We found countermeasures to protocols using P300 in concealed information tests. One, the "six-probe" protocol, in Experiment 1, uses six different crime details in one run. The countermeasure: generate covert responses to irrelevant stimuli for each probe category. Hit rates were 82% in the guilty group; 18% in the countermeasure group. The average reaction time (RT) distinguished these two groups, but with overlap in RT distributions. The "one-probe" protocol, in the second experiment, uses one crime detail as a probe. Here, one group was run in 3 weeks as a guilty group, a countermeasure group, and again as in Week 1. COUNTERMEASURE: Covert responses to irrelevant stimuli. In Week 1, hit rate was 92%. In Week 2, it was 50%. In Week 3, 58%. There was no overlap in the irrelevant RT distribution in Week 2: Countermeasure use was detectable. However, in Week 3, the RT distributions resembled those of Week 1; test-beaters could not be caught. These studies have shown that tests of deception detection based on P300 amplitude as a recognition index may be readily defeated with simple countermeasures that can be easily learned.
When individuals who commit a crime are questioned, they often show involuntary physiological responses to remembered details of that crime. This phenomenon is the basis for the concealed information test, in which rarely occurring crime-related details are embedded in a series of more frequently occurring crime-irrelevant items while respiratory, cardiovascular, and electrodermal responses are recorded. Two experiments were completed to investigate the feasibility of using facial skin surface temperature (SST) measures recorded using high definition thermographic images as the physiological measure during a concealed information test. Participants were randomly assigned to nondeceptive or deceptive groups. Deceptive participants completed a mock-crime paradigm. A focal plane array thermal imaging radiometer was used to monitor SST while crime-relevant and crime-irrelevant items were verbally presented to each participant. During both experiments, there were significant facial SST differences between deceptive and nondeceptive participants early in the analysis interval. In the second experiment, hemifacial (i.e., "half-face" divided along the longitudinal axis) effects were combined with the bilateral responses to correctly classify 91.7% of participants. These results suggest that thermal image analysis can be effective in discriminating deceptive and nondeceptive individuals during a concealed information test.
Heightened concerns about the treatment of individuals during interviews and interrogations have stimulated efforts to develop "non-intrusive" technologies for rapidly assessing the credibility of statements by individuals in a variety of sensitive environments. Methods or processes that have the potential to precisely focus investigative resources will advance operational excellence and improve investigative capabilities. Facial expressions have the ability to communicate emotion and regulate interpersonal behavior. Over the past 30 years, scientists have developed human-observer based methods that can be used to classify and correlate facial expressions with human emotion. However, these methods have proven to be labor intensive, qualitative, and difficult to standardize. The Facial Action Coding System (FACS) developed by Paul Ekman and Wallace V. Friesen is the most widely used and validated method for measuring and describing facial behaviors. The Automated Facial Expression Recognition System (AFERS) automates the manual practice of FACS, leveraging the research and technology behind the CMU/PITT Automated Facial Image Analysis System (AFA) system developed by Dr. Jeffery Cohn and his colleagues at the Robotics Institute of Carnegie MellonUniversity. This portable, near real-time system will detect the seven universal expressions of emotion (figure 1), providing investigators with indicators of the presence of deception during the interview process. In addition, the system will include features such as full video support, snapshot generation, and case management utilities, enabling users to re-evaluate interviews in detail at a later date.
In a preliminary attempt to determine the generalizability of data from laboratory mock-crime studies, the authors examined the similarities and differences among the cardiovascular, electrodermal, and respiration responses of deceptive and nondeceptive individuals elicited to crime-relevant and crime-irrelevant questions. Participants in the laboratory group were randomly assigned to nondeceptive (n = 28) or deceptive (n = 27) treatment groups, and a mock-crime scenario was used. The field participants were confirmed nondeceptive (n = 28) or deceptive (n = 39) criminal suspects who underwent polygraph examinations between 1993 and 1997. The results indicated that there were salient differences between field and similarly obtained laboratory polygraph response measures. However, accuracy of laboratory participants' classifications using logistic regression analysis was not significantly different from field participants' classification accuracy.
Using Blood Oxygen Level Dependent (BOLD) functional MRI (fMRI) to detect deception is feasible in simple laboratory paradigms. A mock sabotage scenario was used to test whether this technology would also be effective in a scenario closer to a real-world situation. Healthy, nonmedicated adults were recruited from the community, screened, and randomized to either a Mockcrime group or a No-crime group. The Mock-crime group damaged and stole compact discs (CDs), which contained incriminating video footage, while the No-crime group did not perform a task. The Mock-crime group also picked up an envelope from a researcher, while the No-crime group did not perform this task. Both groups were instructed to report that they picked up an envelope, but did not sabotage any video evidence. Participants later went to the imaging center and were scanned while being asked questions regarding the mock crime. Participants also performed a simple laboratory based fMRI deception testing (Ring-Watch testing). The Ring-Watch testing consisted of "stealing" either a watch or a ring. The participants were instructed to report that they stole neither object. We correctly identified deception during the Ring-Watch testing in 25 of 36 participants (Validated Group). In this Validated Group for whom a determination was made, computer-based scoring correctly identified nine of nine Mock-crime participants (100% sensitivity) and five of 15 No-crime participants (33% specificity). BOLD fMRI presently can be used to detect deception concerning past events with high sensitivity, but low specificity. Intense interest exists in the scientific community and lay press concerning the possibility of using Blood Oxygen Level Dependent (BOLD) functional magnetic resonance imaging (fMRI) to measure brain activation during deception. A number of studies using fMRI to investigate the neural correlates of deception have been published (1)(2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14). The design and analysis methods across these studies vary considerably, making it difficult to integrate the results. At the group analysis level, however, these studies have consistently found significant brain activation in deception versus telling the truth. There has been variability in the specific brain regions activated during deception in these studies. One explanation for this array of findings is the diversity in tasks and questioning paradigms. To date, successful individual analysis has only been achieved in two studies (2,5). The University of Pennsylvania group (Langleben et al.) also reported on using a different analytic approach to the same imaging data to improve their accuracy (12). NIH Public AccessAlthough these studies reported reasonably high individual accuracy rates, there are several concerns which must be addressed prior to moving this technology to real-world application.One concern is that relatively simple deception paradigms (theft of a watch or ring, deception about which playing card one is holding) were used with perceived financial c...
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