E-Book, Englisch, 488 Seiten, Format (B × H): 216 mm x 276 mm
Cognitive Neuroscience and Neuropathology
E-Book, Englisch, 488 Seiten, Format (B × H): 216 mm x 276 mm
ISBN: 978-0-12-801175-1
Verlag: William Andrew Publishing
Format: EPUB
Kopierschutz: 6 - ePub Watermark
In this critical and timely update, revised and new contributions by internationally renowned researchers-edited by the leaders in the field of consciousness research-provide a unique and comprehensive focus on human consciousness. The new edition of The Neurobiology of Consciousness will continue to be an indispensable resource for researchers and students working on the cognitive neuroscience of consciousness and related disorders, as well as for neuroscientists, psychologists, psychiatrists, and neurologists contemplating consciousness as one of the philosophical, ethical, sociological, political, and religious questions of our time.
- New chapters on the neuroanatomical basis of consciousness and short-term memory, and expanded coverage of comas and neuroethics, including the ethics of brain death
- The first comprehensive, authoritative collection to describe disorders of consciousness and how they are used to study and understand the neural correlates of conscious perception in humans.
- Includes both revised and new chapters from the top international researchers in the field, including Christof Koch, Marcus Raichle, Nicholas Schiff, Joseph Fins, and Michael Gazzaniga
Zielgruppe
Researchers, clinicians, and graduate students in cognitive neuroscience, cognitive neurology, neuroscience, translational neuroscience, neurology, and neuropsychology, as well as cognitive psychology, clinical psychology, and psychiatry
Autoren/Hrsg.
Fachgebiete
- Medizin | Veterinärmedizin Medizin | Public Health | Pharmazie | Zahnmedizin Medizinische Fachgebiete Psychiatrie, Sozialpsychiatrie, Suchttherapie
- Interdisziplinäres Wissenschaften Wissenschaften Interdisziplinär Neurowissenschaften, Kognitionswissenschaft
- Sozialwissenschaften Psychologie Psychotherapie / Klinische Psychologie
- Sozialwissenschaften Psychologie Allgemeine Psychologie Kognitionspsychologie
- Medizin | Veterinärmedizin Medizin | Public Health | Pharmazie | Zahnmedizin Klinische und Innere Medizin Neurologie, Klinische Neurowissenschaft
Weitere Infos & Material
Section 1: Basics 1. Neuroanatomical and basis of consciousness Hal Blumenfeld 2. Functional Neuroimaging and Electrophysiology Marcello Massimini and Olivia Gosseries 3. Consciousness and Synchronization Andreas Engel and Pascal Fries 4. Studying the Neural Correlates of Visual Consciousness Geraint Rees 5. Consciousness and Attention Naotsugu Tsuchiya and Christof Koch
Section 2: Waking, Sleep, and Anesthesia 6. Intrinsic Brain Activity and Consciousness Athena Demertzi 7. Sleep and Dreaming Francesca Siclari and Giulio Tononi 8. Focal Brain Lesions and Disturbances of Consciousness Claudio L. Bassetti 9. General Anesthesia George Mashour
Section 3: Coma and Related Conditions 10. Coma and Vegetative State Adrian M. Owen, Steven Laureys and Nicholas Schiff 11. Minimally Conscious State Caroline Schnakers and Joseph Giacino 12. Locked-in Syndrome Steven Laureys 13. Dementia Pietro Pietrini, Eric Salmon and Paul Nichelli 14. Brain Computer Interfaces Andrea Kübler and Donatella Mattia 15. Neuroethics Joseph Fins
Section 4: Seizures, Splits, Neglects, and Assorted Disorders 16. Epileptic Loss of Consciousness Hal Blumenfeld 17. Split Brain Michael Gazzaniga and Michael Miller 18. Blindsight, Agnosia, Neglect and Capgras Lionel Naccache 19. Conversion Disorders Patrik Vuilleumier 20. Out of Body and Near Death Experiences Olaf Blanke 21. Memory Bradley R. Postle 22. Transient Global Amnesia Chris Butler and Adam Zeman 23. Aphasia and Consciousness Paolo Frigio Nichelli 24. Blindness and Consciousness Ron Kupers and Pietro Pietrini 25. Overview Steven Laureys, Giulio Tononi and Olivia Gosseries
Foreword
Richard Frackowiak, Centre Hospitalier Universitaire Vaudois, University of Lausanne and Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland Jean-Pierre Changeux, Pasteur Institute and Collège de France, Paris, France Looking back is often disappointing and not really a good way of deciding what to do next. But in cognition research we can’t help but muse on those who claimed as little as 25 years ago that consciousness was not a subject respectable neuroscientists should concern themselves with. The problem was too complex, the concept too ill-defined, the level of organization unreachable and so on. Predicting the future is a difficult game, which is presumably why, as a community, scientists prefer experimentation based on models, peer review, and evaluation. Happily so, this book clearly demonstrates that not only is consciousness a viable subject for scientific study but also that the diverse meanings of the word “consciousness” firm up as new measuring instruments and experimental methods become available. As a word, “consciousness” is rich, means too many things and requires deconstruction to become tractable. There are, for example, the contents of consciousness, mechanisms that access them, issues of awareness, implicit and explicit ways of recovering conscious events and so on. In common language, all these are subsumed in one way or another under the single term, consciousness. A simple analogy might be with the term “memory”—understood by all, but dissection of that concept by science into various types and mechanisms has enriched its comprehension considerably. An initial division into normal “conscious access” and its disorders in humans is potentially helpful. It is a universal experience to oscillate daily between sleep and wakefulness, thereby regularly to experience loss of conscious access. Similarly, general anesthesia systematically manifests by a chemically elicited and reversible “loss of consciousness,” a widely accepted use of the word consciousness in a medical context. From the neurological standpoint, it is commonly held that to lose consciousness (in the sense of a global loss of conscious access) it is necessary to suffer bilateral hemispheric damage or a midbrain lesion. Certainly this is true, but there are states in which apparent changes in consciousness are found that are limited to bilateral thalamic damage; so, bi-hemispheric, but limited in extent to critical regions. Consciousness can be impaired by large intracerebral lesions, such as hemorrhages, tumors, or aneurysms, that distort the brain by occupying space and impinging directly on both hemispheres, or pushing down onto the midbrain or by disease of local origin that spreads to involve these regions, as in focal epilepsies. It can also result from metabolic starvation as in hypoxia or with poisoning, for example, with gases such as carbon dioxide, carbon monoxide, or nitrous oxide. These phenomena have been known for a long time and, though dramatic, they give little insight into the neurobiology of consciousness, other than by providing the gross anatomical substrate described above. Generally disturbed consciousness can occur in milder form, sometimes manifesting as confusion, and can also be caused by poisoning or metabolic insults from various pharmacological or toxic agents. Sometimes these are taken voluntarily; often they can modify the contents of consciousness in a repeatable and predictable manner. Alcohol is a clear example and various psychoactive drugs can either alter consciousness by instilling a negative state (such as opiates) while others distort consciousness, invoking hallucinations or heightened awareness that is often imaginary but easily communicated to others (e.g., LSD, magic mushrooms, and the like). In this latter situation, the disturbances of consciousness are not just due to altered access but also to an interaction with the contents of consciousness. As mentioned, an unconscious state that resembles slow-wave sleep can be induced in a controlled fashion by infusion of general anesthetics, with remarkable precision. Propofol, for instance, can induce a loss of consciousness and subsequent recovery in seconds by manipulating intravenous doses, indicating a precise threshold effect. The mechanisms by which drugs such as propofol, barbiturates, and benzodiazepines act are known in detail at the molecular level, and their sites have been explored by photo-labeling and X-ray crystallography at the atomic level. They act as positive allosteric modulators of receptors and ion channels, such as the GABAA receptor (the ionotropic receptor of the inhibitory neurotransmitter gamma-aminobutyric acid). By enhancing inhibition in the brain at this level, they depress a general excitation of the cerebral cortex that seems necessary for conscious access. But the precise sub-cellular and neuronal targets at which they cause a loss of consciousness are still not fully identified. The unconscious state that has been the most intriguing and that, it must be said, has caused the most difficulty is that of sleep. For example, sleep, in which we are considered unconscious, can be associated with total muscle atony but also with muscular activity, be it of the eyes or manifesting as more general movements. It is a state into which one can “drop,” or awaken from with a startle. One cause of ambiguity is the observation that we dream in sleep and at times are able to recount some of the substance of those dreams when awake again. If an account of a dream can be given, is a subject conscious whilst unconscious? The awareness of spontaneous inner states implies access to content and hence consciousness, while unresponsiveness to the external world implies the opposite. Is a recounted dream episode a form of deferred consciousness, or is it the product of an interaction between level of awareness and access to the contents of consciousness? Different phenomenological features co-occur in different ways to produce a rich tapestry of sleep states, which is why we struggle with understanding a unitary concept of consciousness. There are many, mostly anecdotal, accounts of people reporting altered states of consciousness, in the sense of loss of access, which nevertheless leave them with remembered fragments. One example is the reports of relative retention of memory from islands of time in otherwise severe retrograde amnesiacs. This may also be an explanation for the phenomenon of patchy abnormal memories that are retained in dementing amnesiacs. Also, being unresponsive in the motor sense does not mean being unconscious. This is manifested clinically in sleep paralysis, and in certain post-traumatic states, notably the locked-in syndrome. More intriguing theoretically is the observation that whilst apparently unresponsive, people can access information, albeit often in fragmentary fashion, and implicitly or explicitly memorize and then recount such “experiences” when returned to awareness or contact with the environment. We also have to consider states of partial loss of consciousness. Some are states of altered consciousness in which some awareness is retained, though very frequently distorted, and about which some often partial report is possible. An example is the so-called out-of-body experience, which experimentation suggests is mainly due to alteration of multisensory integrative processes that are thought to underpin an awareness of “self” and so result in syndromes sometimes referred to as altered self-consciousness. The body is seen as extraneous, returning to the self before normal consciousness is established. In strokes, feelings can be attributed falsely to others or to other parts of the body. Lesions in local, relatively specific, cortical areas may induce states of partial consciousness, or even supernumerary consciousness. For example, the conviction that a person owns a third limb that appears or disappears when the real limb on the same side is moved. The phenomenon of painful phantom limbs is a particularly dramatic example of altered local consciousness. The phenomenon appears to depend on whether a limb is amputated when painful or painless. Amputation when pain is not controlled results in a phantom limb much more frequently than if there is good pre-operative analgesia. Such a phenomenon suggests the presence of a nociceptive memory that cannot be eradicated and remains as a conscious reportable local percept. The physiological basis of such partial phenomena has been explored in some detail experimentally in monkeys by intracortical recordings and in humans by neuroimaging, leading to suggestions that there is re-mapping and distortion of sensory fields corresponding to the body parts affected. Even more dramatic are the disturbances of consciousness that affect a half-body. These can manifest as complete denial of the presence of paralysis, usually in the left side of the body, or misattribution of limbs to others with considerable conviction and against all evidence. Neuropsychologists have documented such phenomena at length. A very dramatic example occurs in normal people who fail to notice major changes in a visual scene, despite normal awareness, because they do not expect to see what happens. The classical example is the perambulation of a gorilla across a student campus; the gorilla is simply not seen despite, or perhaps because of, its extreme incongruity. The inability to detect an object in a visual hemi-field when another is shown simultaneously in the other one, despite normal recognition when shown alone, is but one example in patients with lesions of the parietal cortex...
