Evaluating Photoplethysmogram as a Real-Time Cognitive Load Assessment during Game Playing

Abstract

ABSTRACTAccurate evaluation for user experience during computer game playing is very important in optimizing game design to improve the gaming experience. When evaluating user experiences, the concept of cognitive load is crucial for dynamically responding to game players’ mental status. In our former studies, the photoplethysmogram (PPG)-based Stress-Induced Vascular Response Index (sVRI) shows better sensitivity and reliability in measuring cognitive loads compared with heart-rate variation, blood pressure, and galvanic skin response. In this study, we use memory matrixes and Pop Cap’s tower defense game Plants vs. Zombies as cognitive tasks and use sVRI to assess players’ cognitive load dynamically during the real-time computer games. Evaluations on cognitive tasks verified the usability of sVRI in comparison with other indexes derived from PPG, such as heartbeat interval, area under curve, digital pulse amplitude, reflection index, and inflection point area ratio. Our findings indicate the potential of sVRI for assessing game players’ mental workload in real time.