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After six decades of research it has been well established that physiological measures can validly detect concealed memories. However, the exact theoretical underpinnings of concealed information testing remain to be elucidated. In the present chapter we review the various theoretical accounts of the Concealed Information Test (CIT) effect and discuss their development over time. We start with several unitary theories that each focus on a single emotional-motivational factor. As it appeared that such factors have little impact on the CIT, cognitive factors became the early focus of examination. The orienting response theory in particular has dominated the field for years. Although evidence suggests that orienting theory may well apply to the skin conductance measure, it may not fully explain physiological reactivity in the CIT for other response measures such as respiration and heart rate (HR). Hence, a response fractionation model that suggests that the skin conductance measure reflects orienting and the respiration and HR measures reflect attempts at arousal inhibition was proposed. Future work is needed to validate this model and test whether it holds under real-life circumstances. Furthermore, more research is needed to examine the underlying mechanisms of other physiological and behavioral measures.

The validity of the CIT has been demonstrated in hundreds of laboratory studies. Most studies, however, lack key ingredients of real‐life deception. One such factor is self‐initiated deception; in contrast to perpetrators committing real crimes, research participants are typically instructed to commit a mock crime and deny involvement. Yet, the intention to deceive is a crucial factor when studying deception. Self‐initiated cheating might increase both motivation to avoid detection and the significance of the crime‐relevant items in the CIT, which could result in more obvious differences between guilty and innocent individuals. Hence, while laboratory research is important for establishing a controlled environment in which particular variables can be disentangled, it has a limited external validity to the field. This disparity between research and practice may affect the generalizability of laboratory based CIT findings. Participants in the experimental condition were provided with the opportunity to cheat on a trivia quiz for an incentive, yet without explicit instructions to do so. Participants in the control (instructed) condition were explicitly asked to cheat on the quiz. Using a psychophysiological CIT, participants’ recognition memory for the answers to the critical questions was assessed. Does externally valid deception result in increased detection efficiency of the CIT compared to instructed cheating?

The Concealed Information Test (CIT) is a well-validated tool for physiological and behavioral detection of concealed knowledge. Two distinct theoretical frameworks have been proposed to explain the differential responses to the concealed critical items: orienting response theory versus arousal inhibition theory. klein Selle, Verschuere, Kindt, Meijer, and Ben-Shakhar (2016), however, argued for a response fractionation model and showed that, while the skin conductance reflects pure orienting, both the respiratory and heart rate measures reflect arousal inhibition. The present study intends to (1) provide a constructive replication of klein Selle et al. (2016) using the autobiographical CIT, and (2) extend their work by testing an additional prediction derived from orienting theory, using an item-salience manipulation. One hundred and nine participants were tested on four high salient and four low salient identity items. Half of the participants were motivated to hide their identity (orienting + arousal inhibition), while the other half were motivated to reveal their identity (orienting only). Confirming earlier findings, the results revealed a fractionation between the different measures: while the skin conductance response (SCR) increased to a similar extent in the two motivational conditions, the respiration line length (RLL) shortened and the heart rate (HR) decelerated solely in the conceal condition. Moreover, while the SCR was larger for high than for low salient critical items, the RLL and HR responses were similar for these two item types. These data led us to conclude that, in the CIT, the skin conductance measure reflects orienting and the respiratory and heart rate measures reflect arousal inhibition.

The Concealed Information Test (CIT) aims to detect concealed information through differential physiological and behavioral responses to the concealed items. Although extensive experimental research has demonstrated the empirical validity of the CIT, the external validity of these studies has been questioned. One essential difference between experimental setups and realistic contexts is the voluntary act of committing the crime and concealing the critical (crime‐related) items. The present study examined whether the detection efficiency of the CIT alters under conditions of free choice to commit a mock crime. In the ‘choice’ condition, participants chose to perform a mock crime or a computerized task, while in the control, ‘instructed’ condition participants were instructed either to commit the mock crime or a computerized task. The results revealed no significant differences in the detection efficiency between the two conditions in electrodermal, respiration, and reaction time measures.

The detection of deception has attracted increased attention among psychological researchers, legal scholars, and ethicists during the last decade. Much of this has been driven by the possibility of using neuroimaging techniques for lie detection. Yet, neuroimaging studies addressing deception detection are clouded by lack of conceptual clarity and a host of methodological problems that are not unique to neuroimaging. We review the various research paradigms and the dependent measures that have been adopted to study deception and its detection. In doing so, we differentiate between basic research designed to shed light on the neurocognitive mechanisms underlying deceptive behavior and applied research aimed at detecting lies. We also stress the distinction between paradigms attempting to detect deception directly and those attempting to establish involvement by detecting crime-related knowledge, and discuss the methodological difficulties and threats to validity associated with each paradigm. Our conclusion is that the main challenge of future research is to find paradigms that can isolate cognitive factors associated with deception, rather than the discovery of a unique (brain) correlate of lying. We argue that the Comparison Question Test currently applied in many countries has weak scientific validity, which cannot be remedied by using neuroimaging measures. Other paradigms are promising, but the absence of data from ecologically valid studies poses a challenge for legal admissibility of their outcomes.

The Concealed Information Test (CIT) provides a valid tool for psychophysiological detection of concealed knowledge. However, its precise theoretical underpinnings remain a matter of debate. The differential physiological responses elicited by concealed, relevant items, relative to control items, were traditionally explained as reflecting an orienting response (OR). According to an alternative account, these responses reflect attempts to inhibit arousal. The present study examined whether and to what extent CIT detection efficiency is affected by instructions aimed at manipulating arousal inhibition (AI). One hundred and forty-eight undergraduate students completed a CIT, while electrodermal, cardiac, and respiratory measures were recorded. Half of the participants were requested to imagine that they are suspected of committing a crime and were motivated to avoid detection (presumably eliciting both OR and AI), while the other half were requested to imagine that they are witnesses of a crime and were motivated to be detected (presumably eliciting OR only). All participants were further requested to remain silent throughout the test. In both conditions, concealed items led to a similar increase in skin conductance as compared to the control items. However, the typically observed heart rate deceleration and respiratory suppression were found in suspects, but not in witnesses. These data imply that different mechanisms drive the responding of different psychophysiological measures used in the CIT, with skin conductance reflecting OR, and heart rate and respiration primarily reflecting AI.

The Concealed Information Test (CIT) uses psychophysiological measures to determine the presence or absence of crime-related information in a suspect's 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.

Considerable evidence suggests that subliminal information can trigger cognitive and neural processes. Here, we examined whether elicitation of orienting response by personally significant (PS) verbal information requires conscious awareness of the input. Subjects were exposed to the Concealed Information Test (CIT), in which autonomic responses for autobiographical items are typically larger than for control items. These items were presented subliminally using two different masking protocols: single or multiple presentation of the masked item. An objective test was used to verify unawareness to the stimuli. As predicted, PS items elicited significantly stronger skin conductance responses than the control items in both exposure conditions. The results extend previous findings showing that autonomic responses can be elicited following subliminal exposure to aversive information, and also may have implications on the applied usage of the CIT.

This study examined, using the Concealed Information paradigm, whether interstimulus intervals (ISI) typically used for electrodermal measurement can be shortened. An ISI ranging from 16 s to 24 s (with a mean of 20 s) was compared with an ISI shortened by 50% using a within-participants design. It was demonstrated that this shortening had no effect on the differential skin conductance responses to the personally significant details and nearly identical detection efficiency was observed under the 2 ISIs. However, overall responses were attenuated with the shorter ISI. The implications of these results for various types of studies, using skin conductance responses, were discussed.

Traditional techniques for detecting deception, such as the 'lie-detector test' (or polygraph), are based upon the idea that lying is associated with stress. However, it is possible that people telling the truth will experience stress, whereas not all liars will. Because of this, the validity of such methods is questionable. As an alternative, a knowledge-based approach known as the 'Concealed Information Test' has been developed which investigates whether the examinee recognizes secret information - for example a crime suspect recognizing critical crime details that only the culprit could know. The Concealed Information Test has been supported by decades of research, and is used widely in Japan. This is the first book to focus on this exciting approach and will be of interest to law enforcement agencies and academics and professionals in psychology, criminology, policing and law.

Concealed information can be accurately assessed with physiological measures. To overcome the practical limitations of physiological measures, an assessment using response latencies has been proposed. At first sight, research findings on response latency based concealed information tests seem inconsistent. Our procedural analysis of the various latency-based tests indicates that tests based on a manipulation of relevant stimulus-response compatibility, such as the oddball task (Farwell & Donchin, 1991; Seymour, Seifert, Shafto, & Mosmann, 2000), have typically produced robust results. These results are promising, but need to be extended with research examining vulnerability to faking and performance under more realistic circumstances.

The most common application of concealed information detection is crime knowledge assessment in crime suspects. The validity of this application has mainly been investigated in healthy subjects. Criminals may differ in important aspects from healthy subjects. Psychopathy, for example, is quite common among criminal populations. Psychopathy is characterized by affective-interpersonal (e.g., shallow affect) and behavioural-lifestyle (e.g., impulsivity) features. The latter is associated with physiological hyporesponsivity, and could threaten the validity of concealed information detection. I will review empirical research that has examined this possibility. Directions for future research will be discussed.

Traditional techniques for detecting deception, such as the 'lie-detector test' (or polygraph), are based upon the idea that lying is associated with stress. However, it is possible that people telling the truth will experience stress, whereas not all liars will. Because of this, the validity of such methods is questionable. As an alternative, a knowledge-based approach known as the 'Concealed Information Test' has been developed which investigates whether the examinee recognizes secret information - for example a crime suspect recognizing critical crime details that only the culprit could know. The Concealed Information Test has been supported by decades of research, and is used widely in Japan. This is the first book to focus on this exciting approach and will be of interest to law enforcement agencies and academics and professionals in psychology, criminology, policing and law.

It is now well established that physiological measures can be validly used to detect concealed information. An important challenge is to elucidate the underlying mechanisms of concealed information detection. We review theoretical approaches that can be broadly classified in two major categories: Theories that emphasize emotional-motivational factors, and those that emphasize cognitive factors. While emotional-motivational factors do not appear to be necessary for the detection of concealed information, they may enhance discriminability. Research with realistic setups is needed to examine whether emotional-motivational factors may exert a more prominent role in real-life concealed information tests compared with those performed under laboratory conditions. Empirical research largely supports the cognitive approaches and particularly Orienting Response (OR) theory, which can explain most of the research findings related to the concealed information test (CIT). Future work needs to test whether OR theory holds under real-life circumstances, and whether OR theory needs to incorporate other processes (e.g., response inhibition) to fully account for the differential physiological responding to the relevant items in the CIT.

Since the 2001 attacks on the twin towers, policies on security have changed drastically, bringing about an increased need for tools that allow for the detection of deception. Many of the solutions offered today, however, lack scientific underpinning. We recommend two important changes to improve the (cost) effectiveness of security policy. To begin with, the emphasis of deception research should shift from technological to behavioural sciences. Secondly, the burden of proof should lie with the manufacturers of the security tools. Governments should not rely on security tools that have not passed scientific scrutiny, and should only employ those methods that have been proven effective. After all, the use of tools that do not work will only get us further from the truth.

Determining the true perpetrator of a crime while exonerating innocent suspects forms the foundation of a fair justice system. Specific psychophysiological and behavioral responses, indicating knowledge of critical details derived from a criminal investigation, have been found effective in linking individuals to a crime. While the theory underlying memory detection and the mechanisms contributing to these response patterns have been investigated thoroughly, important questions regarding the external validity remain unanswered. The current dissertation extends the body of knowledge on concealed information detection in three ways. First, research participants have typically been instructed to commit staged crimes, whereas actual perpetrators freely choose whether or not to engage in antisocial behavior. The findings suggest that intrinsic, self-initiated behavior does not undermine CIT validity. Second, memory detection techniques can accurately detect the presence of a memory, but not its origin. Results indicate that presenting items at the exemplar level may reduce the risk of false positives otherwise expected when innocents are contaminated with crime information. Moreover, the appropriate level of questioning in memory detection (using categorical or exemplar details) depends on the initial memory formation at the crime scene, thereby challenging examiners to adopt a perpetrators’ perspective when selecting items. Third, the field lacks an independent method to assess the veracity of suspect confessions. A new application of memory detection shows that recognition of critical details could distinguish true from false confessors. Taken together, the present dissertation provides insight into the external validity of memory detection to enhance the application in the legal arena.

The notion that physiological and behavioral measures can be used to detect concealed memories is intriguing, to say the least. Although years of research on the Concealed Information Test (CIT) have proven the validity of this method, it also raised new questions. The present dissertation focused on three questions that shared a common desire to deepen our understanding of the memory detection phenomenon. First, what are the mechanisms underlying the differential responses to concealed memory items? The experiments presented in Chapters 1 and 2 revealed that while the skin conductance measure reflects orientation to the critical items, the respiration and heart rate measures reflect attempts at arousal inhibition. Second, is the CIT only sensitive to explicit memory or also to implicit memory? The experiments presented in Chapter 3 provided no compelling evidence for the CIT’s sensitivity to implicit memory and showed that the test’s validity depends to a large extent on explicit recognition. Third, does the emotional value of the concealed items affect detection efficiency? The experiments presented in Chapter 4 indicate that both memory and CIT detection efficiency with the skin conductance measure may be heightened for emotional compared to neutral pictures, whereas detection based on heart rate and respiration is unaffected by the emotional level of the items. Taken together, the present results provide novel insights in the theoretical underpinnings of the CIT, with a fractionation of the physiological measures, and help mapping the factors that contribute to successful detection of concealed memory items.