Neuroscience of Consciousness最新文献

This article presents a neuroscientific interpretation of Carl Jung's theory of archetypes and their experience in altered states of consciousness. We begin by rehearsing the Free Energy Principle and Predictive Processing as foundational frameworks that subserve and inform the thesis that follows. The following sections examine three aspects of archetypes: the affective core rooted in subcortical systems, archetypal imagery emergent in altered states such as psychedelic experiences, and archetypal stories encoded in higher cortical areas. Specifically, we propose a trilogical interplay between the high-level cortex, the low-level cortex, and subcortical/affective systems in instantiating these archetypal phenomena. We then explore how archetypes may be transmitted between individuals, developing into a collective unconscious through social learning and subsequent attunement. Throughout, we provide syntheses of Jungian psychology with contemporary neuroscience, offering testable hypotheses regarding the neurological bases of archetypal phenomena. We conclude by discussing implications for both psychoanalytic theory and neuroscientific research. By bridging these disciplines, we aim to lend construct validity to Jungian concepts and encourage further empirical investigation of archetypes and the collective unconscious.

Theoretical accounts link mind wandering with attentional and executive processes, both of which exhibit time-of-day fluctuations influenced by chronotype. While previous studies have proposed increased mind wandering at nonpreferred times of the day, these findings come from methodologically limited designs. Using ecological momentary assessment (EMA), we revisited this hypothesis and examined how mind wandering is associated with time of day and chronotype, hypothesizing that mind wandering would be more likely to occur during nonpreferred times of the day. Additionally, we took an exploratory approach and investigated previously unexplored daily fluctuations in temporal orientations of mind wandering in different chronotypes. A total of 152 participants were involved in an EMA, rendering a total of 13 001 successfully completed samples. Generalized linear and linear mixed models were employed to investigate the associations between chronotype, time of day, mind wandering, and its temporal orientations. A pronounced time-of-day dynamic was observed, pointing to a gradually decreasing probability of mind wandering over the course of the day; however, no chronotype synchrony effect was observed. Daily dynamics of the temporal orientation of mind wandering were significantly predicted by chronotype. While eveningness was associated with an increase in the proportion of future-oriented thoughts and a decrease in that of present-oriented thoughts throughout the day, the opposite was found for morningness. These findings suggest that time of day is associated with the probability of mind wandering and its temporal orientation, the latter moderated by an individual's chronotype.

It is well known that in interdisciplinary consciousness studies there are various competing hypotheses about the neural correlate(s) of consciousness (NCCs). Much contemporary work is dedicated to determining which of these hypotheses is right (or the weaker claim is to be preferred). The prevalent working assumption is that one of the competing hypotheses is correct, and the remaining hypotheses misdescribe the phenomenon in some critical manner and their associated purported empirical evidence will eventually be explained away. In contrast to this, we propose that each hypothesis-simultaneously with its competitors-may be right and its associated evidence be genuine evidence of NCCs. To account for this, we develop the multiple generator hypothesis (MGH) based on a distinction between principles and generators. The former denotes ways consciousness can be brought about and the latter how these are implemented in physical systems. We explicate and delineate the hypothesis and give examples of aspects of consciousness studies where the MGH is applicable and relevant. Finally, to show that it is promising we show the MGH has implications which give rise to novel questions or aspects to consider for the field of consciousness studies.

The role of the prefrontal cortex (PFC) in consciousness is hotly debated. Frontal theories argue that the PFC is necessary for consciousness, while sensory theories propose that consciousness arises from recurrent activity in the posterior cortex alone, with activity in the PFC resulting from the mere act of reporting. To resolve this dispute, we re-analysed an electroencephalography (EEG) dataset of 30 participants from a no-report inattentional blindness paradigm where faces are (un)consciously perceived. We performed source reconstruction on the EEG data to first establish the robustly active regions, which were then used to build the networks in the dynamic causal modelling analysis. Dynamic causal modelling was used to estimate the effective connectivity between the key contended brain regions, the prefrontal and the posterior cortices. Then, a second-level parametric empirical Bayesian model was conducted to determine how connectivity was modulated by awareness and task-relevance. While an initial data-driven search could not corroborate neither sensory nor frontal theories of consciousness, a more directed hypothesis-driven analysis revealed strong evidence that both theories could explain the data, with a very slight preference for frontal theories. Specifically, a model with backward connections switched off within the posterior cortex explained awareness better (53%) than a model without backward connections from the PFC to sensory regions. Our findings provide some support for a subtle, yet crucial, contribution of the frontal cortex in consciousness, and highlight the need to revise current theories of consciousness.

A major distinction in early visual processing is the magnocellular (MC) and parvocellular (PC) pathways. Prior work has theorized that the PC pathway more strongly contributes to conscious object recognition via projections to the ventral ``what'' visual pathway, whereas the MC pathway underlies non-conscious, action-oriented motion and localization processing via the dorsal stream ``where/how'' pathway. This invites the question: are we equally aware of activity in both pathways? And if not, do task demands interact with which pathway is more accessible to awareness? We investigated this question in a set of two studies measuring participants' metacognition for stimuli biased toward MC or PC processing. The "Steady/Pulsed Paradigm" has two conditions that present brief stimuli alongside temporally distinct luminance pedestals, thought to bias stimulus processing to either pathway. Experiment 1 was a spatial localization task thought to rely on information relayed from the MC pathway. Using both a model-based and model-free approach to quantify participants' metacognitive sensitivity to their own task performance, we found greater metacognitive efficiency in the steady (MC-biased) condition compared to the pulsed (PC-biased) condition. Experiment 2 was a fine-grained orientation-discrimination task more reliant on PC pathway information. Our results show an abolishment of the MC pathway advantage seen in Experiment 1 and suggest that the advantage in metacognitive efficiency for MC processing may hold for stimulus localization tasks only. More generally, our results highlight the need to consider the possibility of differential access to low-level stimulus properties in studies of visual metacognition.

The signals registered by our senses are inherently ambiguous. Subjective experience, by contrast, is informative: it portrays one's interpretation of the sensory environment at a time while discarding competing alternatives. This is exemplified by bistable perception, where ambiguous sensory information induces prolonged intervals of alternating unambiguous perceptual states. According to neurocomputational predictive-processing accounts of bistable perception, perceptual experiences in the recent past constitute a predictive context that stabilizes perception, while sensory information in conflict with this predictive temporal context evokes perceptual prediction errors. These perceptual prediction errors are thought to drive spontaneous perceptual switches. In this study, we compared neural correlates of perceptual conflicts induced by violations of temporal context to conflicts induced by spatial context. To this aim, we used functional magnetic resonance imaging and a bistable perception paradigm with temporal and spatial context modulation. Twenty-six healthy participants viewed intermittent presentations of ambiguous structure-from-motion stimuli either in isolation (conflict with temporal context) or embedded in a similar but unambiguous surround stimulus (conflict with spatial context). Only the anterior insula bilaterally showed brain activation associated with both types of perceptual conflict. Approximate perceptual prediction errors derived from generalized linear mixed-effects models yielded signals in the anterior insula bilaterally, the right inferior frontal gyrus, and the right inferior parietal lobe. Together, these findings point to a key role of the anterior insular cortex in detecting perceptual conflicts and thus in the construction of unambiguous perceptual experiences.

When the eyes view separate and incompatible images, the brain suppresses one image-removing it from visual awareness. A popular paradigm for doing this is continuous flash suppression (CFS). One eye views a static 'target', the other is presented with a complex dynamic stimulus which very effectively suppresses the target. Measuring the time needed for the suppressed target to break suppression as it slowly increases in contrast (bCFS) has been widely used to investigate unconscious processing and the results have generated controversy regarding the scope of visual processing without awareness. In particular, upright faces and fearful faces have been claimed to have priority access to awareness. Here, we address this controversy with a new 'CFS tracking' paradigm (tCFS) in which the suppressed monocular target steadily increases in contrast until breaking into awareness (as in bCFS) after which it decreases until it becomes suppressed again (reCFS), with this cycle continuing for many reversals. Unlike bCFS, tCFS provides measures of breakthrough thresholds as well as suppression thresholds, and the difference between breakthrough and suppression thresholds defines the important metric of 'suppression depth'. The suppression depth results over two experiments are consistent in showing no face inversion effects (i.e. no priority for upright faces relative to inverted) and no effect of emotion (no priority for fearful faces relative to happy or neutral). Given this consistent non-selectivity, we conclude that CFS elicits a strong suppression in early visual cortex at a level preceding face processing.

Fluctuations in the presence, experiential quality and contents of consciousness occur naturally during sleep and wakefulness and are core features of the healthy human mind. The purpose of this article is to consider the possibility that such fluctuations, including mind wandering and dreaming, which we refer to collectively as spontaneous thoughts and experiences (STE), may also be important elements of experience in certain patients with disorders of consciousness (DoC). The presence of these states may have urgent implications for DoC diagnosis, which centres on the detection of consciousness. Furthermore, learning more about STE in DoC may provide insight into subjective experience and quality of life in DoC, about which little is currently known. Given the challenges that exist in studying conscious experience in this population, much of the evidence about STE we consider is indirect and involves triangulation from the healthy population and other brain-injured patients. The evidence we consider is inconclusive, but it indicates that the occurrence of mind wandering and dreaming in DoC is a real possibility that, because of its important implications in these patients, requires further research. We argue that, given the possible life-or-death consequences of diagnosis in DoC, it is of pressing importance to use diagnostic measures that are sensitive to these internally directed forms of conscious experience. We also consider some lines of research that may deepen our understanding of STE in DoC, and how further knowledge about these states may impact inferences about quality of life in this population.

Integrated information theory (IIT) offers an axiomatic framework based on phenomenological properties, allowing the quantification and characterization of consciousness through a measure known as Φ. According to IIT, Φ reflects the level of consciousness and is expected to decrease with loss of consciousness, although empirical data supporting this claim remain limited. In this study, we analyzed two functional magnetic resonance imaging (fMRI) datasets acquired during anesthesia (propofol-induced) and natural sleep to determine whether Φ changes with the loss and recovery of consciousness. Our analysis was conducted using the fourth version of IIT. We constructed systems composed of five functional brain networks, computed transition probability matrices from fMRI time series data, and derived Φ values based on these matrices. As predicted by IIT, Φ decreased during anesthesia-induced loss of consciousness at both global and local levels. Similarly, Φ was locally reduced within a system centered on posterior brain regions during sleep-induced loss of consciousness. Considering functional networks as system units, we found that the integrated information (Φ) of the brain is linked to fluctuations in consciousness levels. These findings indicate a strong association between consciousness and integrated information within the large-scale functional networks.