The field of neuroscience is progressing so rapidly that even expressions such as “by leaps and bounds” fail to capture the pace of its growth. Questions that at one time were thought to be unanswerable – perhaps even unaskable – have now been asked and in some cases answered, and new questions once unthinkable are now asked matter-of-factly. Much of this acceleration is due to the maturing of the field – advances in techniques as well as in theory – fueled by an infusion of research support during the 1990s “Decade of the Brain” effort.

It is impossible to capture fully the sweep of discoveries and advances that emerged from that decade within the covers of a single volume. It is possible, however, to provide a sample of the best of that work, both as recognition of what has been accomplished during that period of time and since, and as a harbinger of what is surely to come as the pace of neuroscience shows no hint of slowing down.

Our goal in the present volume is to provide that sample through carefully chosen topics and even more carefully chosen researchers in those fields. Singling out the four most important problems in neuroscience is probably an unwise goal and is a surefire way to start an argument. That said, however, few would argue that the four featured here are anything less than powerful candidates for that inner circle: higher order perception; language; memory systems; and sensory processes.