Faces of emotion in human-computer interaction

The study of users' emotional behavior in the Human-Computer Interaction (HCI) field has received increasing attention during the last few years. Our work in this area focuses on the relationship between user emotions and perceived usability problems. Specifically, we propose to observe users' spontaneous facial expressions as a method to identify adverse-event occurrences at the user interface level.This paper reports on the results of an experiment designed to investigate the association between adverse-event occurrences during a word processing task and users' facial expressions monitored using electromyogram (EMG) sensor devices. The results suggest that an increase of task difficulty is related to an increase in specific facial muscle activity, thus creating a baseline for future developments using camera-based monitoring of facial activities.