Skip navigation

Cognitive Neuroscience

  • Page 4 of 11
It's Not What You Think

In Seeing and Visualizing, Zenon Pylyshyn argues that seeing is different from thinking and that to see is not, as it may seem intuitively, to create an inner replica of the world. Pylyshyn examines how we see and how we visualize and why the scientific account does not align with the way these processes seem to us "from the inside." In doing so, he addresses issues in vision science, cognitive psychology, philosophy of mind, and cognitive neuroscience.

First, Pylyshyn argues that there is a core stage of vision independent from the influence of our prior beliefs and examines how vision can be intelligent and yet essentially knowledge-free. He then proposes that a mechanism within the vision module, called a visual index (or FINST), provides a direct preconceptual connection between parts of visual representations and things in the world, and he presents various experiments that illustrate the operation of this mechanism. He argues that such a deictic reference mechanism is needed to account for many properties of vision, including how mental images attain their apparent spatial character without themselves being laid out in space in our brains.

The final section of the book examines the "picture theory" of mental imagery, including recent neuroscience evidence, and asks whether any current evidence speaks to the issue of the format of mental images. This analysis of mental imagery brings together many of the themes raised throughout the book and provides a framework for considering such issues as the distinction between the form and the content of representations, the role of vision in thought, and the relation between behavioral, neuroscientific, and phenomenological evidence regarding mental representations.

In Natural Minds Thomas Polger advocates, and defends, the philosophical theory that mind equals brain—that sensations are brain processes—and in doing so brings the mind-brain identity theory back into the philosophical debate about consciousness. The version of identity theory that Polger advocates holds that conscious processes, events, states, or properties are type- identical to biological processes, events, states, or properties— a "tough-minded" account that maintains that minds are necessarily indentical to brains, a position held by few current identity theorists. Polger's approach to what William James called the "great blooming buzzing confusion" of consciousness begins with the idea that we need to know more about brains in order to understand consciousness fully, but recognizes that biology alone cannot provide the entire explanation. Natural Minds takes on issues from philosophy of mind, philosophy of science, and metaphysics, moving freely among them in its discussion.

Polger begins by answering two major objections to identity theory—Hilary Putnam's argument from multiple realizability (which discounts identity theory because creatures with brains unlike ours could also have mental states) and Saul Kripke's modal argument against mind-brain identity (based on the apparent contingency of the indentity statement). He then offers a detailed account of functionalism and functional realization, which offer the most serious obstacle to consideration of identity theory. Polger argues that identity theory can itself satisfy the kind of explanatory demands that are often believed to favor functionalism.

Amniotic Fluid Studies

This pioneering study looks at the effects of prenatal testosterone on postnatal development and behavior. Hormonal effects on behavior have long been studied in animals; the unique contribution of this book is to suggest a connection between human fetal hormones and later behavior. It details for the first time testosterone's effect on social and language development, opening a new avenue of research for cognitive neuroscience.

The authors look at samples of amniotic fluid taken during amniocentesis at 16 weeks' gestation, and relate the fetal level of testosterone (which is present in fetuses of both sexes, although in different quantities) to behavior at ages 1, 2, and 4 years. They argue that the amniotic fluid provides a window into the child's past—a chemical record of that child's time in the womb—that allows informed prediction about the child's future brain, mind, and behavior. This is not the retrospective speculation of psychoanalysis, they point out, but an opportunity to study development prospectively and trace developmental precursors and causes of later cognition.

The study suggests that prenatal levels of testosterone affect a range of later behaviors in children, from the inclination to make eye contact with others to the size of the vocabulary. It also suggests that prenatal testosterone level may be related to the development of typically "masculine" and "feminine" behaviors. The study's ongoing research explores whether fetal testosterone has any link with the risk of developing autism. Connecting endocrinology and psychology, the authors propose that there is a biological component to behaviors often thought to be produced by the social environment.

A Parallel Distributed Processing Approach

This groundbreaking monograph offers a mechanistic theory of the representation and use of semantic knowledge, integrating the strengths and overcoming many of the weaknesses of hierarchical, categorization-based approaches, similarity-based approaches, and the approach often called "theory theory." Building on earlier models by Geoffrey Hinton in the 1980s and David Rumelhart in the early 1990s, the authors propose that performance in semantic tasks arises through the propagation of graded signals in a system of interconnected processing units. The representations used in performing these tasks are patterns of activation across units, governed by weighted connections among them. Semantic knowledge is acquired through the gradual adjustment of the strengths of these connections in the course of day-to-day experience.

The authors show how a simple computational model proposed by Rumelhart exhibits a progressive differentiation of conceptual knowledge, paralleling aspects of cognitive development seen in the work of Frank Keil and Jean Mandler. The authors extend the model to address aspects of conceptual knowledge acquisition in infancy, disintegration of conceptual knowledge in dementia, "basic-level" effects and their interaction with expertise, and many findings introduced to support the idea that semantic cognition is guided by naive, domain-specific theories.

The cognitive disorders that follow brain damage are an important source of insights into the neural bases of human thought. This second edition of the widely acclaimed Patient-Based Approaches to Cognitive Neuroscience offers state-of-the-art reviews of the patient-based approach to central issues in cognitive neuroscience by leaders in the field.

The second edition has been thoroughly updated, with new coverage of methods from imaging to transcranial magnetic stimulation to genetics and topics from plasticity to executive function to mathematical thought. Part I, on the history and methods of cognitive neuroscience and behavioral neurology, includes two new chapters on imaging, one covering the basics of fMRI in normal humans and the other on the functional imaging of brain-damaged patients, as well as updated chapters on electrophysiological methods and computer modeling. Part II, on perception and attention, includes new chapters on visual perception and spatial cognition as well as attention, visual, tactile, and auditory recognition, music perception, body concept, and delusions. Part III, on language, covers many aspects of language processing in adults and children, including reading. Part IV discusses memory and prefrontal function, including semantic memory and executive functions. Part V covers dementias and developmental disorders, among them Alzheimer's and Parkinson's diseases, mental retardation, ADHD, and autism, and includes a chapter on the molecular genetics of cognitive disorders.

The event-related potential (ERP) technique in cognitive neuroscience allows scientists to observe human brain activity that reflects specific cognitive processes. In An Introduction to the Event-Related Potential Technique, Steve Luck offers the first comprehensive guide to the practicalities of conducting ERP experiments in cognitive neuroscience and related fields, including affective neuroscience and experimental psychopathology. The book can serve as a guide for the classroom or the laboratory and as a reference for researchers who do not conduct ERP studies themselves but need to understand and evaluate ERP experiments in the literature. It summarizes the accumulated body of ERP theory and practice, providing detailed, practical advice about how to design, conduct, and interpret ERP experiments, and presents the theoretical background needed to understand why an experiment is carried out in a particular way. Luck focuses on the most fundamental techniques, describing them as they are used in many of the world's leading ERP laboratories. These techniques reflect a long history of electrophysiological recordings and provide an excellent foundation for more advanced approaches.

The book also provides advice on the key topic of how to design ERP experiments so that they will be useful in answering questions of broad scientific interest. This reflects the increasing proportion of ERP research that focuses on these broader questions rather than the "ERPology" of early studies, which concentrated primarily on ERP components and methods. Topics covered include the neural origins of ERPs, signal averaging, artifact rejection and correction, filtering, measurement and analysis, localization, and the practicalities of setting up the lab.

A Neurochronometrics of Mind

The mainstays of brain imaging techniques have been positron emission tomography (PET), functional magnetic resonance imaging (fMRI), magnetoencephalography (MEG), and event-related potentials (ERPs). These methods all record direct or indirect measures of brain activity and correlate the activity patterns with behavior. But to go beyond the correlations established by these techniques and prove the necessity of an area for a given function, cognitive neuroscientists need to be able to reverse engineer the brain—i.e., to selectively remove components from information processing and assess their impact on the output.

This book is about transcranial magnetic stimulation (TMS), a technique that emerged during the same period as neuroimaging and has made it possible to reverse engineer the human brain's role in behavioral and cognitive functions. The subject areas that can be studied using TMS run the gamut of cognitive psychology—attention, perception, awareness, eye movements, action selection, memory, plasticity, language, numeracy, and priming. The book presents an overview of historical attempts at magnetic brain stimulation, ethical considerations of the technique's use, basic technical and practical information, the results of numerous TMS studies, and a discussion of the future of TMS in the armamentarium of cognitive neuropsychology.

How did the human brain evolve so that consciousness of art could develop? In The Psychology of Art and the Evolution of the Conscious Brain, Robert Solso describes how a consciousness that evolved for other purposes perceives and creates art. Drawing on his earlier book Cognition and the Visual Arts and ten years of new findings in cognitive research (as well as new ideas in anthropology and art history), Solso shows that consciousness developed gradually, with distinct components that evolved over time. One of these components is an adaptive consciousness that includes the ability to imagine objects that are not presentan ability that allows us to create (and perceive) visual art. Solso describes the neurological, perceptual, and cognitive sequence that occurs when we view art, and the often inexpressible effect that a work of art has on us. He shows that there are two aspects to viewing art: nativistic perceptionthe synchronicity of eye and brain that transforms electromagnetic energy into neuro-chemical codeswhich is "hard-wired" into the sensory-cognitive system; and directed perception, which incorporates personal history and knowledgethe entire set of our expectations and past experiences. Both forms of perception are part of the appreciation of art, and both are products of the evolution of the conscious brain over hundreds of thousands of years. Solso also investigates the related issues of neurological and artistic perception of the human face, the effects of visual illusions, and the use of perspective. The many works of art used as examples are drawn from a wide range of artistic traditions, from ancient Egypt to Africa and India and the European Renaissance.

Head direction cells—neurons that fire only when an animal orients its head in a certain direction—are found in several different brain areas, with different neurons selective for different head orientations; they are influenced by landmarks as well as motor and vestibular information concerning how the head moves through space. These properties suggest that head direction cells play an important role in determining orientation in space and in navigation. Moreover, the prominence, strength, and clarity of head direction signals indicate their importance over the course of evolution and suggest that they can serve as a vital key for understanding brain function. This book presents the latest findings on head direction cells in a comprehensive treatment that will be a valuable reference for students and researchers in the cognitive sciences, neuroscience, computational science, and robotics.

The book begins by presenting head direction cell properties and an anatomical framework of the head direction system. It then looks at the types of sensory and motor information that control head direction cell firing, covering topics including the integration of diverse signals; the relationship between head direction cell activity and an animal's spatial behavior; and spatial and directional orientation in nonhuman primates and humans. The book concludes with a tutorial demonstrating the implementation of the continuous attractor network, a computational model of head direction cells, and an application of this approach for a navigational system for mobile robots.

A Fyssen Foundation Symposium

The extraordinary overlap between human and chimpanzee genomes does not result in an equal overlap between human and chimpanzee thoughts, sensations, perceptions, and emotions; there are considerable similarities but also considerable differences between human and nonhuman primate brains. From Monkey Brain to Human Brain uses the latest findings in cognitive psychology, comparative biology, and neuroscience to look at the complex patterns of convergence and divergence in primate cortical organization and function.

Several chapters examine the use of modern technologies to study primate brains, analyzing the potentials and the limitations of neuroimaging as well as genetic and computational approaches. These methods, which can be applied identically across different species of primates, help to highlight the paradox of nonlinear primate evolution—the fact that major changes in brain size and functional complexity resulted from small changes in the genome. Other chapters identify plausible analogs or homologs in nonhuman primates for such human cognitive functions as arithmetic, reading, theory of mind, and altruism; examine the role of parietofrontal circuits in the production and comprehension of actions; analyze the contributions of the prefrontal and cingulate cortices to cognitive control; and explore to what extent visual recognition and visual attention are related in humans and other primates.

The Fyssen Foundation is dedicated to encouraging scientific inquiry into the cognitive mechanisms that underlie animal and human behavior and has long sponsored symposia on topics of central importance to the cognitive sciences.

  • Page 4 of 11