Have you been there before? Decoding recognition of spatial scenes from fMRI signals in precuneus.

One potential application of forensic "brain reading" is to test whether a suspect has previously experienced a crime scene. Here, we investigated whether it is possible to decode real life autobiographic exposure to spatial locations using fMRI. In the first session, participants visited four out of eight possible rooms on a university campus. During a subsequent scanning session, subjects passively viewed pictures and videos from these eight possible rooms (four old, four novel) without giving any responses. A multivariate searchlight analysis was employed that trained a classifier to distinguish between "seen" versus "unseen" stimuli from a subset of six rooms. We found that bilateral precuneus encoded information that can be used to distinguish between previously seen and unseen rooms and that also generalized to the two stimuli left out from training. We conclude that activity in bilateral precuneus is associated with the memory of previously visited rooms, irrespective of the identity of the room, thus supporting a parietal contribution to episodic memory for spatial locations. Importantly, we could decode whether a room was visited in real life without the need of explicit judgments about the rooms. This suggests that recognition is an automatic response that can be decoded from fMRI data, thus potentially supporting forensic applications of concealed information tests for crime scene recognition.

Resistance of a short-term memory concealed information test with famous faces to countermeasures.

The concealed information test (CIT) aims at identifying knowledge that a person wants to hide, by measuring physiological indices during the presentation of known versus unknown items. Recently, Lancry-Dayan et al. (Journal of Applied Research in Memory and Cognition, 7 (2), 291-302, 2018) proposed a new version of this test that included a short-term memory task to maximize differences between responses to items. Participants were asked to memorize four pictures of faces that included one face of an acquaintance. The authors observed that participants looked at the familiar face during the first second and then tended to avoid it. This specific orientation-avoidance pattern occurred even in participants instructed to conceal their familiarity with the known faces (in a spontaneous or a guided manner). In a first experiment, we reproduced Lancry-Dayan et al.'s (2018) study using photos of famous faces. The pattern found by Lancry-Dayan et al. was observed in participants asked to perform the memory task only, participants asked to conceal their familiarity with the famous faces, and participants of a countermeasure group. In a second experiment, we tested the robustness of Lancry-Dayan et al.'s countermeasure. We modified the instructions by emphasizing the oculomotor task or giving feedback. While between-group differences in gaze-pattern appeared after feedback was provided, classification analyses were still able to distinguish between familiar and unfamiliar faces accurately, which revealed the good resistance of this new CIT protocol to countermeasures.

Assessing partial errors via analog gaming keyboards in response conflict tasks: A proof-of-concept study with the concealed information test.

The response time-based Concealed Information Test (RT-CIT) is an established memory detection paradigm. Slower RTs to critical information (called 'probes') compared to control items (called 'irrelevants') reveal recognition. Different lines of research indicate that response conflict is a strong contributor to this RT difference. Previous studies used electromyography (EMG) to measure response conflict, but this requires special equipment and trained examiners. The aim of this study was to explore if response conflict can also be measured with an analog gaming keyboard that is sensitive to minimal finger movements. In a preregistered study, participants completed an autobiographical RT-CIT (n = 35) as well as a cued recognition task (modified Sternberg task; n = 33) for validation purposes. Partial errors, partial button presses of the incorrect response key, were more frequent in trials with response conflict than in trials without conflict. Partial errors were rare (CIT: 2.9%; Sternberg: 1.7% of conflict trials), suggesting analogue keyboards have lower sensitivity than EMG. This is the first evidence that analog keyboards can measure partial errors. Although likely less sensitive than EMG measures, potential benefits of analog keyboards include their accessibility, their compatibility with all tasks that use a standard keyboard, that no physical contact with the participant is needed, and ease of data collection (e.g., allowing for group testing).

Response time concealed information test using fillers in cybercrime and concealed identity scenarios.

The Response Time Concealed Information Test (RT-CIT) can reveal that a person recognises a relevant item (e.g., a murder weapon) among other control items, based on slower responses to the former compared to the latter ones. To date, the RT-CIT has been predominantly examined only in the context of scenarios that are very unlikely in real life, while sporadic assessment has shown that it suffers from low diagnostic accuracy in more realistic scenarios. In our study, we validated the RT-CIT in the new, realistic, and very topical mock scenario of a cybercrime (Study 1, n = 614; Study 2; n = 553), finding significant though moderate effects. At the same time (and expanded with a concealed identity scenario; Study 3, n = 250), we assessed the validity and generalizability of the filler items presented in the RT-CIT: We found similar diagnostic accuracies when using specific, generic, and even nonverbal items. However, the relatively low diagnostic accuracy in case of the cybercrime scenario reemphasizes the importance of assessments in realistic scenarios as well as the need for further improving the RT-CIT.

Breakthrough percepts of online identity: Detecting recognition of email addresses on the fringe of awareness.

A key issue facing cybercrime investigations is connecting online identities to real-world identities. This paper shows that by combining the Fringe-P3 method with a concealed information test, we can detect a participant's familiarity with their own email address, thus connecting their real-world identity to their online one. Participants were shown Rapid Serial Visual Presentation (RSVP) streams of email addresses, some including their own email address (probe) or a target email address. Familiarity with the probe was accurately detected with significant results at the group level and for 7 of 11 participants at the individual level. These promising results demonstrate that the method can be successfully used to detect online identities. Factors that may affect how well an email address probe stands out in the RSVP streams are also discussed.

An Independent Validation of the EEG-Based Complex Trial Protocol with Autobiographical Data and Corroboration of its Resistance to a Cognitively Charged Countermeasure.

The Complex Trial Protocol (CTP) is a P300-based Concealed Information Test (CIT). The theoretical underpinnings of the CIT in the context of law enforcement usage are sound. The CTP is said to effectively discriminate individuals who recognize novel and meaningful stimuli and to be countermeasure resistant. Forty-five undergraduate students were assigned to three groups and instructed to perform a computer task using autobiographical data in connection to a mock burglary script. P300 peak-to-peak amplitude differences between probe (surname) and irrelevant (patronymic foils) items accurately identified 100% (14/14) of Innocent Controls (IC), 94% (15/16) of Simply Guilty (SG) participants, and 93% (14/15) of Guilty Countermeasure (GCM) subjects who were asked to counter all stimuli by mentally counting backwards continuously during their test presentation. Increased number of mistakes during the test, from combined cognitive erroneous responses to pop quizzes and behavioral errors with button presses, significantly discriminated GCM from IC and SG individuals. GCM participants committed more errors than IC and SG which did not differ from one another. Reaction Time (RT) was only significant between GCM and IC groups. Implications for forensic issues are discussed.

Seen this scene? Scene recognition in the reaction-time Concealed Information Test.

Detecting a suspect's recognition of a crime scene (e.g., a burgled room or a location visited for criminal activity) can be of great value during criminal investigations. Although it is established that the Reaction-Time Concealed Information Test (RT-CIT) can determine whether a suspect recognizes crime-related objects, no research has tested whether this capability extends to the recognition of scenes. In Experiment 1, participants were given an autobiographic scene-based RT-CIT. In Experiment 2, participants watched a mock crime video before completing an RT-CIT that included both scenes and objects. In Experiment 3, participants completed an autobiographic scene-based RT-CIT, with half instructed to perform a physical countermeasure. Overall, the findings showed that an equivalent RT-CIT effect can be found with both scene and object stimuli and that RT-CITs may not be susceptible to physical countermeasure strategies, thereby increasing its real-world applicability.

Hide or Seek? Physiological Responses Reflect Both the Decision and the Attempt to Conceal Information.

The process of information concealment is more relevant than ever in this day and age. Using a modified concealed-information test (CIT), we aimed to unmask this process by investigating both the decision and the attempt to conceal information in 38 students. The attempt to conceal (vs. reveal) information induced a differential physiological response pattern within subjects-whereas skin conductance increased in both conditions, respiration and heart rate were suppressed only in the conceal condition-confirming the idea that these measures reflect different underlying mechanisms. The decision to conceal (vs. reveal) information induced enhanced anticipatory skin conductance responses. To our knowledge, this is the first study that observed such anticipatory responses in an information-concealment paradigm. Together, these findings imply that our physiological responses reflect, to some degree, both the decision and the attempt to conceal information. In addition to strengthening CIT theory, this knowledge sheds novel light on anticipatory responding in decision making.

Item Roles Explored in a Modified P300-Based CTP Concealed Information Test.

In this study, we introduced familiarity-related inducer items (expressions referring to the participant's self-related, familiar details: "mine," "familiar"; and expressions referring to other, unfamiliar details, e.g., "other," "irrelevant") to the Complex Trial Protocol version of the P300-based Concealed Information Test (CIT), at the same time using different item categories with various levels of personal importance to the participants (forenames, birthdays, favorite animals). The inclusion of inducers did not significantly improve the overall efficiency of the method as we would have expected considering that these inducers should increase awareness of the denial of the recognition of the probes (the true details of the participants), and hence the subjective saliency of the items (Lukács in J Appl Res Mem Cognit, 6:283-284, 2017a). This may be explained by the visual similarity of inducers to the probe and irrelevant items and the consequent distracting influence of inducers on probe-task performance. On the other hand, the CIT effect (probe-irrelevant P300 differences) was always lower for less personally important (low-salient) and higher for more personally important (high-salient) items.

Electrophysiological markers of working memory usage as an index for truth-based lies.

People prefer to lie using altered truthful events from memory, perhaps because doing so can increase their credibility while reducing cognitive and working memory (WM) load. One possible way to counter such deceptive behavior is to track WM usage, since fabricating coherent lies or managing between truth and lies is likely to involve heavy WM load. In this study, participants memorized a list of words in the study session and used these old words to provide deceptive answers when cued later, in the testing session. Our behavioral results showed that people needed more time to make a deceptive response during the execution stage, and this prolonged deceptive reaction time (RT) was negatively correlated with each participant's WM capacity. Event-related potential findings showed a more negative-going frontal amplitude between the lie and truth conditions during the preparation stage, suggesting that WM preparatory processes can be detected long before a deceptive response is verbalized. Furthermore, we observed a larger positive frontal-central amplitude during the execution stage, which was negatively correlated with participants' lie-truth RT differences, suggesting that participants' efficiency in producing deceptive responses can be readily traced electrophysiologically. Together, these findings suggest that WM capacity and preparation are crucial to efficient lying and that their related electrophysiological signatures can potentially be used to uncover deceptive behaviors.

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.

Through the eyes to memory: Fixation durations as an early indirect index of concealed knowledge.

In three experiments, we investigated an early memory effect in eye fixations, namely increased durations of the second fixations to known relative to unfamiliar stimuli. This effect occurs even if knowledge of the stimulus is deliberately concealed. In Experiment 1, we found the early memory effect using object materials and a gaze-contingent stimulus presentation that controlled for parafoveal stimulus processing. In Experiment 2a, we looked for the effect under conditions commonly used in the concealed information test (CIT). To this end, participants encoded the "to-be-concealed" knowledge incidentally while doing a mock crime task, which was followed by a CIT. Beyond the control of parafoveal stimulus processing in Experiment 1, this procedure allowed minimization of influences of carry-over processes associated with the preceding stimulus. Experiment 2b replicated Experiment 2a but applied a 1-week retention interval between the encoding of the to-be-concealed knowledge and the CIT. We observed an early memory effect in all experiments, suggesting that the effect is robust, irrespective of the paradigm, stimulus materials, and retention interval used.

Memory detection using fMRI - does the encoding context matter?

Recent research revealed that the presentation of crime related details during the Concealed Information Test (CIT) reliably activates a network of bilateral inferior frontal, right medial frontal and right temporal-parietal brain regions. However, the ecological validity of these findings as well as the influence of the encoding context are still unclear. To tackle these questions, three different groups of subjects participated in the current study. Two groups of guilty subjects encoded critical details either only by planning (guilty intention group) or by really enacting (guilty action group) a complex, realistic mock crime. In addition, a group of informed innocent subjects encoded half of the relevant details in a neutral context. Univariate analyses showed robust activation differences between known relevant compared to neutral details in the previously identified ventral frontal-parietal network with no differences between experimental groups. Moreover, validity estimates for average changes in neural activity were similar between groups when focusing on the known details and did not differ substantially from the validity of electrodermal recordings. Additional multivariate analyses provided evidence for differential patterns of activity in the ventral fronto-parietal network between the guilty action and the informed innocent group and yielded higher validity coefficients for the detection of crime related knowledge when relying on whole brain data. Together, these findings demonstrate that an fMRI-based CIT enables the accurate detection of concealed crime related memories, largely independent of encoding context. On the one hand, this indicates that even persons who planned a (mock) crime could be validly identified as having specific crime related knowledge. On the other hand, innocents with such knowledge have a high risk of failing the test, at least when considering univariate changes of neural activation.

Area measure of skin conductance in the Concealed Information Test.

Skin conductance (SC) is one of the indices commonly used in the autonomic Concealed Information Test (CIT), but SC amplitude is sometimes difficult to quantify. This study investigated the applicability of SC area to the CIT as an unambiguous measure of SC. Secondary analyses of an existing dataset indicated that SC area could be used to classify examinees according to their knowledge status, although the equivalence of its performance with the SC amplitude was inconclusive. Classification performance was best when the SC signal was converted to the difference from question onset and summed over 10 s after question onset. SC area produced relatively consistent evaluations of differential responses based on the amplitude for inter-item comparisons. In addition, the classification performance of SC area exceeded the chance level even for participants who showed few measurable amplitudes (low-responsive participants). A possible implication is that a tonic increase in SC occurred in response to the relevant question even in low-responsive participants, who are traditionally excluded from analysis. The use of SC area might contribute to more impartial data evaluation and broader application of the CIT. These results indicate that SC area can be used as an alternative measure of SC in the CIT.

Conditioning to true content and artificial intelligence in psychophysiological intention recognition.

OBJECTIVE: The objective is to introduce a novel method for classical conditioning to true content (CtTC), and for the first time, apply this approach in the concealed information test (CIT) to effectively discern intentions. During CtTC, participants are trained to exhibit electrodermal responses whenever they recognize true content on a screen. Additionally, the objective is to evaluate a novel CIT-dataset preprocessing algorithm, employed to enhance machine learning (ML) classification performance. METHODS: A total of 84 participants were evenly divided into four groups. Two groups of participants devised plans for stealing money from a supermarket, while the other two groups did not engage in any planning. One planning group and one non-planning group underwent CIT examination, while the remaining groups were subjected to CtTC. RESULTS: The CIT accuracy initially stood at 52 % and increased to 71 % after Z-score and ML classification (McNemar test, p < 0.05). Conversely, the CtTC accuracy was 76 % and significantly improved to 93 % following Z-score and 95 % following ML classification (McNemar test, p < 0.05). In the best-performing classifiers, CtTC exhibited significantly superior metrics for guilty/innocent classification compared to CIT (Fisher's exact test, p < 0.05, power 1 - ß > 0.90). In the CtTC group, reactivity and sensitivity significantly increased, indicated by higher EDR amplitudes (p < 0.05, two-tailed t-test, power 1 - ß = 0.89) and the number of EDRs (p < 0.05, Fisher's exact test, power 1 - ß = 0.90). There was no statistically significant difference between the Z-score and ML classification. CONCLUSIONS: In the assessment of intentions, CtTC enhances both the sensitivity and accuracy of the CIT.

Psychology and the lie detector industry: A fifty-year perspective.

Fifty years ago, in a trenchant analysis that challenged applied lie detection theory and science, David Lykken (1974) brought polygraphic interrogation methods to the attention of academia with the hope that these techniques would come under the purview of psychology and psychophysiology. In this perspective, I examine how this application of psychophysiology has evolved over the last half century and how its status has changed for 1) the comparison (control) question test (CQT), used in forensic applications; 2) polygraph screening tests, used to evaluate examinee integrity; and 3) the concealed information technique (CIT), used to assess recognition memory of crime details. The criticisms of the CQT and screening tests advanced by Lykken have been amplified and focused by the academic community over the last half century. However, this has had little effect on how these methods are practiced and has not curtailed their use. Although most private sector employee screening tests are now prohibited, personnel screening of government employees has increased, and screening tests of sex offenders are now commonplace. Even though the CIT has captured the interest of psychophysiologists as a scientifically defensible technique, its field use is negligible. A primary purpose of polygraphic interrogations continues to be the extraction of admissions and confessions. The lack of change in the polygraph testing status quo stems in large part from unwavering government support for the use of these methods. As a result, polygraph theory and research support continues to rest on shaky ground while practice continues unfettered by valid criticism.

Selective memory detection: Context-dependent stimulus significance in the concealed information test.

Previous studies have posited that the significance of a crime-relevant item in a question produces differential physiological responses in the Concealed Information Test (CIT). However, this term is equivocal and needs to be clarified in order to strengthen the theoretical underpinnings of the CIT. The present study examined the hypothesis that differential responding depends on the examinee's understanding of which item in a question is relevant to a given context. Participants performed a mock theft task, in which they were instructed to steal one item from each of two different locations. An identical CIT question asking about each stolen item was presented under different location contexts while skin conductance response, heart rate, and respiratory activity were recorded. Results indicated that only the relevant item specified by the context of the instruction elicited reliable differential physiological responses. This finding implies that differential responding in the CIT is flexible and context-dependent, and that specifying the subject of a given question is important for detecting crime-relevant memories in practical criminal investigations.

Orienting versus inhibition: The theory behind the ocular-based Concealed Information Test.

When trying to conceal one's knowledge, various ocular changes occur. However, which cognitive mechanisms drive these changes? Do orienting or inhibition-two processes previously associated with autonomic changes-play a role? To answer this question, we used a Concealed Information Test (CIT) in which participants were either motivated to conceal (orienting + inhibition) or reveal (orienting only) their knowledge. While pupil size increased in both motivational conditions, the fixation and blink CIT effects were confined to the conceal condition. These results were mirrored in autonomic changes, with skin conductance increasing in both conditions while heart rate decreased solely under motivation to conceal. Thus, different cognitive mechanisms seem to drive ocular responses. Pupil size appears to be linked to the orienting of attention (akin to skin conductance changes), while fixations and blinks rather seem to reflect arousal inhibition (comparable to heart rate changes). This knowledge strengthens CIT theory and illuminates the relationship between ocular and autonomic activity.

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.