title: Impact of Stress and Glucocorticoids on Schema-Based Learning.
abstract: Pre-existing knowledge, a 'schema', facilitates the encoding, consolidation, and retrieval of schema-relevant information. Such schema-based memory is key to every form of education and provides intriguing insights into the integration of new information and prior knowledge. Stress is known to have a critical impact on memory processes, mainly through the action of glucocorticoids and catecholamines. However, whether stress and these major stress mediators affect schema-based learning is completely unknown. To address this question, we performed two experiments, in which participants acquired a schema on day 1 and learned schema-related as well as schema-unrelated information on day 2. In the first experiment, participants underwent a stress or control manipulation either immediately or about 25 min before schema-based memory testing. The second experiment tested whether glucocorticoid and/or noradrenergic activation is sufficient to modulate schema-based memory. To this end, participants received orally a placebo, hydrocortisone, the α2-adrenoceptor-antagonist yohimbine, leading to increased noradrenergic stimulation, or both drugs, before completing the schema-based memory test. Our data indicate that stress, irrespective of the exact timing of the stress exposure, impaired schema-based learning, while leaving learning of schema-unrelated information intact. A very similar effect was obtained after hydrocortisone, but not yohimbine, administration. These data show that stress disrupts participants' ability to benefit from prior knowledge during learning and that glucocorticoid activation is sufficient to produce this effect. Our findings provide novel insights into the impact of stress and stress hormones on the dynamics of human memory and have important practical implications, specifically for educational contexts.
authors.affiliation: Department of Cognitive Psychology, University of Hamburg, Hamburg, Germany.
authors.forename: Lisa Marieke
authors.initials: LM
authors.lastname: Kluen
authors.affiliation: Department of Cognitive Psychology, University of Hamburg, Hamburg, Germany.
authors.forename: Patricia
authors.initials: P
authors.lastname: Nixon
authors.affiliation: Department of Psychiatry, University Clinic Hamburg- Eppendorf, Hamburg, Germany.
authors.forename: Agorastos
authors.initials: A
authors.lastname: Agorastos
authors.affiliation: Department of Psychiatry, University Clinic Hamburg- Eppendorf, Hamburg, Germany.
authors.forename: Klaus
authors.initials: K
authors.lastname: Wiedemann
authors.affiliation: Department of Cognitive Psychology, University of Hamburg, Hamburg, Germany.
authors.forename: Lars
authors.initials: L
authors.lastname: Schwabe
mesh_terms: D058669:Adrenergic alpha-2 Receptor Antagonists / Q000009:adverse effects*; D000328:Adult; D060825:Cognitive Dysfunction / Q000139:chemically induced / Q000209:etiology* / Q000503:physiopathology*; D005260:Female; D005938:Glucocorticoids / Q000009:adverse effects*; D006801:Humans; D006854:Hydrocortisone / Q000009:adverse effects; D007858:Learning / Q000187:drug effects / Q000502:physiology*; D008297:Male; D013315:Stress, Psychological / Q000150:complications*; D015016:Yohimbine / Q000009:adverse effects; D055815:Young Adult
chemical_list: D058669:Adrenergic alpha-2 Receptor Antagonists; D005938:Glucocorticoids; D015016:Yohimbine; D006854:Hydrocortisone