Date of Award

Summer 2013

Access Type

Thesis - Open Access

Degree Name

Master of Science in Human Factors & Systems


Human Factors and Systems

Committee Chair

Albert J. Boquet, Ph.D.

First Committee Member

Shawn Doherty, Ph.D.

Second Committee Member

Mike Wiggins, Ed.D.


The purpose of this study was to examine the effects of acute psychosocial stress on cognitive performance. Psychosocial stress evolves from the perceived presence of a social evaluative threat and results in the activation of the home hypothalamic-pituitary-adrenal axis. As part of this reaction the stress hormone cortisol is secreted into the blood stream, ultimately crossing the blood-brain barrier, where it can have profound effects on various aspects of cognition. A review of the literature reveals that that attention, working memory, spatial judgment and cognitive processing efficiency are particularly susceptible to stress induced changes in performance level. A test battery from the Automated Neuropsychological Assessment Metrics library was utilized to test these aspects of cognition under basal and stressed conditions. Specifically, the Manikin task, Mathematical Processing task and Switching task were utilized. The Trier Social Stress Test protocol was employed to induce a psychosocial stress reaction in participants. Eight male volunteers were recruited as participants for this study and a within subjects design was used. Participants demonstrated significantly elevated salivary cortisol concentrations following exposure to the stress manipulation, suggesting that the Trier Social Stress Test was successful at eliciting a psychosocial stress response amongst participants. In the Stressed condition performance on the Manikin task demonstrated a reduction in response latency and an increase throughput, calculated as an accuracy-speed ratio. Performance on the Switching task also demonstrated a reduction in response latency in the Stressed condition. These findings lend support to the theory that performance under stress follows an inverted-U shaped curve as cognitive performance improved under moderate amounts of stress.