A beneficial effect of estrogen on working memory in postmenopausal women taking hormone replacement therapy

Recent neurophysiological data suggest that the prefrontal cortex (PFC) may be susceptible to modulation by estrogen. In humans, the PFC mediates a nu mber of cognitive processes that contribute to memory function, particularl y working memory. The present study examined whether memory tasks that recr uit PFC-dependent information processing might exhibit estrogen sensitivity in women. Performance on several memory tasks, including measures of worki ng memory, was evaluated in three groups of postmenopausal women: (1) women who were tested when taking estrogen only (n = 38, M-age = 55.1 years), (2 ) women who were tested when taking estrogen and a progestin concurrently ( n = 23, M-age = 55.9 years), and (3) women who were not taking hormone repl acement therapy (n = 35, M-age = 56.0 years). Estrogen users exhibited sign ificantly better performance on a verbal task and on a spatial task, each w ith a prominent working memory component, but did not differ from nonusers on control tasks involving simple passive recall. These findings are consis tent with the hypothesis that estrogen is active within PFC and is capable of influencing functions dependent on this region. The results of this stud y raise the possibility that estrogen may play a role in maintaining certai n frontal lobe functions in women. (C) 2000 Academic Press.