Neuroscience of Consciousness最新文献

Current theories of consciousness often emphasize its ego-centric functions, highlighting the role of the insular cortex in interoceptive self-modeling and subcortical brain regions in qualitative experience and motivation, aptly described as the 'hidden spring' of consciousness. From ecological and pragmatic perspectives, conscious experience may facilitate the self-organization of complex organisms by optimizing goals that are typically parallel, multifaceted, and difficult to reconcile. However, the notion that all forms of conscious experience are ego-centric, or at least grounded in a minimal sense of self, is challenged by credible reports of minimal phenomenal experience (MPE), which occur without any self-referential content. I propose that this apparent duality in conscious experience can be explained by the dual-origin theory of cortical development. This theory suggests a gradual expansion of cortical cytoarchitecture from two distinct subcortical origins. The 'Amygdala-System' supports interoceptive self-modeling for habitual interactions with the body and the environment. It expands ventrally from the olfactory system and amygdala, enabling ego-centric processing. In contrast, the 'Hippocampus-System', centered on the hippocampus and expanding dorsally, supports allocentric cognition and experiences that are not constrained by self-referential processing. This complementary system allows for open-ended, selfless forms of experience, akin to an 'endless ocean'. In this framework, MPE may represent a fragile form of consciousness, typically overshadowed by the self-related interoceptive and exteroceptive functions of the Amygdala-System. Finally, I discuss how real-time functional magnetic resonance imaging (fMRI) neurofeedback could be used to upregulate the Hippocampus-System, potentially enabling the controlled study of MPE in neuroscientific settings.

Rapid eye movement (REM) sleep consists of phasic and tonic microstates with unique neurophysiological properties, yet their fractal characteristics remain underexplored. Using Higuchi's fractal dimension (HFD) analysis of electroencephalographic data from healthy adults, this study investigated complexity differences between REM microstates. The results showed that both phasic and tonic REM exhibited significantly lower global HFD values compared to wakefulness, while displaying similar overall complexity levels between microstates. Importantly, phasic REM demonstrated regionally specific reductions in fractal dimensionality, with pronounced decreases observed in frontocentral areas. These localized reductions exhibited a negative association with theta band power, yet remained statistically unrelated to Lempel-Ziv complexity (LZC) measures, indicating that HFD and LZC capture distinct aspects of neural signal organization. The findings reveal that although phasic and tonic REM maintain comparable global complexity, they differ in their spatiotemporal fractal patterns. The association between increased theta power and reduced fractal dimensionality suggests that phasic REM represents a neurophysiological state favoring rhythmic regularity, potentially optimized for internal information processing. These results position HFD as a valuable complementary approach for characterizing REM microstates, with potential applications in elucidating the pathophysiology of sleep disorders.

Is valence an intrinsic dimension of conscious experience, as different authors have suggested? If so, all conscious experiences, and hence all conscious perceptions, should be valenced, even if only minimally so, and similarity judgments should be at least partly driven by one's affective dispositions. Leveraging the concept of micro-valence, we explore the extent to which valence judgments correlate with similarity judgments and with the different stages of processing in deep neural networks (DNNs). One hundred forty-nine participants provided both similarity and valence judgments for 120 images of everyday objects, using an odd-one-out task (Study 1), a spatial arrangement task (Study 2), and the Birthday task, which asks people to choose an object they would like to keep (or give away) as their birthday gift. We also extracted activations from the layers of DNNs trained to classify objects in response to the same images. Representation similarity analysis and multidimensional scaling analyses highlight the role of micro-valence in the similarity space, suggesting that valence permeates similarity judgments. DNN analyses show that this valence-similarity relationship is not entirely mediated by stimulus perceptual features and suggest that low-level visual features play a role in the computation of valence.

Current theoretical accounts of perception and high-level cognition suggest that awareness plays an active role in disambiguating incoming sensory information. However, the relationship between ambiguity resolution and conscious access remains unclear, partially due to a lack of quantifiable measures of ambiguity. Here, we describe a novel paradigm designed for testing whether more ambiguous stimuli would enjoy preferential access to awareness, as indexed by the time it takes them to break interocular suppression in the breaking continuous flash suppression paradigm. In a series of three experiments, we found that stimuli's mid-level perceptual features (most likely, visual symmetry levels), rather than their ambiguity, facilitated access to awareness. We therefore propose that such features can drive preferential access to awareness and hypothesize that the potential effect of symmetry might be driven by information redundancy due to the invariance of symmetric patterns under geometric transformation.

Meditation practices often involve sustaining attention on the body. Typically, attention is understood to enhance both neural resource allocation and the subjective salience of the attended target. However, in deep meditative states, practitioners sometimes report a dissolution of bodily boundaries, a phenomenon known in Pali as bha[Formula: see text]ga. This presents a paradox: why does focused attention, which typically heightens sensory perception, instead lead to its dissolution? This article addresses this apparent contradiction by integrating computational, phenomenological, and empirical perspectives on attention, interoception, and meditation. We focus on the body-scan technique, as practiced in Theravada Buddhist traditions, and its powerful capacity to produce experiences of the dissolution of bodily boundaries. Working within the predictive processing framework, we propose that this "dissolution" of bodily boundaries results from the body-scan's impact on attentional processes. We argue that by optimizing low-level predictions over somatosensory signals, the body-scan effectively attenuates these signals, thereby diminishing perception of the body's boundaries. In support of this claim, we first describe the body-scan technique and its phenomenological outcomes. We then introduce key concepts from the predictive processing framework and provide a detailed analysis of attentional processes during the body-scan. We conclude that the attenuation of somatosensory signals during the body-scan not only contributes to the experience of bha[Formula: see text]ga but also suggests a broader potential of this practice for enhancing well-being. With appropriate therapeutic integration, this attentional modulation offers promising applications in addressing conditions characterized by disrupted self-regulation, such as addiction and emotional dysregulation.

Large Language Models (LLMs) have rapidly become a central topic in AI and cognitive science, due to their unprecedented performance in a vast array of tasks. Indeed, some even see "sparks of artificial general intelligence" in their apparently boundless faculty for conversation and reasoning. Their sophisticated emergent faculties, which were not initially anticipated by their designers, have ignited an urgent debate about whether and under which circumstances we should attribute consciousness to artificial entities in general and LLMs in particular. The current consensus, rooted in computational functionalism, proposes that consciousness should be ascribed based on a principle of computational equivalence. The objective of this opinion piece is to criticize this current approach and argue in favor of an alternative "behavioral inference principle", whereby consciousness is attributed if it is useful to explain (and predict) a given set of behavioral observations. We believe that a behavioral inference principle will provide an epistemologically valid and operationalizable criterion to assess machine consciousness.

This article challenges the assumption that the science of consciousness can proceed from a theory-neutral foundation. I argue that even ostensibly theory-neutral (or theory-light) programmes inevitably rely on substantive background commitments that cannot be cleanly bracketed. The analysis demonstrates that the aspiration to eliminate or minimize theory-dependence in favour of pure observation risks collapsing into naïve empiricism. More broadly, the paper contends that there is no context-independent scientific method-certainly not one that seeks to purge theoretical commitments from the neuroscience of consciousness without significant epistemic cost.

Active inference describes motor action as a prediction-driven inferential process, whereby ascending proprioceptive prediction errors are attenuated to allow the fulfillment of expected movement. Meditative practices typically involve a heightened attention to bodily sensations, begging the question of whether this could partially offset the normal proprioceptive suppression during a simple motor act. In this study, 42 experienced meditators completed a tactile force-matching task, designed to measure somatosensory attenuation. The active group ([Formula: see text]) performed the task before (T1), during (T2), and three weeks after (T3) an intensive 10-day mindfulness meditation retreat, while a control waiting list group ([Formula: see text]) was also measured three times, but before participating in the retreat. Analysis of T1 data confirmed the presence of a general somatosensory attenuation effect across groups, which correlated negatively with pre-retreat trait measures of mindfulness, as predicted by our hypothesis. Contrary to our expectations, however, longitudinal analyses did not reveal a global reduction in somatosensory attenuation as an effect of intensive meditation practice. We observed instead a subtler regression-to-the-mean effect at T1, which increased with task repetition in control participants (T1>T2>T3), a training-related phenomenon not previously reported for the force-matching task. Interestingly, this habituation behavior was not shown by the active participants, who maintained the level of regression-to-the-mean observed at baseline at T2, suggesting that the formation of prior expectations about the presented force intensity may be affected by the retreat. We discuss how multiple, opposite effects of meditation on proprioceptive active inference mechanisms, and/or an alteration of prior formation and their influence, may explain these findings.

Dreams have arguably been a source of creative insight for millennia. The specific assertion that dreams during rapid eye movement (REM) sleep promote creative problem-solving, however, has only anecdotal support, lacking strong empirical support from rigorous studies. Experimental manipulations of dream content have been confounded by waking components, such that any boost in creative problem-solving could be attributable to waking cognition rather than sleep cognition. Likewise, correlational evidence cannot unequivocally establish that dreams cause insights. Evidence that memory reactivation during sleep promotes creative problem-solving is also insufficient for implicating dreaming per se. Better methods for directly manipulating REM-sleep dreaming are needed. Here, we studied individuals who frequently have lucid dreams-realizing they are dreaming while still asleep. Participants slept after failing to solve several puzzles that had unique soundtracks, and they were instructed to continue working on a puzzle if they heard its soundtrack in a dream. Half of the soundtracks were played during REM sleep to reactivate memories of corresponding puzzles, with the goal of biasing dreams to connect with those specific puzzles versus the remaining puzzles. Those sound cues reliably increased dreaming about the associated puzzles. Furthermore, a post-hoc analysis showed that, for participants with an increase in cue-related dreaming, cues boosted later puzzle-solving. We thus expanded on a well-known phenomenon, that sounds can be incorporated into dreams and can change dream content, by substantiating experimental procedures to align dreams with the search for creative answers to specific challenges. Results highlight that REM dreams can contribute to next-day problem solving.

Modern technology frequently places the consequences of our actions at a distance (e.g. remote surgery, smart-home control, virtual reality). Does spatial distance between an action and its outcome weaken the sense of agency (SoA) - the feeling of control over one's actions and consequences? Two recent studies, by Jenkins and Obhi and Mariano et al., answered "yes," reporting stronger temporal binding (TB) in near than far space and interpreting this as greater implicit agency. A third study - our own work with a similar paradigm - found no distance effect. Here we (i) provide a rigorous side-by-side methodological comparison of the three studies, (ii) argue why a direct test to establish a distance modulation of TB (the Near - Far difference of the Active - Passive delta) should be performed in order to reach meaningful conclusions, and (iii) report new reanalyses of our data and direct tests on the two target studies. Overall, current evidence does not support a distance effect on SoA. Our reassessment provides alternative explanations that converge with available evidence suggesting that distance may influence temporal interval perception, but that effect is independent of action intention and therefore of agency. Public Significance Statement: In our increasingly connected world, we often interact with devices and influence events that are physically distant from us - like controlling smart appliances remotely or engaging in virtual reality experiences. Does the distance between us and the effects of our actions change how much we feel in control of the outcomes of our actions? Recent studies have suggested that we feel less responsible when action outcomes appear in far space compared to near space. However, methodological limitations in these studies, as well as our own results with a similar paradigm, challenge the validity of this claim. We aim to contribute to the crucial debate on the role of spatial distance on humans' feeling of responsibility by providing a respectful though critical analysis of recent findings and offering recommendations for future research.