- The influence of cortisol on the balance between episodic memory and semantic information

Stress (or elevated cortisol concentration) typically impairs memory retrieval. The scenario model from Cheng et al. (2016) proposes that during retrieval, specifically during the construction of a scenario, only the gist is remembered, and missing information is substituted semantically. Since cortisol administration has been linked to reduced episodic memory retrieval, it remains to be explored if cortisol also impacts scenario construction. We have developed a new virtual reality-based paradigm that induced conflicts between episodic memory and semantic knowledge of the participants. In the current study, we investigated scenario construction in 60 participants with this virtual task during functional magnetic resonance imaging (fMRI). In addition, we administered 20 mg of hydrocortisone or placebo prior to retrieval. Cortisol was expected to lead to a stronger reliance on semantic information. This shift should be reflected in altered activations in medial temporal lobe regions. Cortisol-treated participants exhibited increased salivary cortisol concentrations relative to the placebo group. We found no group differences on the behavioral level. On the neural level, cortisol modulated hippocampal activity during retrieval of semantic responses. We will present further results of our currently ongoing analysis of the fMRI data. Our current findings illustrate for the first time the influence of cortisol on the interplay of episodic memory and semantic information and its underlying neural correlates. Results might help to mechanistically explain the reduced autobiographic memory specificity observed in patients with major depressive disorder.