OXYGEN ADMINISTRATION ENHANCES MEMORY FORMATION IN HEALTHY-YOUNG ADULTS

Despite numerous studies indicating that transient cerebral oxygen dep letion has a detrimental effect on cognition, surprisingly little rese arch has examined the possibility of cognitive enhancement following e levated oxygen levels in healthy adults. Here, we present evidence dem onstrating that oxygen administration improves memory formation, Inhal ation of oxygen immediately prior to learning a word list resulted in a significant increase in mean number of words recalled 10 min later, compared to subjects who inhaled oxygen immediately prior to recall or to controls who underwent no intervention. In a second experiment, th e learning-test interval was increased to 24 h and, again, only pre-le arning (but not pre-test) oxygen administration resulted in significan t memory facilitation,In experiment 3, inhalation of oxygen prior to l earning was compared to inhalation of compressed air, oxygen (but not compressed air) resulted in a significant increase in word recall 24 h later. In no experiment did oxygen have a significant effect on any m ood item measured. We interpret these data as indicating that increase d availability of cerebral oxygen facilitates cognition, including mem ory consolidation. The implications for the psychopharmacology of cogn itive enhancement are considered in the context of cholinergic systems and neural metabolism.