Neuroscience

Scientists' understanding of two central problems in neuroscience, psychology, and philosophy has been greatly influenced by the work of David Hubel and Torsten Wiesel: What is it to see? This relates to the machinery that underlies visual perception, How do we acquire the brain's mechanisms for vision? This is the nature-nurture question as to whether the nerve connections responsible for vision are innate or whether they develop through experience in the early life of an animal or human. This is a book about the collaboration between Hubel and Wiesel, which began in 1958, lasted until about 1982, and led to a Nobel Prize in 1981. It opens with short biographies of both men, describes the state of the field when they started, and talks about the beginnings of their collaboration. It emphasizes the importance of various mentors in their lives, especially Stephen W. Kuffler, who opened up the field by studying the cat retina in 1950, and founded the department of neurobiology at Harvard Medical School, where most of their work was done. The main part of the book consists of Hubel and Wiesel's most important publications. Each reprinted paper is preceded by a foreword that tells how they went about the research, what the difficulties and the pleasures were, and whether they felt a paper was important and why. Each is also followed by an afterword describing how the paper was received and what developments have occurred since its publication. The reader learns things that are often absent from typical scientific publications, including whether the work was difficult, fun, personally rewarding, exhilarating, or just plain tedious. The book ends with a summing-up of the present state of the field.

Broca's region has been in the news ever since scientists realized that particular cognitive functions could be localized to parts of the cerebral cortex. Its discoverer, Paul Broca, was one of the first researchers to argue for a direct connection between a concrete behavior—in this case, the use of language—and a specific cortical region. Today, Broca's region is perhaps the most famous part of the human brain, and for over a century, has persisted as the focus of intense research and numerous debates. The name has even penetrated mainstream culture through popular science and the theater. Broca's region is famous for a good reason: As language is one of the most distinctive human traits, the cognitive mechanisms that support it and the tissues in which these mechanisms are housed are also quite complex, and so have the potential to reveal a lot not only about how words, phrases, sentences, and grammatical rules are instantiated in neural tissue, but also, and more broadly, about how brain function relates to behavior. Paul Broca's discoveries were an important, driving force behind the more general effort to relate complex behavior to particular parts of the cerebral cortex, which, significantly, produced the first brain maps.

This book presents a comprehensive account of the regions of the brain that control the performance of skilled voluntary movements, especially the accurate and precise control of the use of the fingers and the hand by monkeys and humans. The significance of recent and clinical observations concerning the details of the cortico-cortical connections that contribute to the determination of these functions is discussed.

This book provides a comprehensive, easy-to-read survey of excitatory amino acids and synaptic transmission. It begins with descriptions of the structure, function, and pharmacology of both the ionotropic and the metabotropic glutamate receptors and the glutamate transporters. Subsequent chapters deal with molecular aspects of the regulation of glutamatergic transmission, including receptor trafficking, the role of glutamate transport, the unique molecular architecture of the synapses (post-synaptic density), and the signal transduction pathways mediated by glutamate. Also unique to the book is a chapter on synaptic plasticity that covers long-term potentiation and long-term depression in relationship to synaptic function. It is striking that glutamate is implicated in most of the major neurological diseases, such as stroke, Alzheimer's disease, and schizophrenia.

A well-known example of filling-in involves the blind spot, a region in the back of the eye that is devoid of photoreceptors. The term blind spot is somewhat of a misnomer, because the corresponding region of visual space is not simply perceived as dark, as one would expect. Instead, it is “filled-in” with the same color and texture as the surrounding background. This phenomenon is often considered as little more than a curiosity. However, this book argues that completion mechanisms similar to those that fill in the blind spot are pervasive and necessary for normal perception. The book reviews evidence suggesting a link between particular neural processes and the perception of filling-in. It then introduces the idea that these processes can instigate various types of long-term neural plasticity, which may underlie recovery and rehabilitation after peripheral injury, as well as other types of skill learning. The connection between completion phenomena and long-term plasticity is explored not only in the visual system, but also in the auditory, somatosensory, and motor systems.

The nerve impulse is the basis of all human thoughts and emotions, and of all sensations and movements. As such, it has been the subject of scientific enquiry for more than two centuries, beginning with Galvani’s chance observation that a frog’s leg twitched in response to an electrostatic discharge nearby. From being a metaphysical concept, the impulse became a phenomenon that could be recorded and have its velocity determined. However, the nature of the brief permeability changes in the nerve membrane that made the impulse possible, and of the way in which the nerve endings influenced the excitability of connecting neurons, remained problems that taxed the ingenuity of physiologists for many years. An important breakthrough was the discovery of giant nerve fibres in the squid, fibres large enough for new techniques to be employed, as in the voltage-clamp experiments of Hodgkin and Huxley immediately after World War II. The story culminates with the recent discovery of the 3-dimensional structure and detailed functioning of the ion channels, following MacKinnon’s X-ray diffraction studies, and with the revelation that a host of clinical disorders result from malfunction of the ion channels.

The head carries most of the sensory systems that enable us to function effectively in our three-dimensional habitat. Without adequate head movement control, efficient spatial orientation and motor responses to visual and auditory stimuli could not be carried out. This book is an account of the control of vertebrate head movements and its biomechanical and neural basis. It covers the entire spectrum of research on head-neck movements, ranging from the global description and analysis of a particular behavior to its underlying mechanisms at the level of neurotransmitter release and membrane biophysics. Physiological and anatomical aspects are stressed. The role of head movements in upright stance and other functional contexts within the vertebrate hierarchy is juxtaposed with the mechanisms of orienting behavior in a number of invertebrates. This reveals a plethora of solutions among different animal species for the problem of orientation in three-dimensional space. Although head movement control in humans figures prominently in this volume, the anatomical-physiological comparisons show that the human system is not unique. The conference from which this volume originated surveyed research and theory on motor control mechanisms in the head-neck sensory-motor system. It was held in Fontainbleau, France, from July 17–24, 1989. The book provides a broad panorama of methodological and theoretical approaches to the field of head movement control.

The study of conscious experience has seen remarkable strides in the last ten years, reflecting important technological breakthroughs and the enormous efforts of researchers. Although still embroiled in debate, scientists are now beginning to find common ground in their understanding of consciousness, which may pave the way for a unified explanation of how and why we experience and understand the world around us. This book brings the subject to life with a metaphor that has been used to understand consciousness since the time of Aristotle—the mind as theater. Here consciousness is seen as a “stage” on which our sensations, perceptions, thoughts, and feelings play to a vast, silent audience (the immensely complicated inner-workings of the brain's unconscious processes). Behind the scenes, silent context operators shape conscious experience; they include implicit expectations, self systems, and scene setters. Using this framework, the book presents compelling evidence that human consciousness rides on top of biologically ancient mechanisms. In humans it manifests itself in inner speech, imagery, perception, and voluntary control of thought and action. Topics like hypnosis, absorbed states of mind, adaptation to trauma, and the human propensity to project expectations on uncertainty, all fit into the expanded theater metaphor.

This book provides an overview by international authorities, spanning the disciplines of neuroscience, psychology, ophthalmology, optometry, and paediatrics, of normal and pathological infant visual development. It covers the development of retinal receptors; infant sensitivity to detail, colour, contrast, and movement; binocularity, eye movements, and refraction; and cognitive processing. Childrens' visual deficits, including amblyopia and cataract, are covered.

This book offers a fundamental new theory of motor cortex organization: the rendering of the movement repertoire onto the cortex. The action repertoire of an animal is highly dimensional, whereas the cortical sheet is two-dimensional. Rendering the action space onto the cortex therefore results in a complex pattern, explaining the otherwise inexplicable details of motor cortex organization. This book includes a complete history of motor cortex research from its discovery to the present, a discussion of the major issues in motor cortex research, and an account of recent experiments that led to the book's “action map” view. Though focused on motor cortex, the book includes a range of topics from an explanation of how primates put food in their mouths, to the origins of social behavior such as smiling and laughing, to the mysterious link between movement disorders and autism.