Publication Date


Document Type


Committee Members

Subhashini Ganapathy, Ph.D. (Advisor); Jennie J. Gallimore, Ph.D. (Committee Member); Mary E. Fendley, Ph.D. (Committee Member); Thomas Wischgoll, Ph.D. (Committee Member); Michael E. Miller, Ph.D. (Committee Member)

Degree Name

Doctor of Philosophy (PhD)


Recent advancements in virtual environment (VE) technology and the growth of VE use in treating and training individuals are opening up new possibilities for rehearsal in safe and rich environments. Research has shown that VEs can be used to treat those with Post Traumatic Stress Disorder (PTSD), but very little research has been done to suggest good guidelines for creating an effective environment. This research was conducted to help inform the design of systems that let veterans rehearse potentially stressful experiences in a safe environment before having to physically step into that environment. We investigated responses to specific design components of a VE to aid in the development of systems that are effective for the military veteran participant. We evaluated the response to six stimuli as suggested and two types of system perspectives: first and third. Measures used included participant behavior, subjective unit of discomfort (SUD), and physiological responses including heart rate, heart rate variability, and respiration rate. The most effective system for veterans with PTSD should include an initial set of stimuli that can be configured to allow focus on specific traumas experienced by the individual, perhaps with the ability to vary stimulus intensity. These stimuli should include both a crowded room and startle noise scenario. A first person perspective with a head mounted display is the preferred design except in cases of individuals with previous motion sickness. These individuals should be tested for cyber sickness in a neutral first person VE before being exposed in a rehearsal setting. Results indicated that heart rate response is significantly different in those with PTSD than those who do not have PTSD, and SUD score change in those with PTSD provides useful information about the individual's reaction to each of the stimuli. Individuals with PTSD will also exhibit behaviors, such as avoidance of a stimulus, in VEs. Findings of this study imply that VEs other than virtual combat zones can elicit behavioral, emotional and physiological responses in those with PTSD, and these types of environments should be further studied for use with veterans with PTSD.

Page Count


Department or Program

Ph.D. in Engineering

Year Degree Awarded




Included in

Engineering Commons