Developed as an alternative to traditional deception detection methods, the concealed information test (CIT) assesses recognition of critical (e.g., crime-relevant) "probes." Most often, recognition has been measured as enhanced skin conductance responses (SCRs) to probes compared to irrelevant foils (CIT effect). More recently, also differentially enlarged reaction times (RTs) and increased neural activity in the bilateral inferior frontal gyrus, the right middle frontal gyrus, and the right temporo-parietal junction have been observed. The aims of the current functional magnetic resonance imaging (fMRI) study were to (1) investigate the boundary conditions of the CIT effects in all three measures and thereby (2) gain more insight into the relative contribution of two mechanisms underlying enhanced responding to concealed information (i.e., orienting versus response inhibition). Therefore, we manipulated the proportion of probe versus irrelevant items, and whether suspects were instructed to actively deny recognition of probe knowledge (i.e., deceive) during the test. Results revealed that whereas overt deception was not necessary for the SCR CIT effect, it was crucial for the RT and the fMRI-based CIT effects. The proportion manipulation enhanced the CIT effect in all three measures. The results indicate that different mental processes might underlie the response pattern in the CIT. While skin conductance responding to concealed information may best be explained by orienting theory, it seems that response inhibition drives RT and blood oxygen level dependent responding to concealed information.

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The Concealed Information Test (CIT) is a psychophysiological technique that allows for detecting crime-related knowledge. Usually, autonomic response measures are used for this purpose, but ocular measures have also been proposed recently. Prior studies reported heterogeneous results for the usage of countermeasures (CM) to corrupt the CIT's validity, depending on the CM technique and the dependent measure. The current study systematically compared the application of physical and mental CM on autonomic and ocular measures during the CIT. Sixty participants committed a mock crime and were assigned to one of three guilty conditions: standard guilty (without CM), physical CM, or mental CM. An additional group of 20 innocents was investigated with the same CIT to calculate validity estimates. Electrodermal responses were more vulnerable for CM usage compared to heart rate and respiration, and physical CM were more effective than mental CM. Independent of CM usage, a combined score of autonomic responses enabled a valid differentiation between guilty and innocent examinees. Fixations and blinks also allowed for detecting crime-related knowledge, but these measures were more affected by CM application than autonomic responses. The current study delivered further evidence that CM differentially impact physiological and ocular responses in the CIT. Whereas individual data channels were strongly affected by CM usage, a combination of different response measures yielded a relatively stable differentiation of guilty and innocent examinees when mental CM were used. These findings are especially relevant for field applications and might inspire future studies to detect or prevent CM usage in CIT examinations.

Previous studies demonstrated that concealed crime-related memories can be validly identified using the Concealed Information Test (CIT). However, its field applicability is still debated, and it is specifically unknown how emotional arousal during a crime would influence CIT results. In the current study, emotional arousal during a mock crime and the time delay between mock crime and CIT examination were manipulated. At the immediate and the delayed CIT occasion, central crime details were better remembered than peripheral ones and enhanced emotional arousal further reduced memory for peripheral information. Electrodermal, respiratory, and cardiovascular responses to central crime details were strong and CIT validity was unaffected by delaying the test when arousal was induced during the mock crime. These findings indicate that emotional arousal might facilitate the detection of concealed information some time after a crime occurred.