No retrieval-induced forgetting under stress

Stress affects memory, yet no study has investigated the effects of stress on memory inhibition: Remembering not only facilitates later recall, but also inhibits retrieval of related material, a phenomenon known as retrieval-induced forgetting. We investigated the effects of stress on this mechanism, which is thought to adaptively guide memory selection. Participants learned categorized lists and were then exposed to either a psychosocial laboratory stressor or a cognitively challenging control treatment. They then actively retrieved parts of the previously learned material. Finally, memory for all initially learned items was tested. In the stress group, unlike in the control group, intervening retrieval practice did not impair final recall. Moreover, salivary cortisol levels increased and psychological well-being decreased in the stress group only. Thus, psychosocial stress abolishes retrieval-induced forgetting. This effect may result from stress-induced hormone release from the hypothalamic-pituitary-adrenal (HPA) axis and may have implications for educational, legal, and clinical issues.