One of the most common methods of inducing stress in the laboratory in order to examine the stress response in healthy and clinical populations is the Trier Social Stress Test (TSST). Briefly, the participant is asked to deliver a speech and to perform an arithmetic task in front of an evaluating committee. The committee, consisting of three trained actors, does not respond emotionally during the test, which makes the situation very stressful for the participant. One disadvantage of the TSST is that it can be difficult to hold the experimental conditions constant. In particular, it may be difficult for actors to hold their acting constant across all sessions. Furthermore, there are several practical problems and costs associated with hiring professional actors. A computerized version of the TSST using virtual humans could be a way to avoid these problems provided that it is able to induce a stress response similar to the one of the original TSST. The purpose of the present pilot study was therefore to investigate the stress response to a virtual reality (VR) version of the TSST visualized using an immersive VR system (VR-TSST). Seven healthy males with an average age of 24 years (range: 23–26 years) performed the VR-TSST. This included delivering a speech and performing an arithmetic task in front of an evaluating committee consisting of three virtual humans. The VR equipment was a CAVE equipped with stereoscopy and head tracking. ECG and respiration were recorded as well as the participant's behavior and comments. Afterward, a semi-structured interview was carried out. In general, the subjective and physiological data from the experiment indicated that the VR version of the TSST induced a stress response in the seven participants. In particular, the peak increase in heart rate was close to rates observed in studies using the traditional TSST with real actors. These results suggest that virtual humans visualized with an immersive VR system can be used to induce stress under laboratory conditions.

It is speculated that virtual environments (VE) might be used as a training tool in brain injury rehabilitation. The rehabilitation process often involves practicing so-called instrumental activities of daily living (IADL), such as shopping, cooking, and using a telephone. If a brain injury patient is to practice such activities in a VE, the patient must be able to navigate the viewpoint and interact with virtual objects in an understandable way. People with brain injury may be less tolerant to a poor interface and a VE might therefore become unusable due to, for example, an unsuitable input device. In this paper we present two studies aimed to do initial usability testing of VE interaction methods on people without experience of 3D computer graphics. In the first study four navigation input device configurations were compared: the IntelliKeys keyboard and the Microsoft Sidewinder joystick, both programmed with two and three degrees of freedom (DOF). The purpose of the second study was to evaluate a method for interaction with objects, and to find a sufficiently usable input device for this purpose. The keyboard was found to be more suitable for navigation tasks in which the user wants to give the viewpoint a more advantageous position and orientation for carrying out a specific task. No big differences could be found between two and three DOFs. The method for interaction with objects was found to work sufficiently well. No difference in performance could be found between mouse and touch screen, but some evidence was found that they affect the usability of the VE interface in different ways.