The study of mental representation is a central concern in contemporary cognitive psychology. Knowledge, Concepts, and Categories is unusual in that it presents key conclusions from across the different subfields of cognitive psychology. Readers will find data from many areas, including developmental psychology, formal modelling, neuropsychology, connectionism, and philosophy.

The difficulty of penetrating the fundamental operations of the mind is reflected in a number of ongoing debates discussed - for example, do distinct brain systems underlie the acquisition and storage of implicit and explicit knowledge, or can the evidence be accommodated by a single-system of knowledge representation?