Cortisol-induced impairments of working memory require acute sympathetic activation

The present study assessed whether the effects of cortisol on working memory depend on the level of adrenergic activity (as measured by sympathetic activation) during memory performance. After exposure to a psychosocial stress task, participants were divided into cortisol responders and nonresponders. Cortisol responders showed working memory impairments during the psychosocial stress phase, when cortisol and adrenergic activity were enhanced, whereas nonresponders did not. During recovery, however, when cortisol levels were elevated but adrenergic activity was normalized, working memory of responders did not differ from that of nonresponders. Among several stress measures, cortisol was the only significant predictor for working memory performance during stress. These findings suggest that adrenergic activation is essential for the impairing effects of stress-induced cortisol on working memory. It is well established that glucocorticoid (GC) hormones re-leased from the adrenal cortex during stressful or emotionally arousing experiences play an important role in the regulation of cognitive functions (see De Kloet, Oitzl, & Joëls, 1999; Lupien & Lepage, 2001; Roozendaal, 2002). Several studies in humans have documented a deleterious effect of GCs on the retrieval of previ-ously learned material, although they may enhance long-ter