It has long been thought that the experience and expression of emotions is lateralized in the brain. Based on behavioral observations of patients with brain lesions, sodium amytal studies, and EEG recordings, current models postulate that positive (or approach- related) emotions are more strongly lateralized toward the left hemisphere, whereas neg ative (or withdrawal-related) emotions are more strongly lateralized toward the right hemisphere. The recent application of functional brain imaging to the study of emotion has generated new data that seem inconsistent with this position. In reviewing these brain-imaging studies, methodological and theoretical considerations are offered that may explain why this line of research has so far been largely unsuccessful in detecting hem ispheric asymmetry in emotional experience. NEUROSCIENTIST 5:201-207, 1999