Enhanced Human Memory Consolidation With Post-Learning Stress: Interaction With the Degree of Arousal at Encoding

TLDR

Endogenous stress hormones such as epinephrine and corticosterone modulate memory consolidation in animals. The authors aimed to test whether post‑learning stress interacts with encoding arousal to influence memory consolidation. They administered cold pressor stress or a control after subjects viewed slides of varying emotional content and assessed memory one week later. The study showed that post‑learning stress hormones enhance memory for emotionally arousing slides but not for neutral slides, confirming that the effect depends on encoding arousal.

Abstract

Abundant evidence indicates that endogenous stress hormones such as epinephrine and corticosterone modulate memory consolidation in animals. We recently provided the first demonstration that an endogenous stress hormone (epinephrine) can enhance human memory consolidation. However, these findings also suggested that post-learning stress hormone activation does not uniformly enhance memory for all recently acquired information; rather, that it interacts with the degree of arousal at initial encoding of material in modulating memory for the material. Here we tested this hypothesis by administering cold pressor stress (CPS) or a control procedure to subjects after they viewed slides of varying emotional content, and assessing memory for the slides 1 wk later. CPS, which significantly elevated salivary cortisol levels, enhanced memory for emotionally arousing slides compared with the controls, but did not affect memory for relatively neutral slides. These findings further support the view that post-learning stress hormone-related activity interacts with arousal at initial encoding to modulate memory consolidation.