Mental and physical countermeasures reduce the accuracy of the concealed knowledge test (original) (raw)
Related papers
Effects of mental countermeasures on psychophysiological detection in the guilty knowledge test
International Journal of Psychophysiology, 1991
This study focused on the effects of mental countermeasures on psychophysiological detection in a guilty knowledge paradigm. Two experiments which utilized a 3 X 2 between subjects factorial design were conducted. Two types of mental countermeasures (specific dissociations from the relevant stimulus and continuous dissociation throughout the entire test, as well as a control-no countermeasure condition were used). Each group was further subdivided into two conditions — a high attention condition created by motivational instructions and a deceptive verbal response to the relevant question; and a low attention condition in which no motivational instructions were provided and no verbal response was required. The results of both experiments (one was conducted in a field set up, and the other utilized more standard experimental equipment and measurement procedures) revealed the following pattern: the item-specific countermeasures tended to increase psychophysiological detection, whereas the continuous dissociations tended to decrease detection efficiencies. The pattern was consistent across attention conditions and experiments but it was stronger in the field experiment where overall detection efficiency was relatively high. In other respects the present results replicated previous findings and revealed a significant effect for the attention factor.
International Journal of Psychophysiology, 2010
The accuracy of the Concealed Information Test (CIT) in detecting information concealed by informed innocent participants was assessed under varying levels of probability that the obtained information is related to the crime and is therefore correct. For this purpose, 64 participants were randomly assigned to four experimental conditions that were formed by probability levels that the gathered information is correct and is related to the crime. Either absolutely correct (100% correct), highly correct (80%, correct), highly incorrect (20% correct) or totally incorrect (0%, correct) conditions were created. Response generalization was manipulated by replacing 3 of 6 correct items with related stimuli. The replaced stimuli were related to the correct items either semantically, phonetically, or numerically. Informed innocent participants showed larger electrodermal responses to items with a higher probability of being correct. It was further found that participants elicited stronger responses to correct than to replaced items. Theoretical and practical implications of the present results are discussed.
Journal of Applied Psychology, 1996
The effects of mental countermeasures on the efficiency of psychophysiological detection with the Guilty Knowledge Technique were examined in a mock-crime experiment with 4 groups of participants: innocent participants who were not involved in the mock crime, guilty controls who committed the mock crime but received no countermeasure instructions, and guilty participants who received countermeasure instructions, and guilty participants who received countermeasure instructions and were allowed to practice the countermeasures. The countermeasure instructions encouraged participants to recall emotional situations from their past and imagine themselves in these situations during presentation of irrelevant questions. Results revealed a significant reduction in electrodermal detection efficiency under the 2 countermeasure conditions with no differences between them. No countermeasures effects were observed with the respiration line length measure.