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Screening individuals with pretest data improves the performance of concealed information tests
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International Journal of Psychophysiology 94 (2014) 120–261
Then, participants were instructed to commit a mock-theft in which they took an envelope of a certain color, addressed to a certain person, containing a certain amount of money, an item of jewelry, an object, and a photograph of an animal. The participants were instructed to take the content of the envelope and put it in their pocket or bag, and then return to the experimenter. At this stage the CIT polygraph test was administered. The CIT entails a series of multiple-choice questions, each having one critical alternative (e.g., a feature of the crime under investigation) which a guilty suspect should recognize, and several irrelevant (control) alternatives which an innocent suspect, who has no crime-related knowledge, cannot discriminate from each other. Typically, if the suspect's physiological responses to the critical alternatives is consistently larger than to the controls, knowledge about the event in question is inferred. During the test participants denied knowledge about the critical items while their skin conductance response (SCR) amplitude, finger pulse waveform length (FPWL), and respiration line length (RLL) responses were recorded. Results indicated that introverted participants tended to release larger SCRs to the critical items compared to extraverts. Openness to experience predicted FPWL responses where high openness scorers responded more to the critical items than lower scorers. Neuroticism predicted RLL responses where high Neuroticism scores displayed larger RLL responses than low Neuroticism scores. It was concluded that there are identifiable individual differences in attention to crime related items during the CIT. doi:10.1016/j.ijpsycho.2014.08.614
Application of CIT as an information detection technique in Japan Tokihiro Ogawa, Izumi Matsuda, Michiko Tsuneoka National Research Institute of Police Science, Japan Japanese law enforcement is unique in its large-scale application of the concealed Information Test (CIT) within actual criminal investigations. In the first part of this presentation, we outline methodological features of CIT as it is practiced in Japan. CIT is conceptualized as an information detection method rather than as a lie detection method. It examines whether an individual has crime-relevant knowledge to which only a criminal has access. Whereas scientists have advocated CIT as a scientifically sound method, its use in real-life settings has been rare outside of Japan. Japanese CIT application entails some features that are rarely mentioned in the literature. Specifically, Japanese field practice focuses on identifying specific crime details. Therefore, the unit of analysis is a question rather than an individual, even for administration of multiple questions within a single case. This feature leads to differences between Japanese CIT application and laboratory studies in terms of question repetition, data analysis, and verdict description. For example, different questions are commonly integrated within the CIT literature in psychophysiology. However, in Japan, questions are not aggregated. We suggest that these differences can be attributed to different ways of interpreting the concept of “guilty knowledge” in this field. Awareness of these methodological differences is an important presupposition for understanding any information relating to Japanese field data such as the test's accuracy. In the second part of our presentation, we provide an example of physiological data from a field case (n = 170). We limited our analysis to cases for which the actual memory status of examinees was verified through an investigation conducted after CIT implementation. The physiological data recorded included skin conductance, respiration, heart rate, and normalized pulse volume. Our analysis indicated that an individual who was concealing information responded with greater skin conductance,
reduced respiration, a lower heart rate, and a decreased normalized pulse volume (i.e. increased vascular tone) compared with his or her response to irrelevant items. By contrast, the response of an individual with no memory of an item was equivalent to that for relevant and irrelevant items. This pattern of differential physiological response was the same as that observed in laboratory settings. Our results suggest that there is no qualitative difference in the pattern of physiological responses obtained within laboratory and field settings. doi:10.1016/j.ijpsycho.2014.08.615
Screening individuals with pretest data improves the performance of concealed information tests Izumi Matsudaa, Tokihiro Ogawaa, Michiko Tsuneokaa, Bruno Verschuereb,c,d a National Research Institute of Police Science, Japan b University of Amsterdam, The Netherlands c Ghent University, Belgium d Maastricht University, The Netherlands Objective: A Concealed Information Test (CIT), based on autonomic responses, is widely used in Japanese criminal investigations to assess whether an individual knows information relevant to a crime. However, some individuals do not differentially react to a crime-relevant item even if they have the information. Previous studies have attempted to combine different types of measures, such as autonomic measures and eventrelated potentials (ERPs), to improve the performance of a CIT. By contrast, the present study screened out participants who did not show distinctive autonomic responses on a pretest. We then examined whether this screening improved the discrimination performance of a mock-crime CIT. Method: Participants in the mock crime either stole a ring (i.e., guilty; n = 80) or did nothing (i.e., innocent; n = 72). Then, all participants memorized a number from 3 to 7 and received a pretest on the number. They also received a CIT related to the stolen object. In both tests, each of the five items (i.e., numbers 3 to 7 or the names of five objects) was presented five times with an interstimulus interval of more than 25 s. In parallel, respiration, skin conductance, heart rate, and normalized pulse volume were measured. For each measure, an effect size (Cohen's d) was calculated between the relevant item (i.e., memorized number or ring) and the irrelevant items. The average of the effect sizes across all autonomic measures was defined as the combined effect size. Discrimination performances with the combined effect size were evaluated by the area under the receiver operating characteristic curve. Results: For each of the four autonomic measures, the effect sizes from the pretests were significantly correlated to those of the mockcrime CITs. We then removed 51 participants whose effect sizes of the combined measure in the pretests were less than 0.5, reasoning that they may also be less responsive in the mock-crime CIT. The area under the curve of the mock-crime CIT significantly improved through the screening (from 0.919 to 0.967). Conclusions: The pretest data were effective in detecting participants with low reactivity, although a considerable number of these participants were excluded from the discrimination. Such individuals might get an “inconclusive” test result. In the future, for participants screened out by the pretest, applying other types of tests (e.g., an ERP-based CIT) may be preferable. The pretest data may be used to customize the CIT examination and thus accurately test each participant's memory. doi:10.1016/j.ijpsycho.2014.08.616
International Journal of Psychophysiology 94 (2014) 120–261
Then, participants were instructed to commit a mock-theft in which they took an envelope of a certain color, addressed to a certain person, containing a certain amount of money, an item of jewelry, an object, and a photograph of an animal. The participants were instructed to take the content of the envelope and put it in their pocket or bag, and then return to the experimenter. At this stage the CIT polygraph test was administered. The CIT entails a series of multiple-choice questions, each having one critical alternative (e.g., a feature of the crime under investigation) which a guilty suspect should recognize, and several irrelevant (control) alternatives which an innocent suspect, who has no crime-related knowledge, cannot discriminate from each other. Typically, if the suspect's physiological responses to the critical alternatives is consistently larger than to the controls, knowledge about the event in question is inferred. During the test participants denied knowledge about the critical items while their skin conductance response (SCR) amplitude, finger pulse waveform length (FPWL), and respiration line length (RLL) responses were recorded. Results indicated that introverted participants tended to release larger SCRs to the critical items compared to extraverts. Openness to experience predicted FPWL responses where high openness scorers responded more to the critical items than lower scorers. Neuroticism predicted RLL responses where high Neuroticism scores displayed larger RLL responses than low Neuroticism scores. It was concluded that there are identifiable individual differences in attention to crime related items during the CIT. doi:10.1016/j.ijpsycho.2014.08.614
Application of CIT as an information detection technique in Japan Tokihiro Ogawa, Izumi Matsuda, Michiko Tsuneoka National Research Institute of Police Science, Japan Japanese law enforcement is unique in its large-scale application of the concealed Information Test (CIT) within actual criminal investigations. In the first part of this presentation, we outline methodological features of CIT as it is practiced in Japan. CIT is conceptualized as an information detection method rather than as a lie detection method. It examines whether an individual has crime-relevant knowledge to which only a criminal has access. Whereas scientists have advocated CIT as a scientifically sound method, its use in real-life settings has been rare outside of Japan. Japanese CIT application entails some features that are rarely mentioned in the literature. Specifically, Japanese field practice focuses on identifying specific crime details. Therefore, the unit of analysis is a question rather than an individual, even for administration of multiple questions within a single case. This feature leads to differences between Japanese CIT application and laboratory studies in terms of question repetition, data analysis, and verdict description. For example, different questions are commonly integrated within the CIT literature in psychophysiology. However, in Japan, questions are not aggregated. We suggest that these differences can be attributed to different ways of interpreting the concept of “guilty knowledge” in this field. Awareness of these methodological differences is an important presupposition for understanding any information relating to Japanese field data such as the test's accuracy. In the second part of our presentation, we provide an example of physiological data from a field case (n = 170). We limited our analysis to cases for which the actual memory status of examinees was verified through an investigation conducted after CIT implementation. The physiological data recorded included skin conductance, respiration, heart rate, and normalized pulse volume. Our analysis indicated that an individual who was concealing information responded with greater skin conductance,
reduced respiration, a lower heart rate, and a decreased normalized pulse volume (i.e. increased vascular tone) compared with his or her response to irrelevant items. By contrast, the response of an individual with no memory of an item was equivalent to that for relevant and irrelevant items. This pattern of differential physiological response was the same as that observed in laboratory settings. Our results suggest that there is no qualitative difference in the pattern of physiological responses obtained within laboratory and field settings. doi:10.1016/j.ijpsycho.2014.08.615
Screening individuals with pretest data improves the performance of concealed information tests Izumi Matsudaa, Tokihiro Ogawaa, Michiko Tsuneokaa, Bruno Verschuereb,c,d a National Research Institute of Police Science, Japan b University of Amsterdam, The Netherlands c Ghent University, Belgium d Maastricht University, The Netherlands Objective: A Concealed Information Test (CIT), based on autonomic responses, is widely used in Japanese criminal investigations to assess whether an individual knows information relevant to a crime. However, some individuals do not differentially react to a crime-relevant item even if they have the information. Previous studies have attempted to combine different types of measures, such as autonomic measures and eventrelated potentials (ERPs), to improve the performance of a CIT. By contrast, the present study screened out participants who did not show distinctive autonomic responses on a pretest. We then examined whether this screening improved the discrimination performance of a mock-crime CIT. Method: Participants in the mock crime either stole a ring (i.e., guilty; n = 80) or did nothing (i.e., innocent; n = 72). Then, all participants memorized a number from 3 to 7 and received a pretest on the number. They also received a CIT related to the stolen object. In both tests, each of the five items (i.e., numbers 3 to 7 or the names of five objects) was presented five times with an interstimulus interval of more than 25 s. In parallel, respiration, skin conductance, heart rate, and normalized pulse volume were measured. For each measure, an effect size (Cohen's d) was calculated between the relevant item (i.e., memorized number or ring) and the irrelevant items. The average of the effect sizes across all autonomic measures was defined as the combined effect size. Discrimination performances with the combined effect size were evaluated by the area under the receiver operating characteristic curve. Results: For each of the four autonomic measures, the effect sizes from the pretests were significantly correlated to those of the mockcrime CITs. We then removed 51 participants whose effect sizes of the combined measure in the pretests were less than 0.5, reasoning that they may also be less responsive in the mock-crime CIT. The area under the curve of the mock-crime CIT significantly improved through the screening (from 0.919 to 0.967). Conclusions: The pretest data were effective in detecting participants with low reactivity, although a considerable number of these participants were excluded from the discrimination. Such individuals might get an “inconclusive” test result. In the future, for participants screened out by the pretest, applying other types of tests (e.g., an ERP-based CIT) may be preferable. The pretest data may be used to customize the CIT examination and thus accurately test each participant's memory. doi:10.1016/j.ijpsycho.2014.08.616