Acute stress impairs memory retrieval independent of time of day

SummaryIt is widely recognized that acute stress and associated glucocorticoid stress responses yield memory-enhancing effects when the memory consolidation phase is targeted, while impairing effects are generally found with regard to memory retrieval performance. While some evidence exists that the memory-enhancing effects of consolidation stress are modulated by time of day, no study to date has investigated whether stress-induced retrieval deficits are also prone to such time of day effects. To address this issue, participants (N = 76) were exposed to a stressor or control condition before a retrieval test that probed for neutral and negative words learned 24 h before. Results show that stress exposure resulted in impaired retrieval of both neutral and negative words, but that time of day did not moderate this effect. This memory-impairing effect was larger for negative than for neutral information, and was significantly associated with stress-induced cortisol responses. The current findings demonstrate the robustness of stress-induced retrieval deficits throughout the day, in particular for emotional memory material, and further underscore the importance of cortisol reactivity in impairing memory retrieval.