Drug-induced changes in cognitive functions such as memory are generally domain specific rather than general effects, that is, only some components of memory are altered. Changes in memory can be secondary to alterations in other cognitive domains such as attention, or non-cognitive domains (mood and arousal), or the direct result of alterations on those neurobiological systems that determine memory functions. The selective memory impairing effects of benzodiazepines are used to illustrate how cognitive neuroscience methods and theory can be useful in assessing the memory changes produced by psychoactive drugs.