Gershon Ben-Shakhar

Psychophysiologic assessment of aversive conditioning in posttraumatic stress disorder.

BACKGROUND The objective of this study was to evaluate the acquisition, generalization, and extinction of conditioned physiologic responses to aversive stimuli in posttraumatic stress disorder (PTSD). METHODS Thirty-six PTSD patients, 20 individuals with past trauma and no current PTSD, and 30 mentally healthy individuals without exposure to major trauma underwent a differential aversive conditioning experiment. Bursts of 105 dB white noise were used as unconditioned stimuli (UCSs), and 35x24 mm slides of different colors served as either CS+ (paired) or CS- (unpaired) stimuli. Heart rate (HR) and nondominant palm skin conductance (SC) were measured at rest and between 1 and 4 sec following each CS presentation. RESULTS The PTSD group showed higher levels of resting SC and resting HR, larger SC responses to the initial presentation of unpaired CSs, larger HR responses following paired CS+ stimuli, larger SC responses to unpaired CS- during acquisition and extinction, and larger SC and HR responses to CS+ during extinction. The group differences in responses to CS+ during extinction remained statistically significant after controlling for age, resting physiologic levels, and initial responsivity. CONCLUSIONS PTSD is associated with elevated autonomic responses to both innocuous and aversive stimuli, with larger responses to unpaired cues and with reduced extinction of conditioned responses.

Theories and Applications in the Detection of Deception

1. History and Description.- 2. A Critical Comparison of the Major Methods of Polygraph Interrogation.- 3. Reliability and Validity of Polygraph-Based Classifications.- 4. Laboratory Studies: Factors Affecting Psychophysiological Detection.- 5. The Detection of Deception: A Psychophysiological, Specific-Effects-Oriented Perspective.- 6. Theoretical Issues in Psychophysiological Detection.- 7. International Usage Contrasts: Cultural Factors.- 8. Beyond Validity: Utility and Legal Considerations in the Application of Psychophysiological Detection.- 9. Future Perspectives.- References.

Memory detection: theory and application of the concealed information test

Part I. Introduction: Introduction. Science on the rise: birth and development of the Concealed Information Test Christopher J. Patrick 1. Encouraging the use of the Guilty Knowledge Test (GKT): what the GKT has to offer law enforcement William G. Iacono Part II. The Laboratory: Theoretical and Empirical Foundations of the Concealed Information Test: 2. Detecting concealed information using autonomic measures Matthias Gamer 3. Detecting concealed information in less than a second: response latency-based measures Bruno Verschuere and Jan De Houwer 4. P300 in detecting concealed information J. Peter Rosenfeld 5. Detecting of deception and concealed information using neuroimaging techniques Matthias Gamer 6. New and old covert measures in the Concealed Information Test Eitan Elaad 7. Theory of the Concealed Information Test Bruno Verschuere and Gershon Ben-Shakhar Part III. Field Applications of Concealed Information Detection: Promises and Perils: 8. Limitations of the Concealed Information Test in criminal cases Donald J. Kraphol 9. Validity of the Concealed Information Test in realistic contexts Eitan Elaad 10. Leakage of information to innocent suspects M. T. Bradley, Clair A. Barefoot and Andrea M. Arsenault 11. Countermeasures Gershon Ben-Shakhar 12. Psychopathy and the detection of concealed information Bruno Verschuere 13. Clinical applications of the Concealed Information Test John J. B. Allen 14. Daily application of the Concealed Information Test: Japan Akemi Osugi 15. The Concealed Information Test in the courtroom: legal aspects Gershon Ben-Shakhar and Mordechai Kremnitzer Part IV. Conclusions: 16. Practical guidelines for developing a Concealed Information Test Ewout Meijer, Bruno Verschuere and Gershon Ben-Shakhar Epilogue Gershon Ben-Shakhar, Bruno Verschuere and Ewout Meijer.

Estimating the validity of the guilty knowledge test from simulated experiments: the external validity of mock crime studies

This experiment was designed to examine the external validity of the standard mock-crime procedure used extensively to evaluate the validity of polygraph tests. The authors manipulated the type of mock-crime procedure (standard vs. a more realistic version) and the time of test (immediate vs. delayed) and examined their effects on the validity of the Guilty Knowledge Test (GKT) and the recall rate of the relevant items. The results indicated that only the type of mock-crime affected the 2 outcome variables. The realistic procedure was associated with a lower recall rate and weaker detection efficiency than the standard procedure. However, these effects were mediated by the type of GKT questions used. Practical implications of these results are discussed.

Novelty and significance in orientation and habituation : a feature-matching approach

A feature-matching model to account for the effects of novelty and significance on psychophysiological responsivity is presented. 2 experiments based on a modified version of the Guilty Knowledge Technique were designed to test predictions derived from the proposed model. Results of Experiment 1 demonstrated that electrodermal responsivity to the test stimulus reflected the degree to which the subjects were habituated to its components. Experiment 2 provided additional support for the proposed model and suggested that the effects of novelty and significance were additive. These findings support the hypothesis that responsivity is positively related to the degree of match between the input and the representation of significance, and it is negatively related to the similarity between the input and the preceding stimuli. It is argued that the proposed model clarifies the processes involved in orienting response elicitation.

Posttraumatic Stress Disorder and Depression in Battered Women: The Mediating Role of Learned Helplessness

Learned helplessness (LH) may mediate the link between violence exposure and mental disorders in battered women. This study evaluated the contribution of LH to Posttraumatic Stress Disorder (PTSD) and major depression (MDD) in women with prolonged exposure to partner violence in 101 residents of shelters for battered women in Israel. DSM-IV axis-I disorders were assessed by a structured clinical interview. Self-report questionnaires evaluated exposure to violence, symptoms of PTSD and depression, LH, history of child abuse, SES and the extent of male-dominance and prejudice against women in the participants prior socialization background. LH significantly mediated the effect of violence on PTSD and depression symptoms. Male-dominated background contributed to LH. Thus, LH may increase the risk of mental disorders in battered women and should be addressed in interventions designed to reduce the burden of mental illness in this population.

Memory detection with the Concealed Information Test: A meta analysis of skin conductance, respiration, heart rate, and P300 data

The Concealed Information Test (CIT) uses psychophysiological measures to determine the presence or absence of crime-related information in a suspects memory. We conducted a meta-analysis on the validity of the CIT based on four physiological measures-skin conductance response (SCR), respiration line length (RLL), changes in heart rate (HR), and enhanced amplitudes of the P300 component of the event-related potential (P300). This meta-analysis relied on laboratory studies that used either the mock-crime or the personal-item paradigm. Results showed a mean effect size (d*) of 1.55 for SCR, 1.11 for RLL, 0.89 for HR, and 1.89 for P300. However, P300 outperformed SCR only in the personal-item paradigm, but not in the mock-crime paradigm. Motivation level, number of questions, publication year, and the inclusion of innocent participants emerged as significant moderators for the SCR, while only the type of paradigm used moderated the P300 effect.

Behavioral and physiological measures in the detection of concealed information.

The authors examined the incremental validity of the reaction time (RT) measure beyond that of skin conductance response (SCR) in the detection of concealed information. Participants performed a Stroop-like task in which they named the color of critical and neutral words. Results show that the SCR highly differentiated between the relevant and neutral words. However, the RT demonstrated a significant differentiation only when the critical words denoted personally significant items (e.g., ones own name) and not when they denoted crime-relevant items related to a simulated crime. In both cases, combining the 2 measures yielded no advantage over the use of SCR alone. Thus, although behavioral measures may differentiate between relevant and neutral information in some cases, their practical use is questionable.

Detecting concealed information from groups using a dynamic questioning approach: simultaneous skin conductance measurement and immediate feedback

Lie detection procedures typically aim at determining the guilt or innocence of a single suspect. The Concealed Information Test (CIT), for example, has been shown to be highly successful in detecting the presence or absence of crime-related information in a suspect’s memory. Many of today’s security threats, however, do not come from individuals, but from organized groups such as criminal organizations or terrorist networks. In this study, we tested whether a plan of an upcoming mock terrorist attack could be extracted from a group of suspects using a dynamic questioning approach. One-hundred participants were tested in 20 groups of 5. Each group was asked to plan a mock terrorist attack based on a list of potential countries, cities, and streets. Next, three questions referring to the country, city, and street were presented, each with five options. Skin conductance in all five members of the group was measured simultaneously during this presentation. The dynamic questioning approach entailed direct analysis of the data, and if the average skin conductance of the group to a certain option exceeded a threshold, this option was followed up, e.g., if the reaction to the option “Italy” exceeded the threshold, this was followed up by presenting five cities in Italy. Results showed that in 19 of the 20 groups the country was correctly detected using this procedure. In 13 of these remaining 19 groups the city was correctly detected. In 7 of these 13, the street was also correctly detected. The question about the country resulted in no false positives (out of 20), the question about the city resulted in two false positives (out of 19), while the question about the streets resulted in two false positives (out of 13). Furthermore, the two false positives at the city level also yielded a false positive at the street level. Even though effect sizes were only moderate, these results indicate that our dynamic questioning approach can help to unveil plans about a mock terrorist attack.

Effects of questions' repetition and variation on the efficiency of the guilty knowledge test: a reexamination.

The effect of question repetition and variation on the efficiency of the Guilty Knowledge Test (GKT), based on electrodermal and respiration measures, was examined in a between-subjects experiment with 3 conditions. Each participant was presented with a sequence of 12 biographical questions. In Condition 1, a single question was repeated 12 times; in Condition 4, each of 4 different questions was repeated 3 times; and in Condition 12, 12 different questions were used. A monotonic relationship between the number of different questions used and detection efficiency was observed only with the electrodermal measure (the areas under the receiver operating characteristic curves, obtained with this measure in Conditions 1, 4, and 12 were .68, .81, and .99, respectively). These results demonstrate that a GKT based on multiple questions is superior to the use of many repetitions of a single or a few questions, and it can reach an almost perfect detection efficiency.