Theories of consciousness are often based on the assumption that a single, unified neurobiological account will explain different types of conscious awareness. However, recent findings show that, even within a single modality such as conscious visual perception, the anatomical location, timing, and information flow of neural activity related to conscious awareness vary depending on both...
Recent findings suggesting the potential transdiagnostic efficacy of psychedelic-assisted therapy have fostered the need to deepen our understanding of psychedelic brain action. Functional neuroimaging investigations have found that psychedelics reduce the functional segregation of large-scale brain networks. However, beyond this general trend, findings have been largely inconsistent. We argue...
No contemporary unifying framework has been provided for the study of non-ordinary states of consciousness (NSCs) despite increased interest in hypnosis, meditation, and psychedelics. NSCs induce shifts in experiential contents (what appears to the experiencer) and/or structure (how it appears). This can allow the investigation of the plastic and dynamic nature of experience from a multiscale...
Subjective experiences often feel rich, yet are most often quantified with simple metrics, such as a few levels on a predefined scale. What are the dimensions and topological organization of subjective experience? How do they relate to behavioral output? And how do they map onto the classical cognitive domains?
What are the functional roles of subjective experiences? Answering this question amounts to charting a course for the cognitive science of consciousness, where mental processes can be described in terms of their functions. If we strategically focus on mental disorders, preliminary answers may be in sight within 25 years.
The integrated information theory of consciousness (IIT) is divisive: while some believe it provides an unprecedentedly powerful approach to address the 'hard problem', others dismiss it on grounds that it is untestable. We argue that the appeal and applicability of IIT can be greatly widened if we distinguish two flavours of the theory: strong IIT, which identifies consciousness with specific...
The neural correlates supporting our perceptual experience of the world remain largely unknown. Recent studies have shown how stimulus detection and related confidence involve evidence accumulation (EA) processes similar to those involved in perceptual decision-making. Here, we propose that independently from any tasks, percepts are not static but fade in and out of consciousness according to...
Findings demonstrating decision-related neural activity preceding volitional actions have dominated the discussion about how science can inform the free will debate. These discussions have largely ignored studies suggesting that decisions might be influenced or biased by various unconscious processes. If these effects are indeed real, do they render subjects' decisions less free or even unfree?...
Much research on the neural correlates of consciousness (NCC) has focused on two evoked potentials, the P3b and the visual or auditory awareness negativity (VAN, AAN). Surveying a broad range of recent experimental evidence, we find that repeated failures to observe the P3b during conscious perception eliminate it as a putative NCC. Neither the VAN nor the AAN have been dissociated from...
Dreamers were long thought absolutely isolated from the outside world. Yet psychophysiological studies over the past 40 years have firmly established that lucid dreamers can use eye movements to report on their dream content in real time while in rapid eye movement (REM) sleep. We now also know that sensory input is not completely suppresssed during sleep. A recent study by Konkoly et al....
Recent breakthroughs in neurobiology indicate that the time is ripe to understand how cellular-level mechanisms are related to conscious experience. Here, we highlight the biophysical properties of pyramidal cells, which allow them to act as gates that control the evolution of global activation patterns. In conscious states, this cellular mechanism enables complex sustained dynamics within the...
How does consciousness vary across the animal kingdom? Are some animals 'more conscious' than others? This article presents a multidimensional framework for understanding interspecies variation in states of consciousness. The framework distinguishes five key dimensions of variation: perceptual richness, evaluative richness, integration at a time, integration across time, and self-consciousness....
During binocular rivalry (BR), incongruent, unchanged visual stimulation induces intrinsically generated transitions in conscious content. Due to this astonishing property, BR is commonly combined with functional magnetic resonance imaging (fMRI) or single neuron recordings to identify the neural correlates of consciousness (NCCs); namely, brain activity reflecting conscious contents and...
Consciousness remains a formidable challenge. Different theories of consciousness have proposed vastly different mechanisms to account for phenomenal experience. Here, appealing to aspects of global workspace theory, higher-order theories, social theories, and predictive processing, we introduce a novel framework: the self-organizing metarerpresentational account (SOMA), in which consciousness...
Forty-five years ago, the first evidence of near-death experience (NDE) during comatose state was provided, setting the stage for a new paradigm for studying the neural basis of consciousness in unresponsive states. At present, the state of consciousness associated with NDEs remains an open question. In the common view, consciousness is said to disappear in a coma with the brain shutting down,...
The higher-order theory (HOT) of consciousness has often been misunderstood by critics. Here, we clarify its position on several issues, and distinguish it from other views, such as the global workspace theory (GWT) and early sensory models (e.g., first-order local recurrency theories). For example, HOT has been criticized for overintellectualizing consciousness. We show that, while...
Emotions are often assumed to manifest in subcortical limbic and brainstem structures. While these areas are clearly important for representing affect (e.g. valence, arousal), we propose that the default mode network (DMN) is additionally important for constructing discrete emotional experiences (of anger, fear, disgust, etc.). Findings from neuroimaging studies, invasive electrical stimulation...
The two leading cognitive accounts of consciousness currently available concern global workspace (a form of working memory) and metacognition. There is relatively little interaction between these two approaches and it has even been suggested that the two accounts are rival and separable alternatives. Here, we argue that the successful function of a global workspace critically requires that the...
The concepts of agency of one's actions and ownership of one's experience have proved useful in relating body representations to bodily consciousness. Here we apply these concepts to cognitive maps. Agency is defined as 'the sense that I am the one who is generating the experience represented on a cognitive map', while ownership is defined as 'the sense that I am the one who is undergoing an...
Although recent studies on self-consciousness emphasized the importance of bodily processing and multisensory integration, such research has focused solely on bodily signals originating from the outside of the body (i.e., exteroceptive bodily signals) or internal bodily signals from visceral organs (i.e., interoceptive bodily signals) and how each system contributes to self-consciousness,...
Modern psychology has long focused on the body as the basis of the self. Recently, predictive processing accounts of interoception (perception of the body 'from within') have become influential in accounting for experiences of body ownership and emotion. Here, we describe embodied selfhood in terms of 'instrumental interoceptive inference' that emphasises allostatic regulation and physiological...
General anesthesia provides an invaluable experimental tool to probe the essential neural circuits that underlie consciousness. A new study reports that cholinergic stimulation of the prefrontal cortex restores wake-like behaviors in anesthetized rodents, suggesting that cholinergic inputs to the prefrontal cortex play a fundamental role in modulating consciousness.
The split-brain phenomenon is caused by the surgical severing of the corpus callosum, the main route of communication between the cerebral hemispheres. The classical view of this syndrome asserts that conscious unity is abolished. The left hemisphere consciously experiences and functions independently of the right hemisphere. This view is a cornerstone of current consciousness research. In this...
Consciousness is often said to disappear in deep, dreamless sleep. We argue that this assumption is oversimplified. Unless dreamless sleep is defined as unconscious from the outset there are good empirical and theoretical reasons for saying that a range of different types of sleep experience, some of which are distinct from dreaming, can occur in all stages of sleep. We introduce a novel...
Recent experiments demonstrate that invisible stimulus features can induce binocular rivalry, indicating the phenomenon may be caused by differences in perceptual signal strength rather than conscious selection processes. Here, we clarify binocular rivalry's role in consciousness research by highlighting a critical difference between two distinct types of visual awareness.