The Neuropsychology of Attention Ronald A. Cohen The Neuropsychology of Attention Second Edition Ronald A. Cohen, PhD, ABPP, ABCN Professor Departments of Neurology, Psychiatry and Aging Director, Center for Cognitive Aging and Memory University of Florida College of Medicine Gainesville , FL , USA Adjunct Professor Department of Psychiatry and Human Behavior Warren Alpert School of Medicine Brown University Providence , RI , USA ISBN 978-0-387-72638-0 ISBN 978-0-387-72639-7 (eBook) DOI 10.1007/978-0-387-72639-7 Springer New York Heidelberg Dordrecht London Library of Congress Control Number: 2013941376 © Springer Science+Business Media New York 2014 This work is subject to copyright. 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Printed on acid-free paper Springer is part of Springer Science+Business Media (www.springer.com) Foreword It has been about 20 years since Dr. Cohen authored the fi rst edition of his book, The Neuropsychology of Attention. In the decade prior to the fi rst edition, major advances had occurred on how the brain mediates attention and the impact of brain disturbances on attentional functions. This Neuropsychology of Attention did a brilliant job of summarizing and organizing this information. The book was written so clearly and provided so much information that both the novice and expert could understand and learn much from reading it. But this book did even more. When it was written, there was still much that was not understood, and this book excited curiosity and promoted further research. The Malthusian growth model predicts that the world’s population will increase exponentially. I suspect this mathematical growth model also char- acterizes how our knowledge of brain-mediated processes, including atten- tion, has grown. Since the fi rst edition was published two decades ago, the neuropsychology of attention has continued to evolve, and there is now a vast research literature exploring this topic. Thus, the time is ripe for a second edition of The Neuropsychology of Attention. Objects and actions can more easily be de fi ned than mental processes such as attention. Since William James wrote the Principles of Psychology , atten- tion has been de fi ned as “…taking possession of the mind.” We humans are aware that our sensory systems are continuously bombarding our brains with more information than our brains can simultaneously process in full. Stimuli, however, are not just from external sources. We have the ability to activate stored sensory, perceptual, and conceptual representations. We can see, hear, feel, smell, and taste stimuli that are currently being presented, as well as recall or imagine stimuli that have been previously sensed and even stimuli that have never been sensed. How do we decide what stimuli to fully process and what stimuli not to process and how does our brain implement this triage process? How do we decide to allocate our processing resources on internal vs. external stimuli, and how do we decide as to whether to allocate our resources to a speci fi c sensory modality or a spatial location? How do we decide whether to focus on a speci fi c stimulus or to take a more global view? How does the brain make decisions regarding how and to what it will selectively allocate atten- tion when engaging in strategic controlled cognitive processes, such as reasoning, problem solving, or creative thinking. In regard to attention, our brains have to make four critical attentional deci- sions: When to initiate attention to a stimulus? When to continue to attend? vii viii Foreword When to stop attending? And when not to attend? How does our brain mediate these “when” functions? When there is brain dysfunction, one or more of these stages may be impaired and may produce inattention, unawareness, and neglect; impaired vigilance; impaired habituation and extinction; and distractibility. There are many acquired neurological diseases, such as stroke where peo- ple may have dysfunction in one or more of these four processes. However, clinicians and investigators are becoming increasingly aware that these disor- ders of attention are often associated with other diseases, including degenera- tive diseases of the brain, traumatic brain injury, general medical illnesses, and even with normal aging. Attentional disorders have long been recognized as a critical feature of the attention de fi cit hyperactivity disorder; however, atten- tional disorders also can play an important role in other developmental disor- ders. Patients with several psychiatric disorders, including autism, depression, bipolar, anxiety, and schizophrenia, also have impairments of attention. As mentioned in the foreword for the fi rst edition, there are many means by which attention and disorders of attention have been studied. Cognitive and experimental psychologists who initially studied normal subjects using behav- ioral paradigms such as priming, cueing, reaction times, dichotic listening, and tachistoscopic presentations are now using functional imaging, especially func- tional magnetic resonance imaging (fMRI), and there has been an explosion of studies using fMRI. For example, I opened PubMed and typed in “attention and fMRI.” There were more than 7,000 papers listed. Electrophysiological studies of healthy people and patients with neurological and psychiatric disorders con- tinue to provide important insights into the neural mechanisms of attention. Findings from humans have been augmented by a large body of research in laboratory animals employing single-cell recordings and other neurophysiolog- ical methods. Neuropsychologists have developed many new tests for assess- ing disorders of attention, and they along with neurologists, psychiatrists and other neuroscientists continue to study the pathophysiology of diseases that affect attention. This second edition of the Neuropsychology of Attention takes the reader on a wonderful journey, from the late eighteenth century to the twenty- fi rst cen- tury. While the title of this book is Neuropsychology and does discuss testing, this book covers almost all methods of studying attention, including the con- tributions made by the cognitive and experimental psychologists, the physio- logical psychologists, the neuropsychologists, as well as the behavioral neurologists and psychiatrists. When viewing a Navon fi gure, the normal per- son will allocate both local and global attention. Thus, they will be able to see the local stimuli as well as how these local stimuli relate to each other, the global picture. In parallel, the means in which this book has been written not only allows the reader to learn about the important speci fi c clinical and research reports of specialized investigators but also allows the reader to see the “big picture” about what we have learned and what we still need to learn. Kenneth M. Heilman, MD Professor of Neurology and Health Psychology Department of Neurology University of Florida College of Medicine Gainesville, Fl, USA Preface Attention played a vital role in the historical development of the fi eld of psychology. Early psychologists pondered the nature of attention and attempted to characterize its phenomenology and constituent processes. Attention was considered to be a fundamental and inescapable aspect of human experience by Wilhelm Wundt, William James, and other founders of modern psychology. Yet, for much of the early twentieth century, psychologists avoided the construct of attention, and relatively little experimental study of attention took place before the 1960s. Because attention has an intangible quality and cannot be speci fi ed as a unitary process, many behavioral scientists considered the construct of attention to be metaphysical or at the very least theoretically incoherent. Some of their concerns regarding the nature of atten- tional phenomena were clearly justi fi ed. Yet, it was also apparent to most psychologists