A non-arousing test situation abolishes the impairing effects of cortisol on delayed memory retrieval in healthy women.

Animal and human studies have repeatedly shown that stress hormones influence memory. Glucocorticoids (GCs) enhance memory consolidation but impair memory retrieval. Studies in rodents indicate that adrenergic activation is necessary for GC induced effects on memory. We have shown, in two previous placebo-controlled double-blind experiments, that memory retrieval is significantly impaired after oral cortisol (30 mg) treatment in healthy young women. Here, we changed the experimental setting before and during the retrieval testing, so that the participants (n=31) experienced a more relaxed test situation. The learning material, the timing and the tester used were identical to the two previous studies. In the relaxed condition no effect of cortisol on memory retrieval occurred (p=0.84). The results indicate that the experimental setting can influence the effect of cortisol on memory. Our findings suggest that glucocorticoid effects on memory retrieval require testing-associated arousal in humans.