Evaluating the Efficacy of Lie-Detection Technology
Credibility assessment instruments (commonly known as lie detectors) are a critical component of homeland security efforts. Agencies rely on these technologies to evaluate the credibility of information provided by suspects and witnesses in investigations in the U.S. and abroad. Investigators must have a high degree of confidence in the results for these technologies to be useful.
Evaluating credibility assessment instruments presents significant challenges for investigators. To determine the efficacy of the instrument, researchers must create psychological and physiological states in research subjects that mirror the responses
of potential suspects and witnesses. However, this is difficult to do in an artificial environment in which subjects know that the stakes are not real. A client asked Battelle to design and conduct a series
of studies to evaluate next-generation credibility assessment technologies and determine their efficacy in detecting possible deception.
Battelle evaluated prototypes of four next-generation credibility assessment technologies, including eye-tracking, detection of arterial trembling using laser Doppler vibrometry, thermal imaging of blood flow patterns in the face, and a hand-held system collecting electrodermal and vasomotor measurements using a fingertip device.
To collect valid and reliable data, Battelle designed the studies using principles of cognitive science and psychology. The Battelle team brought together experts in human factors and human centric design, including psychologists, cognitive scientists, communication experts, designers and engineers. The study was conducted under the guidance of Battelle’s Internal Review Board (IRB) to ensure compliance with ethical requirements for studies involving human subjects.
Battelle recruited more than 1,200 test subjects representing a broad range of demographics, and ultimately tested more than 600. During the tests, subjects participated in a mock crime exercise in which they were directed to either provide or withhold
certain information from investigators. Researchers used a variety of psychological techniques to create a state of heightened arousal and sense of jeopardy similar to the state of mind of a subject in a criminal investigation. For example, participants
were asked to engage in physical activity, put in uncomfortable social situations, and offered monetary rewards if they could successfully “fool” investigators. The resulting state of heightened physiological and psychological arousal
allowed investigators to gather valid and reliable efficacy data for each of the four technologies.
The results of these studies allowed our client to evaluate the technological maturity of the candidate systems. Results showed that one instrument in particular was a reliable screening tool that can be used to provide a preliminary assessment of the credibility of statements provided by suspects and witnesses. Since then, this instrument has proved to be a valuable asset in investigations of all kinds around the globe.