Sex steroid hormones and Cognition

Abstract

Apart from their obvious role in the regulation of reproductive functions, sex steroid hormones also appear to influence cognition. Estrogen, testosterone and progesterone affect spatial cognition and non-spatial working memory. Testosterone supplementation seems to have a beneficial effect on spatial cognition. A curvilinear relationship between testosterone and performance on spatial tasks has been proposed. The testosterone to estrogen ratio might also play a role. Estrogen seems to have a detrimental effect on spatial abilities in humans as well as in animals. The effects of progesterone are less clear. Progesterone could modulate the effects of estrogen, but more research is needed to drawn final conclusions. There is not much evidence on sex steroid hormones influencing non-spatial working memory. Effects of sex steroid hormones on spatial cognition were found in many different circumstances. They arise when hormone levels are exogenously elevated and during the endogenous hormonal fluctuations of the menstrual and estrous cycles. Sex steroids affect spatial cognition in both humans and animals. Many of the effects mentioned could arise by adult neurogenesis in the dentate gyrus of the hippocampus. Steroid hormones can enhance the survival of newly formed neurons, thereby affecting spatial cognition. Evolutionary benefits of testosterone enhancing and estrogen impairing spatial cognition have been proposed. However, correlations between hormone levels and performance are often weak and it remains to be determined how significant they are. Whether results are found, depends on type and duration of hormone treatment, dosage, task, and other nonmnemonic variables. Sex steroid hormone levels can also influence the strategy chosen to solve a task. To conclude: sex steroids have a small effect, but they are just one of many factors that influence cognition.