일화기억과 의미기억 간의 차이를 이용한 거짓말 탐지

엄진섭 ( Jin-sup Eom ),전하정 ( Hajung Jeon ),손진훈 ( Jin-hun Sohn ) 한국감성과학회 2018 감성과학 Vol.21 No.3

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.

P300 숨긴정보검사와 대응수단

엄진섭 ( Jin Sup Eom ),음영지 ( Young Ji Eum ),장은정 ( Un Jung Jang ),정이내 ( E Nae Cheong ),손진훈 ( Jin Hun Sohn ) 한국감성과학회 2015 감성과학 Vol.18 No.1

It is known that P300-based concealed information test (P300 CIT) was not greatly affected by the traditional countermeasures. This study was to test whether P300 CIT is affected by the new countermeasures. We used three types of countermeasures. First type was a sequential countermeasure in which participants had to respond in alternating ways to irrelevants by pressing the left index finger covertly when the encountered irrelevant firstly, by wiggling the right big toe inside the shoe when encountered irrelevant secondly, by imaging his or her mother``s name when encountered irrelevant thirdly, and by imaging his or her father``s name when encountered irrelevant fourthly until all stimuli were presented. Second type was a partial matching and physical countermeasure. Participants in this type were asked to press the left index finger imperceptibly after one of the irrelevants and wiggle the right big toeafter another of the irrelevants. Third type was a partial matching and mental countermeasure. Participants were required to imagine mother``s name for one irrelevant and father``s name for another irrelevant. The results showed that contrary to our expectation, the use of sequential countermeasure increased the detection rate from 77% to 92%. The partial matching countermeasure had a negative effect on P300 CIT. The physical countermeasure decreased the detection rate from 77% to 46%, and the mental countermeasure decreased the detection rate from 100% to 69%. The necessity for the development of methods to prevent or detect countermeasure is discussed.

시선응시 방법과 시각도가 P300 문자입력기의 정확도에 미치는 영향

엄진섭 ( Jin Sup Eom ),손진훈 ( Jin Hun Sohn ) 한국감성과학회 2014 감성과학 Vol.17 No.2

This study was to examine how visual angle of matrix corresponding to the physical properties of P300 speller and eye gaze corresponding to the user`s personal characteristics influence on the accuracy of P300. Visual angle of the matrix was operated as the distance between the user and the matrix and three groups were composed: 60 cm group, 100 cm groups, and 150 cm group. Eye gaze methods was consisted three conditions. Head moving condition was putting eye gaze using head, pupil moving condition was moving pupil with the head fixed, while the eye fixed condition is to fix the eye gaze at the center of the matrix. The results showed that there was significant difference in the accuracy of P300 speller according to the eye gaze method. The accuracy of the head moving condition was higher than the accuracy of pupil moving conditions, accuracy of pupil moving conditions was higher than the accuracy of the eye fixed conditions. However, the effect of visual angle of matrix and interaction effect were not significant. When P300 amplitude of target character was measured depending on how you stare at the target character, P300 amplitude of the head moving condition was greater than P300 amplitude of the pupil moving condition. There was no significant difference in the error distribution in head moving condition and pupil moving condition, while there was a significant difference between two eye gaze conditions and fixed gaze condition. The error was located at the neighboring characters of the target character in head moving condition and pupil moving condition, while the error was relatively distributed widely in fixed eye condition, error was occurred with high rate in characters far away from the center of matrix

P300-기반 숨긴정보검사에서 자극유사성이 P300의 진폭에 미치는 영향

엄진섭 ( Jin Sup Eom ),한유화 ( Yu Hwa Han ),손진훈 ( Jin Hun Sohn ),박광배 ( Kwang Bai Park ) 한국감성과학회 2010 감성과학 Vol.13 No.3

The present study examined whether the physical similarity of test stimuli affects P300 amplitude and detection accuracy for the P300-based concealed information test (P300 CIT). As the participant pretended suffering from memory impairment by an accident, own name was used as a concealed information to be probed by the P300 CIT in which the participant discriminated between a target and other (probe, irrelevant) stimuli. One group of participants was tested in the easy task condition with low physical similarity among stimuli, the other group was tested in the difficult task condition with high physical similarity among stimuli. Using the base-to-peak P300 amplitude, the interaction effect of task difficulty and stimulus type was significant at α=.1 level (p=.052). In the easy task condition the difference of P300 amplitude between the probe and the irrelevant stimuli was significant, while in the difficult task condition the difference was not significant. Using peak-to-peak P300 amplitude, on the other hand, the interaction effect of task difficulty and stimulus type was not significant with significant differences of P300 amplitude between the probe and the irrelevant stimuli in both task difficulty conditions. The difference of detection accuracy between task conditions was not significant with both measures of P300 amplitude although the difference was much smaller when peak-to-peak P300 amplitude was used. The results suggest that the efficiency of P300 CIT would not decrease even when the perceptual similarity among test stimuli is high.

고역통과필터 값이 P300의 파형에 미치는 영향

엄진섭 ( Jin Sup Eom ),음영지 ( Young Ji Eum ),손진훈 ( Jin Hun Sohn ),박광배 ( Kwang Bai Park ) 한국감성과학회 2010 감성과학 Vol.13 No.1

The present study is a partial extension of the Duncan-Johnson and Donchin (1979) and Soskins, Rosenfeld, and Niendam (2001) studies that found some effects of high pass filter (HPF) setting on P300 waveform. EEGs were recorded while the subjects performed a visual three-stimulus oddball task, and the Fz and Pz EEG signals were passed through 0.01 Hz, 0.3 Hz, and 1.0 Hz HPFs. P300 amplitudes at Fz and Pz were reduced at 1.0 Hz HPF compared to 0.01 Hz and 0.3 Hz HPFs. The negative peaks post P300 at Fz and Pz were not observed at 0.01 Hz HPF, but observed at 0.3 Hz and 1.0 Hz HPFs. The combination of 0.3 Hz HPF and peak-to-peak P300 measures was more useful than that of 0.01 Hz, 0.3 Hz, or 1.0 Hz HPF and baseline-to-peak P300 measures to discriminate between non-target and standard stimuli. The peak-to-peak P300 measures were more useful than the baseline-to-peak P300 measures at 1.0 Hz HPF setting.

반응시간기반 숨긴정보검사에 대한 실험 패러다임의 효과

엄진섭 ( Jin-sup Eom ) 한국감성과학회 2021 감성과학 Vol.24 No.2

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.

컴퓨터교과교육 : 사이버대학의 질에 영향을 미치는 요인 도출을 위한 탐색적 연구

엄진섭 ( Jin Sup Eom ) 한국컴퓨터교육학회 2013 컴퓨터교육학회 논문지 Vol.16 No.5

본 논문에서는 선행연구자료 분석을 통해 사이버대학의 질에 영향을 미치는 요인을 도출하고자 하였다. 그동안의 연구는 사이버대학의 질에 영향을 미치는 요인을 대학중심으로만 파악하고자 하였으나, 대학 외에 국가, 사회적, 개인적 요인들도 중요한 변인이며, 상호 유기적이고 시스템적으로 묶여 작용하고 있었다. 따라서 본 연구에서는 시스템적 구조하에서 투입요인이 중요하며, 그 요인에는 양질의 교육을 제공하기 위해 갖추어야 하는 기본적인 교육여건(교사·교직원.시스템)과 관련규정, 관리시스템, 학생의 학습참여 의욕 및 동기, 정부의 사이버대학에 대한 인식 및 정책적 지원, 사회적인 인식 또는 평가가 질에 영향을 미치는 요인임을 제시하였다. The purpose of this review is to identify factors that affect the quality of cyber universities. While the previous studies focused on the university-level factors, the review revealed that the country-level, social-level, and individual-level variables are also important factors influencing the quality of cyber universities organically and systematically. Therefore, the current study asserts that additional predictors should be added with regard to its systemic structure. These variables would include basic educational environment (e.g., teachers, staff, educational system), related regulations, management system, student willingness to participate in learning and their motivation, the government`s awareness of cyber universities and polity support, and societal recognition/assessment of cyber universities.

놀람 자극에 대한 심혈관 반응

엄진섭 ( Jin Sup Eom ),박혜준 ( Hye Jun Park ),노지혜 ( Ji Hye Noh ),손진훈 ( Jin Hun Sohn ) 한국감성과학회 2011 감성과학 Vol.14 No.1

Basic emotions such as happiness, sadness, anger, fear, and disgust have been widely used to investigate emotion-specific autonomic nervous system activity in many studies. On the contrary, surprise emotion, Suggested also as one of the basic emotions suggested by Ekman et al. (1983), has been least investigated. The purpose of this study was to provide a description of cardiovascular responses on surprise stimulus using electrocardiograph (ECG) and photoplethysmograph (PPG). ECG and PPG were recorded from 76 undergraduate students, as they were exposed to a visuo-acoustic surprise stimulus. Heart rate (HR), standard deviation of R-R interval (SD-RR), root mean square of successive R-R interval difference (RMSSD-RR), respiratory sinus arrhythmia (RSA), finger blood volume pulse amplitude (FBVPA), and finger pulse transit time (FPTT) were calculated before and after the stimulus presentation. Results show significant increase in HR, SD-RR, and RMSSD-RR, decreased FBVPA, and shortened FPTT. Evidence suggests that surprise emotion can be characterized by vasoconstriction and accelerated heart rate, sympathetic activation, and increased heart rate variability, parasympathetic activation. These results can be useful in developing an emotion theory, or profiling surprise-specific physiological responses, as well as establishing the basis for emotion recognition system in human-computer interaction.

ERP와 동공 반응을 이용한 숨긴정보검사

엄진섭 ( Jin Sup Eom ),박광배 ( Kwang Bai Park ),손진훈 ( Jin Hun Sohn ) 한국감성과학회 2012 감성과학 Vol.15 No.2

In a P300-based concealed information test (P300 CIT), the result of the test is greatly affected by the value of the probe stimulus. With a probe stimulus of low value, the detection rate decreases. The aim of this study was to determine whether the pupil-based concealed information test (Pupil CIT) could be used in addition to the P300 CIT for the probes of low value. Participants were told to choose one card from a deck of five cards (space 2, 3, 4, 5, 6), Then a P300 CIT and a Pupil CIT for the selected card were administered. P300s were measured at 3 scalp sites (Fz, Cz, and Pz), and the pupil sizes of left and right eyes were recorded. The P300 amplitude measured at Fz, Cz, and Pz was significantly different between the probe and irrelevant stimuli. And, in the Pupil CIT, the pupil size was also different between the two stimuli for both eyes. The detection rates of the P300 CIT were 44% at Fz and Cz sites and 36% at Pz site. And the detection rates of the Pupil CIT were 52% for the left eye and 60% for the right eye. There is a trend that the detection rate of the Pupil CIT was higher than that of the P300 CIT, but the difference didn`t reach significance partly because of the relatively small sample size. The correlation between the decision based on the P300 CIT and that based on the Pupil CIT was not significant. As a conclusion, it is recommended to use a Pupil CIT instead of a P300 CIT when the value of the probe is low. And a combination of the measures may be superior to either one of them in detection rate.

Backster ZCT를 사용한 폴리그라프 검사절차의 일반화가능도: 관련 질문의 개수, 반복측정 횟수, 채점자의 수에 따른 신뢰도의 변화

엄진섭 ( Jin Sup Eom ),한유화 ( Yu Hwa Han ),지형기 ( Hyung Ki Ji ),박광배 ( Kwang Bai Park ) 한국감성과학회 2008 감성과학 Vol.11 No.4

Generalizablity theory was employed to examine how the reliability of polygraph test is affected by the number of relevant questions, the number of repeated tests (the number of of charts), and the number of raters (scorers). The data consisted of the results of the polygraph tests administered to 31 crime suspects. The sample was drawn from the real polygraph tests based on Backster ZCT and archived by the Prosecutor`s Office of the Republic of Korea. The numerical scores assigned by thirteen raters to the test charts were analyzed to determine the generalizablity of the scores. The largest variance component was accounted for by the examinee factor (43.97%) and the residual variance component was 16.84% of the total variance. The variance component due to the interaction between the examinee and the chart factors was 12.17% and the variance component due to the three way interaction of the examinee, the repeated test, and the relevant question factors was 10.31%. The generalizability coefficient for the current measurement procedure as practiced by the Korean Prosecutor`s Office was 0.74 which suggests that the current procedure is acceptable. However, measurement procedures with the combination of more than two relevant questions, more than three repeated tests, and more than two raters were generally found to yield generalizability coefficients larger than 0.80. Therefore, such procedures need to be considered seriously in order to significantly improve the reliability of polygraph test.