Accuracy Demonstrations, Threat, and the Detection of Deception: Cardiovascular, Electrodermal, and Pupillary Measures

Abstract

The small amount of laboratoïy data available does not clearly support this assumption and data from field work has never been gathered. The present study was designed to assess the consequences of demonstrating varied levels of detection effectiveness to suspecÈs prior to an interrogation. A mock crime involving money, threat of shock, and a fierd gues tioning technique were incl-uded to create a more realistic interrogation situation. Pupil size, pupil change, heart rate, heart change, and. the galvanic skin response \¡¡ere used to assess detection. AlI subjects, half of whom had committed a mock crime, \^rere instructed to appear innocent throughout a questioning session conducted by an interrogator blind to their actuar guilt or innocence. rn addition, half of the subjects in each group had also read that they would receive a painful but not permanently damaging electric shock if found guilty of the crime. Prior to the interrogation subjects received a demonstration of the physiological detection measurest effectiveness. Demonstrated effectiveness was manipurated through a series of rigged tests in which a subject chose a number from a set of cards and attempted to conceal the number. The feedback led subjects in different groups to berieve they had been detected 0å, 33 r/32, 66 2/3e", or looe" of the time. The A few respecÈable valÍdity studies have been reporËed. Lyon (1936) found 40 cases in a random selection of l-00 which could be confirmed by outside critería and of those 40

An interfering Go/No-go task does not affect accuracy in a Concealed Information Test

“…In accordance with previous studies on detection of concealed knowledge (e.g. Bradley and Janisse, 1981;Ben-Shakhar and Elaad, 2003;Gamer, et al, 2006), electrodermal activity, respiration line length and phasic heart rate differentiated between falsely denied recognition of known objects (probe items) and correct denying of knowledge about new objects (irrelevant items). 1 Here, skin conductance showed the largest effect, followed by respiratory activity and phasic heart rate.…”

“…The phasic heart rate (pHR) was calculated by subtracting this value from each second-per-second poststimulus value. For extracting the trialwise information of the phasic HR, the mean change in HR within 15 s after trial onset, compared to the pre-stimulus baseline, was calculated (Bradley and Janisse, 1981).…”

The Effects of Augmented Physiological Feedback on Detection of Deception

“…Moreover, if participants learned from the APF that the technique failed to detect their deception during the numbers test, the accuracy of the subsequent CQT might suffer (Bradley & Janisse, 1981).…”

The Investigative Interview: A Review of Practice and Related Research

“…Limited research on the usefulness of stimulation tests suggests they may improve the accuracy of polygraph examinations (Senese, 1976;Bradley & Janisse, 1981). Thus, persuading subjects that deception will be detected may be an important factor in minimizing deception.…”