This essay addresses Cartesian duality and how its implicit dialectic might be repaired using physics and information theory. Our agenda is to describe a key distinction in the physical sciences that may provide a foundation for the distinction between mind and matter, and between sentient and intentional systems. From this perspective, it becomes tenable to talk about the physics of sentience and ‘forces’ that underwrite our beliefs (in the sense of probability distributions represented by our internal states), which may ground our mental states and consciousness. We will refer to this view as Markovian monism, which entails two claims: (1) fundamentally, there is only one type of thing and only one type of irreducible property (hence monism). (2) All systems possessing a Markov blanket have properties that are relevant for understanding the mind and consciousness: if such systems have mental properties, then they have them partly by virtue of possessing a Markov blanket (hence Markovian). Markovian monism rests upon the information geometry of random dynamic systems. In brief, the information geometry induced in any system—whose internal states can be distinguished from external states—must acquire a dual aspect. This dual aspect concerns the (intrinsic) information geometry of the probabilistic evolution of internal states and a separate (extrinsic) information geometry of probabilistic beliefs about external states that are parameterised by internal states. We call these intrinsic (i.e., mechanical, or state-based) and extrinsic (i.e., Markovian, or belief-based) information geometries, respectively. Although these mathematical notions may sound complicated, they are fairly straightforward to handle, and may offer a means through which to frame the origins of consciousness.

Dreams and psychosis share several important features regarding symptoms and underlying neurobiology, which is helpful in constructing a testable model of, for example, schizophrenia and delirium. The purpose of the present communication is to discuss two major concepts in dreaming and psychosis that have received much attention in the recent literature: insight and dissociation. Both phenomena are considered functions of higher order consciousness because they involve metacognition in the form of reflective thought and attempted control of negative emotional impact. Insight in dreams is a core criterion for lucid dreams. Lucid dreams are usually accompanied by attempts to control the dream plot and dissociative elements akin to depersonalization and derealization. These concepts are also relevant in psychotic illness. Whereas insightfulness can be considered innocuous in lucid dreaming and even advantageous in psychosis, the concept of dissociation is still unresolved. The present review compares correlates and functions of insight and dissociation in lucid dreaming and psychosis. This is helpful in understanding the two concepts with regard to psychological function as well as neurophysiology.

Ponto-Geniculo-Occipital (PGO) waves are biphasic field potentials identified in a range of mammalian species that are ubiquitous with sleep, but can also be identified in waking perception and eye movement. Their role in REM sleep and visual perception more broadly may constitute a promising avenue for further research, however what was once an active field of study has recently fallen into stasis. With the reality that invasive recordings performed on animals cannot be replicated in humans; while animals themselves cannot convey experience to the extent required to elucidate how PGO waves factor into awareness and behavior, innovative solutions are required if significant research outcomes are to ever be realized. Advances in non-invasive imaging technologies and sophistication in imaging methods now offer substantial scope to renew the study of the electrophysiological substrates of waking and dreaming perception. Among these, Magnetoencephalogram (MEG) stands out through its capacity to measure deep brain activations with high temporal resolution. With the current trend in sleep and dream research to produce translational findings of psychopathological and medical significance, in addition to the clear links that PGO wave generation sites share, pharmacologically, with receptors involved in expression of mental illness; there is a strong case to support scientific research into PGO waves and develop a functional understanding of their broader role in human perception.

This article offers a formal account of curiosity and insight in terms of active (Bayesian) inference. It deals with the dual problem of inferring states of the world and learning its statistical structure. In contrast to current trends in machine learning (e.g., deep learning), we focus on how people attain insight and understanding using just a handful of observations, which are solicited through curious behavior. We use simulations of abstract rule learning and approximate Bayesian inference to show that minimizing (expected) variational free energy leads to active sampling of novel contingencies. This epistemic behavior closes explanatory gaps in generative models of the world, thereby reducing uncertainty and satisfying curiosity. We then move from epistemic learning to model selection or structure learning to show how abductive processes emerge when agents test plausible hypotheses about symmetries (i.e., invariances or rules) in their generative models. The ensuing Bayesian model reduction evinces mechanisms associated with sleep and has all the hallmarks of “aha” moments. This formulation moves toward a computational account of consciousness in the pre-Cartesian sense of sharable knowledge (i.e., con: “together”; scire: “to know”).

Chapter 9 States of Consciousness Waking, Sleeping, and Dreaming J. Allan Hobson, J. Allan HobsonSearch for more papers by this author J. Allan Hobson, J. Allan HobsonSearch for more papers by this author Book Editor(s):Susan Schneider, Susan SchneiderSearch for more papers by this authorMax Velmans, Max VelmansSearch for more papers by this author First published: 17 March 2017 https://doi.org/10.1002/9781119132363.ch9Citations: 1 AboutPDFPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShareShare a linkShare onFacebookTwitterLinked InRedditWechat Summary Consciousness undergoes dramatic and stereotyped changes in parallel with changes in brain state over the sleep-wake cycle. No change is more striking or more informative than that which differentiates waking and REM sleep dreaming. For example, dreaming is characterized by internally generated perceptions, by false beliefs, by cognitive impairments, by emotional intensification, and by amnesia. When they occur in waking, these formal state features characterize what is called mental illness. Because the underlying changes in brain state are well described, it is possible to create a model which links the formal features of the mental state to changes in brain physiology and chemistry. The resulting synthesis of conscious state phenomenology and brain neurophysiology provides a solid foundation for mind-body integration in both normal and abnormal conditions. Citing Literature The Blackwell Companion to Consciousness, Second Edition RelatedInformation

Consciousness, Dreams, and Inference : The Cartesian Theatre Revisited. This paper considers the Cartesian theatre as a metaphor for the virtual reality models that the brain uses to make inferences about the world. This treatment derives from our attempts to understand dreaming and waking consciousness in terms of free energy minimization. The idea here is that the Cartesian theatre is not observed by an internal (homuncular) audience but furnishes a theatre in which fictive narratives and fantasies can be rehearsed and tested against sensory evidence. We suppose the brain is driven by the imperative to infer the causes of its sensory samples ; in much the same way as scientists are compelled to test hypotheses about experimental data. This recapitulates Helmholtz’s notion of unconscious inference and Gregory’s treatment of perception as hypothesis testing. However, we take this further and consider the active on our virtual reality. The ensuing picture of consciousness (or active inference) resolves a number of seemingly hard problems in consciousness research and is internally consistent with current thinking in systems neuroscience and theoretical neurobiology. In this formalism, there is a dualism that distinguishes between the (conscious) process of inference and the (material) process that entails inference. This separation is reflected by the distinction between beliefs (probability distributions over hidden world states or res cogitans) and the physical brain states (sufficient statistics or res extensa) that encode them. This formal approach allows us to appeal to simple but fundamental theorems in information theory and statistical thermodynamics that dissolve some of the mysterious aspects of consciousness.

We would like to thank Dolega and Dewhurst (2015) for a thought-provoking and informed deconstruction of our article, which we take as (qualified) applause from valued members of our audience. In brief we fully concur with the theatre-free formulation offered by Dolega and Dewhurst and take the opportunity to explain why (and how) we used the Cartesian theatre metaphor. We do this by drawing an analogy between consciousness and evolution. This analogy is used to emphasize the circular causality inherent in the free energy principle (aka active inference). We conclude with a comment on the special forms of active inference that may be associated with self-awareness and how they may be especially informed by dream states.

Subjective reports have supported the assumption that dream sleep and waking manifest differences that correlate with the neurobiological bases of the 2 conscious states. These differences should appear in the quality and quantity of cognition and reasoning. Using the affirmative probe method, we compared quantity, recognition and consequences (logic reasoning) of unusual events (bizarre, unreal, irrational, and not possible in reality) during dreaming and waking. In 2 studies, students created dream and waking reports, and indicated unusual events and their cognitive processing. While dreaming, significantly more unusual events occurred than while waking. During waking, almost all unusual events were recognized as such, whereas while dreaming only 21% of unusual events were identified. Thoughts about the logical (in) consistency of the events were significantly fewer while dreaming than while waking, but, if the situation elicited logical reasoning, consequential behavior was initiated equally often. Our results, therefore, support the notion of qualitatively different states of consciousness during dreaming and waking.

The idea that dreaming can serve as a model for psychosis has a long and honourable tradition, however it is notoriously speculative. Here we demonstrate that recent research on the phenomenon of lucid dreaming sheds new light on the debate. Lucid dreaming is a rare state of sleep in which the dreamer gains insight into his state of mind during dreaming. Recent electroencephalogram (EEG) and functional magnetic resonance imaging (fMRI) data for the first time allow very specific hypotheses about the dream–psychosis relationship: if dreaming is a reasonable model for psychosis, then insight into the dreaming state and insight into the psychotic state should share similar neural correlates. This indeed seems to be the case: cortical areas activated during lucid dreaming show striking overlap with brain regions that are impaired in psychotic patients who lack insight into their pathological state. This parallel allows for new therapeutic approaches and ways to test antipsychotic medication.

In “What is the state-of-the-art on lucid dreaming? Recent advances and questions for future research”, Ursula Voss and Allan Hobson provide a detailed view of the features characterizing lucid dreaming and put forward four innovative hypotheses to explain why and how lucid dreaming occurs, as well as how lucid dream states are related to other states of consciousness. Their aim is to show that not only is there benefit to studying lucid dreaming in itself, as this would give us a deeper understanding of dream consciousness, but also that it is an important endeavor because of the kind of conscious state lucid dreaming is. To be sure, Voss and Hobson make important in-roads into the empirical study of lucid dreaming that ought to sprout new and exciting research in the area. As I will show, however, there remains much conceptual work to be done. In this commentary I tease out three aspects of Voss and Hobson’s view that would greatly benefit from philosophical consideration. First, I highlight the lingering confusion with what exactly insight is, and I point to how one might go about clarifying this notion. Second, I argue that our understanding of insight and meta-awareness in lucid dreaming could be greatly increased by looking at how these concepts are used and understood in relation to meditative states. Last, I explore the role of the body in lucid dreaming and argue that one’s bodily awareness in lucid dreams is far more multi-faceted than at it might at first seem.

This article argues both rapid eye movement (REM) and non-rapid eye movement (NREM) sleep contribute to overnight episodic memory processes but their roles differ. Episodic memory may have evolved from memory for spatial navigation in animals and humans. Equally, mnemonic navigation in world and mental space may rely on fundamentally equivalent processes. Consequently, the basic spatial network characteristics of pathways which meet at omnidirectional nodes or junctions may be conserved in episodic brain networks. A pathway is formally identified with the unidirectional, sequential phases of an episodic memory. In contrast, the function of omnidirectional junctions is not well understood. In evolutionary terms, both animals and early humans undertook tours to a series of landmark junctions, to take advantage of resources (food, water and shelter), whilst trying to avoid predators. Such tours required memory for emotionally significant landmark resource-place-danger associations and the spatial relationships amongst these landmarks. In consequence, these tours may have driven the evolution of both spatial and episodic memory. The environment is dynamic. Resource-place associations are liable to shift and new resource-rich landmarks may be discovered, these changes may require re-wiring in neural networks. To realise these changes, REM may perform an associative, emotional encoding function between memory networks, engendering an omnidirectional landmark junction which is instantiated in the cortex during NREM Stage 2. In sum, REM may preplay associated elements of past episodes (rather than replay individual episodes), to engender an unconscious representation which can be used by the animal on approach to a landmark junction in wake.

Click to increase image sizeClick to decrease image size Additional informationNotes on contributorsJ. Allan HobsonJ. Allan Hobson, M.D., is Professor of Psychiatry Emeritus at Harvard Medical School, Boston, Massachusetts. He was born in Hartford, Connecticut, on June 3, 1933, and obtained an AB degree from Wesleyan University in 1955, followed by his M.D. from Harvard Medical School in 1959. Between 1959 and 1960 he served his internship in medicine at Bellevue Hospital, New York, and from 1960 to 1961 and 1964 to 1966, he was a resident in Psychiatry at Massachusetts Mental Health Center, Boston. From 1962 to 1963, Hobson was a clinical scientist at the National Institute of Mental Health. During the academic year 1963−1964, Hobson was Special Fellow of the National Institute of Mental Health, Department of Physiology at the University of Lyon, France.His successful career has brought Hobson many honors and awards including admission to the Boylston Medical Society and the Benjamin Rush Gold Medal for Best Scientific Exhibit, American Psychiatrist Association, 1978. He was the recipient of the 1998 Distinguished Scientist Award of the Sleep Research Society. In addition to several committee assignments at Harvard Medical School, Hobson has participated in numerous national and regional medical committees and served on the editorial boards of many medical journals. He has held many consulting appointments including Consultant in Psychiatry for the Massachusetts Rehabilitation Commission since 1965. In 2004, Hobson received the Peter Farrell Prize from the Division of Sleep Medicine, Harvard Medical School, for his lifetime dedication to sleep research at Harvard.His major research interests are the neurophysiological basis of the mind and behavior, sleep and dreaming, and the history of neurology and psychiatry. He has contributed numerous articles to scientific journals and chapters to medical textbooks and is the author or co-author of many books and monographs, including The Dreaming Brain (Basic Books, 1988) and Sleep (Scientific American Library, 1989). Hobson's work has focused on the cognitive features and benefits of sleep. The results and concepts of this work are reported in The Chemistry of Conscious States (Little Brown, 1994), Consciousness (Scientific American Library, 1998), Dreaming as Delirium (MIT Press, 1999), The Dream Drugstore (MIT Press, 2001), Out of Its Mind: Psychiatry in Crisis (Perseus Books, 2001), Dreaming: An Introduction to Sleep Science (Oxford, 2002), 13 Dreams Freud Never Had (Pi Press, 2005), Angels to Neurones (Mattioli 1885, 2005), Dream Life: An Experimental Memoir (MIT Press, 2011), Psychodynamic Neurology: Dreams, Consciousness, and Virtual Reality (CRC Press, 2014), Ego Damage and Repair (Karnac, 2014), and Dream Consciousness: Allan Hobson's New Approach to the Brain and Its Mind (Springer, 2014).