Research Round-up 5: Polygraphy

Part 5 in the rapid research round-up for 2008 includes some of the articles to appear over the last year relating to physiological detection of deception.

The first paper here is the most interesting to me, particularly because there are rather few published research findings relating to what happens when people are polygraphed in their non-native language, but the others are probably only really of interest to hard-core psychophysiologists. If these all seem pretty heavy then I’d recommend heading over to a delightful post about William Moulton Marsden, one of the early pioneers of the polygraph, written by Romeo Vitelli at the Providentia blog, for some light relief.

Bilingual speakers frequently report experiencing greater emotional resonance in their first language compared to their second. In Experiment 1, Turkish university students who had learned English as a foreign language had reduced skin conductance responses (SCRs) when listening to emotional phrases in English compared to Turkish, an effect which was most pronounced for childhood reprimands. A second type of emotional language, reading out loud true and false statements, was studied in Experiment 2… Results suggest that two factors influence the electrodermal activity elicited when bilingual speakers lie in their two languages: arousal due to emotions associated with lying, and arousal due to anxiety about managing speech production in non-native language. Anxiety and emotionality when speaking a non-naive language need to be better understood to inform practices ranging from bilingual psychotherapy to police interrogation of suspects and witnesses.

The effects of the state of guilt and the context in which critical information was received on the accuracy of the Concealed Information Test (CIT) were examined in a between-subjects mock crime experiment… Results indicated that accomplices were more effectively detected than innocent participants, although both were given the same critical information. Information gathered in the crime context yielded stronger orientation to the critical items than similar information gathered in a neutral context.

The present mock-crime study concentrated on the validity of the Guilty Actions Test (GAT) and the role of the orienting response (OR) for differential autonomic responding. N = 105 female subjects were assigned to one of three groups: a guilty group, members of which committed a mock-theft; an innocent-aware group, members of which witnessed the theft; and an innocent-unaware group… For informed participants (guilty and innocent-aware), relevant items were accompanied by larger skin conductance responses and heart rate decelerations whereas irrelevant items elicited HR accelerations. Uninformed participants showed a non-systematic response pattern.

Following the idea that response inhibition processes play a central role in concealing information, the present study investigated the influence of a Go/No-go task as an interfering mental activity, performed parallel to the Concealed Information Test (CIT), on the detectability of concealed information… No physiological evidence for an interaction between the parallel task and sub-processes of deception (e.g. inhibition) was found. Subjects’ performance in the Go/No-go parallel task did not contribute to the detection of concealed information.

The Concealed Information Test (CIT) requires the examinee to deceptively deny recognition of known stimuli and to truthfully deny recognition of unknown stimuli. Because deception and orienting are typically coupled, it is unclear how exactly these sub-processes affect the physiological responses measured in the CIT…The present study aimed at separating the effects of deception from those of orienting…The findings further support the notion that psychophysiological measures elicited by a modified CIT may reflect different mental processes involved in orienting and deception.

The final part of this research round-up includes papers on children’s deception, and on technotreachery.

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