The work of Richard M. Shiffrin has highly impacted the field of cognitive science, and current developments within perception and memory have been influenced by his ideas. In this volume, several key figures in the field will comment on these developments and put them in a wider perspective. Although many theories and models have been presented in recent years for various aspects of human cognition, there have not been many comparative evaluations that focus on how these models have really advanced our understanding of the underlying mechanisms. This volume will be a valuable source of information for both cognitive scientists working in the field, and researchers and students looking for a clear, accessible presentation of the key problems in cognitive science. Highlighted sections include attention and perception, memory functions and processes, knowledge representation and semantics, modelling approaches and applications.