Quantifying Resilience to Enhance Individualized Training

Resilience is the human ability to adapt in the face of tragedy, trauma, adversity, hardship, and ongoing life stressors. To date, experimental reports on this subject have focused on long-term trajectories (weeks to months) of resilience, with little or no focus on whether significant changes to resilience could be achieved by short-term interventions. Currently, an individual’s resilience is defined either by self-report or by behavioral changes such as the development of depression, post-traumatic stress disorder, or suicide. We propose that the quantification of an individual’s physiological and behavioral response to stress under controlled conditions is an indication of the individual’s level of resilience. To address such real-time resilience, we propose the first in a series of studies to evaluate real-time human resilience by exposing participants to controlled stressors while assessing the stress response. Activation of the hypothalamus-pituitary-adrenal cortex axis and sympathetic branch of the autonomic nervous system via monitoring of the pupil constriction, heart and respiration rate, muscle tonicity, salivary cortisol, and electrodermal activity will be assessed. Stress exposure will consist of virtual stressors presented using Virtual Battlespace 2 software-based scenarios, such as noise exposure, time pressure, and emotion-induction tasks, as well as external stressors such as socio-evaluative stress via the Trier social stress task, while evaluating decision-making and performance. The relationship between performance and the physiological stress response will be quantified, including the creation of a series of stress-performance trajectories based upon individual differences. Such an analysis is similar to probing for resilience in material testing, in which a load is applied to a candidate material, and the resulting forces and observable changes in dimension are quantified and reported via stress-strain curves. Ongoing studies will examine how this resilience measure may be integrated into a closed-loop training system to provide appropriate coping strategies to optimize resilience training. Such training programs, which take into account individual perceptions of stressors and physiological responses, are expected to be effective in helping trainees develop resiliency during high-stress operations.