  The objective of this study is to develop and use a virtual reality game as a
tool to assess the effects of realistic stress on the behavioral and
physiological responses of participants. The game is based on a popular Steam
game called Keep Talking Nobody Explodes, where the player collaborates with
another person to defuse a bomb. Varying levels of difficulties in solving a
puzzle and time pressures will result in different stress levels that can be
measured in terms of errors, response time lengths, and other physiological
measurements. The game was developed using 3D programming tools including
Blender and virtual reality development kit (VRTK). To measure response times
accurately, we added LSL (Lab Stream Layer) Markers to collect and synchronize
physiological signals, behavioral data, and the timing of game events. We
recorded Electrocardiogram (ECG) data during gameplay to assess heart rate and
heart-rate variability (HRV) that have been shown as reliable indicators of
stress. Our empirical results showed that heart rate increased significantly
while HRV reduced significantly when the participants under high stress, which
are consistent with the prior mainstream stress research. We further
experimented with other tools to enhance communication between two players
under adverse conditions and found that an automatic speech recognition
software effectively enhanced the communication between the players by
displaying keywords into the player's headset that lead to the facilitation of
finding the solution of the puzzles or modules. This VR game framework is
publicly available in Github and allows researchers to measure and synchronize
other physiological signals such as electroencephalogram, electromyogram, and
pupillometry.
