The effect that vasopressin has upon memory in young and old males was tested in a double-blind crossover study. There were two 1-week medication periods; during one, subjects received 60 micrograms of vasopressin daily; during the other, placebo. Reaction time tasks were used to measure their speed of retrieval from: short-term memory (STM), long-term memory (LTM), and semantic memory (SM). While vasopressin did not affect SM retrieval time or simple vocal reaction time, it did reduce memory comparison time and perceptual-motor time in STM and retrieval time in LTM. The degree of facilitation was similar in young and old.
