scholarly journals Item Roles Explored in a Modified P300-Based CTP Concealed Information Test

2019 ◽  
Author(s):  
Gáspár Lukács ◽  
Alicja Grządziel ◽  
Marleen Kempkes ◽  
Ulrich Ansorge
Keyword(s):  
Task Performance ◽  
Visual Similarity ◽  
The Other ◽  
Trial Protocol ◽  
Concealed Information Test ◽  
Probe Task ◽  
Other Hand ◽  
Overall Efficiency ◽  
Concealed Information ◽  
Information Test

In this study, we introduced familiarity-related inducer items (expressions referring to the participant’s self-related, familiar details: “mine,” “familiar”; and expressions referring to other, unfamiliar details, e.g., “other,” “irrelevant”) to the Complex Trial Protocol version of the P300-based Concealed Information Test (CIT), at the same time using different item categories with various levels of personal importance to the participants (forenames, birthdays, favorite animals). The inclusion of inducers did not significantly improve the overall efficiency of the method as we would have expected considering that these inducers should increase awareness of the denial of the recognition of the probes (the true details of the participants), and hence the subjective saliency of the items (Lukács, Kleinberg, & Verschuere, 2017). This may be explained by the visual similarity of inducers to the probe and irrelevant items and the consequent distracting influence of inducers on probe-task performance. On the other hand, the CIT effect (probe-irrelevant P300 differences) was always lower for less personally important (low-salient) and higher for more personally important (high-salient) items.

Attentional bias of guilty and innocent participants in a concealed information test

2017 ◽  
Vol 45 (10) ◽  
pp. 1585-1594
Author(s):  
Yu Na Hong ◽  
Min Jin Jin ◽  
Hyoen Gi Hong ◽  
Hee Song Kim ◽  
Hyung Ki Ji ◽  
...  
Keyword(s):  
Avoidance Response ◽  
Attentional Bias ◽  
Exposure Duration ◽  
Group Versus ◽  
Relevant Information ◽  
Concealed Information Test ◽  
Related Information ◽  
Probe Task ◽  
Concealed Information ◽  
Information Test

We examined the attentional bias between guilt and innocence in a concealed information test using a dot-probe task. The participants were 20 individuals in a guilty group, who were told they had committed a crime, 21 individuals in an innocent group, who were told they had not committed a crime, and 19 individuals in an informed-innocent group, who were told they had not committed a crime but who were given crime-relevant information. Participants in the guilty group were instructed to try to deceive the examiner so that their crime would not be detected, whereas those in the 2 innocent groups were told to be open and frank. The avoidance response of the guilty group was much stronger than that of the 2 innocent groups at an exposure duration of 1,250 ms. We also confirmed that a group not involved in a criminal act, but with crime-relevant information, could be distinguished effectively at an exposure duration of 1,250 ms. Thus, it is possible to distinguish between not only the guilty versus innocent group, but also the guilty group versus the innocent group with crime-related information.

scholarly journals The first independent study on the complex trial protocol version of the P300-based concealed information test: Corroboration of previous findings and highlights on vulnerabilities

2019 ◽  
Author(s):  
Gáspár Lukács ◽  
Huszár Katalin ◽  
Vera Daniella Dalos ◽  
Tünde Kilencz ◽  
Szabina Tudja ◽  
...  
Keyword(s):  
High Accuracy ◽  
Independent Study ◽  
Trial Protocol ◽  
Concealed Information Test ◽  
Probe Item ◽  
Irrelevant Item ◽  
Concealed Information ◽  
Practical Implications ◽  
Information Test

More than a dozen studies of the Complex Trial Protocol (CTP) version of the P300-based Concealed Information Test have been published since its introduction (Rosenfeld et al., 2008), and it has been fairly consistently proven to provide high accuracy and strong resistance to countermeasures (Rosenfeld et al., 2013). However, no independent authors have verified these findings until now. In the present, first independent study, we corroborate the accuracy and countermeasure-resistance of the CTP, when the probe item (critical presented information, e.g., crime detail; P) vs. all irrelevant items (Iall) comparison is used for classifying participants as guilty or innocent, but we also show that the CTP is severely vulnerable to countermeasures, when the P vs. the irrelevant item with the largest P300 responses (Imax) comparison is used. This latter measure can be defeated by creating “oddball” items among the irrelevant items (through targeting them with covert responses), and thereby making their P300 responses statistically indistinguishable from those of the probe item. Practical implications are discussed.

scholarly journals The Intention to Conceal Does Not Always Affect Time Perception

2021 ◽  
Vol 12 ◽  
Author(s):  
Izumi Matsuda ◽  
Hiroshi Nittono
Keyword(s):  
Time Perception ◽  
The Other ◽  
Concealed Information Test ◽  
Display Duration ◽  
Online Experiments ◽  
The Difference ◽  
Arousal Effect ◽  
High Level ◽  
Concealed Information ◽  
Information Test

The display duration of stimuli is overestimated due to the increase in phasic arousal induced by the stimuli or high levels of background arousal. A previous study demonstrated that display duration of items (2 s) was overestimated when a participant attempted to conceal one of the items so as not to be detected in the concealed information test (CIT). As the time perception remained the same between the item to be concealed and the other items, the overestimation was thought to be due to the high level of background arousal under the conceal condition. Duration of 2 s may be too long to examine the phasic arousal effect induced by the concealed item. The present study conducted three online experiments with shorter durations, that is, each of three items was presented with duration of 1, 0.5, and 2 s in Experiments 1, 2, and 3, respectively. The participants were instructed to conceal one of the three items under the conceal condition and did not conceal any item in the innocent condition. The difference in time perception between the conceal and innocent conditions or between items under the conceal condition was observed in none of the three experiments. The result indicates that temporal overestimation does not occur when a participant is only concealing an object. Rather, temporal overestimation would occur only when the level of background arousal is amplified by the concealment.

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