Stress-Induced Increase in Cortisol Negatively Affects the Consolidation of Contextual Elements of Episodic Memories

Stress can modulate episodic memory in various ways. The present study asks how post-encoding stress affects visual context memory. Participants encoded object images centrally positioned on background scenes. After encoding, they were either exposed to cold pressure stress (CPS) or a warm water control procedure. Forty-right hours later, participants were cued with object images, and for each image, they were asked to select the background scene with which it was paired during study among three highly similar options. Only male but not female participants reacted with a significant increase in salivary cortisol to CPS, and the stress and control group did not differ in recognition performance. Comparing recognition performance between stress responders and non-responders, however, revealed a significant impairment in context memory in responders. Additionally, proportional increase in cortisol was negatively correlated with the number of correctly recognized scenes in responders. Due to the small number of responders, these findings need to be interpreted with caution but provide preliminary evidence that stress-induced cortisol increase negatively affects the consolidation of contextual elements of episodic memories.