About This Project

Exposure therapy (EXP) is an intervention based upon behavioral extinction. Many technologies have been used to augment EXP by presenting multi-sensory cues (e.g., sights, sounds) to increase patients’ sense of presence. Exploratory research has only broadly examined the effect of odorants on the patient’s sense of presence (feeling "really there") during EXP. In this study, the effect of smell and memory will be assessed via physiological and self-report measures.

Ask the Scientists

What is the context of this research?

Exposure therapy is a first-line intervention for combat-related Posttraumatic Stress Disorder (PTSD). The goal of exposure therapy is to extinguish behaviors that are, or have become, maladaptive by exposing the patient to the anxiety or fear-producing stimulus (or a facsimile of that stimulus) without exposing the patient to actual danger. VR systems are increasingly being utilized to this end. However, the specific effect of odorants (smells) has been largely neglected.

Presence refers to how much a person feels "really there" within VR. If odorants influence how present or immersed an individual feels while engaged in a virtual environment, it is possible that augmenting VR exposure may improve or accelerate clinical improvement in individuals suffering from PTSD.

What is the significance of this project?

Understanding the relationship between memory, presence, and olfaction may result in improved intervention planning and treatment outcome. If memory influences presence, special attention may be required to ensure the deployment of VR congruent with patient memories. Similarly, if odorants enhance the sense of presence in veterans and service members in an environment during simulated exposure tasks, it seems logical that exposure therapy may be more effective when olfactory cues are added.

What are the goals of the project?

The first goal will be equip our lab with the needed equipment to drive this study. This includes the virtual reality equipment and physiological recording devices. Once we complete setup, we will begin recruiting.

We conducted a power analysis to determine our required sample size for this study. We require 78 subjects across all four conditions for a 80% chance of detecting differences between groups. Our groups consist of military service members, veterans, and nonmilitary controls, who will be located from the local community. We hope to have recruitment completed by June, 2017.

Once subject recruitment and data collection are complete, we will analyse our data set. Utilizing appropriate statistical models, we will examine differences between groups.