New features include: a new "Fact or Fiction?" section in Chapter 1 spotlights some popular beliefs about biological psychology, each linked by page reference to in-depth discussions in subsequent chapters; research methods are given greater emphasis and are described in greater detail; discussions of clinical disorders are delineated more clearly in the text; the full-colour art programme has been further refined; more than 300 new references, all cited in the text, have been added; new research helps to round out or give new perspectives on major topics; and some older material has been condensed or deleted, keeping the text at its previous length.