It's not Just Polygraph anymore

Within the behavioral sciences community, the polygraph is a controversial device that has often generated a polarizing reaction.

By John G. Capps and Andrew Ryan

The polygraph. It has been a principle fixture in the federal government's security processes for decades. However, within the behavioral sciences community, the polygraph is a controversial device that has often generated a polarizing reaction. Advocates point to research indicating accuracy rates exceeding 80%, the growing acceptance of the polygraph in the court system and beneficial use of polygraph in sex offender rehabilitation. Opponents cite high false positive rates and question the underlying theories coupling the act of lying with physiological arousal. This dichotomy of opinion was most recently highlighted in a National Academy of Sciences National Research Council study which recognized polygraph weaknesses but ultimately concluded that ". . .potential alternatives to the polygraph show promise, but none has yet shown to outperform the polygraph."

While opinions differ among researchers on use, application and effectiveness of polygraph in the detection of deception, the field has began to take some interesting and exciting leaps forward. At the federal level, these efforts are being spearheaded by the Department of Defense Polygraph Institute (DoDPI) at Fort Jackson in Columbia, South Carolina.


DoDPI began in 1985 with the passage of the National Security Directive which transformed what had since 1951 been the U.S. Army Polygraph School to the Department of Defense Polygraph Institute. The Institute began to aggressively focus on polygraph related research, curriculum development and training of examiners for the federal government. In 1994, the Joint Security Commission recommended that the government establish a more robust research program and DoDPI become the principle agent for polygraph research. However, research remained focused almost entirely on the evaluation and validation of current and innovative polygraph approaches and technologies. Recognizing continuing advances in both science and technology, DoDPI developed a new vision for its research division in the mid-1990s. With the movement of DoDPI from the Defense Security Service, to the DoD Counterintelligence Field Activity in 2002, the focus on expanding DoDPI's research division and its funding has increased. Existing DoDPI research focuses on the science and technology of alternate methods of deception detection while continuing research designed to improve on traditional polygraph.


The Institute has sought to establish collaborative relationships designed to advance the science of deception detection and routinely reaches out to other organizations by providing consultive expertise, project management, and project funding. DoDPI has worked with such well regarded research institutions as the Washington University School of Medicine, the University of Utah, the University of Oklahoma, Johns Hopkins, Honeywell Technology Center, the University of South Carolina, the Mayo Clinic, Veridical Research and Design, and the University of Houston. DoDPI's own internal research initiatives, coupled with the establishment of this network of "Science Partners,"

advanced the field and lead many scientists and researchers to begin to see a new paradigm for assessing the genuineness of human information and solidify the theoretical bases for human veracity.

A recent report by the National Research Council recognized DoDPI as an organization "working to put polygraph research on a more scientific footing" (NRC, 2003 p. 230). This change reflects a ubiquitous increase in the contextual demands for the psychophysiological detection of deception. In the last few years, the term "credibility assessment" has replaced the more narrow "detection of deception" as it purports to encompass a much wider range of situation and contexts in which determining the existence of concealed and hidden information is vital. The continuation of these efforts and new research collaborations is leading to new and exciting avenues in the field of credibility assessment that are vital in assisting our troops in the global war on terrorism.


New areas of research in the field of credibility assessment cover a wide spectrum, some based on autonomic measures as is the polygraph, others contingent on central nervous system measures, and still others addressing naturalistic measures. In the area of autonomic measures, a great deal of promise is being shown in thermal imaging research at DoDPI. Thermal imaging, as a tool for credibility assessment, focuses on the use of a mid-level infrared thermal camera which looks at the spectrum of body heat based on changes in facial blood flow. Specifically, DoDPI is seeking to determine if the changes in facial blood flow resulting from the activation of the sympathetic nervous system occurring when someone is anxious is because they are being deceptive. This increase in blood increases facial skin surface temperature, which is picked up by the infrared camera.

DoDPI first became interested in thermal imagery around ten years ago when DoDPI researchers looked at thermal imagery and the hand. The findings in this area were not conclusive, but in 2000 Honeywell approached DoDPI with a much improved infrared camera. The initial study conducted by DoDPI showed promise in the area of use of thermal imagery in credibility assessment and DoDPI began to fully explore this new technology.

Current research in detecting deception has found accuracy rates in excess of 80%; however, there is much more research to be done in this area. Researchers continue to explore the underlying reasons why blood tends to pool in the periorbital area and whether other areas of the face offer valuable data. In addition, there are efforts underway to address tracking concerns due to head movement and modifications needed to the existing algorithm. Nevertheless, this technology shows excellent promise to enhance our ability in assessing credibility.

Research is also underway at DoDPI on use of the laser Doppler vibrometry (LDV) as remote measures of assessment of individual physiological responses to emotional stress. Through LDV, DoDPI researchers study changes in respiration, cardiovascular activity, muscle contraction, and body tremor at a distance of up to hundreds of feet. Since this technology is both noninvasive and can be conducted without the subject's awareness offers significant advantages to traditional polygraph techniques that require a cooperative subject and attachment of sensors.

Another exciting technology under investigation at DoDPI is the eye tracking technology (Eye Movement Memory Assessment). Eye tracker technology follows the pattern of the subjects' visual attention to a scene. For example, when an individual initially scans a photo of an object it is usually with their peripheral vision, he then focuses in on what is of interest for a more attentive, higher detailed observation. Visual scene inspection is based on the process of putting together small regions of what is being viewed and integrating this into a coherent whole representation.

Studying how the eye scans a familiar object versus an unfamiliar object is the focus of current work at DoDPI. Current research has shown that with unfamiliar objects, the number of points the eye briefly fixates is greater, the time in which the eye fixates is longer, the number of regions where fixation occurs increases, and the complexity of the gaze patterns is greater. Additional research efforts involve event-related potentials (ERPs). Because certain brain processes elicit ERPs, researchers have found that particular wave forms are believed to be associated with deception. At DoDPI the three principle waveforms being studied are the P3b, the P3a and the N4.

Functional Magnetic Resonance Imaging is being used to determine what actually goes on in the brain when a person is lying. In short, researchers at DoDPI are comparing scans of an individual's brain when they are lying to scans when they are not. Researchers hope to target what parts of the brain are activated and require increased blood flow when an individual is deceptive.

These are representative of the varied research efforts currently underway at DoDPI and at institutions DoDPI is coordinating with. Since the challenge has never been greater and there is an urgency to search for improved methods to protect America and Americans, this in the forefront of the DoDPI mission.


The Institute is interested in expanding their network of Science Partners through their contracts and grants program. Research awards are available to funds thesis, dissertation, and institutional research awards. It is strongly suggested that potential Science Partners visit the Institute's web page located at http://www.dodpoly.army.mil to obtain information on applying for support and all are invited to contact any member of the Research Division to discuss the possibilities and opportunities.

From the polygraph suite to the global war on terrorism, scientists, engineers, software specialists, field operatives and others in the public and private sector are joining DoDPI in advancing research, science and technology in the field of Credibility Assessment. There are endless opportunities for those in the field of psychology to join efforts to advance the degree of certainty in credibility assessment.