A key aspect of consciousness is that it represents bound or integrated information, prompting an increasing conviction that the physical substrate of consciousness must be capable of encoding integrated information in the brain. However, as Ralph Landauer insisted, 'information is physical' so integrated information must be physically integrated. I argue here that nearly all examples of...
The Dream Catcher test defines the criteria for a genuine discovery of the neural constituents of phenomenal consciousness. Passing the test implies that some patterns of purely brain-based data directly correspond to the subjective features of phenomenal experience, which would help to bridge the explanatory gap between consciousness and brain. Here, we conducted the Dream Catcher test for the...
Abstract The regulatory role of the serotonergic system on conscious perception can be investigated perturbatorily with psychedelic drugs such as N,N-Dimethyltryptamine. There is increasing evidence that the serotonergic system gates prior (endogenous) and sensory (exogenous) information in the construction of a conscious experience. Using two generative deep neural networks as examples, we...
In 'REBUS and the Anarchic Brain: Towards a Unified Model of the Brain Action of Psychedelics', Carhart-Harris and Friston offer an important analysis of what the predictive processing framework has to offer our understanding of psychedelic experiences, providing an invaluable ground for psychedelic psychiatry. While applauding this, we encourage paying greater attention to contextual factors...
Abstract The subjective features of psychological phenomena have been studied intensively in experimental science in recent years. Although various methods have been proposed to identify subjective features of psychological phenomena, there are elusive subjective features such as the spatiotemporal structure of experience, which are difficult to capture without some additional methodological...
The sense of agency is typically defined as the experience of controlling one's own actions, and through them, changes in the external environment. It is often assumed that this experience is a single, unified construct that can be experimentally manipulated and measured in a variety of ways. In this article, we challenge this assumption. We argue that we should acknowledge four possible...
Abstract Bayne and Carter argue that the mode of consciousness induced by psychedelic drugs does not fit squarely within the traditional account of modes as levels of consciousness, and favors instead a multi-dimensional account according to which modes of consciousness differ along several dimensions—none of which warrants a linear ordering of modes. We discuss the assumption that psychedelic...
Abstract: Abundant evidence from slow wave sleep, anesthesia, coma, and epileptic seizures links high-voltage, slow electroencephalogram (EEG) activity to loss of consciousness. This well-established correlation is challenged by the observation that children with Angelman syndrome (AS), while fully awake and displaying volitional behavior, display a hypersynchronous delta (1–4 Hz) frequency EEG...
Abstract The association between neural oscillations and functional integration is widely recognized in the study of human cognition. Large-scale synchronization of neural activity has also been proposed as the neural basis of consciousness. Intriguingly, a growing number of studies in social cognitive neuroscience reveal that phase synchronization similarly appears across brains during...
Perceptual filling-in (PFI) occurs when a physically present visual target disappears from conscious perception, with its location filled-in by the surrounding visual background. These perceptual changes are complete, near instantaneous, and can occur for multiple separate locations simultaneously. Here, we show that contrasting neural activity during the presence or absence of multi-target PFI...
For the materialist, the hard problem is fundamentally an explanatory problem. Solving it requires explaining why the relationship between brain and experience is the way it is and not some other way. We use the tools of the interventionist theory of explanation to show how a systematic experimental project could help move beyond the hard problem. Key to this project is the development of...
Abstract An increasing amount of studies suggest that brain dynamics measured with resting-state functional magnetic resonance imaging (fMRI) are related to the state of consciousness. However, the challenge of investigating neuronal correlates of consciousness is the confounding interference between (recovery of) consciousness and behavioral responsiveness. To address this issue, and validate...
In a recent opinion piece, Abid (2019) criticizes the hypothesis that subjective inflation may partly account for apparent phenomenological richness across the visual field and outside the focus of attention. In response, we address three main issues. First, we maintain that inflation should be interpreted as an intraperceptual-and not post-perceptual-phenomenon. Second, we describe how...
Abstract This article discusses a hypothesis recently put forward by Kanai et al., according to which information generation constitutes a functional basis of, and a sufficient condition for, consciousness. Information generation involves the ability to compress and subsequently decompress information, potentially after a temporal delay and adapted to current purposes. I will argue that...
All of us involved in the mind and brain sciences, in whatever capacity, are increasingly aware of the importance of ensuring the credibility of our research. This credibility—which for experimental work turns on its reliability—is particularly salient for consciousness research, given the at-times precarious perception of consciousness science within the wider landscapes of psychology and...
Based on its ability to increase brain complexity, a seemingly reliable index of conscious level, we propose testing the capacity of the classic psychedelic, psilocybin, to increase conscious awareness in patients with disorders of consciousness. We also confront the considerable ethical and practical challenges this proposal must address, if this hypothesis is to be directly assessed.
This article provides an ethical analysis of psychedelic research involving disorders of consciousness patients. We apply two internationally accepted approaches for analyzing the ethics of human research, the Value-Validity Framework and Component Analysis, to a research program recently proposed by Scott and Carhart-Harris. We focus on Scott and Carhart-Harris's proposal, but the ethical...
Some people report memories of near-death experiences (NDEs) after facing situations of impending death and these memories appear to have significant consequences on their lives (here referred to as “real NDE experiencers”; real NDErs). We assessed to what extent NDE memories are considered self-defining: memories that help people to define clearly how they see themselves. We screened 71...
Nielsen proposes that a microdynamic approach to experiences occurring in the earliest stages of sleep onset, which he calls microdreams, can shed light on the process of dream imagery formation. I discuss microdreams in the context of simulation views, in which dreaming is defined as the immersive experience of a virtual world centered on a virtual self. I also evaluate his proposal to expand...
Is consciousness a continuous stream, or do percepts occur only at certain moments of time? This age-old question is still under debate. Both positions face difficult problems, which we proposed to overcome with a 2-stage model, where unconscious processing continuously integrates information before a discrete, conscious percept occurs. Recently, Fekete et al. criticized our model. Here, we...
Subjective experience can be influenced by top-down factors, such as expectations and stimulus relevance. Recently, it has been shown that expectations can enhance the likelihood that a stimulus is consciously reported, but the neural mechanisms supporting this enhancement are still unclear. We manipulated stimulus expectations within the attentional blink (AB) paradigm using letters and...
What is the biological advantage of having consciousness? Functions of consciousness have been elusive due to the subjective nature of consciousness and ample empirical evidence showing the presence of many nonconscious cognitive performances in the human brain. Drawing upon empirical literature, here, we propose that a core function of consciousness be the ability to internally generate...
It has often been suggested in the popular and academic literature that the psychedelic state qualifies as a higher state of consciousness relative to the state of normal waking awareness. This article subjects this proposal to critical scrutiny, focusing on the question of what it would mean for a state of consciousness to be 'higher'. We begin by considering the contrast between conscious...
A recently proposed model of sensory processing suggests that perceptual experience is updated in discrete steps. We show that the data advanced to support discrete perception are in fact compatible with a continuous account of perception. Physiological and psychophysical constraints, moreover, as well as our awake-primate imaging data, imply that human neuronal networks cannot support discrete...
The ability to respond to hypnotic suggestibility (hypnotizability) is a stable trait which can be measured in a standardized procedure consisting of a hypnotic induction and a series of hypnotic suggestions. The SWASH is a 10-item adaptation of an established scale, the Waterloo-Stanford Group C Scale of Hypnotic Suggestibility (WSGC). Development of the SWASH was motivated by three distinct...