Modern humans spend much of their early lives participating in formal educational programs designed to increase their cognitive competencies. Despite this concerted effort to maximize individuals intellectual capacities, scientists and educators know relatively little about the neural factors that determine when and how learning experiences lead to improvements in cognitive abilities. Current theories of how brains are changed by learning focus on incremental adjustments to connections between neurons that are driven by increases in neural activity. This article summarizes past theoretical and experimental research on the relationship between neural plasticity and experience-dependent changes in cognition, briefly describes recent technological advances in measuring and inducing brain plasticity mechanisms, and outlines key questions that researchers must address to provide a more complete understanding of the factors that enable people to learn new cognitive skills. Answering such questions will require the combined efforts of neuroscientists, psychologists, and educational researchers, as well as the development of new technologies for monitoring neural changes in humans and other animals as they learn to perform a variety of cognitive tasks.