Review of research on endorphins and learning

Advances in the neurochemistry of learning suggest that many endogenous substances modulate learning processes. Endorphins promote or interfere with learning depending on dose (physiologic versus pharmacologic), task (negative versus positive consequences), and learning stage during which the substance is administered. Endorphins cause amnesia for extraneous details of a task (allowing focusing on main events) and prevent extinction of a learned task (even when forgetting might be adaptive). We have summarized endorphin physiology and review studies of endorphins in animal learning. Implications for the study of human attention and learning disorders are presented.