polygraph. In our judgment, even such a result would be positive because it would help agencies make more accurate interpretations of the information they have.

  • Research could be conducted on the effectiveness of polygraph countermeasures and on their detectability. Great progress can be made in learning how polygraph measures respond to different kinds of countermeasures, how much effort is needed to learn effective countermeasures, and how otherwise effective countermeasures can be detected. The value of this research depends on the usefulness of the polygraph for detection in particular contexts, which could be made clearer with the other suggested research.

  • Careful documentation of polygraph examinations as they are being administered, combined with individual background information and reports on subsequent outcomes, would generate a valuable body of epidemiological data that could provide better estimates of the accuracy of field polygraph testing, both generally and with specific populations.

  • Planned experiments, embedded in the operation of an ongoing polygraph program, in which examiners might potentially be experimental subjects uninformed about certain aspects of the research design, might be used to separate the effects of different components of the polygraph examination, elucidate the impact of expectancies, and more generally improve understanding of the polygraph examination process in real-world populations of examinees on whom the outcome has potentially serious impact.

Other Approaches to Detection of Deception in Individuals
  • Research on indicators of deception from demeanor have not been given much systematic attention, even though some of them might yield measures of comparable or perhaps greater accuracy than the polygraph. This line of research might yield practical supplements or complements to the polygraph in the relatively near term because demeanor indicators may yield indicators of deception that are somewhat different from those measured by the polygraph.

  • Investigations of brain activity through electrical and imaging studies may yield basic understanding of neural processes in deception. Such investigations, especially if theoretically grounded in central nervous system psychophysiology, have the potential in principle to yield techniques of deception more accurate than the polygraph, as well as to supplement information from polygraph and other sources and to identify signatures in the brain of particular polygraph countermeasures. Not enough is known, however, to tell whether it will ever be possible in practice to identify deception in real time through brain measurement. We are con-



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