware like the brain.^[48] Putnam emphasized multiple realizability, where a single mental state type (e.g., pain) can be instantiated by diverse physical states across different organisms or artificial systems, rejecting strict type-identity while allowing token-identity for particular instances. This substrate-neutral approach allows consciousness to potentially arise in non-biological systems as long as they perform the requisite functional organization. Functionalism encompasses several variants, each specifying how functional roles are defined and realized. Machine-state functionalism, central to Putnam's original formulation, conceives the mind as a computational device where mental states correspond to the internal states of a Turing machine, determined empirically by psychological theory. In contrast, analytic functionalism, advanced by David Lewis, derives functional roles a priori from the conceptual content of common-sense psychology, positing that terms like "belief" or "desire" are synonymous with descriptions of their inferential and causal connections. Realizer functionalism, developed by Sydney Shoemaker, shifts focus to the physical properties that actually realize these roles in a given system, accommodating multiple realizers while preserving causal efficacy for mental states. These types collectively underscore functionalism's commitment to explaining mental phenomena, including consciousness, through abstract causal structures independent of material substrate. When applied to consciousness, functionalism typically identifies it with functional capacities such as information integration and accessibility for cognitive control, but faces challenges in accounting for subjective experience. Ned Block introduced the distinction between access consciousness—states that are poised for use in reasoning, speech, and action—and phenomenal consciousness, the raw feels of experience, arguing that functionalism naturally captures the former but may fail to guarantee the latter.^[49] In his absent qualia argument, Block envisions a hypothetical system, such as a population of homunculi simulating neural activity, that fulfills all functional roles associated with conscious vision (e.g., guiding behavior) yet lacks any qualitative experience, suggesting that functional specification alone does not entail qualia.^[48] This raises doubts about whether consciousness reduces fully to functional organization. Prominent critiques highlight functionalism's limitations in addressing intentionality and subjectivity. John Searle's Chinese Room thought experiment illustrates that a system could manipulate symbols according to functional rules (e.g., syntax) without genuine understanding or semantic content, implying that computational functionalism cannot produce conscious intentionality.^[50] Similarly, David Chalmers' hard problem of consciousness questions why any physical or functional process should give rise to phenomenal experience, arguing that functionalist accounts explain "easy problems" like reportability and behavior but leave unexplained the "why" of subjective feels.^[51] Functionalism remains compatible with higher-order theories, where conscious states involve meta-representational access functions.

Panpsychism

Panpsychism posits that consciousness, or some form of mentality, is a fundamental and ubiquitous feature of the physical world, present in all matter to varying degrees. This view addresses the "hard problem" of consciousness by suggesting that subjective experience does not emerge mysteriously from non-conscious matter but is instead an intrinsic property inherent to physical entities themselves. Historically, panpsychist ideas trace back to philosophers like Baruch Spinoza, who in his monistic framework described mind and matter as parallel attributes of a single substance, such that "a circle existing in nature and the idea of the existing circle… are one and the same thing." Similarly, Gottfried Wilhelm Leibniz developed a version through his monadology, where simple substances called monads possess perceptions and appetites, forming the basis of all reality. These early formulations influenced later thought by embedding mentality within the fabric of existence rather than treating it as derivative.^[52] In modern philosophy, panpsychism has been revitalized by thinkers such as Galen Strawson and David Chalmers. Strawson argues that a truly realistic physicalism must entail panpsychism, as physical facts alone cannot account for experiential phenomena without positing mentality as the intrinsic nature of matter—physics describes only relational structures, leaving the underlying "what-it's-like" aspect unexplained otherwise. Chalmers, while exploring panpsychism as a solution to the hard problem, emphasizes its potential to bridge materialism and dualism but cautions against unresolved issues like the combination problem. This problem, first articulated by William James in 1890 and formalized by Chalmers, questions how numerous micro-level conscious states in fundamental particles could aggregate to produce unified macro-level experiences, such as human consciousness, without resulting in mere summation rather than holistic unity.^[53]^[53] Panpsychism encompasses several variants, distinguishing how fundamental mentality relates to complex consciousness. Constitutive panpsychism, often called micropsychism, holds that macro-level experiences are grounded in and constituted by combinations of micro-experiences at the level of basic physical entities, such as electrons or quarks. In contrast, emergent panpsychism allows for mentality at fundamental levels but posits that higher-level phenomenal properties arise through novel emergence, avoiding strict reduction while still rooting consciousness in widespread mentality. Cosmopsychism reverses the direction, proposing that the universe as a whole possesses a fundamental consciousness from which individual minds derive, potentially sidestepping micro-macro aggregation challenges. These variants aim to reconcile panpsychism with scientific realism, though they differ in their ontological commitments.^[52]^[53]^[52] Key arguments for panpsychism include its avoidance of "emergence magic," where consciousness inexplicably arises from purely non-mental processes—a brute fact that Thomas Nagel and Strawson deem philosophically untenable. Instead, by treating consciousness as the intrinsic nature of physical properties, panpsychism aligns with the limitations of physics, which, as Bertrand Russell noted, reveals only extrinsic relations, leaving room for mentality to fill the intrinsic gap. Critics, however, highlight the combination problem as a core flaw, arguing that no coherent mechanism explains how disparate micro-minds form a single macro-mind, potentially leading to issues like the "palette problem," where familiar qualia fail to derive from alien micro-experiences. Chalmers' fading qualia thought experiments, while primarily targeting functionalism, indirectly challenge panpsychist accounts by questioning whether gradual replacements of conscious components preserve unified experience without invoking implausible disunity.^[52]^[54]^[53] Recent developments integrate panpsychism with scientific ideas on consciousness, particularly through philosophical interpretations of information and quantum processes. For example, panpsychism has seen a resurgence in discussions from 2024–2025, with growing interest in its compatibility with physics and critiques of strict materialism.^[55] These integrations position panpsychism as a bridge between philosophy and empirical science.^[52]

Psychological and Computational Models

Attention Schema Theory

Attention Schema Theory (AST), proposed by neuroscientist Michael Graziano, posits that consciousness arises as an internal, simplified model of the brain's attention processes, enabling better control and prediction of cognitive focus. The theory suggests that the brain constructs an "attention schema," analogous to a body schema that tracks physical states, but here representing attention as a selective spotlight illuminating certain information while excluding others. This schema encodes basic properties of attention, such as its intensity, location, and dynamic shifts, allowing the brain to monitor and regulate its own information processing without needing to access every detail of neural activity. Developed in the 2010s, AST frames consciousness not as a mystical essence but as an evolved computational tool for managing complex cognitive demands.^[56] Central to AST are mechanisms by which the attention schema facilitates introspection and control. The brain uses this model to attribute awareness to itself and others, extending to social cognition where it underpins theory of mind by simulating attentional states in conspecifics. For instance, just as one might model another's gaze direction, the schema enables predictions about what information another entity is processing. This representational process explains subjective reports of consciousness: when the brain introspects its schema, it generates the impression of a unified, spotlight-like awareness, even though attention itself is a distributed, competitive selection mechanism involving biased competition across neural networks. AST distinguishes this schema from attention proper, emphasizing that consciousness is the brain's imperfect, schematic description of attentional dynamics rather than the dynamics themselves.^[56]^[57] Empirical support for AST draws from perceptual illusions and neurological impairments that disrupt the attention schema's function. Change blindness and inattentional blindness demonstrate how attention can shift without conscious registration; for example, in the classic gorilla experiment, participants fail to notice a salient event when attention is directed elsewhere, revealing that awareness relies on the schema's update rather than direct perception. Lesions in regions like the temporoparietal junction, as seen in hemispatial neglect, impair the schema, leading to anosognosia where patients deny deficits despite intact sensory processing, thus disrupting self-reports of awareness. Experimental evidence further shows that without awareness of attentional cues, endogenous attention control falters—reaction times become inconsistent and distractor suppression weakens—while exogenous attention persists, underscoring the schema's role in voluntary regulation. Blindsight cases, where patients respond to stimuli without conscious vision, also align with AST by indicating preserved attention minus the introspective schema.^[56]^[57]^[58] AST has significant implications for artificial intelligence, suggesting that machine consciousness could be engineered by implementing attention schemas in neural networks to enhance control and social simulation. Computational models demonstrate that agents equipped with such schemas exhibit more stable attention and error correction, performing better in tasks requiring predictive focus than those without. For example, a 2021 study trained a neural network to manage visual attention using an attention schema, resulting in improved target detection and reduced interference.^[59] This approach posits that AI systems could claim subjective experience by modeling their own attentional states, bridging the gap toward human-like cognition without invoking non-physical properties.^[57]

Recurrent Processing Theory

The Recurrent Processing Theory (RPT), proposed by Victor Lamme in 2006, posits that phenomenal consciousness emerges from local recurrent neural loops within sensory cortices, rather than requiring global integration or higher-order access. According to this view, recurrent processing amplifies and stabilizes sensory representations, generating subjective experience independently of prefrontal involvement or reportability. Lamme argued that this local mechanism in posterior brain areas, such as the visual cortex, is both necessary and sufficient for conscious perception, challenging traditional definitions tied to behavioral or introspective criteria. The theory distinguishes between feedforward and recurrent processing stages. Feedforward sweeps, occurring rapidly within approximately 100 milliseconds, enable unconscious detection and basic feature extraction in early sensory areas like V1, allowing for reflexive actions without awareness. In contrast, recurrent processing—initiated by top-down feedback from higher sensory regions around 100-300 milliseconds—amplifies these signals through horizontal and vertical loops, leading to conscious awareness by enhancing contextual integration and figure-ground segregation locally in the sensory cortices. This recurrence does not necessitate widespread broadcasting to frontal areas, emphasizing that consciousness is a content-specific phenomenon confined to posterior regions.^[60] Empirical support comes from visual masking paradigms, where brief stimuli followed by masks prevent awareness. In seen (unmasked) conditions, neuronal responses in V1 show enhanced figure-ground modulation due to recurrent activity, persisting beyond the initial feedforward phase. However, in unseen (masked) conditions, this recurrence is disrupted, with V1 activity limited to feedforward responses, correlating with the absence of conscious report. These findings, observed in monkey electrophysiology, demonstrate that recurrent amplification in early visual areas distinguishes conscious from unconscious processing. Unlike the Global Neuronal Workspace Theory, which requires global ignition for awareness, RPT localizes consciousness to sensory recurrence, rejecting the necessity of prefrontal globality.^[61] The implications of RPT highlight that conscious experience is modular and tied to specific sensory contents in posterior cortices, potentially explaining phenomena like attentional overflow where more is seen than reported. This framework suggests consciousness serves to enrich perceptual organization locally, without obligatory links to decision-making or memory, reshaping understandings of neural correlates by prioritizing recurrent dynamics over hierarchical access.

Predictive Coding Framework

The predictive coding framework posits that the brain functions as a hierarchical inference machine, continuously generating top-down predictions about sensory inputs and updating them based on prediction errors to minimize surprise. Originally developed in the context of visual processing, this model was introduced by Rao and Ballard in 1999, who proposed that neurons in the visual cortex encode predictions of expected sensory signals, with lower-level areas transmitting only residual errors to higher levels when predictions mismatch incoming data.^[62] This approach provided a functional explanation for extra-classical receptive field effects, such as surround suppression, by interpreting them as mechanisms for efficient coding where matched predictions reduce neural activity.^[62] In the 2010s, researchers including Jakob Hohwy and Andy Clark extended predictive coding to account for conscious perception, framing consciousness as emerging from the brain's effort to resolve prediction errors at higher hierarchical levels. Hohwy argued that conscious experience arises when high-level generative models integrate sensory evidence, minimizing free energy through Bayesian inference. Clark similarly described the brain as "surfing uncertainty," where predictive processing constructs a coherent world model that underpins subjective awareness. Core mechanisms involve top-down predictions from higher cortical areas suppressing bottom-up sensory signals that align with expectations, thereby explaining phenomena like perceptual suppression in attention tasks; when mismatches occur, unsuppressed prediction errors propagate upward, driving perceptual updates and potentially entering conscious awareness.^[62] Precision weighting further modulates this process by assigning higher reliability to signals with low noise—such as stable priors over volatile sensory inputs—allowing the brain to balance exploitation of expectations against exploration of novel data.^[63] Empirical support for predictive coding includes electrophysiological markers like mismatch negativity (MMN) in EEG, an event-related potential elicited by deviant stimuli that violates predicted patterns, interpreted as a neural correlate of prediction error signaling in auditory cortex.^[64] Studies using bistable perception paradigms, such as binocular rivalry, have tested the Bayesian brain hypothesis by showing that perceptual switches align with the resolution of accumulated prediction errors, as evidenced in fMRI where higher-level areas exhibit stronger activity during transitions. These findings demonstrate how the framework accounts for perceptual dynamics without invoking post hoc explanations. Linking predictive coding to consciousness, high-level predictions are thought to generate the content of conscious percepts by synthesizing a unified, error-minimized representation of the world, with disruptions in this process implicated in disorders like autism spectrum disorder (ASD). In ASD, atypical high precision weighting of sensory prediction errors (and low precision on top-down priors) may lead to over-reliance on bottom-up details and reduced integration of top-down expectations, resulting in heightened perceptual sensitivity and challenges in social inference.^[65] This model integrates recurrent processing via feedback loops in the hierarchy, where errors trigger iterative refinements akin to amplification in neural circuits.^[63] Distinct from broader predictive processing that encompasses action-oriented inference, predictive coding emphasizes discrete coding levels for efficient neural representation.

Medical and Clinical Models

Clouding of Consciousness

Clouding of consciousness represents a mild form of altered mental status, characterized by reduced wakefulness, impaired attention, and subtle confusion, often serving as the earliest manifestation within the delirium spectrum as defined in the DSM-5 criteria for delirium, which emphasize a disturbance in attention and awareness of the environment.^[66] This state involves a global reduction in cognitive clarity without complete loss of responsiveness, distinguishing it from more profound alterations like stupor, where arousal is markedly diminished.^[67] Common causes of clouding of consciousness include metabolic disturbances such as hypoxia or glucose dysregulation, toxic exposures from drugs or substances, and infectious processes like encephalitis that disrupt cerebral function.^[67] These etiologies lead to diffuse brain dysfunction rather than localized lesions, resulting in fluctuating symptoms that impair daily functioning.^[68] Neuroanatomically, clouding arises from impaired signaling in the ascending reticular activating system (ARAS), a brainstem network essential for maintaining arousal and attention by projecting to the thalamus and cortex; disruptions here, often due to the aforementioned causes, reduce overall vigilance without abolishing consciousness entirely.^[69]^[70] Clinical assessment typically employs the Confusion Assessment Method (CAM), a validated bedside tool that identifies delirium—including its mild clouding phase—through evaluation of acute onset, inattention, altered level of consciousness, and disorganized thinking, with high sensitivity and specificity in medical settings.^[71] If untreated, clouding can progress along a continuum to deeper states like stupor, marked by increased lethargy and need for stimulation to arouse, or ultimately coma, underscoring the importance of early intervention to address underlying causes.^[67] Historically, clouding of consciousness was first systematically described in the 19th century by French psychiatrist Jean-Étienne-Dominique Esquirol, who differentiated acute confusional states from chronic dementias and focal neurological deficits like those from localized brain injuries, emphasizing their reversible, global nature tied to systemic factors.^[72] This framework laid the groundwork for modern understandings, distinguishing clouding as a diffuse impairment rather than one confined to specific neural pathways, as seen in aphasias or hemiparesis.^[67] In clinical contexts, clouding shares conceptual overlaps with anesthesia-induced reductions in awareness but differs in its pathological, often fluctuating etiology versus deliberate pharmacological suppression.^[68]

Anesthesia and Coma Models

Anesthesia and coma represent profound disruptions to consciousness, often modeled as breakdowns in neural integration and arousal systems that differ from partial impairments like clouding of consciousness, which serves as a milder precursor state. In anesthesia, general anesthetics induce a reversible loss of awareness through targeted molecular actions and network-level decoupling, while coma typically arises from structural damage, particularly in brainstem regions, leading to sustained unresponsiveness with potential for partial recovery. These models emphasize the thalamocortical complex and ascending arousal pathways as critical for maintaining conscious states, with disruptions resulting in total or near-total loss of behavioral responsiveness and subjective experience. General anesthetics, such as propofol, primarily target GABA_A receptors to enhance inhibitory neurotransmission, hyperpolarizing neurons and suppressing excitatory signaling across cortical and subcortical networks. This action promotes decoupling between the thalamus and cortex, particularly affecting higher-order association areas like the prefrontal cortex, while sparing primary sensory processing. In contrast, coma often stems from lesions in the brainstem, such as in the rostral dorsolateral pontine tegmentum near the medial parabrachial nucleus, which impair the ascending reticular activating system and disrupt connectivity to the ventral anterior insula and pregenual anterior cingulate cortex, essential for integrating arousal and awareness.^[73] Theoretical frameworks interpret these disruptions through reductions in integrated information and oscillatory dynamics. According to integrated information theory, consciousness requires high levels of causal integration, quantified by the perturbational complexity index (PCI), where values below 0.31 indicate unconscious states, as observed in propofol- and xenon-induced anesthesia (mean PCI 0.24 and 0.17, respectively).^[74] In anesthesia, the induction of slow-wave oscillations (<1 Hz) fragments neuronal networks, limiting activity to brief "ON" periods and causing asynchronous phasing that breaks long-range functional connectivity, correlating with loss of consciousness.^[75] Coma models similarly highlight brainstem lesions' role in abolishing these integrated dynamics, leading to low PCI values and absent network ignition. Empirical evidence from functional MRI (fMRI) demonstrates connectivity breakdowns, with propofol significantly reducing frontoparietal and thalamocortical correlations during unconsciousness, while preserving local sensory networks. In coma and related disorders, fMRI reveals impaired metabolism and reduced connectivity in posterior cingulate and precuneus regions.^[76] Clinical assessment relies on the Coma Recovery Scale-Revised (CRS-R), a standardized tool scoring auditory, visual, motor, oromotor, communication, and arousal functions (0-23 total), which differentiates unresponsive wakefulness syndrome (vegetative state, VS; no awareness) from minimally conscious state (MCS; inconsistent but definite evidence of self/environmental awareness, e.g., following commands).^[77] VS features preserved sleep-wake cycles without behavioral signs of consciousness, whereas MCS shows partial recovery potential, with CRS-R scores ≥10 indicating MCS or emergence. Emergence from anesthesia is modeled as a reversal of ignition processes, where the brain's intrinsic dynamics restore global neuronal workspace activation, overcoming inhibitory suppression to reinstate thalamocortical integration and oscillatory coherence. This active reboot contrasts with passive drug clearance, highlighting bistable network transitions in recovery from both anesthesia and coma. Recent advances as of 2025 include neuromodulation techniques, such as deep brain stimulation targeting the thalamic centromedian-parafascicular complex, which have shown promise in restoring consciousness in some patients with disorders of consciousness following coma.^[78] Additionally, sub-anesthetic ketamine has been explored in pilot studies for treating prolonged disorders of consciousness post-coma.^[79]

Collective Consciousness

Collective consciousness refers to a sociological framework positing that shared beliefs, sentiments, and representations emerge at the group level, transcending individual minds through social interactions and symbols. Émile Durkheim first articulated this concept in the 1890s, defining it as the totality of beliefs and feelings common to the average members of a society, functioning as "social facts" that exert coercive power over individuals. In his 1893 work The Division of Labor in Society, Durkheim argued that collective consciousness binds societies through mechanical solidarity in simpler forms, where shared values dominate, evolving into organic solidarity in complex societies via division of labor while retaining core collective elements.^[80] Durkheim further elaborated in The Elementary Forms of Religious Life (1912), proposing that totemic rituals among indigenous groups generate a "group mind" through collective effervescence—a heightened emotional state arising from synchronized group activities that produce collective representations, such as sacred symbols, which reinforce social unity. These rituals transform individual participants into a unified moral entity, where the collective overrides personal consciousness, fostering a sense of the sacred derived from social origins rather than supernatural forces.^[81]^[82] Building on Durkheim, contemporary sociologist Randall Collins developed interaction ritual chains in his 2004 book Interaction Ritual Chains, emphasizing how momentary co-presence in groups—through bodily assembly, mutual focus, and rhythmic synchronization—produces emotional energy that charges individuals with shared symbols and motivations. These chains link successive interactions, sustaining collective consciousness by circulating emotional energy, which motivates participation in future rituals and strengthens group solidarity. Collins highlights that barriers to co-presence, such as in virtual settings, can weaken this energy, though adaptations occur. Empirical evidence supports these ideas through crowd psychology studies, where collective effervescence manifests in synchronized physiological responses, such as heart-rate alignment during rituals like fire-walking, indicating emergent group-level emotional cohesion beyond individual aggregates. Similarly, social media platforms extend collective consciousness by enabling shared symbols and interactions that mimic ritual chains, fostering distributed cognition where users co-create narratives and emotional alignments across networks, though with reduced intensity compared to physical co-presence. Recent studies have applied these concepts to online brand communities, showing how collective consciousness influences sustained user participation through shared norms and emotional investment.^[83]^[84] Critiques of collective consciousness often center on whether it truly emerges as a sui generis social reality or merely aggregates individual psychologies, with methodological individualists arguing Durkheim's holism reifies society at the expense of personal agency. Others contend that emergent properties, like effervescence, are overstated, as group phenomena can be explained by micro-level interactions without invoking supra-individual entities, potentially overlooking conflicts within collectives. Cultural variations in ritual expressions, such as differing symbolic emphases in Eastern versus Western groups, further nuance these models without altering the core emergent dynamic.^[85]^[86]

Cultural Construction of Consciousness

The cultural construction of consciousness posits that subjective experience, including awareness and self-perception, is profoundly shaped by societal norms, linguistic structures, and communal practices rather than being a purely biological universal. Anthropological research highlights how emotions and mental states, integral to consciousness, vary across cultures through socially transmitted frameworks. For instance, Catherine Lutz's ethnographic study of the Ifaluk people in Micronesia demonstrates that emotions like fago—a blend of compassion, love, and sadness—are not innate but constructed through cultural narratives that emphasize social harmony and moral obligations, contrasting sharply with Western individualistic emotional categories.^[87] This variability underscores how consciousness emerges from enculturated interpretations of internal states, where cultural schemas dictate what counts as a conscious experience. Philosophical perspectives further illuminate this construction, particularly Ludwig Wittgenstein's concept of language games, which argues that meaning and understanding, including of consciousness, arise from rule-bound social practices embedded in cultural "forms of life." In Wittgenstein's framework, expressions of mental states such as pain or awareness are not private but publicly negotiated through linguistic interactions, rendering consciousness a product of communal language use rather than isolated introspection.^[88] Complementing this, Edwin Hutchins' model of distributed cognition extends the idea by showing how cognitive processes, including aspects of conscious awareness, are distributed across individuals, tools, and environments in culturally specific ways. Hutchins' analysis of navigation practices among Palauan sailors reveals that conscious decision-making relies on shared cultural artifacts and routines, challenging individualistic views of the mind. Empirical evidence from cross-cultural psychology supports these models, revealing differences in theory of mind—the ability to attribute mental states to others—which is a core component of conscious social interaction. Studies indicate that while basic theory of mind develops universally, its expression varies; for example, East Asian cultures often prioritize holistic attributions of mental states influenced by contextual interdependence, differing from the analytic focus in Western samples.^[89] This WEIRD bias—Western, Educated, Industrialized, Rich, and Democratic—in psychological research has skewed understandings of consciousness, as up to 96% of studies use such participants, who exhibit atypical patterns in self-perception and emotional awareness compared to global populations.^[90] Cultural practices like meditation further demonstrate this malleability, as seen in Buddhist traditions where sustained practice cultivates experiences of anatta (no-self), dissolving the illusion of a fixed, independent conscious entity. Neuroscientific and psychological investigations confirm that such practices reorganize self-related neural patterns, leading to altered states of awareness that align with cultural teachings on impermanence and interdependence, rather than inherent traits.^[91] These findings imply that consciousness is not a static, universal phenomenon but an enculturated process, adaptable through socialization and practice, with profound implications for how societies conceptualize identity, morality, and mental health.

Spiritual and Alternative Models

Eight-Circuit Model

The Eight-Circuit Model of Consciousness, proposed by psychologist Timothy Leary in the 1970s, posits that human consciousness operates through eight distinct circuits, each representing evolutionary stages of development and capable of activation through various means such as drugs, meditation, or life experiences. Leary initially outlined the model in his 1977 book Exo-Psychology, framing it as a framework for understanding neurological evolution beyond terrestrial limits, and later refined it in Info-Psychology (1987). Robert Anton Wilson expanded and popularized the model in his 1983 book Prometheus Rising, integrating it with psychological and philosophical insights to describe circuits as dynamic "imprinting" mechanisms.^[92] The model divides the circuits into two groups: the lower four, considered terrestrial and focused on survival and socialization through early-life imprinting, and the upper four, post-terrestrial circuits involving higher-order awareness and collective or cosmic dimensions. The lower circuits include: Circuit 1 (Bio-Survival), governing basic physical safety and attachment formed at birth; Circuit 2 (Emotional-Territorial), handling dominance hierarchies and emotional bonds developed in toddlerhood; Circuit 3 (Rational-Symbolic), enabling logical reasoning and language acquisition during school years; and Circuit 4 (Sociosexual), addressing moral and reproductive roles in adolescence. The upper circuits encompass: Circuit 5 (Neurosomatic), promoting body-mind harmony and sensory ecstasy via somatic practices; Circuit 6 (Neuroelectric), facilitating self-reprogramming and metaconsciousness through advanced meditation or psychedelics; Circuit 7 (Neurogenetic), accessing archetypal and genetic memory for holistic health; and Circuit 8 (Neuroatomic), representing quantum-level unity and non-local awareness achievable in transcendent states.^[93] In applications, the model suggests that psychedelic substances, such as psilocybin, can temporarily activate higher circuits like 5 and 8, leading to expanded states of awareness; proponents link this to therapeutic outcomes in mental health, such as reduced anxiety and enhanced creativity, as observed in broader psychedelic research. Leary advocated these activations as pathways to evolutionary advancement, drawing from his research on LSD and other entheogens during the 1960s counterculture era.^[94] Critics have dismissed the model as pseudoscience due to its speculative nature, lack of empirical validation, and blending of untested neuroscientific claims with spiritual utopianism, rendering it incompatible with rigorous psychological standards.^[94] Despite mainstream skepticism, the model has influenced transpersonal psychology by providing a structured map for psychospiritual growth, inspiring therapies that integrate higher-circuit activations for personal transformation. Its non-local upper circuits share conceptual overlaps with idealist views of interconnected consciousness, though the model emphasizes staged development over pure ontology.^[93]

Idealist Models

Idealist models of consciousness posit that consciousness or mind is the fundamental reality, with the physical world emerging as a manifestation, construct, or illusion within it. In this ontology, matter lacks independent existence, inverting the materialist assumption that consciousness arises from physical processes. These models trace back to philosophical traditions emphasizing perception and mental primacy, including Eastern non-dualistic views such as Advaita Vedanta, where reality is ultimately consciousness (Brahman), offering an alternative to physicalism by treating experiential qualities as ontologically basic rather than emergent.^[95] The roots of idealism lie in George Berkeley's subjective idealism, articulated in his principle esse est percipi—to be is to be perceived—where objects exist only as ideas in perceiving minds, denying the independent reality of unperceived matter. Berkeley argued that sensory experiences constitute reality, sustained ultimately by God's infinite mind to avoid solipsism. This framework influenced later idealists by prioritizing mental phenomena as the ground of existence.^[96]^[97] A modern variant is Bernardo Kastrup's analytic idealism, which posits a universal "mind-at-large" as the sole ontological primitive, with individual consciousnesses as dissociated segments of this transpersonal mind. Kastrup's model draws on empirical neuroscience, interpreting brain activity as the image of mental processes rather than their cause, thereby accommodating scientific observations within an idealist metaphysics.^[98]^[99] Another historical variant is Georg Wilhelm Friedrich Hegel's absolute idealism, where consciousness evolves dialectically toward absolute knowledge, with the finite world reflecting an underlying rational mind or Geist that unifies subject and object. In Hegel's system, reality is the self-unfolding of this absolute spirit through historical and logical processes.^[100]^[101] Contemporary extensions include computational approaches like Stephen Wolfram's digital physics model, which frames the universe as a hypergraph evolving via simple rules, with consciousness arising as observer-dependent processes within this structure.^[102] Idealist models argue that they resolve the hard problem of consciousness—explaining why physical processes give rise to subjective experience—by making consciousness fundamental, thus eliminating the need to derive qualia from non-experiential matter. This inversion avoids the explanatory gap of materialism, as physical reality becomes a representation within mind, akin to images on a screen. Proponents also reinterpret quantum mechanics' observer effects not as consciousness collapsing wave functions, but as excitations in mind-at-large, challenging materialist readings of measurement problems.^[103]^[104]^[105] Critics contend that idealism risks solipsism, where only one's own mind is certain, undermining intersubjective reality unless invoking a shared universal mind, which some view as ad hoc. Additionally, these models face challenges in empirical falsifiability, as predictions about mental ontology are difficult to test against observable physical data, potentially rendering them unfalsifiable in scientific terms.^[95]^[106] In a 2024 taxonomy of over 200 consciousness theories, Robert Lawrence Kuhn positions idealism at the non-physicalist extreme of a landscape ranging from materialism to non-materialism, highlighting its emphasis on mind as the essence of reality. This placement underscores idealism's role in contrasting physicalist models, with precursors in panpsychism sharing a commitment to mental fundamentality but differing by denying matter's independence.^[107]

References

[1]
Theories of consciousness | Nature Reviews Neuroscience
May 3, 2022 · We review four prominent theoretical approaches to consciousness: higher-order theories, global workspace theories, re-entry and predictive processing theories.
[2]
https://doi.org/10.1016/j.neuron.2011.03.018
[3]
https://doi.org/10.1038/nrn.2016.44
[4]
[PDF] Towards a neurobiological theory of consciousness
Where in the brain are the neural correlates of to us is short-term memory ... Kulli J, Koch C (1990) Does anesthesia cause loss of consciousness ...
[5]
Future directions for identifying the neural correlates of consciousness
Jul 28, 2016 · For this reason, the term 'posterior cortical hot zone' may turn out to be inaccurate, and our focus in the search for correlates of sensory ...
[6]
Adversarial testing of global neuronal workspace and integrated ...
Apr 30, 2025 · To advance this goal, we tested two theories of consciousness, through a large-scale, open-science adversarial collaboration11,12,20,21,22 ...
[7]
Are the Neural Correlates of Consciousness in the Front or in the ...
Oct 4, 2017 · In this Perspective, we will critically review the evidence for the role of the “front” versus the “back” of the cortex in supporting consciousness.
[8]
Investigating neural correlates of conscious perception by frequency ...
In binocular rivalry, a subject views two incongruent stimuli through each eye but consciously perceives only one stimulus at a time, with a switch in ...Missing: lesion | Show results with:lesion
[9]
Neural correlates of the contents of visual awareness in humans
This review focuses on recent attempts to identify experimentally the neural correlates of the contents of consciousness related to visual perception in humans.
[10]
Frontiers | Consciousness and the Prefrontal Parietal Network
Mar 11, 2012 · Empirical work has centered on identifying potential neural correlates of consciousness (NCCs), with a converging view that the prefrontal ...
[11]
Neural correlates of consciousness: progress and problems - PubMed
In this Review, we describe recent findings showing that the anatomical neural correlates of consciousness are primarily localized to a posterior cortical hot ...
[12]
Conscious Processing and the Global Neuronal Workspace ...
Mar 4, 2020 · The central thesis of the original global workspace theory was proposed by Baars (1988). It is a psychological construct arguing that ...
[13]
A neuronal model of a global workspace in effortful cognitive tasks
Our theory predicts that workspace neurons are the specific targets of projections from neuronal structures that provide reward and vigilance inputs, presumably ...
[14]
Experimental and Theoretical Approaches to Conscious Processing
Apr 28, 2011 · We introduced the Global Neuronal Workspace (GNW) model as an alternative cortical mechanism capable of integrating the supervision, limited ...
[15]
[PDF] The Global Neuronal Workspace Model of Conscious Access
An important statement of the GNW model is that the GNW network is the seat of a particular kind of brain-scale activity state characterized by spontaneous. “ ...
[16]
An information integration theory of consciousness
Nov 2, 2004 · This paper presents a theory about what consciousness is and how it can be measured. According to the theory, consciousness corresponds to the capacity of a ...
[17]
Integrated information theory - Scholarpedia
Jun 23, 2015 · Based on these criteria, the axioms of IIT are intrinsic existence, composition, information, integration, and exclusion (Figure 1). The axioms ...Axioms: Essential properties of... · Postulates: Properties required...
[18]
Consciousness as Integrated Information: a Provisional Manifesto
In what follows, I discuss the integrated information theory of consciousness (IIT; Tononi, 2004)—an attempt to understand consciousness at the fundamental ...Missing: original | Show results with:original
[19]
How to be an integrated information theorist without losing your body
However, this is not yet feasible for realistic systems, due to combinatorial explosions in the calculations, manipulations and observations needed, making it ...
[20]
The Problem with Phi: A Critique of Integrated Information Theory
Sep 17, 2015 · The goal of this paper is to show that IIT fails in its stated goal of quantifying consciousness. The paper will challenge the theoretical and empirical ...
[21]
A theoretically based index of consciousness independent of ...
Aug 14, 2013 · Adenauer G Casali ... We introduce and test a theory-driven index of the level of consciousness called the perturbational complexity index (PCI).Missing: original paper
[22]
[PDF] The Conscious Electromagnetic Information (Cemi) Field Theory
Abstract: In the April 2002 edition of JCS I outlined the conscious electromag- netic information field (cemi field) theory, claiming that consciousness is ...
[23]
Integrating information in the brain's EM field: the cemi field theory of ...
Sep 22, 2020 · The cemi field theory proposes a scientific dualism that is rooted in the difference between matter and energy, rather than matter and spirit.Abstract · Introduction · Results · Discussion and Conclusions
[24]
Gamma coherence and conscious perception - Neurology.org
We proposed to test whether the primary sensory cortex is directly involved in conscious awareness by determining if consistent differences in gamma coherence ...Gamma Coherence And... · Abstract · Methods
[25]
Field theories of consciousness - Scholarpedia
Dec 2, 2013 · First, it has never been disputed that electromagnetic fields can and do affect neuronal function. Chapter 7 of Pockett (2000) lists a number of ...Köhler's field theory · Libet's field theory of... · The electromagnetic field...
[26]
The Electromagnetic Field Theory of Consciousness A Testable ...
Aug 7, 2025 · The electromagnetic field theory of consciousness proposes that conscious experiences are identical with certain electromagnetic patterns generated by the ...
[27]
Consciousness in the universe: A review of the 'Orch OR' theory
The best measurable correlate of consciousness through modern science is gamma synchrony electro-encephalography (EEG), 30 to 90 Hz coherent neuronal membrane ...
[28]
Consciousness, Cognition and the Neuronal Cytoskeleton - Frontiers
In the mid 1990s, Penrose and Hameroff suggested that microtubules inside brain neurons orchestrate quantum vibrational superpositions through resonance, ...
[29]
A quantum microtubule substrate of consciousness is experimentally ...
May 6, 2025 · Recent experimental evidence, briefly reviewed here, points to intraneuronal microtubules as a functional target of inhalational anesthetics.Missing: critique | Show results with:critique
[30]
The importance of quantum decoherence in brain processes - arXiv
Based on a calculation of neural decoherence rates, we argue that that the degrees of freedom of the human brain that relate to cognitive processes should be ...
[31]
Is Consciousness a Quantum Phenomenon? Recent Findings…
Jun 19, 2023 · Results of recent experiments show that quantum states can be formed in microtubules, and that anesthetic molecules shorten the lifetimes of these quantum ...
[32]
Conscious active inference II: Quantum orchestrated objective ...
Sep 13, 2025 · Keywords: Microtubules, Orch ... These experiments strongly support the physical plausibility of the quantum microtubule consciousness hypothesis.
[33]
Holonomic brain theory - Scholarpedia
Oct 21, 2011 · The Holonomic Brain Theory describes a type of process that occurs in fine fibered neural webs. The process is composed of patches of local field potentials.Roots of the Holonomic Theory · Misconceptions · Holonomy is Patch HolographyMissing: seminal | Show results with:seminal
[34]
https://acornabbey.com/blog/?p=31687
[35]
The free-energy principle: a unified brain theory? - Nature
Jan 13, 2010 · Karl Friston shows that different global brain theories all describe principles by which the brain optimizes value and surprise.
[36]
Predictive Processing and Some Disillusions about Illusions
Nov 24, 2021 · In this chapter we'll review PEM explanations of several illusions, including the Müller-Lyer Illusion (MLI), the Rubber Hand Illusion (RHI) and ...
[37]
[PDF] Two concepts of consciousness - David Rosenthal
For. Page 23. TWO CONCEPTS OF CONSCIOUSNESS. 351 one thing, the concept of a mental state with propositional content is more complex than the concept of a ...
[38]
Two concepts of consciousness | Philosophical Studies
Cite this article. Rosenthal, D.M. Two concepts of consciousness. Philosophical Studies 49, 329–359 (1986). https://doi.org/10.1007/BF00355521. Download ...
[39]
Higher-Order Theories of Consciousness
Apr 3, 2001 · Higher-order theories of consciousness try to explain the difference between unconscious and conscious mental states.Missing: seminal | Show results with:seminal
[40]
Understanding the Higher-Order Approach to Consciousness
Jun 14, 2019 · We propose a reconceptualization of lower-order states that contribute to higher-order awareness, including states of prefrontal cortex and ...
[41]
Empirical support for higher-order theories of conscious awareness
Higher-order theories of consciousness argue that conscious awareness crucially depends on higher-order mental representations.Missing: thought seminal paper
[42]
https://www.sciencedirect.com/science/article/pii/S1364661319301615
[43]
Peter Carruthers, Higher-order theories of consciousness - PhilPapers
Actualist higher‐order thought theory has the advantage that no special organs or mechanisms need to be postulated. Dispositionalist higher‐order thought ...
[44]
Multiple drafts model - Scholarpedia
Feb 8, 2008 · The multiple drafts model is an attempt to show how this can be true, and how it makes sense of otherwise paradoxical findings.Escape from the Cartesian... · Fame in the brain · The onset of consciousness...
[45]
[PDF] To what extent Dennett's Multiple Drafts Model better accounts ...
The analysis will use primary sources like. Dennett's own texts and experiments he cites, as well as secondary sources including critical responses by the ...
[46]
[PDF] troubles with functionalism - ned block
The Absent Qualia Argument rested on an appeal to the intuition that the homunculi-headed simulations lacked mentality, or at least qualia. I said that this ...
[47]
[PDF] Some Concepts of Consciousness
Apr 7, 2009 · Phenomenal consciousness is experience; the phenomenally conscious aspect of a state is what it is like to be in that state. The mark of access- ...<|separator|>
[48]
[PDF] ; Minds, brains, and programs - CSULB
The project is to reproduce and explain the mental by designing programs, but unless the mind is not only conceptually but empirically independent of the brain ...
[49]
[PDF] Facing Up to the Problem of Consciousness - David Chalmers
The really hard problem of consciousness is the problem of experience. When we think and perceive, there is a whir of information-processing, but there is ...Missing: primary | Show results with:primary
[50]
Panpsychism - Stanford Encyclopedia of Philosophy
May 23, 2001 · This argument has its roots in Leibniz, Schopenhauer, Russell (1927) and Whitehead (1933 [1967]), and is defended by many panpsychists ...
[51]
[PDF] The Combination Problem for Panpsychism - David Chalmers
I have argued in “Panpsychism and Panprotopsychism” that it promises to share the advantages of both materialism and dualism and the disadvantages of neither.Missing: Galen | Show results with:Galen
[52]
[PDF] The 'Intrinsic Nature' Argument for Panpsychism
Either consciousness emerges from non-conscious features of the world or else consciousness is a fundamental and ubiquitous feature. 2. Emergence is impossible.
[53]
[PDF] Is the Integrated Information Theory of Consciousness Compatible ...
Abstract: The Integrated Information Theory (IIT) is a leading scientific theory of consciousness, which implies a kind of panpsychism.Missing: implications | Show results with:implications
[54]
https://www.utsc.utoronto.ca/~seager/intnat.pdf
[55]
https://www.vox.com/future-perfect/353430/what-if-absolutely-everything-is-conscious
[56]
https://doi.org/10.3389/fpsyg.2015.00500
[57]
Recurrence affects the geometry of visual representations across the ...
The core finding is that recurrent processing indeed is present at ~100 ms in early visual cortex and then emerges at ~175 and ~300 ms in lateral occipital ...
[58]
Masking interrupts figure-ground signals in V1 - PubMed
Victor A F Lamme , Karl Zipser, Henk Spekreijse. Affiliation. 1 Department ... masking selectively interrupts the recurrent interactions between V1 and higher ...
[59]
Predictive coding in the visual cortex: a functional interpretation of ...
Predictive coding in the visual cortex: a functional interpretation of some extra-classical receptive-field effects. Rajesh P. N. Rao &; Dana H. Ballard. Nature ...
[60]
Evaluating the neurophysiological evidence for predictive ...
Mar 8, 2020 · Hence, precision‐weighting provides a mechanism through which the brain can promote the influence of error channels that will provide the most ...
[61]
A Neuronal Model of Predictive Coding Accounting for the Mismatch ...
Mar 14, 2012 · We propose here a detailed neuronal model of auditory cortex, based on predictive coding, that accounts for the critical features of MMN.Missing: bistable | Show results with:bistable
[62]
A predictive coding perspective on autism spectrum disorders
In predictive coding schemes, higher brain areas attempt to “explain” input from lower brain areas, and then project these predictions down to lower areas, ...
[63]
The DSM-5 criteria, level of arousal and delirium diagnosis
Sep 25, 2014 · A. Disturbance of consciousness (i.e. reduced clarity of awareness of the environment) with reduced ability to focus, sustain or shift attention ...
[64]
Level of Consciousness - Clinical Methods - NCBI Bookshelf - NIH
Clouding of consciousness is a very mild form of altered mental status in which the patient has inattention and reduced wakefulness.
[65]
Metabolic encephalopathy and metabolic coma - MedLink Neurology
Metabolic encephalopathy is diffuse, nonstructural brain dysfunction ranging from mild delirium to coma, caused by systemic organ or metabolic…
[66]
Neuroanatomy, Reticular Activating System - StatPearls - NCBI - NIH
Jul 24, 2023 · The reticular activating system (RAS) is a component of the reticular formation in vertebrate brains located throughout the brainstem.Missing: clouding | Show results with:clouding
[67]
Disorders of Consciousness
Apr 20, 2023 · Clouding of consciousness ... A conscious state depends on intact cerebral hemispheres and an intact ascending reticular activating system (ARAS) ...
[68]
The Confusion Assessment Method (CAM): A Systematic Review of ...
The CAM was designed to allow non-psychiatric clinicians to diagnose delirium quickly and accurately following brief formal cognitive testing. The CAM ...Missing: clouding | Show results with:clouding
[69]
Delirium and Confusion in the 19th Century: A Conceptual History
Jan 29, 2018 · It emphasized chaotic thinking and cognitive failure. The notion of clouding of consciousness (and temporo-spatial disorientation) established ...
[70]
Durkheim, Emile | Internet Encyclopedia of Philosophy
As Durkheim argues, society can only become conscious of these forces circulating in the social world by representing them somehow.
[71]
The Elementary Forms of the Religious Life (1912) - Emile Durkheim
Durkheim's primary purpose in The Elementary Forms was to describe and explain the most primitive 1 religion known to man.
[72]
[PDF] Emile Durkheim and C. G. Jung - Digital Commons @ CIIS
Jul 1, 2013 · 1. The collective consciousness contains sacred religious beliefs, or collective representations, and binds societies together through publicly ...
[73]
Emotional processes, collective behavior, and social movements
Approaches to collective effervescence. Collins' interaction ritual theory. Collins' (2004) developed an interaction ritual theory inspired by Goffman's (1959) ...
[74]
Quantifying collective effervescence: Heart-rate dynamics at a fire ...
Famously, Emile Durkheim proposed the notion of collective effervescence, a feeling of belonging and assimilation produced by collective ritual action. Yet, ...Missing: crowd | Show results with:crowd
[75]
Investigating the relationship between shared social identity ... - PMC
Positive experiences in crowds arise when participants enact their collective identity and feel close to others, which is linked to shared identity.Abstract · From Shared Identity To... · Results
[76]
Collective Thought, Will and Action in the Age of Social Media - jstor
This will be a view of consciousness as a form of thinking together that is augmented and extended by gadgets, and that includes the sense of consciousness as ...Missing: cognition | Show results with:cognition
[77]
[PDF] Emergence in Sociology - Keith Sawyer
Durkheim's theory of social causation was famously criticized for seem- ing to hypostatize the social. Likewise, higher-Ievel causation is problem- atic in the ...
[78]
[PDF] Durkheim and Organizational Culture | IRLE
Jun 4, 2004 · Durkheim's portrait of culture is often criticized as: (a) holistic, seamless, and homogenous—admitting to no divisions or conflicts; (b) ...
[79]
Unnatural Emotions - The University of Chicago Press
1. The Cultural Construction of Emotions · 2. Paths to Ifaluk · 3. Emotion, Thought, and Estrangement: Western Discourses on Feeling · 4. The Ethnopsychological ...
[80]
Ludwig Wittgenstein - Stanford Encyclopedia of Philosophy
Nov 8, 2002 · In the Tractatus Wittgenstein's logical construction of a philosophical system has a purpose—to find the limits of world, thought, and language; ...Wittgenstein's Logical Atomism · Wittgenstein's Aesthetics
[81]
The influence of in-groups and out-groups on the theory-of-mind ...
Jan 24, 2023 · Cross-cultural research on adults' ToM found that they show egocentricity in the ToM processing in collectivist and individualistic cultures and ...
[82]
[PDF] The weirdest people in the world? - Description
The findings suggest that members of. WEIRD societies, including young children, are among the least representative populations one could find for generalizing ...<|control11|><|separator|>
[83]
The Mindful Self: A Mindfulness-Enlightened Self-view - Frontiers
Oct 12, 2017 · The central tenet of Buddhist psychology with respect to the self is that of “no self,” which posits that there is no unchangeable self. This ...
[84]
Exploring the Eight-Circuit Model of Consciousness - Scirp.org.
This article explores the intersection of the Eight-Circuit Model of Consciousness (ECM), initially conceptualized by Timothy Leary and expanded by Robert Anton ...
[85]
Timothy Leary's Eight-Circuit Model of Consciousness
Aug 24, 2024 · Yet the optimism behind the theory lacks justification; Leary falls prey to utopianism, pseudoscience, elitism, and spiritual narcissism in his ...
[86]
Idealism - Stanford Encyclopedia of Philosophy
Aug 30, 2015 · This entry discusses philosophical idealism as a movement chiefly in the eighteenth and nineteenth centuries, although anticipated by certain aspects of ...
[87]
[PDF] Idealism and the Mind-Body Problem - David Chalmers
Idealism is the thesis that the universe is fundamentally mental, or that all concrete facts are grounded in mental facts.<|separator|>
[88]
George Berkeley - Stanford Encyclopedia of Philosophy
to be is to be ...Berkeley's critique of... · Berkeley's positive program... · The basics of Berkeley's...
[89]
George Berkeley's Subjective Idealism: The World Is In Our Minds
Esse est percipi: to be is to be perceived. Reflections like those above led Berkeley to famously declare esse est percipi: to be is to be perceived. This ...
[90]
[PDF] Analytic Idealism: A consciousness-only ontology - PhilPapers
Bernardo Kastrup. Page 4. Kastrup, Bernardo. Analytic Idealism: A consciousness-only ontology. ISBN/EAN: 978-94-028-1400-2. Copyright © 2016-2019 by Bernardo ...
[91]
New Analytic Idealism literature - Bernardo Kastrup, PhD, PhD
The overall theme is the emergence of a new theory of reality for basing a scientific way of looking upon nature. The times are most definitely changing and ...
[92]
Georg Wilhelm Friedrich Hegel - Stanford Encyclopedia of Philosophy
Feb 13, 1997 · But in contrast to both forms of idealism, Hegel, according to this reading, postulated a form of absolute idealism by including both ...Hegel's Philosophy · The traditional metaphysical... · Hegel's Published Works
[93]
Absolute Idealism | German Philosophy, Hegel & Kant | Britannica
Sep 27, 2025 · Idealism for Hegel meant that the finite world is a reflection of mind, which alone is truly real. He held that limited being (that which comes ...
[94]
What Is Consciousness? Some New Perspectives from Our Physics ...
Mar 22, 2021 · Stephen Wolfram sketches some preliminary ideas on the complex subject of consciousness and its connection to his research into the ...Top; “ · What about Consciousness?” · So, What Is Consciousness?Missing: digital | Show results with:digital
[95]
The Wolfram Physics Project: Finding the Fundamental Theory of ...
Stephen Wolfram leads a new approach to discover the fundamental theory of physics. Follow project development as it is livestreamed.Visual Summary · Technical Introduction · Launch Documents · Software ToolsMissing: digital consciousness
[96]
The true, hidden origin of the so-called 'Hard Problem of ...
Oct 11, 2024 · The hard problem of consciousness is the inability to deduce experiential qualities from physical parameters, due to the absence of a logical ...
[97]
Does Idealism Solve the Problem of Consciousness? - PhilPapers
But I argue that idealism has no advantage over dualism and physicalism in the face of this problem. In approaching this issue I also make some taxonomical ...
[98]
Response to Rupert Sheldrake's criticisms of Analytic Idealism
Dec 6, 2024 · A scientific theory must be falsifiable in the sense that it must make predictions about nature's future behavior that can be checked against ...
[99]
A landscape of consciousness: Toward a taxonomy of explanations ...
Diverse explanations or theories of consciousness are arrayed on a roughly physicalist-to-nonphysicalist landscape of essences and mechanisms.