Neuroscience of Consciousness最新文献

The context for our paper comes from the neurophenomenology (NPh) research programme initiated by Francisco Varela at the end of the 1990s. Varela's working hypothesis was that, to be successful, a consciousness research programme must progress by relating first-person phenomenological accounts of the structure of experience and their third-person counterparts in neuroscience through "mutual constraints". Leveraging Bayesian mechanics, in particular deep parametric active inference, we demonstrate the potential for epistemically advantageous mutual constraints between phenomenological, computational, behavioural, and physiological vocabularies. Specifically, the dual information geometry of Bayesian mechanics serves to establish, under certain conditions, generative passage between lived experience and its physiological instantiation. This paper argues for the epistemological necessity of such a passage and the inclusion of trained reflective awareness in neurophenomenological empirical approaches. In particular, it showcases incremental explanatory gains for the scientist that arise from incorporating the participants' epistemic insights, shifting the focus from the contents of experience (i.e. what a subject experiences in a given experimental set-up) to the how of experience (i.e. the activities of consciousness that allow for a meaningful world to appear to us as such in lived experience). The explanatory power of the resulting 'meta-Bayesian' framework, deep computational NPh, arises from the disciplined circulation between first and third-person perspectives enabled by the formalism of deep parametric active inference, where parametric depth refers to a property of generative models that can form beliefs about the parameters of their own modelling process. Hence, this computational formalism contributes to understanding consciousness by bridging phenomenological descriptions and physiological instantiations, whilst also highlighting the significance of trained first-person investigation in experimental protocols.

This commentary engages with recent work on computational functionalist theories of consciousness through a structural lens. We address three key aspects: the role of subjective experience in theory building, the hypothesis regarding local lateral connectivity in sensory areas, and the implications of "silent units" for consciousness. We argue that while their structural turn is welcome, many of their insights were previously predicted by Integrated Information Theory. We question the coherence of these claims within the functionalist paradigm and emphasize the importance of distinguishing genuine predictions from post-hoc accommodations in consciousness science.

Recent years have seen growing interest in the use of metrics inspired by complexity science for the study of consciousness. Work in this field has shown remarkable results in discerning conscious from unconscious states, and in characterizing states of altered conscious experience following psychedelic intake as involving enhanced complexity. Here, we study the relationship between complexity and a different kind of altered state of consciousness: meditation. We provide a scoping review of the growing literature studying the complexity of neural activity in meditation, disentangling different families of measures, short-term (state) from long-term (trait) effects, and meditation styles. Beyond families of measures used, our review uncovers a convergence toward identifying higher complexity during the meditative state when compared to waking rest or mind-wandering and decreased baseline complexity as a trait following regular meditation practice. In doing so, this review contributes to guide current debates and provides a framework for understanding the complexity of neural activity in meditation, while suggesting practical guidelines for future research.

People vary in their capacity for phenomenological control, which enables them to align their perceptual experiences with their intentions and goals. The Phenomenological Control Scale was developed to measure this trait, and we developed and validated a Japanese version of this scale (PCS-J) based on preregistered online surveys (n = 261; retest n = 152). The PCS-J demonstrated sufficient internal consistency and test-retest reliability. Given the known association between hypnotic susceptibility and positive schizotypy, the convergent validity of the PCS-J was supported by a weak positive correlation with positive schizotypy. The discriminant validity of the PCS-J was demonstrated by the absence of a correlation with negative schizotypy. The PCS-J would be useful for research on perception, phenomenological control, and their individual differences in Japanese samples, as well as for intercultural studies.

Autonomous sensory meridian response (ASMR) is a sensory-emotional phenomenon characterized by distinct tingling sensations and a sense of relaxation induced by specific auditory and visual stimuli. Although ASMR is recognized as a cross-modal experience, psychological and physiological mechanisms behind ASMR remain only partially understood. Across two experiments, we investigated these mechanisms. Experiment 1 showed that ASMR videos with combined audiovisual content elicited stronger tingling sensations than those with auditory-only content, suggesting an additive effect through sensory processing. In Experiment 2, we measured responses to ASMR and nature videos using finger photoplethysmography (PPG) and found that both types of videos reduced pulse rates compared to rest. Notably, ASMR videos caused a greater reduction in pulse rate than nature videos. These findings are discussed in relation to autonomic nervous system activation, cross-modal interactions, and the social grooming hypothesis, which posits that ASMR may replicate comforting effects of social bonding behaviors, such as grooming.

The scope of unconscious integration is widely debated. Here, we examined this question, focusing specifically on deciphering the relations between two associatively related objects, in a set of five behavioral and electrophysiological experiments. Participants were presented with masked pairs of related and unrelated objects and were asked to judge their relatedness. When the masked pairs were visible, we found both a behavioral priming effect and a difference in the magnitude of the electrophysiological N400 component for unrelated compared with related pairs. In sharp contrast, when the pairs were invisible (validated using both subjective and objective awareness measures), no convincing evidence was found for relatedness processing: with electroencephalography, no difference in N400 amplitude nor above-chance decoding of pair relations was found in two separate experiments. Based on these results, we conclude that the data do not support unconscious relatedness processing, suggesting that consciousness might have a prominent role in enabling relational integration beyond the single object level, which is in line with leading theories of consciousness.

Recent experimental evidence, briefly reviewed here, points to intraneuronal microtubules as a functional target of inhalational anesthetics. This finding is consistent with the general hypothesis that the biophysical substrate of consciousness is a collective quantum state of microtubules and is specifically predicted by the Orchestrated Objective Reduction theory of Penrose and Hameroff. I also review experimental evidence that functionally relevant quantum effects occur in microtubules at room temperature, and direct physical evidence of a macroscopic quantum entangled state in the living human brain that is correlated with the conscious state and working memory performance. Having established the physical and biological plausibility of quantum microtubule states related to consciousness, I turn to consider potential practical advantages of a quantum brain and enormous theoretical advantages of a quantum consciousness model. In particular, I explain how the quantum model makes panprotopsychism a viable solution to physicalism's hard problem by solving the phenomenal binding or combination problem. Postulating a quantum physical substrate of consciousness solves the binding problem in principle but appears to leave us with an epiphenomenalism problem, meaning that consciousness seems to have no causal power to confer a fitness advantage, so its evolution remains as an inexplicable mystery. I propose that, contrary to a certain (zombie) intuition, the quantum approach can also solve this problem in a nontrivial way. The Orchestrated Objective Reduction (Orch OR) theory of Penrose and Hameroff embodies these advantages of a quantum model and also accounts for nonalgorithmic human understanding and the psychological arrow of time.

This paper examines the constraints that the free-energy principle (FEP) places on possible model of consciousness, particularly models of attentional control and imaginative experiences, including episodic memory and planning. We first rehearse the classical and quantum formulations of the FEP, focusing on their application to multi-component systems, in which only some components interact directly with the external environment. In particular, we discuss the role of internal boundaries that have the structure of Markov blankets, and hence function as classical information channels between components. We then show how this formal structure supports models of attentional control and imaginative experience, with a focus on (i) how imaginative experience can employ the spatio-temporal and object-recognition reference frames employed in ordinary, non-imaginative experience and (ii) how imaginative experience can be internally generated but still surprising. We conclude by discussing the implementation, phenomenology, and phylogeny of imaginative experience, and the implications of the large state and trait variability of imaginative experience in humans.

5-MeO-DMT is a short-acting psychedelic that is anecdotally reported to induce a radical disruption of the self and a paradoxical quality of aroused, waking awareness that is nevertheless devoid of any specific perceptual contents. Here, we conducted an exploratory observational study of the phenomenological and neuronal effects of this compound. We collected micro-phenomenological interviews, psychometric questionnaires, and electroencephalography (EEG) in naturalistic ceremonial settings where 5-MeO-DMT was ingested. Results revealed that the 5-MeO-DMT experience followed a dynamic progression that-only in the most extreme cases-manifested as a complete absence of self-experience and other phenomenal content with preserved awareness. Furthermore, visual imagery, bodily self-disruption, narrative self-disruption, and reduced phenomenal distinctions occurred in a variable fashion. EEG analyses revealed the 5-MeO-DMT experience was characterised by (global) alpha and (posterior) beta power reductions, implying a mode of brain functioning where top-down models are inhibited. Our preliminary phenomenological findings confirm the potential utility of 5-MeO-DMT as a pharmacological model for deconstructed consciousness while noting the limitations of employing retrospective questionnaires for this purpose. Considering the exploratory nature of this study and its limitations inherent to its naturalistic nature, further research employing real-time experience sampling and phenomenologically trained participants in controlled environments could expand our findings to meaningfully inform the potential of this tool for the scientific study of consciousness.

Visual imagery is a dynamic process recruiting a network of brain regions. We used electroencephalography (EEG) and functional magnetic resonance imaging (fMRI) fusion to investigate the dynamics of category selective imagery in medial parietal cortex (MPC), ventral temporal cortex (VTC), and primary visual cortex (V1). Subjects attended separate EEG and fMRI sessions where they created mental images of personally familiar people and place stimuli. The fMRI contrast comparing people and place imagery replicated previous findings of category-selectivity in the medial parietal cortex. In addition, greater activity for places was found in the ventral and lateral place memory areas, the frontal eye fields, the inferior temporal sulcus, and the intraparietal sulcus. In contrast, greater activity for people was found in the fusiform face area and the right posterior superior temporal sulcus. Using multivariate decoding analysis in fMRI, we could decode individual stimuli within the preferred category in VTC. A more complex pattern emerged in MPC, which represented information that was not restricted to the preferred category. We were also able to decode category and individual stimuli in the EEG data. EEG-fMRI fusion indicated similar timings in MPC and VTC activity during imagery. However, in the VTC, fusion was higher in place selective regions during an early time window, and higher in face selective regions in a later time window. In contrast, fusion correlations in V1 occurred later during the imagery period, possibly reflecting the top-down progression of mental imagery from category-selective regions to primary visual cortex.