Introduction to the special issue in honor of Edward E. Smith.

This special issue is dedicated to the life, work, and legacy of Edward E. Smith, PhD. Ed’s career as a psychologist and cognitive neuroscientist was remarkable in virtually every respect: He had a tremendous impact on multiple areas of study, he received an impressive array of awards and honors, he mentored a number of students who have gone on to impressive careers of their own, and he was widely regarded by those who knew him as one of the kindest andmost humble people that the field of psychology has ever known. Shortly after I (J.X.V.S.) first met Ed as a prospective graduate student at Columbia University in 2005, a faculty member at another school asked whom else I was considering working with. When I said Ed Smith, I received the reply “I can’t say anything bad about Ed. He is probably the nicest man in psychology.” Deanna first met Ed when he came to give a colloquium at Carnegie Mellon when she was a new postdoctoral fellow. He seemed more than happy to spend time with postdoctoral fellows and graduate students, was intellectually generous in his discussions, and insightfully shared his early experience in schizophrenia research, which presaged his later return to this field of study at the end of his career. To attempt to list all of Ed’s accomplishments, accolades, and influential articles would be a nearly Herculean task. An excellent summary of Ed’s career can be found in the APS Observerarticle in his memory by his long-time colleague and collaborator Douglas L. Medin (2013), which also includes commentary (and some excellent anecdotes) from no fewer than 24 of his friends and colleagues. Suffice it to say that at the time of his death, Ed’s curriculum vitae contained exactly 200 articles and chapters, many of which have been cited over 1,000 times, and that he continues to coauthor articles posthumously, as his collaborators complete the work that he was engaged in at the time of his death. It is particularly fitting that several of these projects are included in this volume. One of the hallmarks of Ed’s career was the tremendous impact that he had on multiple fields of study, and one of the major goals in putting together this volume has been to obtain submissions from Ed’s collaborators, colleagues, and former students who have carried out work in each of these fields. The articles in this special issue generally fall into three broad categories that highlight the diversity of areas to which Ed made contributions: concepts and categories, working memory and cognitive control, and cognitive and rewardprocessing impairments in schizophrenia. Early in Ed’s career, he focused on understanding how humans form concepts and on the structure of categorical knowledge representations, coauthoring many seminal studies in that field. The articles focused on concepts and categories in this special issue attest to the influence that his work had on the evolution of this domain of research. Ed was also an early adopter of hemodynamic imaging techniques, first positron emission tomography, and later functional magnetic resonance imaging, because he recognized almost immediately that an understanding of how the human brain works could be used to adjudicate between competing theories of human cognition. As Ed often pointed out, no matter how appealing a theory of some aspect of human cognition was, it could only be taken seriously if it was consistent with the known functioning of the human brain. His application of these then-new imaging techniques to the study of working memory and cognitive control—and in particular, his work with his close colleague and friend John Jonides at the University ofMichigan—quickly made him one of the preeminent experts on working memory. This was due J. X. Van Snellenberg Division of Cognitive Neuroscience, New York State Psychiatric Institute, New York, NY, USA