Successful voluntary recruitment of cognitive control under acute stress.

In highly complex task situations (dual tasking), stressed individuals have been shown to adapt the most resource-efficient task processing strategy, accepting costs of performance. We argue that an interpretation of this behavior in terms of a stress-induced impairment of cognitive control might be too simplified. In the present study, we therefore tested whether stressed individuals are still capable to up-regulate cognitive control when instructed to adapt more resource-intensive strategies, enabling preservation of task performance. Fifty-six participants underwent either an established psychosocial stress induction protocol (Trier Social Stress Test) or a standardized control intervention. Afterwards, all participants performed a dual task in which task prioritization was systematically varied, calling for the adoption of different task processing strategies that require more or less voluntary top-down control. Although individuals of the stress group showed a pronounced stress response, as indicated by salivary cortisol, they were able to recruit more resources and to engage more voluntary top-down control when instructed to do so. This finding suggests an adaptive nature of control regulation under acute stress that reflects a compensatory capacity with the potential to account for some of the observed ostensible impairments of cognitive control. Our finding calls for careful empirical examination of whether stressed individuals cannot or do not recruit certain cognitive control functions in a given situation that will inform novel interventions to optimize performance in high-stress environments.