Effects of the combination of P3-based GKT and reality monitoring on deceptive classification

Abstract

The study aimed to investigate whether a combination of the P3-based Guilty Knowledge Test (GKT) and reality monitoring (RM) distinguished between individuals who are guilty, witnesses, or informed, and using both tests provided more accurate information than did the use of either measure alone. Participants consisted of 45 males that were randomly and evenly assigned to three groups (i.e., guilty, witness, and informed). The guilty group conducted a mock crime where they intentionally crashed their vehicle into another vehicle in a virtual environment (VE). As those in the witness group drove their own vehicles, they observed the guilty groups' vehicle crash into another vehicle. The informed group read an account and saw screenshots of the accident. All participants were instructed to insist that they were innocent. Subsequently, they performed the P3-based GKT and wrote an account of the accident for the RM analysis. A higher P3 amplitude corresponded to how well the participants recognized the presented stimulus, and a higher RM score corresponded to how well the participants reported vivid sensory information and how much less they reported uncertain information. Findings for the P3-based GKT indicated that the informed group showed lower P3 amplitude when presented with the probe stimulus than did the guilty and witness groups. Regarding the RM analysis, the informed group obtained higher RM scores on visual, temporal, and spatial details and lower scores on cognitive operations than the guilty and witness groups. Finally, discriminant analysis revealed that the combination of the P3-based GKT and RM more accurately distinguished between the three groups than the use of either measure alone. The findings suggest that RM may build upon a weakness of the P3-based GKT's. More specifically, it may build upon its susceptibility to the leakage of information about the crime, therefore helping protect innocent individuals who have information about a crime from being perceived as guilty.

Deception research today

“…Several studies focused on event-related brain potentials and demonstrated that ERP components were susceptible to contextual factors such as the personal involvement in a misdeed during encoding (Jang et al, 2013 ) or the nature of memory tested in the CIT (episodic vs. semantic, Ganis and Schendan, 2013 ). Furthermore, it was found that depth of encoding modulated electrodermal responses to crime-related details but did not affect P300 responses in the CIT (Gamer and Berti, 2012 ).…”

“…These studies collectively demonstrate that a number of behavioral and physiological variables are susceptible to concealed information and therefore allow for detecting individuals with crime-related knowledge. Moreover, several of these studies reported enhanced classification accuracy when combining different indices of concealed information (Ambach et al, 2012 ; Seymour et al, 2012 ; Jang et al, 2013 ).…”

The Roles of Left Versus Right Anterior Temporal Lobes in Conceptual Knowledge: An ALE Meta-analysis of 97 Functional Neuroimaging Studies

“…Specifically, it has been proposed that the left ATL is preferentially involved in processing names of people and the right ATL is preferentially involved in processing familiar faces ( Damasio et al 2004 ; Snowden et al 2004 ; Gainotti 2013 ). There is also an ongoing debate as to whether the ATLs preferentially process semantic knowledge for familiar people ( Simmons et al 2010 ; Von Der Heide, Skipper, Olson 2013 ), which could be related to their high intrinsic social relevance.…”

Individual differences in ERPs during deception: Observing vs. demonstrating behavior leading to a small social conflict

“…Some studies compared the P300-based CIT effect for culprits of a mock-crime with witnesses or participants who were informed about the mock-crime (Jang et al, 2013;Rosenfeld, Ozsan, et al, 2017;Winograd & Rosenfeld, 2014). Culprits performed or imagined performing an immoral behavior, like stealing a ring or intentionally hitting another person in a car crash.…”