Humans strive to maintain a constant internal environment by generating physiological responses to external stimuli. Stimuli that elicit physiological and psychological responses are called stressors, and the body’s response to a stressor is called the stress response. The stress responses of aversion or fear play important roles in survival. Additionally, it has been suggested that if an organism does not have sufficient resilience to an acute stress response, central nervous system damage or psychosomatic disorders may occur. The concept of “resilience” is used in research focusing on stress reactions, especially to psychosocial stressors. Quantitative measurements are required to examine recovery from stress reactions. This paper describes the importance of resilience research and provides an overview of the neurophysiological mechanisms and measurement methods of stress responses.
