The ways in which we attend, learn, and remember are related to our transitory moods and to our enduring emotional states. Intuitively appealing to the self-reflective person, this claim has been verified by experimental and clinical psychologists in both laboratory and naturalistic studies. In some studies, psychologists measure differences in emotional states and determine whether those differences are associated with differences in the ways that the participants perform cognitive tasks. These studies usually focus on unpleasant emotions and moods, such as depression and anxiety. In other studies, psychologists attempt to induce either unpleasant or pleasant moods in the participants (perhaps by having them listen to different types of music) and then examine how performance is affected by these manipulations. Both types of research have tried to answer two major questions about the interaction of mood and memory: Do people remember events that...