The Polygraph and Lie Detection (2003) / Chapter Skim
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6 Alternative Techniques and Technologies
6 Alternative Techniques and Technologies
Pages 154-177
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From page 154... ...
This chapter considers some of those alternative techniques. It focuses in particular on the potential of recently emerging technologies, including those that measure brain activity, some of which have recently received considerable attention, and those that rely on measures of externally observable behaviors.
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From page 155... ...
and magnetic resonance imaging (MRI, often referred to as functional MRI or fMRI when used to relate brain function to behavior) , as well as by recording event-related potentials, characteristics of brain electrical activity following specific discrete stimuli or "events." The third class of techniques attempts to achieve detection of deception from demeanor: these techniques usually involve careful observation of specific behaviors of examinees (e.g., voice, facial expression, body movements, choice of words)
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From page 156... ...
However, although some of these measures have advantages over polygraph measures on grounds of theoretical psychophysiology, they may not actually map more closely to psychological variables. Like the polygraph indicators, measures such as myocardial contractility and respiratory sinus arrhythmia are influenced by sundry social and psychological factors (e.g., Berntson et al., 1997; Gardner, Gabriel, and Diekman, 2000~.
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From page 157... ...
Functional Brain Imaging Over the past 15 years, the field of cognitive neuroscience has grown significantly. Cognitive neuroscience combines the experimental strategies of cognitive psychology with various techniques to actually examine how brain function supports mental activities.
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From page 158... ...
Their use to study brain activity associated with deception is only beginning. PET uses a measure of local blood flow, which invariably accompanies changes in the cellular activity of the brain of normal, awake humans and unanesthetized laboratory animals (for a review, see Raichle, 1987~.
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From page 159... ...
These investigations seek to identify signatures of particular kinds of cognitive activity in brain processes. Yet even if fMRI studies could eventually identify signatures of acts of deception, it would be premature to conclude that fMRI techniques would be useful in practice for lie detection.
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From page 160... ...
For these reasons, fMRI is not presently useful for the psychophysiological detection of deception in many applied settings, and the complexity of analysis may be a prohibitive factor for all applications, for quite some time. Nonetheless, much valuable new information can be learned from research using this powerful technique to advance theoretical understanding of the kinds of cognitive processes involved in deception and perhaps to identify the brain mechanisms underlying countermeasures designed to prevent its detection.
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From page 161... ...
There are many advantages and a number of distinct disadvantages of this method for measuring human brain function. One of the key advantages is that brain electrical activity measures have excellent time resolution, allowing researchers to resolve changes that occur in milliseconds.
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From page 162... ...
used a composite measure of brain electrical activity, including the P300 and other metrics, to examine reactivity to autobiographical information. They report extremely high accuracies of classifying examiners according to the knowledge they possess.
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From page 163... ...
Because thermal imaging primarily measures infrared emissions, we classify it with techniques for the psychophysiological detection of deception. Several authors have reviewed the large body of research connecting lying or truth-telling to cues from demeanor (Zuckerman, DePaulo, and Rosenthal, 1981, 1986; Zuckerman and Driver, 1985; DePaulo, Stone, and Lassiter, 1985; DePaulo et al., 2001; Ekman, 2001~.
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From page 164... ...
These studies suggest that the right measures of facial and motion features can offer accuracy better than chance for the detection of deception from demeanor in somewhat realistic situations. At present, the measurement of facial behavior and body movement is very labor intensive; recent work suggests, however, that it will be possible to automate the measurement of facial movements (Bartlett et al., 1999; Cohn et al., 1999~.
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From page 165... ...
Very little research has been done, however, on the technique's applicability to statements by criminal suspects, some of whom may be unwilling or unable to provide detailed accounts (Porter and Yuille, 1995~. In sum, the available evidence suggests that analysis of language usage and of facial and body movement might be useful in distinguishing lies from truth.
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From page 166... ...
Voice Stress Analysis The research on the detection of deception from demeanor includes the presumption that liars experience more stress than truth-tellers, especially in high-stakes circumstances, and that this stress shows in various channels, including in the voice. Recent meta-analytic evidence shows consistent associations of lying with vocal tension and high pitch (DePaulo et al., in press)
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From page 167... ...
In addition to manufacturing the computer voice stress analyzer, NITV publishes its own journal reporting on the ease of use of the analyzer and its utility in obtaining confessions. NITV also trains and certifies voice stress analysts using protocols for question format and sequences of relevant and irrelevant questions that are remarkably like those used for polygraph testing.
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From page 168... ...
Department of Defense Polygraph Institute (DoDPI) carried out a series of laboratory tests comparing the use of the computer voice stress analyzer and the polygraph using peak of tension and control question test formats.
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From page 169... ...
Graphologists typically insist that the sample must be spontaneous and that handwriting samples that involve copying text from a book or writing a passage from memory will not yield a valid reading. Graphologists often request a brief autobiographical sketch or some other sort of self-description (Ben-Shakhar, 1989; Ben-Shakhar et al., 1986~.
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From page 170... ...
Voice stress analysis and graphology, two commonly used techniques, have not convincingly demonstrated accuracy for detecting deception. The gap between the promise and the practice of the detection of deception from demeanor has several possible explanations.
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From page 171... ...
This track record supports the validity of investigations; it does not provide scientific evidence on their incremental value over polygraph testing or the incremental value of polygraph testing over background checks. Some scientific evidence exists on reference checks and background investigations as used in the private sector for preemployment screening.
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From page 172... ...
Current figures for integrity test use are probably even higher because of increasing awareness of the cost and extent of employee theft and increasing evidence of the validity of several widely distributed tests. Virtually all integrity tests include items that refer to one or more of the following areas: (a)
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From page 173... ...
Nevertheless, there are important differences between the two criteria, and more important, differences in the validity of integrity tests for predicting the two. There is no literature correlating the results of these tests with indicators of the more specific kinds of counterproductive behavior of interest in national security settings.
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From page 174... ...
If so, their only potential value as supplements would be to help correct for error in polygraph-based estimates of those phenomena. Measurements of Brain Function Functional brain imaging techniques have important advantages over the polygraph, in theory, because they examine directly what the brain is doing.
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From page 175... ...
Most of the research on deception and demeanor has not been seriously applied to criminal or security investigation contexts. The evidence indicates that the right measure or measures might achieve a useful level of accuracy in those contexts, even though some techniques on the market, such as voice stress analysis, have not demonstrated such accuracy.
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From page 176... ...
We have much greater confidence in concluding that security and law enforcement agencies need to improve their capability to independently evaluate claims proffered by advocates of new techniques for detecting deception. The history of the polygraph makes clear that such agencies typically let clinical judgment outweigh scientific evidence in their assessment of the validity of techniques for the psychophysiological detection of deception or the detection of deception from demeanor.
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From page 177... ...
2. Integrity tests, conscientiousness measures, and structured interviews typically show correlations in the range of 0.30 to 0.40 with indicators of job performance (Schmidt and Hunter, 1999~.
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