viii Handbook of Psychology Preface and for persons outside of psychology seeking information about psychological matters, the Handbook volumes serve as a reference source for expanding their knowledge and directing them to additional sources in the literature The preparation of this Handbook was made possible by the diligence and scholarly sophistication of the 25 volume editors and co-editors who constituted the Editorial Board As Editor-in-Chief, I want to thank each of them for the pleasure of their collaboration in this project I compliment them for having recruited an outstanding cast of contributors to their volumes and then working closely with these authors to achieve chapters that will stand each in their own right as valuable contributions to the literature I would like finally to express my appreciation to the editorial staff of John Wiley and Sons for the opportunity to share in the development of this project and its pursuit to fruition, most particularly to Jennifer Simon, Senior Editor, and her two assistants, Mary Porterfield and Isabel Pratt Without Jennifer’s vision of the Handbook and her keen judgment and unflagging support in producing it, the occasion to write this preface would not have arrived IRVING B WEINER Tampa, Florida Volume Preface This volume is intended to provide thorough, accessible tutorials on the major topic areas in the field of experimental psychology The volume should be useful not only as a reference source for professionals, being part of this Handbook, but also as an effective, stand-alone textbook for students Consequently, the volume is aimed at professional psychologists, entry-level graduate students, and advanced undergraduates who have some relatively limited background in experimental psychology Just as reading this volume does not depend on reading the other volumes in the series, reading a specific chapter in this volume is not contingent on reading any other chapters Each chapter provides an up-to-date, state-of-theart review of a specific subfield of experimental psychology, providing coverage of what is known and what is currently being done, along with some of the historical context experimental method The use of experiments is widespread, including, for example, research in biological, social, developmental, educational, clinical, and industrial psychology Nevertheless, the term experimental psychology is currently limited to cover roughly the topics of perception, performance, learning, memory, and cognition Although by definition empirical in nature, research on experimental psychology is focused on tests of theories, so that theoretical and experimental objectives and methods are necessarily intertwined Indeed, research in experimental psychology has become progressively more interdisciplinary, with an emphasis on not only psychological theories but also theories based on other disciplines including those in the broader fields of cognitive science and neuroscience In addition, since its inception there has been a continued growth and relevance of experimental psychology to everyday life outside of the laboratory The potential applications of the results of psychology experiments are increasingly widespread and include, for example, implications concerning teaching and training, law, and medicine WHAT IS EXPERIMENTAL PSYCHOLOGY? The experimental method is defined by the manipulation of independent variables and the measurement of dependent variables Extraneous variables are either controlled or allowed to vary randomly In particular, care is taken to remove any variables that are confounded with the independent variables Because of the control exerted, this method permits the investigator to isolate causal relations Any change in the dependent variables can be viewed as caused by the manipulation of the independent variables Experimental psychology has a rich heritage that started when Wilhelm Wundt created the first psychology laboratory in 1879 at the University of Leipzig Because of the unique ability to draw causal inferences with experiments, early psychology was essentially experimental psychology Although there are certainly those who think that the experiment is the wrong methodology for many aspects of psychology, the primary methodological goal of most research in psychology has been the exertion of as much control as possible, so that the general idea of the experiment as the ideal research tool is widely accepted in psychology Today the term experimental psychology does not, however, cover all of the areas in psychology that employ the ORGANIZATION OF THE VOLUME In covering the core topics of perception, performance, learning, memory, and cognition, the volume is organized approximately from the least to the most complex processes Each of the first 23 chapters is focused on a different single or pair of psychological processes These chapters are divided into eight sets with three chapters in each set but the last, which includes only two The sets cover the more general topics of (a) modulatory processes, (b) sensory processes, (c) perceptual processes, (d) human performance, (e) elementary learning and memory processes, (f) complex learning and memory processes, (g) language and information processing, and (h) thinking Within the set of modulatory processes, we begin with the fascinating topic of consciousness (and its inverse, unconsciousness), which has deep roots in philosophy as well as in psychology From there we delve into the topic of motivation and then the topic of mood In addressing sensory ix x Volume Preface processes, we focus on three specific senses: vision, audition, and touch More research has been conducted on vision than on any other sense Hence, the first chapter in this set provides an overview of the theoretical and methodological foundations of research on visual perception Visual perception is covered from a different perspective in the following set of chapters on perceptual processes These include chapters focused on organization and identification processes in the visual perception of objects, on depth perception and the perception of events, and on speech production and perception For the set of chapters on performance, we progress through the topics roughly in the order in which they take place, considering first attention, then action selection, and finally motor control The set of chapters on elementary learning and memory processes begins with two focused on work with animals, the first on conditioning and learning and the second on animal memory and cognition, and concludes with one focused on work with humans, involving sensory and working memory For the set of chapters on complex learning and memory processes, we include chapters on the specific topics of semantic memory and priming, episodic and autobiographical memory, and procedural memory and skill acquisition, with each of these chapters containing coverage of two different but related themes The chapters on language and information processing address first psycholinguistics, with a focus on language comprehension and production, then reading, with a focus on word identification and eye movements, and finally the most complex of these processes, those involving text comprehension and discourse processing We end with other complex processes, those that underlie thinking, again considering them in pairs, starting with concepts and categorization and concluding with reasoning and problem solving Our final chapter provides a historical and modern overview of applied experimental psychology, showing how psychological experimentation addresses practical concerns The earlier chapters in the volume also provide some discussion of applications as well as a review of the historical development of their topic, but the emphasis on those chapters is on recent empirical results and theory LIMITATIONS AND ACCOMPLISHMENTS As should be clear from this outline, the volume is quite comprehensive in scope Nevertheless, notable gaps could not be avoided For instance, in considering the sensory processes, we could only focus on three of the senses, ignoring the important senses of taste and smell The length of the volume did not allow us to include separate chapters on these senses, and it proved to be unreasonable to expect one chapter to include a summary of more than one sense There are also more subtle omissions from our coverage because chapter authors often, reasonably, chose to emphasize that aspect of their topic that was of most interest to them or for which they had the strongest background and expertise To give just one example, the chapter on perceptual organization and identification focuses on those processes as they occur in visual perception rather than including the similar processes in audition and other senses This is a single volume, but to provide a full, complete, and detailed coverage of experimental psychology, more than one volume would be necessary In fact, John Wiley & Sons has just published the third edition of the classic Stevens’ Handbook of Experimental Psychology, which is now four volumes long The original version appeared in 1951 in a single volume, and the increase in size since then reflects the large growth of research in this area Readers of the present volume who wish to delve more deeply into particular topics in experimental psychology are referred to the new four-volume set of the Stevens’ Handbook The present volume makes up for any deficiency in quantity of coverage with its extraordinary quality of coverage When we were asked to edit this volume, we developed a wish list of contributors including the leaders in each of the specific chapter topics We constructed a list including two or three names of potential senior authors for each chapter With very few exceptions, the current volume is comprised of authors from that original list Even though we thus had extremely high expectations about the chapters in the volume from the beginning, in many cases the authors went way beyond our initial expectations because of the keen insights they introduced in their chapters Therefore, these chapters serve not only as lucid summaries of the current state of the field but also as roadmaps leading to the most fruitful avenues of future investigation ACKNOWLEDGMENTS We would like to express our deep appreciation to our team of chapter authors for their exceptional contributions In addition, we are indebted to a number of others who have helped us in our efforts to put this volume together First, we are indebted to Irv Weiner, the editor-in-chief for the Handbook Not only did he oversee the entire project, giving us invaluable guidance at each step as we progressed from the early conception of the volume through the finished product, Volume Preface but he also read the draft of every chapter and offered many valuable, specific comments and suggestions Second, we are grateful to our colleagues and collaborators, most notably Lyle Bourne and John Capaldi, for their helpful advice at many stages of this project Third, preparation of the book and Chapter 11 benefited from the appointment of the second edition as a fellow of the Center for Behaviorial and Social Sciences, School of Liberal Arts, Purdue University during fall, 2000 The book preparation also benefited from Army Research Institute Contract DASW01-99-K-0002 to xi the University of Colorado, which supported the first editor during summer, 1999, 2000, and 2001 Finally but by no means least, we wish to thank our spouses, Bruce Healy and Janet Proctor, who have provided unfailing support, understanding, and encouragement as we required extra time to devote to this project on top of our normal teaching, research, and writing schedule ALICE F HEALY AND ROBERT W PROCTOR ... an up-to-date, state -of- theart review of a specific subfield of experimental psychology, providing coverage of what is known and what is currently being done, along with some of the historical context... Today the term experimental psychology does not, however, cover all of the areas in psychology that employ the ORGANIZATION OF THE VOLUME In covering the core topics of perception, performance,... published the third edition of the classic Stevens’ Handbook of Experimental Psychology, which is now four volumes long The original version appeared in 1951 in a single volume, and the increase