Proponents of concealed information tests argue that they rest on a different series of inferential links because the tests do not detect deception and that their admissibility in courts should therefore be judged against different criteria than comparison question tests under the Daubert rule (Ben-Shakhar, Bar-Hillel, and Kremnitzer, 2002). We discuss the different theoretical underpinnings of polygraph testing later in the chapter.


The questions in this section are phrased with the presumption that the polygraph is being used to detect deception. With slightly different phrasing, they can be used to assess the validity of a polygraph test procedure that is being used to detect the examinee’s possession of concealed information.


The relevant-irrelevant test format has not been the subject of sophisticated theory development or of much testing to establish construct validity. Most polygraph researchers now consider the technique fundamentally flawed on a theoretical level (e.g., Raskin and Honts, 2002).


For this point to apply under orienting theory, it is necessary to assume that the orienting response is stronger for the specific issues covered by the relevant questions than for the issues evoked by the more generic comparison questions.


The theories of the relevant-irrelevant and concealed knowledge polygraph techniques are somewhat different on this point. In the relevant-irrelevant test, truthful people are expected to be equally reactive to relevant and irrelevant questions, while guilty people are expected to react more strongly to the relevant questions. In the concealed knowledge test format, people without concealed knowledge will have the same reaction to all the questions in a set, while people with concealed knowledge will show a stronger response to the relevant question—the one that touches on their concealed knowledge.


Some commonly used scoring systems give each physiological response equal weight. These include 7-point systems that compare each polygraph channel for each relevant question against the same channel for the appropriate comparison question and then sum these scores across channels. Other scoring methods, including the global, impressionistic scoring used for the relevant-irrelevant format and the various computerized scoring techniques for comparison question testing, do not treat the channels as having equal weight. Computer scoring systems give numerical weights to different channels (or measures using the channels) according to their value in discriminating truthful from deceptive responses in test samples.


More specifically, arousal theory reflects the following empirical observations (see Cacioppo et al., 1992): (a) the autonomic control of the heart, smooth muscles, and glands is divisible into the sympathetic and parasympathetic systems; (b) postganglionic sympathetic fibers innervate the effector, where their catabolic (energetic) actions are typically mediated directly by the postganglionic release of norepinephrine and indirectly through adrenal medullary catecholamines; and (c) postganglionic parasympathetic fibers innervate specific effectors, where their anabolic (energy-conserving) actions are mediated by the neurotransmitter acetylcholine through muscarinic receptors that are not activated by blood borne catecholamines.


We note that some psychological tests that have been constructed in a purely empirical manner can support fairly confident inferences about psychological processes. Confidence in such tests is based on a solid empirical record demonstrating that the particular test procedures used have consistently yielded accurate inferences with people like those being tested. This argument does not strongly justify polygraph testing for two reasons. One is that available theory raises specific doubts about the

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