PURPOSE:: Deception detection studies had established that the detection accuracy was only slightly better than chance. The present study investigated whether deception detection could benefit from feedback treatment, and whether the effect would be modulated by cue modalities. Signal detection theory was applied to get deeper insights into the performance of deception detection.
METHODS: Typical lie detection tests were conducted. In the control condition, the participants passively observed totally 96 video clips of 6 models who were sometimes lying and sometimes telling the truth. The observers were asked to make judgement of whether the models were lying or telling the truth. In the feedback condition, after response, a right or wrong outcome feedback was given. In both conditions, participants completed lie detection tests via either visual modality cues or audiovisual modality cues separately in two successive weeks. The order was counterbalanced between participants.
Results: The overall accuracy results showed that the main effects of feedback and cue modalities were significant, but there’s no interaction between feedback and cue modalities. Separating performance into deceptive and truthful targets, one intriguing finding was the significant feedback × cue modalities × type of stimulus (deceptive vs. truthful) interaction effect. Signal detection theory analysis revealed that feedback treatment enhanced perceptual sensitivity, and led to a more liberal response criterion in both the visual cues based and the audiovisual cues based lie detection tests.
Conclusions: The results suggested that feedback treatment benefited the overall accuracy of deception detection. The feedback effects performed differently on the visual and audiovisual modalities depending on the type of stimulus. Furthermore, signal detection theory analysis suggested that the feedback effects on the overall accuracy might result from the enhanced perceptual sensitivity and the more liberal criterion.