Event-Related Potentials and the Detection of Deception: A Two-Stimulus Paradigm.
Final rept. Apr 93-Nov 94,
OTTAWA UNIV (ONTARIO)
Pagination or Media Count:
Event-related potentials ERP employed in two studies exp. 1, n 20 females exp. 2, n 20 males attempted to distinguish subjects who had participated in a mock crime guilty group from innocent subjects who did not perform in the crime scenario. A two-stimulus paradigm was used in which neutral and crime relevant questions were followed by either a yes or a no target stimulus. Subjects were instructed to indicate their agreement or disagreement that the yes or no target stimulus was consistent with the truth of the preceding question. Guilty subjects were told to deny the truth of the crime relevant items. In both experiments, P3 amplitude was smaller for the guilty subjects in the crime relevant condition than comparison conditions when the task demanded an agree response. In experiment 1, P3 amplitude to the target stimulus was smaller for guilty than innocent subjects in the crime relevant condition when an agree response was demanded. This effect was also apparent in the ERP waveforms for experiment 2, but it was not statistically significant.