Virtual Environments and Virtual Humans for Military Mild Traumatic Brain Injury and Posttraumatic Stress Disorder: An Emerging Concept

Since September 11, 2001, the United States has deployed 1.5 million or more military personnel to Iraq and Afghanistan (Hoge et al, 2008). With increasing deployment, there has been a corresponding increase in the incidence of traumatic brain injury and posttraumatic stress disorder among returning personnel (Bahraini et al., 2014).

Deficits associated with mild traumatic brain injury and posttraumatic stress disorder include disturbances in attention and memory, depression, anxiety, impulsivity, emotional outbursts, intolerance of crowds, and hypervigilance. These render the demands of everyday life overwhelming. Many veterans with mild traumatic brain injury/ posttraumatic stress disorder become isolated as they withdraw from social contact. Cognitive behavioral therapy requires veterans to negotiate daily activities and interactions (e.g., attending appointments). Here, impairments associated with mild traumatic brain injury or posttraumatic stress disorder are most pronounced.

Virtual environments (VEs) and virtual humans (VHs) hold the potential to address these problems. VEs are computer-generated, immersive, and interactive virtual reality constructs for simulation and learning. VHs are specialized types of automated virtual reality human figures, which display lifelike movement, appearance, and gestures and are able to recognize and respond to human speech or textual communication. VHs are an excellent means to present social challenges, probe or train attitudes and beliefs, and teach social strategies and coping mechanisms.

VEs/VHs provide opportunities for interaction between warriors and therapists in fully immersive, customizable, controlled, and low-threat environments (Fig. 1). These environments have the potential for infinite repetitions of assessment or training tasks. They have the capacity to provide customized sensory presentations, task complexity, and response requirements. The nature and pattern of the feedback are easily modified to suit the user. VEs/VHs are well suited for trial-and-error learning and errorless learning and may act as a bridge, facilitating reentry into everyday life. The authors are developing a VE grocery store (Fig. 2) that includes VH cashiers as adjuncts to traditional cognitive behavioral therapy. The V-Mart store allows therapists to select tasks (e.g., purchase items from a list, make change, purchase items) and set environmental parameters (e.g., noise level, number and appearance of shoppers, location, and availability of items). The therapist may choose to introduce additional stressors such as a collision with another shopper. Upon checkout, the therapist will be able to choose a virtual cashier and choose between different dialogue scripts, including scripts with uncooperative or rude content that simulate heated encounters, providing an ecologically valid and dynamic opportunity for assessment and training.

FIGURE 1.

Navigation of the VE and associated tasks (here, inspecting nutritional information from a container of milk) is practiced by a research team member.

FIGURE 2.

View upon entering the VE V-Mart.