Real-time Automatic Deceit Detection from Involuntary Facial Expressions

Being the most broadly used tool for deceit measure-ment, the polygraph is a limited method as it suffers from human operator subjectivity and the fact that target subjects are aware of the measurement, which invites the opportu-nity to alter their behavior or plan counter-measures in ad-vance. The approach presented in this paper attempts to cir-cumvent these problems by unobtrusively and automatically measuring several prior identified Deceit Indicators (DIs) based upon involuntary, so-called reliable facial expres-sions through computer vision analysis of image sequences in real time. Reliable expressions are expressions said by the psychology community to be impossible for a signifi-cant percentage of the population to convincingly simulate, without feeling a true inner felt emotion. The strategy is to detect the difference between those expressions which arise from internal emotion, implying verity, and those expres-sions which are simulated, implying deceit. First, a group of Facial Action Units (AUs) related to the reliable expres-sions are detected based on distance and texture based fea-tures. The DIs then can be measured and finally a decision of deceit or verity will be made accordingly. The perfor-mance of this proposed approach is evaluated by its real time implementation for deceit detection. 1