The Stroop Room: A Virtual Reality-Enhanced Stroop Test

The Stroop Test is a well known and regularly employed stressor in laboratory research. In contrast to other methods, it is not based on fear of physical harm or social shame. Consequently, it is more likely accepted by a wide population. In our always-on, technology-driven, social-media centered world, large-scale in-field stress research will need adequate experimental tools to explore the increasing prevalence of stress-related diseases without bringing subjects into laboratories. This is why we designed the Stroop Room: A virtual reality-based adaptation of the Stroop Test using elements of the virtual world to extend the demands of the original test and at the same time make it easily accessible. It is open source and can be used and improved by anyone as an in-the-wild, repeatable, laboratory-quality stressor. In this work, the method is presented and an evaluation study described, to demonstrate its effectiveness in provoking cognitive stress. 16 male and 16 female subjects were tested in the Stroop Room while recording the electrocardiogram, electrodermal activity, saliva based cortisol and alpha-amylase, performance metrics and an array of questionnaire-based assessments regarding psychological confounders, stress state and likability of the simulation. Our results show that the Stroop Room increases heart rate on average by 19%, other heart rate variability time-domain parameters (RMSSD, pNN50) decrease by 24%-47%, and its most stress-correlated frequency-parameter (LF/HF) increases by 107%. Skin conductance (SC) level increases by 63% and non-specific SC responses by 135% on average. Salivary cortisol and alpha-amylase concentrations increase significantly in some specific conditions. Compared to related work using the Stroop Test, this is an improvement for some metrics by around 30%-40%. Questionnaire evaluation show a strong engagement of users with the simulation and some aspects of a flow-induction. These findings support the effectiveness of a Stroop Test involving 3-dimensional interactivity and thus the Stroop Room demonstrates how this can be applied in a playful interaction that could be used pervasively.