*국립과학연구소 범죄심리과, †중앙대학교 심리학과
*Criminal Psychology Div., Forensic Medicine Dept., National Institute of Scientific Investigation, †Department of Psychology, Chung-Ang University, Seoul, Korea
The CIT examines whether suspects possess knowledge about a particular crime, which they do not want to reveal. when suspect recognize the crime-related evidence, it si assumed that he/she will produce high physiological response. We investigated whether a P300 based Concealed Information Test (CIT) can detect concealed face recognition and the degree of stimulus familiarity (during exposed time) influence hits probability. Participants are assigned in two groups: those who are familiar with relevant face stimulus and those who are not. Individuals of the second group are divided into two groups again. An experimental group is exposed to relevant face stimulus during 10 seconds and a control group did not receive any stimulus. The results show that mean amplitude response of the relevant face stimulus is significantly over P300 mean in exposed group to relevant face stimulus (without reference to exposed period). However, there was a hits probability difference depending on relevant face exposure period. When exposure period was long, its hits probability was 20% higher compared to short exposure period condition. Besides, we compared a new designed P300 mean amplitude analysis with Rosenfeld's (2006) analysis method and, found that newly designed method showed higher hits probability than Rosenfeld's (2006) analysis. (Korean J Str Res 2008;16:335∼342)