Detection Of Concealed Information Research Articles

Fast & furious: Rejecting the hypothesis that secondary psychopathy improves reaction time-based concealed information detection.

Deception, a complex aspect of human behavior, is inherently difficult to detect directly. A valid alternative involves memory detection, particularly through methods such as the Reaction-Time based Concealed Information Test (RT-CIT). The RT-CIT assesses whether an individual possesses specific knowledge by presenting various probe (familiar) items amidst irrelevant (unfamiliar) items. The task-required "unfamiliar" response to probes may induce a response conflict. Resolving this conflict, by inhibiting the automatic "familiar" response, takes time and slows probe RTs-a phenomenon known as the RT-CIT effect. Notably, secondary psychopathy is characterized by disinhibition and impulsivity, traits which may hinder the ability to effectively manage experienced conflict. Therefore, we hypothesized that secondary psychopathy would be associated with an elevated RT-CIT effect. To investigate this hypothesized relation, we conducted a pre-registered study (n = 86, student sample), employing a novel CIT paradigm that incorporates no-go trials to assess response inhibition capacity. Psychopathic traits were measured using the Levenson Self-Report Psychopathy (LSRP) scale, while the Barratt Impulsiveness Scale (BIS-11) assessed impulsivity. The novel CIT paradigm revealed impressive detection efficiency. However, contrary to our expectations, we observed no significant correlation between the RT-CIT effect and secondary psychopathic traits (BF01 = 6.98). This cautiously suggests that while secondary psychopathic tendencies do not improve RT-CIT validity, they also do not compromise it. Although future investigations should explore more diverse contexts and populations, this tentative finding is reassuring and underscores the robustness of the CIT paradigm.

Memory detection with concurrent behavioral, autonomic, and neuroimaging measures in a mock crime.

Concealed information test (CIT) has been utilized for long to perform single measurements. The combination of multiple measures outperforms single measures because of the diverse cognitive processes they reflect and the reduction in random errors facilitated by multiple measures. To further explore the performance of the CIT with multiple measurements, 57 participants were recruited and randomly assigned into guilty and innocent groups. Subsequently, simultaneously recorded reaction time (RT), skin conductance responses (SCRs), heart rate (HR), and neuroimaging data were collected from functional near-infrared spectroscopy (fNIRS) to detect participants' concealed information in a standard CIT. The results demonstrated that all indicators including RT (area under the curve (AUC) = 0.87), SCRs (AUC = 0.79), HR (AUC = 0.78), and fNIRS (channel 8, AUC = 0.85) could differentiate guilty and innocent groups. Importantly, the use of multiple indicators achieved higher detection efficiency (AUC = 0.96) compared to the use of any single indicator. These results illustrate the effectiveness and feasibility of integrating multiple indicators for concealed information detection in CIT.

The role of response conflict in concealed information detection with reaction times

The concealed information test (CIT) presents various probe (familiar) items amidst irrelevant (unfamiliar) items. When the probe items appear, reaction time (RT) slows down. This RT-CIT effect has been accounted for by a conflict resulting from the need to deny familiarity of the familiar probes. The present pre-registered study (n = 292) examined whether response conflict is sufficient to account for the RT-CIT effect, using city and name items. Specifically, we compared the common conflict condition, where the response buttons emphasized familiarity of CIT items (“unfamiliar” versus “familiar”), to a novel no conflict condition, where the buttons emphasized categorical membership (“city” versus “name”). In line with our expectations, the RT-CIT effect was substantially stronger in the conflict condition; yet, it remained significant even in the no conflict condition. This implies a critical role for response conflict, but also suggests that other mechanisms (e.g. orientation to significant stimuli) may contribute to the RT-CIT effect.

Effects of Mood on Psychophysiological Detection of Concealed Information and the Relation to Self-Assessed Lying Ability

The present study examined the effects of mood on physiological responses in the Concealed Information polygraph Test and the relation to self-assessed lying ability. One hundred and eight undergraduate students self-assessed their lie-telling ability, committed a mock theft, and were asked to conceal information related to the crime. Participants were then divided into three equal groups: two groups were asked to provide a detailed written account of either a happy or sad event in order to induce a happy or sad mood, while the third group served as a neutral group. Participants then underwent a polygraph test and were asked to try to avoid detection. An induced happy or sad mood tended to lower relative skin conductance responses to critical (crime related) items and enhance relative cardiovascular responses. Relative respiration responses to critical items obtained for the sad mood condition were more robust than the ones obtained for the happy mood condition. Under induced sad and happy moods, those who self-rated their lie-telling ability as high showed enhanced cardiovascular responsivity to critical items. These results were limited to the initial phase of the test. We discussed possible motivational explanations and implications for the Concealed Information polygraph test.

A new theoretical perspective on concealed information detection.

The concealed information test (CIT) was designed to detect concealed knowledge. It does so by measuring differential physiological and behavioral responses to concealed, compared to control, items - i.e., the CIT effect. Although the CIT has gained extensive empirical support in laboratory studies, scientific validity requires also a theoretical understanding of the method's underlying mechanisms. In this article, we present a new theoretical perspective. Specifically, we elaborate and clarify several features of Orienting Response (OR) theory, which has been the dominant theory in this domain. Importantly, we suggest for the first time that the voluntary (rather than the involuntary) OR modulates the CIT effect. Second, we argue that motivational-emotional accounts of the CIT effect are consistent with OR theory and cannot be considered as alternative approaches. Finally, we discuss some more recent developments which highlight the idea that different physiological measures reflect different underlying mechanisms - an idea dubbed as response fractionation.

RCIT: An RSVP-Based Concealed Information Test Framework Using EEG Signals

Concealed information detection has a strong connection with human cognition. Existing deception detection approaches such as polygraph testing usually exploit psychophysiological changes. However, they often suffer from low accuracy and attacking-by-training. Compared with conventional physiological responses, electroencephalogram (EEG) directly reflects activity responses in the brain, thus can be potentially more accurate in deception detection. In this paper, we propose an EEG-based concealed information detection framework. In this framework, different test trials are designed to evoke effective brain responses corresponding to concealed information while keeping the subject focused. Meanwhile, we employ rapid serial visual presentation (RSVP) for deception detection. Our framework presents the stimuli on the fringe of awareness, making it not easy to take the countermeasures. Furthermore, we develop a method based on neural network to detect brain responses. Experimental results with 10 subjects show that, our approach can effectively detect concealed information with an accuracy of 87.13%.

Deleterious effects of probe-related versus irrelevant targets on the "CIT effect" in the P300- and RT-based three-stimulus protocol for detection of concealed information.

Two groups of participants committed the same mock crime in which one of two items, a watch or a ring, was removed from a drawer and concealed. One group, the crime-familiar group next experienced a three-stimulus protocol (3SP), a Concealed Information Test (CIT), in which they were tested on the stolen (probe) item presented in a random series of five irrelevant (unseen) stimuli from the same jewelry category. A left-hand button press, meaning "I don't recognize" was to follow each of these six items. A right-hand press ("I do recognize") was to follow the one other presented item, the target item, which in the case of the crime-familiar group was the other, not-stolen item in the drawer at the mock crime scene. For the other crime-unfamiliar group, the target was a sixth unseen irrelevant item as in the original P300 CIT. In terms of P300 latency and reaction time (RT), crime-familiar participants processed all stimuli faster than crime-unfamiliar participants. The CIT effects (probe-minus-irrelevant differences) for crime-familiar group members were inferior to those of crime-unfamiliar group members for RT and P300 amplitude measures. Thus, familiar targets negatively impact the 3SP.

Use of cardiometry and oculography in concealed information detection

Use of cardiometry and oculography in concealed information detection

P300 in detecting concealed information and deception: A review.

Studies using the P300 ERP in detection of concealed information are reviewed. An overview of the initial findings, methodological issues, and use of bootstrapping methods for data analysis are considered, with various protocols explicated. Applications to forensic issues, employee screening, cognitive deficit malingering, and facial recognition in lineups are outlined. Countermeasures to the original P300-based tests are described, and a possible approach to this problem using a new complex-trial protocol is offered. Applications of this protocol to forensic and antiterror scenarios are then presented, along with its first independent replication. Studies of visual versus auditory stimulus presentation in the complex-trial protocol are evaluated. Findings from attempted voluntary suppression of P300 as a recognition signal are presented, and the effects of motivational manipulations on the P300-based complex-trial protocol are summarized. Limitations of the research are reviewed, and, based on this review, future directions of P300 methods for detection of concealed information and deception are suggested that may guide the development of more precision and reliability of this promising tool.

Visual presentation modality's superiority in the detection of concealed information: A comparison of the efficiencies of the P300-based Complex Trial Protocol in visual versus auditory modalities

Some studies have shown a superiority of visual vs. auditory item presentation in the Complex Trial Protocol (CTP), which is a countermeasure-resistant version of the P300-based Concealed Information Test (CIT). But those studies used elaborately- rehearsed autobiographical information as stimuli, instead of incidentally-acquired crime-related information. Thus, the relative superiority of the visual as opposed to the auditory modality in detecting episodic crime-related information is still unknown. The present study also improved on the usual mock crime scenario by adding a mock disposal task between a mock theft and administration of a CTP test to increase stimulus saliency. In this CTP, the probe and the irrelevant items were presented visually or acoustically on alternating trials, while target and non-target stimuli were simultaneously presented in visual and auditory modalities. The results showed that the P300 amplitude differences of probe minus irrelevant items presented in the visual modality were significantly larger compared to the auditory modality, and the detection rate of the guilty participants was also significantly higher for the visual (14/16) versus auditory modality (5/16). These results suggest a superiority of visual vs. auditory presentation when a CTP is used to detect crime-related information in a mock crime scenario.

Brain fingerprinting using P300 in the detection of concealed information

Brain fingerprinting using P300 in the detection of concealed information

Crypto-Steganographic LSB-based System for AES-Encrypted Data

The purpose of this work is to increase the level of concealment of information from unauthorized access by pre-encrypting and hiding it in multimedia files such as images. A crypto-steganographic information protection algorithm with LSB-method was implemented. The algorithm hides AES pre-encrypted confidential information in the form of text or images into target containing image files. This method uses the concept of data concealing in the least significant pixel bits of the target image files. The proposed method relies on the use of Diffie-Hellman public key exchange protocol for securely exchanging the stego-key used for LSB as well as the public key used for encrypting the secret information. The algorithm ensures that the visual quality of the image remains unchanged, with no distortions perceived by the human eye. The algorithm also complicates the detection of concealed information embedded in the target image with use of PRNG as an enhancement for LSB. The proposed system scheme achieved competitive results. On an average, the system achieved a Peak Signal-to-Noise Ratio (PSNR) of 96.3 dB and a Mean Square Error (MSE) of 0.00408. The results obtained demonstrate that the proposed system offers high payload capabilities with immunity against visual degradation of resultant stego images.

Effects of practice on Lukacs' (2016) countermeasures (CMs) to the P300-based Complex Trial Protocol (CTP) for detection of concealed information

Restrictive deterrence refers to the strategies offenders use to reduce their risk in response to sanctions. It occurs when offenders reduce the frequency, severity, or duration of their offending, or displace their crimes temporally, spatially, or tactically. We summarize and synthesize qualitative research focused on restrictive deterrence.We conduct a qualitative meta-synthesis (QMS) on research on restrictive deterrence with the aims of integrating, comparing, and translating findings across 17 studies. The studies examine restrictive deterrence in drug dealing, prostitution and auto-theft. The method reveals coherent themes and provides interpretations spanning the works to guide further investigation.Offenders use strategies for avoidance and management of arrest risk and mitigation of punishment in response to sanction threats. Their advance plans and mental preparations structure crime choices. However, both their decisions and their strategies are subject to many influences including variable frictions, restricted options, and bounded rationality.Reductions in offending from deterrent efforts, including the frequency, duration and severity of crime is crime-contingent and partially offset by offenders becoming more embedded in criminal networks and emboldened as they perceive their adaptations as effective.

What mechanisms underlie ERP-based concealed information detection?

What mechanisms underlie ERP-based concealed information detection?

F110. Using brain fingerprinting in the detection of concealed information in Egyptians

Introduction Brain fingerprinting is a forensic science technique that uses electroencephalography (EEG) to determine whether specific information is stored in a subject’s brain. It does this by measuring electrical brainwave responses to pictures that are presented on a computer screen; P300 wave is a specific event-related potential (ERP) component that has the potential for detecting concealed information in the brain. Objectives: this work aimed to evaluate the appearance of P 300 wave in response to relevant visual stimuli and its absence to irrelevant ones and to evaluate the latency and amplitude of P300 wave in response to well-known persons and places. Methods This is a cross sectional prospective study carried out on 225 normal individuals at Clinical Neurophysiology Unit, Faculty of Medicine, Cairo University. It comprised both sexes aged from 18 to 70 years old; participants were divided into 3 groups. An endogenous ERP;P300 wave was seen evoked in response to rare, presented, recognized, meaningful stimulus, the peak amplitude was calculated and peak latency was measured from the time of stimulus onset. Results A photo of a person or place known to the test subject elicited a well-marked P300 response, while that of an unknown personality or place didn’t generate noticeable response. P300 wave latency and amplitude was recorded. There was a significant association between P300 amplitude and latency with age and educational level. Conclusion P300 wave is valuable in detecting concealed knowledge stored in the participant’s brain and is an objective and reliable test.

Using more different and more familiar targets improves the detection of concealed information

When embedded among a number of plausible irrelevant options, the presentation of critical (e.g., crime-related or autobiographical) information is associated with a marked increase in response time (RT). This RT effect crucially depends on the inclusion of a target/non-target discrimination task with targets being a dedicated set of items that require a unique response (press YES; for all other items press NO). Targets may be essential because they share a feature - familiarity - with the critical items. Whereas irrelevant items have not been encountered before, critical items are known from the event or the facts of the investigation. Target items are usually learned before the test, and thereby made familiar to the participants. Hence, familiarity-based responding needs to be inhibited on the critical items and may therefore explain the RT increase on the critical items. This leads to the hypothesis that the more participants rely on familiarity, the more pronounced the RT increase on critical items may be. We explored two ways to increase familiarity-based responding: (1) Increasing the number of different target items, and (2) using familiar targets. In two web-based studies (n = 357 and n = 499), both the number of different targets and the use of familiar targets facilitated concealed information detection. The effect of the number of different targets was small yet consistent across both studies, the effect of target familiarity was large in both studies. Our results support the role of familiarity-based responding in the Concealed Information Test and point to ways on how to improve validity of the Concealed Information Test.

Disrupting dorsolateral prefrontal cortex by rTMS reduces the P300 based marker of deception.

ObjectiveQuite many studies have revealed certain brain‐process signatures indicative of subject's deceptive behavior. These signatures are neural correlates of deception. However, much less is known about whether these signatures can be modified by noninvasive brain stimulation techniques representing methods of causal intervention of brain processes and the corresponding behavior. Our purpose was to explore whether such methods have an effect on these signatures.MethodsIt is well known that electroencephalographic event‐related potential component, P300, is sensitive to perception of critical items in a concealed information test, one of the central methods in deception studies. We examined whether the relative level of expression of P300 as a neural marker of deception can be manipulated by means of noninvasive neuromodulation. We used EEG/ERP recording combined with (i) neuronavigated repetitive transcranial magnetic stimulation (rTMS) and (ii) concealed information detection test. An opportunistically recruited volunteer group of normal adults formed our experimental group.ResultsWe show that offline rTMS to dorsolateral prefrontal cortex attenuated relative P300 amplitude in response to the critical items compared to the neutral items.ConclusionNoninvasive prefrontal cortex excitability disruption by rTMS can be used to manipulate the sensitivity of ERP signatures of deception to critical items in a concealment‐based variant of lie detection test.

Subject-based discriminative sparse representation model for detection of concealed information

Background and objectivesThe use of machine learning approaches in concealed information test (CIT) plays a key role in the progress of this neurophysiological field. In this paper, we presented a new machine learning method for CIT in which each subject is considered independent of the others. The main goal of this study is to adapt the discriminative sparse models to be applicable for subject-based concealed information test. MethodsIn order to provide sufficient discriminability between guilty and innocent subjects, we introduced a novel discriminative sparse representation model and its appropriate learning methods. For evaluation of the method forty-four subjects participated in a mock crime scenario and their EEG data were recorded. As the model input, in this study the recurrence plot features were extracted from single trial data of different stimuli. Then the extracted feature vectors were reduced using statistical dependency method. The reduced feature vector went through the proposed subject-based sparse model in which the discrimination power of sparse code and reconstruction error were applied simultaneously. ResultsExperimental results showed that the proposed approach achieved better performance than other competing discriminative sparse models. The classification accuracy, sensitivity and specificity of the presented sparsity-based method were about 93%, 91% and 95% respectively. ConclusionsUsing the EEG data of a single subject in response to different stimuli types and with the aid of the proposed discriminative sparse representation model, one can distinguish guilty subjects from innocent ones. Indeed, this property eliminates the necessity of several subject EEG data in model learning and decision making for a specific subject.

Attempts to Suppress Episodic Memories Fail but do Produce Demand: Evidence from the P300-Based Complex Trial Protocol and an Implicit Memory Test.

Instructions to voluntarily suppress memories of a mock crime have been reported to result in decreased P300 amplitude during a P300-based concealed information test (CIT) and reduced autobiographical Implicit Association Test (aIAT) D scores, supporting successful suppression. However, one such study, (Hu et al., Psychological science 26(7):1098-1106, 2015) used the P300-based Complex Trial Protocol with a 50-50 target to nontarget ratio, which could impose much response switching and thereby drain cognitive resources, also resulting in reduced P300. The present study replicated Hu et al. (Psychological science 26(7):1098-1106, 2015) with one major variation-a less intrusive 20-80 target to nontarget ratio that required less response switching. Detection rates were high using both the brainwave-based CIT (90% accuracy) and the aIAT (87% accuracy). However we found no significant differences between the suppression and simple guilty groups on the major indices of concealed information detection, which compare probe and irrelevant P300 responses. While we did find that overall P300 amplitude was reduced in the suppression group, this reduction was not specific to probe responses. Additionally, while there were group differences in aIAT hit rates, there were no differences in aIAT D scores. Taken together, these findings suggest that the previously demonstrated reductions in P300 are a reflection of task demand rather than of effective voluntary memory suppression.

High Emotional Arousal Enables Subliminal Detection of Concealed Information

The Concealed Information Test (CIT) is an information-detecting technique for criminal investigations. Although it has been shown that emotional arousal plays a specific role in the CIT, the mechanisms by which emotional arousal affects the CIT are unclear. The main purpose of this study was to elucidate the processing pathway for stimuli encoded with emotional arousal in a mock crime before the CIT. In this study, participants viewed emotionally arousing pictures before the mock crime. Participants were assigned randomly to either a high or low emotional arousal group, viewing pictures expected to arouse emotion at a high or low level, respectively. Subsequently, all participants enacted the same mock crime, in which they were instructed to stab a pillow with a sharp-edged tool (e.g., kitchen knife or ice pick) as if to harass a woman lying on a bed. After the antecedent emotional experience, a P300-based CIT was conducted using subliminal and supraliminal presentation methods. The results revealed a significantly greater CIT effect on the P300 event-related potential (ERP) component in the High Arousal group compared with the Low Arousal group, under both subliminal and supraliminal conditions. The detection of concealed information was successful only in the High Arousal group under subliminal conditions, whereas detection was successful regardless of the emotional arousal group under supraliminal conditions. These results provide strong evidence that emotional arousal can increase P300 amplitude during responses to concealed information in the CIT. This suggests that concealed information may be automatically processed via the bottom-up route in the CIT, but only when it is encoded with high emotional arousal.