Amphetamine enhances human-memory consolidation

Although it is generally accepted that CNS stimulants have enhancing effects on long-term storage processes in laboratory animals, little is known about their influence on human learning. We report a series of experiments with free recall of lists of unrelated words, demonstrating a significant enhancement on long-term retention after amphetamine administration. A gradual increase of recall was observed up to 1 h after learning, remaining stable for at least 3 days, after oral administration before learning as well as intramuscular injection after learning. The results show that research on humans with drug-induced memory-enhancement techniques is necessary to supplement the animal studies for the understanding of the mechanisms involved in information consolidation.