Figure 2.

Memory performance in the metyrapone versus placebo condition of reactivated versus non-reactivated story (A) and relation between individual differences in memory performance and cortisol suppression during sleep (B). A, Pharmacologically suppressing cortisol at 4:00 A.M. directly after re-activation of a story at 3:55 A.M. enhanced memory performance for the re-activated story 4 d later in the metyrapone versus placebo condition. Importantly, cortisol suppression resulted in enhanced memory only for the reactivated but not the non-reactivated story (significant substance by reactivation interaction). Error bars indicate SE and *p < 0.05, **p < 0.01. B, Individual metyrapone memory enhancement for the reactivated versus non-reactivated story was negatively correlated with the individual cortisol decrease because of metyrapone during sleep (τ = –0.450, p = 0.015).