Stressful experiences, especially in childhood, can have impacts that extend far into the future. Fortunately, we humans are endowed with a set of cognitive abilities known as executive function, which enables us to minimize the effects of stress. Executive function allows us to override many of our biological impulses and engage in goal-directed behavior. We all use executive function every day, for everything from playing video games to studying while our friends are out having fun or stopping ourselves before we finish off the whole bag of Flamin’ Hot Cheetos. These abilities also help us organize our lives to avoid stressful situations, and to cope with stress when it inevitably occurs, for instance by framing a seemingly negative situation in a more neutral or positive light.
Evolution has provided us with the fight or flight response, which utilizes a biological pathway known as the hypothalamic-pituitary-adrenal (HPA) axis, to prepare us either to engage or flee from a perceived threat. This was extremely useful back in the days of running from bears and hunting deer with our bare hands, but we have come a long way since then. Nowadays, the fight or flight response can be quite a nuisance if it is triggered by something like an upcoming exam, to which neither fighting nor fleeing is a productive response. Nevertheless, this response is activated whenever the body perceives a threat, and this constant readjustment of the body’s state of arousal to meet environmental demands is called allostasis.
Repeated activation of the HPA axis can cause wear and tear on the body, which is known as allostatic load. This wear and tear is spread across many physiological systems, so it can be measured in a variety of ways. Researchers typically quantify allostatic load using some combination of stress hormone levels, blood pressure, heart rate variability, body mass index, and other potential biomarkers of cumulative stress.
Extreme or chronic stress can be particularly damaging early in life, since the body’s stress response is still developing. For example, if a child grows up in an abusive or unpredictable home environment, he or she will be primed to constantly be on guard and to react strongly to any perceived threat. This priming occurs in part because of an overactive HPA axis, which can harm many other physiological systems and set the stage for the further accumulation of stress later in life.
Although executive function has been shown to reduce the effects of stress, very little work has been done to determine its impact on allostatic load. It is also unclear which components of executive function – including working memory, cognitive inhibition, and set shifting – are responsible for its stress-reducing effects. My project is an attempt to clarify this confusion. I will use questionnaires, cognitive assessments, and physiological data to measure childhood stress, allostatic load, and components of executive function in NIU undergraduate students. If I find that childhood stress contributes to allostatic load, I will use statistical analyses to determine which, if any, components of executive function buffer this effect.