Introduction

Any reader who turns to a book with the word attention in the title, might be forgiven for or thinking that the author would have a clear idea or precise definition of what attention actually is. Unfortunately, attention is a concept that psychologists have been particularly reluctant to define. Despite William James’s (1890) oft-quoted remark that “Everyone knows what attention is”, it would be closer to the truth to say that “Nobody knows what attention is” or at least not all psychologists agree. The problem is that attention is not a single concept, but the name for a variety of psychological phenomena.