Successful detection of verbal and visual concealed knowledge using an RT‐based paradigm

Abstract

An increasing number of researchers are exploring variations of the Concealed Knowledge Test (CKT) as alternatives to traditional 'lie-detector' tests. For example, the response times (RT)-based CKT has been previously shown to accurately detect participants who possess privileged knowledge.Although several studies have reported successful RT-based tests, they have focused on verbal stimuli despite the prevalence of photographic evidence in forensic investigations. Related studies comparing pictures and phrases have yielded inconsistent results. The present work compared an RT-CKT using verbal phrases as stimuli to one using pictures of faces. This led to equally accurate and efficient tests using either stimulus type. Results also suggest that previous inconsistent findings may be attributable to study procedures that led to better memory for verbal than visual items. When memory for verbal phrases and pictures were equated, we found nearly identical detection accuracies.

Electromyographic evidence for response conflict in the exclude recognition task

“…The present behavioral results substantially replicate previous published data Jacoby, Woloshyn, & Kelley, 1989;Seymour & Kerlin, 2008;Seymour et al, 2000). Namely, filler responses were faster and more accurate than target and probe responses, and probe responses were significantly slower and less accurate than target responses, although the differences between these responses were smaller than when either stimulus type was compared with fillers.…”

“…In addition to probe and target items, 24 unstudied filler phrases were randomly selected for each participant, for a total stimulus set of 36 phrases. In general, this procedure was similar to previous exclude recognition paradigms using verbal stimuli (Jacoby, 1991;Jacoby, Woloshyn, & Kelley, 1989;Seymour & Kerlin, 2008;Seymour et al, 2000). In particular, we replicated the procedure previously reported in Seymour et al but added the EMG measure.…”

“…After the participants had been connected to the physiological recorder and moved into position, they received sev- [F(2,44) 26.94, p .001]. As in previous reports using similar procedures (Jacoby, Woloshyn, & Kelley, 1989;Seymour & Kerlin, 2008;Seymour et al, 2000), probe responses were slower and less accurate on average than both target and filler responses. Figure 6 and the pairwise t tests shown in Table 1 reveal that probe responses were significantly slower than both target and filler responses.…”

“…Yet, recent evidence suggests that source confusion is unlikely to cause these effects. Using an identical procedure (except that EMG was not measured), Seymour and Kerlin (2008) showed that participants were near ceiling on both nonspeeded recall and recognition posttests, missing less than one item per list on average. Because source confusion was not evident but the RT and accuracy results were similar to the ones reported here, it seems unlikely that source confusion played a dominant role in the present results.…”

Emotional Consequence of Telling a Lie

“…Interestingly this finding is consistent with those found in previous lie detection studies where researchers explored behavioral indices related to deception [20][21][22][23][24]. These studies have shown that people produce their responses slower when they have to lie than when they can tell a truth.…”