Neuropsychological studies of amnesic patients, cognitive studies of normal individuals, and functional neuroimaging studies have shaped our understanding of the cognitive and neural bases of various forms of human memory. This article reviews the functional and neural characteristics of working memory, declarative memory, and nondeclarative memory. In so doing, it highlights the pattern of impaired and preserved memory abilities that characterize different neurologic populations. This knowledge provides a framework for analyzing patients' neuropsychological deficits in terms of underlying cognitive processes.