Decomposing cognitive processes underlying the concealed information test by event-related potentials(<Special Issue>Psychophysiological Studies)
The concealed information test (CIT) is a psychophysiological method for detecting a suspect's knowledge about a crime by comparing autonomic responses between crime-relevant and crime-irrelevant stimuli. Although the autonomic-based CIT has been widely used for criminal investigations in Japan, the cognitive processes underlying the test remain unclear. In order to examine this, we recorded event-related potentials (ERPs) from 128 scalp sites during an autonomic-based CIT. We asked 20 participants to steal an item and then conducted an autonomic-based CIT about the stolen item. A temporal-spatial principal component analysis revealed that three ERP components differed significantly between crime-relevant and crime-irrelevant items. The first component was a central-dominant negative component that peaked at 180 ms (N2). The second component was a parietal-dominant positive component that peaked at 461 ms (P300), which may be affected by the personal meaning of the crime-relevant item. The third component was an occipital-dominant positive component that occurred at 797 ms (positive slow wave), which may reflect an additional process after identifying the crime-relevant item. The present results suggest that in an autonomic-based CIT, a participant discriminates a crime-relevant item from crime-irrelevant items in around 200 ms after item onset and then performs an additional process to the indentified crime-relevant items.
- International Journal of Biomedical Soft Computing and Human Sciences: the official journal of the Biomedical Fuzzy Systems Association
International Journal of Biomedical Soft Computing and Human Sciences: the official journal of the Biomedical Fuzzy Systems Association 18(2), 5-11, 2013