Abstract
The ability to manipulate exact numbers is a signature human achievement, supporting activities like building bridges, designing computers, and conducting economic transactions. Underlying this ability and supporting its acquisition is an evolutionarily-conserved mechanism for the manipulation of approximate quantity: the analog magnitude system. The behavioral and neural signatures of magnitude representations have been extensively characterized but how these representations interact with other aspects of cognitive and visual processing is still largely unknown. Do magnitude features attach to objects, scenes, or surfaces? Is approximate magnitude representation maintained even for sets for which exact quantity is known? Is magnitude estimation ability altered by experience? The goal of our symposium is to look for answers to these questions by asking both how number is integrated into visual processing and how visual processing in turn forms a basis for the acquisition and processing of exact number. We address these questions through talks on three issues: 1) the basic psychophysical properties of numerical representations (Halberda, Burr), 2) how visual mechanisms integrate representations of number (Franconeri & Alvarez), and 3) how these representations support exact computation, both in standard linguistic representations (Frank) and via alternative representations (Barner). The issues addressed by our symposium have been a focus of intense recent interest. Within the last four years there have been a wide variety of high-profile reports from developmental, neuroscientific, comparative, and cross-linguistic/cross-cultural studies of number. Research on number is one of the fastest moving fields in cognitive science, due both to the well-defined questions that motivate research in this field and to the wide variety of methods that can be brought to bear on these questions. The target audience of our symposium is a broad group of vision scientists, both students and faculty, who are interested in connecting serious vision science with cognitive issues of broad relevance to a wide range of communities in psychology, neuroscience, and education. In addition, the study of number provides an opportunity to link innovations in vision research methods—including psychophysical-style experimental designs, precise neuroimaging methods, and detailed computational data analysis—with deep cognitive questions about the nature of human knowledge. We anticipate that attendees of our symposium will come away with a good grasp of the current state of the art and the outstanding issues in the interface of visual and numerical processing.