Addie Johnson is Professor of Human Performance and Ergonomics at the University of Groningen, The Netherlands. She received her Ph.D. in Cognitive Psychology from Purdue University in 1993 and has been teaching and conducting research in the field of attention and human performance for over 10 years. She has taught courses on attention to over 1,000 students and thus brings broad experience to bear in writing this text for a student audience. After five years as Assistant Professor in Human Factors Psychology at Rice University (with a year off as visiting scientist at the Institute of Occupa...