Detection of concealed information: combining a virtual mock crime with a P300-based Guilty Knowledge Test

The present study examined the detection of concealed information by combining a virtual mock crime with a P300-based Guilty Knowledge Test (GKT). Thirty-eight male participants were assigned to one of two groups: a guilty group that committed a mock crime to conceal a lost roll of bills in a computer simulation of a virtual library and an innocent group that was free from concealed information. Remarkably, the guilty group reacted with stronger P300 peak amplitudes to crime-relevant than to irrelevant stimuli, whereas the innocent group had similar P300 responses between crime-relevant and irrelevant stimuli. Deception-related cognitive activity based on P300 was revealed as a valid marker to differentiate between guilty and innocent. This is a highly empirical study combining a virtual mock crime with a P300-based GKT to detect deception. These results may be applied to a variety of areas dealing with not only forensic investigation but also health and medical research concerning deception as a symptom.