Neural signatures of human psychological resilience driven by acute stress.

Neurophysiological mechanisms underlying psychological resilience-the ability to overcome adversity-have been extensively studied in animals. However, compared to that in animals, human resilience is unique in that it is underpinned by higher-order cognitive functions, such as self-confidence, tenacity, and a positive attitude to challenges. Given these discrepancies, the neurophysiological mechanisms underlying human-specific resilience remain unclear. To address this issue, we aimed to record multimodal responses after acute stress exposure over 1.5 h using functional brain imaging and peripheral physiological measurements. We showed that the degree of individual resilience is indexed by multiple changes in neural dynamics 1 h after acute stress. Functional magnetic resonance imaging and electroencephalography show that activity in the cortical salience network and power in high-beta and gamma oscillations increase in less resilient individuals. Contrastingly, activity in the cortical default mode network and spontaneous activity in the posterior hippocampus increase in more resilient individuals. Machine learning analysis confirmed that, 1 h after stress exposure, the functional connectivity in the salience network was the most influential, followed by that in the default mode network, gamma power, high-beta power, and hippocampal activity. The neurophysiological dynamics for resilience do not occur as previously thought, but rather in a time-lagged manner against stress exposure. Our findings shed light on an approach to recovery from stress-induced deficits such as delayed neuromodulation after a stressful event.