Consciousness and Neuroscience

While dreaming amputees often experience a normal body image and the phantom limb may not be present. However, dreaming experiences in amputees have mainly been collected by questionnaires. We analysed the dream reports of amputated patients with phantom limb collected after awakening from REM sleep during overnight videopolysomnography . Six amputated patients underwent overnight VPSG study. Patients were awakened during REM sleep and asked to report their dreams. Three patients were able to deliver an account of a dream. In all (...) dreaming recalls, patients reported that the amputated limbs were intact and completely functional and they no longer experienced phantom limb sensations. Phantom limb experiences, that during wake result from a conflict between a pre-existing body scheme and the sensory information on the missing limb, were suppressed during sleep in our patients in favour of the image of an intact body accessed during dream. (shrink)

Primatologists generally agree that monkeys lack higher-order intentional capacities related to theory of mind. Yet the discovery of the so-called "mirror neurons" in monkeys suggests to many neuroscientists that they have the rudiments of intentional understanding. Given a standard philosophical view about intentional understanding, which requires higher-order intentionahty, a paradox arises. Different ways of resolving the paradox are assessed, using evidence from neural, cognitive, and behavioral studies of humans and monkeys. A decisive resolution to the paradox requires substantial additional empirical (...) work and perhaps a rejection of the standard philosophical view. (shrink)

This paper explores the changes in cognitive function which occur as someone "loses consciousness" under anesthesia. Seven volunteers attempted a categorization task and a within-list recognition test while inhaling air, 0.2% isoflurane, and 0.4% isoflurane. In general, performance on these tests declined as the dose of anesthetic was increased and returned to baseline after 10 min of breathing air. A measure of auditory evoked responding termed "coherent frequency" showed parallel changes. At 0.2% isoflurane, subjects could still identify and respond to (...) category exemplars but showed impaired short-term memory function. Electrical stimulation at 0.4% isoflurane, intended to mimic the arousing effects of surgery, had a small, beneficial effect on performance. A mean of 63% of category exemplars was identified at this stage, but recognition memory for those exemplars was at chance on recovery. There was no evidence for learning of words presented at 0.8% isoflurane. (shrink)

Neural organization: Structure, function, and dynamics shows how theory and experiment can supplement each other in an integrated, evolving account of the brain's structure, function, and dynamics. (1) Structure: Studies of brain function and dynamics build on and contribute to an understanding of many brain regions, the neural circuits that constitute them, and their spatial relations. We emphasize Szentágothai's modular architectonics principle, but also stress the importance of the microcomplexes of cerebellar circuitry and the lamellae of hippocampus. (2) Function: Control (...) of eye movements, reaching and grasping, cognitive maps, and the roles of vision receive a functional decomposition in terms of schemas. Hypotheses as to how each schema is implemented through the interaction of specific brain regions provide the basis for modeling the overall function by neural networks constrained by neural data. Synthetic PET integrates modeling of primate circuitry with data from human brain imaging. (3) Dynamics: Dynamic system theory analyzes spatiotemporal neural phenomena, such as oscillatory and chaotic activity in both single neurons and (often synchronized) neural networks, the self-organizing development and plasticity of ordered neural structures, and learning and memory phenomena associated with synaptic modification. Rhythm generation involves multiple levels of analysis, from intrinsic cellular processes to loops involving multiple brain regions. A variety of rhythms are related to memory functions. The Précis presents a multifaceted case study of the hippocampus. We conclude with the claim that language and other cognitive processes can be fruitfully studied within the framework of neural organization that the authors have charted with John Szentágothai. Key Words: cognitive maps; computational neuroscience; dynamics; hippocampus; memory; modular architectonics; neural modeling; neural organization; neural plasticity; rhythmogenesis; Szentágothai. (shrink)

What makes us conscious? Many theories that attempt to answer this question have appeared recently in the context of widespread interest about consciousness in the cognitive neurosciences. Most of these proposals are formulated in terms of the information processing conducted by the brain. In this overview, we survey and contrast these models. We first delineate several notions of consciousness, addressing what it is that the various models are attempting to explain. Next, we describe a conceptual landscape that addresses how the (...) theories attempt to explain consciousness. We then situate each of several representative models in this landscape and indicate which aspect of consciousness they try to explain. We conclude that the search for the neural correlates of consciousness should be usefully complemented by a search for the computational correlates of consciousness. (shrink)

This is not the usual kind of self-help book. Indeed, its major premise heeds a Zen master's advice to be _less_ self-centered. Yes, it is "one more book of words about Zen," as the author concedes, yet this book explains meditative practices from the perspective of a " _neural_ Zen." The latest findings in brain research inform its suggestions. In _Meditating Selflessly_, James Austin -- Zen practitioner, neurologist, and author of three acclaimed books on Zen and neuroscience -- guides readers (...) toward that open awareness already awaiting them on the cushion and in the natural world. Austin offers concrete advice -- often in a simplified question-and-answer format -- about different ways to meditate. He clarifies both the concentrative and receptive styles of meditation. Drawing widely from the exciting new field of contemplative neuroscience, Austin helps resolve an ancient paradox: why both insight wisdom _and_ selflessness arise simultaneously during enlightened states of consciousness. (shrink)

The qualitative and quantitative properties of color sensations and neuronal color coding are discussed in relation to physiological color exchanges and their evolutionary constraints. Based on the identity mind/matter thesis, additional physical measurements on color sensations are described that will allow us, at least in principle, to compare the qualitative properties of color sensations in different brains.

Cognitive control is not only componential, but those components may interact in complicated ways in the service of cognitive control tasks. This complexity poses a challenge for developing an ontological description, because the mapping may not be direct between our task descriptions and true component differences reflected in indicators. To illustrate this point, I discuss two examples: (a) the relationship between adaptive gating and working memory and (b) the recent evidence for a control hierarchy. From these examples, I argue that (...) an ontological program must simultaneously seek to identify component processes and their interactions within a broader processing architecture. (shrink)

The phenomenon of consciousness has always been a central question for philosophers and scientists. Emerging in the past decade are new approaches to the understanding of consciousness in a scientific light. This book presents a series of essays by leading thinkers giving an account of the current ideas prevalent in the scientific study of consciousness. The value of the book lies in the discussion of this interesting though complex subject from different points of view ranging from physics, computer science to (...) the cognitive sciences. Reviews of controversial ideas related to the philosophy of mind from western and eastern sources including classical Indian first person methodologies provide a breadth of coverage that has seldom been attempted in a book before. Additionally, chapters relating to the new approaches in computational modelling of higher order cognitive function and consciousness are included. The book is of great value for established as well as young researchers from a wide cross-section of interdisciplinary scientific backgrounds, aiming to pursue research in this field, as well as an informed public. * Presents the latest developments in the scientific study of consciousness * Critically reviews different theoretical and philosophical explanations related to the subject * An important book for both students and researchers in designing research projects on consciousness. (shrink)

Statistical regularities of the environment are important for learning, memory, intelligence, inductive inference, and in fact, for any area of cognitive science where an information-processing brain promotes survival by exploiting them. This has been recognised by many of those interested in cognitive function, starting with Helmholtz, Mach, and Pearson, and continuing through Craik, Tolman, Attneave, and Brunswik. In the current era, many of us have begun to show how neural mechanisms exploit the regular statistical properties of natural images. Shepard proposed (...) that the apparent trajectory of an object when seen successively at two positions results from internalising the rules of kinematic geometry, and although kinematic geometry is not statistical in nature, this is clearly a related idea. Here it is argued that Shepard's term, “internalisation,” is insufficient because it is also necessary to derive an advantage from the process. Having mechanisms selectively sensitive to the spatio-temporal patterns of excitation commonly experienced when viewing moving objects would facilitate the detection, interpolation, and extrapolation of such motions, and might explain the twisting motions that are experienced. Although Shepard's explanation in terms of Chasles' rule seems doubtful, his theory and experiments illustrate that local twisting motions are needed for the analysis of moving objects and provoke thoughts about how they might be detected. Key Words: Chasles' rule; evolution; geometry; perception; redundancy; statistics; twisting. (shrink)

While Sartre scholars cannot fairly be described as being opposed to science, they have, for the most part, stayed aloof. The field of psychology, of course, has been an exception. Sartre himself felt compelled to present his own existential psychoanalysis by marking the parallels and differences between his position and traditional approaches, particularly the Freudian. The same is true with respect to his concept of bad faith and of emotional behavior. Scholars have followed his lead with richly productive results. But (...) we may note that the debate has centered on psychic and therapeutic issues, aspects of what Sartre called le vécu or lived experience, rather than on the findings of cognitive science or neuroscience. Although all existentialists and phenomenologists accept as a central tenet the fact that consciousness is embodied, there has been virtually no concern with the biological substratum. But the study of consciousness cannot be restricted within its own narrow confines—unlike, say, Greek grammar, which can be learned without reference to the rules of Arabic. At some point, there must be established an organic foundation for the behavior of the conscious organism. (shrink)

While Sartre scholars cannot fairly be described as being opposed to science, they have, for the most part, stayed aloof. The field of psychology, of course, has been an exception. Sartre himself felt compelled to present his own existential psychoanalysis by marking the parallels and differences between his position and traditional approaches, particularly the Freudian. The same is true with respect to his concept of bad faith and of emotional behavior. Scholars have followed his lead with richly productive results. But (...) we may note that the debate has centered on psychic and therapeutic issues, aspects of what Sartre called le vécu or lived experience, rather than on the findings of cognitive science or neuroscience. Although all existentialists and phenomenologists accept as a central tenet the fact that consciousness is embodied, there has been virtually no concern with the biological substratum. But the study of consciousness cannot be restricted within its own narrow confines—unlike, say, Greek grammar, which can be learned without reference to the rules of Arabic. At some point, there must be established an organic foundation for the behavior of the conscious organism. (shrink)

Este libro expone, desde el punto de vista de un antrop logo, los extraordinarios avances de las ciencias dedicadas a explorar el cerebro humano.

Explanation does not exist in a metaphysical vacuum. Conceptions of the structure of a phenomenon play an important role in guiding attempts to explain it, and erroneous conceptions of a phenomenon may direct investigation in misleading directions. I believe that there is a case to be made for thinking that much work on the neural underpinnings of consciousness—what is often called the neural correlates of consciousness—is driven by an erroneous conception of the structure of consciousness. The aim of this paper (...) is lay bare some connections between the explanation of consciousness and the structure of consciousness, and to argue for a conception of the structure of consciousness that is more adequate than that which currently drives much research into the neural correlates of consciousness. (shrink)

Hypnosis appears to generate unusual—and sometimes even astonishing—changes in the contents of consciousness. Hypnotic subjects report perceiving things that are not there, they report not perceiving things that are there, and they report unusual alterations in the phenomenology of agency. In addition to apparent alterations in the contents of consciousness, hypnosis also appears to involve alterations in the structure of consciousness. According to many theorists—most notably Hilgard—hypnosis demonstrates that the unity of consciousness is an illusion (Hilgard 1977).

Given its ubiquitous presence in everyday experience, it is surprising that the phenomenology of doing—the experience of being an agent—has received such scant attention in the consciousness literature. But things are starting to change, and a small but growing literature on the content and causes of the phenomenology of first-person agency is beginning to emerge.2 One of the most influential and stimulating figures in this literature is Daniel Wegner. In a series of papers and his book The Illusion of Conscious (...) Will (ICW) Wegner has developed.. (shrink)

At the start of the 20th century the question of whether life could be explained in purely me- chanical terms was as hotly debated as the mind-body problem is today. Two factions opposed each other: Biological mechanists claimed that the properties characteristic of living organisms could be ex- plained mechanistically, in the way the behavior of a clock can be explained by the properties and the arrangement of its cogs, springs, and weights. Substantial vitalists, on the other hand, maintained that (...) the explanation envisaged by the mechanists was impossible and that one had to postulate a special nonphysical substance in order to explain life. (shrink)

Myin, Erik (2000) Direct Self-Consciousness (2)Bermúdez, José Luis (2000) Concepts and the Priority Principle (10)Bermúdez, José Luis (2000) Circularity, "I"-Thoughts and the Linguistic Requirement for Concept Possession (11)Meeks, Roblin R. (2000) Withholding Immunity: Misidentification, Misrepresentation, and Autonomous Nonconceptual Proprioceptive First-Person Content (12)Newen, Albert (2001) Kinds of Self-Consciousness (13)Bermudez, Jose Luis (2000) Direct Self-Consciousness (4)Bermudez, Jose Luis (2000) Prelinguistic Self-Consciousness (5)Gallese, Vittorio (2000) The Brain and the Self: Reviewing the Neuroscientific Evidence (6)Bermudez, Jose Luis (2000) The Cognitive Neuroscience of Primitive Self-Consciousness (...) (7) [Currently Displayed]Robbins, Philip (2000) Paradox Twice Lost (8)Fuller, Gary and Slater, Carol W. (2000) "I"-Thoughts: Criteria, Constitution, and Concept Possession (9)Evans, Cedric Oliver (2000) Prelinguistic Self-Consciousness (3)Bermudez, Jose Luis and Polytechnique, CREA Ecole (1999) The Paradox of Self-Consciousness (representation and Mind) (1). (shrink)

This paper describes the historical background to contemporary discussions of empathy and rationality. It looks at the philosophy of mind and its implications for action explanation and the philosophy of history. In the nineteenth century, the concept of empathy became prominent within philosophical aesthetics, from where it was extended to describe the way we grasp other minds. This idea of empathy as a way of understanding others echoed through later accounts of historical understanding as involving re-enactment, noticeably that of R. (...) G. Collingwood. For much of the late twentieth century, philosophers of history generally neglected questions about action explanation. In the philosophy of mind, however, Donald Davidson inspired widespread discussions of the role of folk psychology and rationality in mental causation and the explanation of actions, and some philosophers of history drew on his ideas to reconsider issues related to empathy. Today, philosophers inspired by the discovery of mirror neurons and the theory of mind debate between theory theorists and simulation theorists are again making the concept of empathy central to philosophical analyses of action explanation and to historical understanding. (shrink)

Although great progress in neuroanatomy and physiology has occurred lately, we still cannot go directly to those levels to discover the neural mechanisms of higher cognition and consciousness. But we can use neurocomputational methods based on these details to push this project forward. Here we describe vector subtraction as an operation that computes sequential paths through high-dimensional vector spaces. Vector-space interpretations of network activity patterns are a fruitful resource in recent computational neuroscience. Vector subtraction also appears to be implemented neurally (...) in primate frontal eye field activity, which computes dimensions of saccadic eye movements. We use this apparent neural implementation as a model and construct from it a general neurocomputational account of an important type of sequential cognitive and conscious process. We defend the biological plausibility of all components of the general model and show that it yields testable anatomical and physiological predictions. We close by suggesting some interesting consequences for consciousness if our model characterizes correctly the neural mechanisms producing a common type of episode in our conscious streams. (shrink)