MS Defense by MacKenzie Hughes

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Name: MacKenzie Hughes

Master’s Thesis Defense Meeting
Monday, January 25, 2021

Time: 10:00 AM – 12:00 PM

Location: https://bluejeans.com/624915361


Advisor: Chris Hertzog, Ph.D. (Georgia Tech)


Thesis Committee Members:

Chris Hertzog, Ph.D. (Georgia Tech)

Scott Moffat, Ph.D. (Georgia Tech)

Shevaun Neupert, Ph.D. (NC State)


Title: Exposure and Physiological Reactivity to Daily Stressors: The Role of Perceived Stress, Perceived Stress Reactivity, Age, and Cognitive Ability


Abstract: Identifying individual differences that buffer or exacerbate physiological reactivity to stressors can have important implications for health and well-being. This study focused on the roles perceived life stress, perceived stress reactivity, age, and cognitive ability have on within-person and between-person associations between naturally occurring stressors and cortisol and alpha-amylase activity. Using ecological momentary assessment for 10 consecutive days, 156 individuals ages 20-77 years old (M = 51.45, SD = 18.30) reported stressor exposures and provided seven saliva samples each day from which cortisol and alpha-amylase were assayed. Multilevel modeling was used to examine the role of daily stressors as well as each individual difference variable on the cortisol and alpha-amylase awakening response, diurnal slope, and area under the curve (i.e., total daily output). Results showed that the frequency of daily stressors had a significant positive correlation with perceived stress reactivity and cognitive ability. Within-persons, days with stressor exposures were associated with higher total daily cortisol output and steeper diurnal alpha-amylase slopes. A significant cross-level interaction emerged between daily fluctuations in the number of stressor exposures and individual differences in perceived stress reactivity, such that individuals high in perceived stress reactivity who experienced days with more stressor exposures had steeper daily alpha-amylase awakening responses. Between-persons, people who experienced more stressors per day tended to have flatter diurnal alpha-amylase slopes. Individuals higher in perceived stress who experienced more stressors on average had steeper diurnal cortisol slopes. Although there were no age differences in the frequency of reported stressors, older people who experienced more stressors on average had steeper alpha-amylase awakening responses compared to younger people. All effects remained significant after controlling on neuroticism. Findings indicated that naturally occurring stressors predict within-person fluctuations as well as individual differences in cortisol and alpha-amylase activity. The Perceived Stress Reactivity Scale may predict within-person variability in alpha-amylase reactivity to stress, whereas the Perceived Stress Scale may be more closely associated with long-term changes in cortisol activity. In a healthy, lifespan sample, this study identified potential vulnerability and resilience factors relevant to the stress process.


  • Workflow Status:Published
  • Created By:Tatianna Richardson
  • Created:01/12/2021
  • Modified By:Tatianna Richardson
  • Modified:01/12/2021