• Science of Emotion and Sensibility
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• v.24 no.2
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• pp.3-12
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• 2021

Most researchers have experimentally evaluated the detection efficiency of reaction time-based concealed information tests (RT CIT). In experimental studies, two experimental paradigms have been mainly used to create a lying situation, mock-crime paradigm and personal-item paradigm. This study is aimed at testing the detection efficiency of RT CIT for the one that could be estimated as the same as the other, regardless of the experimental paradigms. In study 1, it was tested whether the effect size of RT CIT was different in the two experimental paradigms through meta-analysis. As a result of the meta-analysis of 39 studies, the effect size (Hedges'g = 1.330) of the mock-crime paradigm was slightly larger than that (Hedges'g = 1.145) of the personal-item paradigm, but no statistically significant difference was found. Study 2 was an experimental study using both the mock-crime and personal-item paradigms, it was conducted to determine whether the detection efficiency of RT CIT differs in the two experimental paradigms. As a result of ANOVA, it was found that the RT differences between the probe and irrelevant stimuli were not significant in the two experimental paradigms. In the experimental study, the effect size (Cohen's d) of the mock-crime and personal-item paradigms were 1.638 and 1.535, respectively. In the discussion section, the reason of the detection efficiency of RT CIT not affected by the experimental paradigms was discussed.

• Korean Journal of Forensic Psychology
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• v.11 no.2
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• pp.173-190
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• 2020

The purpose of this study is to verify whether it is possible for participants to discriminate between innocent and guilty suspects when they are exposed to criminal information utilizing an autobiographical implicit association test (aIAT). A total of 49 college students were randomly assigned to guilty group, innocent-aware group, or innocent-unaware group. Participants performed an aIAT to detect suspects after performing either mock crime or control task. It was verified that innocent suspect and guilty suspect exposed with crime information could be distinguished through D-score and reaction time, converted to symbolize strength of the association between guilty sentences, innocent sentences, and truth sentences. As a result of the analysis, guilty group showed significantly higher D-score than both innocent-aware group and innocent-unaware group. guilty group also showed faster response time in true-guilty condition than true-innocent condition. This shows that the association of true-guilty conditions is stronger than that of true-innocent conditions. On the other hand, the innocent-aware group showed a faster response time in the true-innocent condition than the true-guilty condition, and innocent-unaware group showed no significant difference between the two conditions. Through this, it was confirmed that innocent suspects exposed to criminal information can be discriminated according to the aIAT pattern, which has a faster reaction rate to the truth and innocence union than the guilty group. This study confirmed that suspects exposed to criminal information can be effectively discriminated using aIAT, and further suggests the usefulness and potential of aIAT in the field of lie detection.

• Science of Emotion and Sensibility
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• v.21 no.3
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• pp.61-72
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• 2018

Items related to a crime that are known only to criminals and investigators can be used in the concealed information test (CIT) to assess whether the suspect is guilty of the offense. However, in many cases wherein the suspect is exposed to information about the crime, the CIT cannot be used. Although the perpetrator's memories about the details of the crime are episodic, the memories of a suspect who has inadvertently discovered the details of the crime are more likely to be semantic. The retrieval of episodic memories is associated with theta wave activity, whereas that of semantic memories is associated with alpha wave activity. Therefore, these aspects of memory retrieval can be useful in identifying the perpetrator of the crime. In this study, P300-based CITs were conducted in a guilty participant in a mock crime and an innocent participant who has been given information about the simulated offense. The results demonstrate that the difference in P300 amplitudes between the probe and the irrelevant stimulus did not differ between the guilty and innocent conditions. As expected, the lower theta band power (4-6 Hz) was higher in the probe than in the irrelevant stimulus in the guilty condition, but there was no difference in the innocent condition. Conversely, the upper alpha band power (8-10 Hz) was lower in the probe than in the irrelevant stimulus in the innocent condition, but there was no difference in the guilty condition. The possibility of using theta and alpha band powers in lie detection is discussed.

• Korean Journal of Forensic Psychology
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• v.11 no.2
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• pp.155-171
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• 2020

The purpose of this study is to examine the effects of emotional arousal and cognitive load on pupil diameter during a lie detection interview. The guilty group (n = 30) committed a mock crime (i.e., stealing cash) and the innocent group (n = 30) performed a mission (i.e., sending a message) in the research assistant's office. After that, their pupil size was measured using a wearable eye-tracker during the interview. The interview questions were classified with the three cognitive load, three emotional arousal, and three neutral questions. The results indicate that the main effects of group and time were not significant, but the interaction between group and time was significant. It means that when answering cognitive load questions, the guilty group showed larger increase in pupil diameter than the innocent group. The present study suggests that inducing cognitive load is more effective than inducing emotional arousal during an interview when using pupil diameter as an index of deception, and it is expected to improve the accuracy of lie detection.

• Science of Emotion and Sensibility
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• v.21 no.2
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• pp.113-124
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• 2018

The logical assumption of the comparison question test (CQT) is that the guilty person pays more attention to the relevant questions than to the comparison questions, and that the innocent person pays more attention to the comparison questions than to the relevant questions. The purpose of this study was to verify the logic of the comparison question test using functional magnetic resonance imaging (fMRI). The participants were tested for brain responses during a mock crime and performed the CQT under guilty and innocent conditions. After brain imaging, we evaluated the psychological burden of responding to the relevant questions and comparison questions. In the guilty conditions, the degree of burden was higher for the relevant questions than the comparison questions, and there was no significant difference in the innocent conditions. The fMRI results showed that, in the guilty conditions, greater activation was observed in the right superior temporal gyrus and right inferior frontal gyrus when relevant questions were presented relative to comparison questions. Based on these findings, the logical assumption of the CQT was discussed.

• Korean Journal of Forensic Psychology
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• v.11 no.1
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• pp.1-20
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• 2020

Witnesses will be exposed to a variety of misinformation after the witnessing of the event and state at the scene of the investigation after the delay period. This study was conducted to promote correct recall reporting without being affected by factors that against correct recall. Self-Administered Interview(SAI) is known to obtain eyewitness accounts quickly and accurately. Therefore, we performed a SAI to see if it reported more information than the control group that did not perform the SAI. Also, it also performed that correct information was maintained without being affected by misinformation and delay. Eighty-eight participants were asked to perform SAI or game after showing a video of mock crime. Misinformation was presented in the first or second session to see if it affected recall. An analysis of responses from the final test conducted in the second session by participants showed that groups that conducted SAI after a four-week delay reported more correct information than control groups, while there was no difference between incorrect- and confabulation information. In particular, the timing of presenting misinformation did not affect the amount of recall. This suggests that conducting the SAI immediately after witnessing the event protects correct information even after four weeks. Finally, the significance and limitations of this study, and subsequent studies were discussed.