Hydrocortisone counteracts adverse stress effects on dual-task performance by improving visual sensory processes

The impact of acute stress on executive processes is commonly attributed to glucocorticoid-induced disruptions of the pFC. However, the occipital cortex seems to express a higher density of glucocorticoid receptors. Consequently, acute stress effects on executive processes could as well be mediated by glucocorticoid e.g., cortisol-induced alterations of visual sensory processes. To investigate this alternative route of stress action by demarcating the effects of acute stress and cortisol on executive from those on visual sensory processes, 40 healthy young men completed a standardized stress induction i.e., the Trier Social Stress Test and control protocol in two consecutive sessions. In addition, they received either a placebo or hydrocortisone 0.12-mg/kg bodyweight pill and processed a dual and a partial report task to assess their executive and visual sensory processing abilities, respectively. Hydrocortisone administration improved both partial report and dual-task performance as indicated by increased response accuracies and/or decreased RTs. Intriguingly, the hydrocortisone-induced increase in dual-task performance was completely mediated by its impact on partial report performance i.e., visual sensory processes. Moreover, RT measures in both tasks shared approximately 26% of variance, which was only in part attributable to hydrocortisone administration ΔR2 = 8%. By contrast, acute stress selectively impaired dual-task performance i.e., executive processes, presumably through an alternative route of action. In summary, the present results suggest that cortisol secretion as mimicked by hydrocortisone administration may counteract adverse residual stress effects on executive processes by improving visual sensory processes e.g., the maintenance and amplification of task-relevant sensory information.