This book is the product of a two-day symposium held at the University of Texas, Austin, in March 1978. There was double motivation for our hosting a symposium on neural mechanisms in behavior. The 1977-1978 academic year marked both the 50th anniversary of the Department of Psychology at Texas and the 30th anniversary of the famous Hixon Symposium organized by the longest serving member of the department, LLOYD JEFFRESS. PHILIP GOUGH, then chairman of the department, suggested that the department celebrate these two historic events, and honor itself in the process, by holding the first of a series of symposia on topics in experimental psychology. Approval and initial funding for this enterprise came from ROBERT KING, then Dean of Social and Behavioral Sciences; additional funds were pro­ vided by the Program in Cognitive Science of the Sloan Foundation. Proceeds from the sale of this volume will all pass into a fund to help support subsequent symposia and volumes. At 50 we are clearly a young department, even for a psy­ chology department, but psychology was at least nominally present from the beginning of The University of Texas in 1883. Then, courses in psychology were offered in the School of Philosophy and had wonderful titles, such as "Mental Science (Strictly Speaking). " In 1898, the first experimental psychology course was offered. (Or at least it was intended to be offered; the catalog indicated that it was contingent upon the availability of necessary equipment.