Lying and executive control: an experimental investigation using ego depletion and goal neglect

The Role of Cognition in Dishonest Behavior

Dishonesty has received increased attention from many professionals in recent years for its relevance in many social areas such as finance and psychology, among others. Understanding the mechanisms underlying dishonesty and the channels in which dishonesty operates could enable the detection and even prevention of dishonest behavior. However, the study of dishonesty is a challenging endeavor; dishonesty is a complex behavior because it imposes a psychological and cognitive burden. The study of this burden has fostered a new research trend that focuses on cognition’s role in dishonesty. This paper reviews the theoretical aspects of how such cognitive processes modulate dishonest behavior. We will pay special attention to executive functions such as inhibitory processes, working memory, or set-shifting that may modulate the decision to be (dis)honest. We also account for some frameworks in cognitive and social psychology that may help understand dishonesty, such as the Theory of Mind, the role of creative processes, and discourse analyses within language studies. Finally, we will discuss some specific cognitive-based models that integrate cognitive mechanisms to explain dishonesty. We show that cognition and dishonest behavior are firmly related and that there are several important milestones to reach in the future to advance the understanding of dishonesty in our society.

Does Ego Depletion Elicit Stronger Cues of Deception?

Lying is cognitively demanding and presumably requires self-regulation. According to ego depletion theory, a task that requires self-regulation should therefore impair an individual’s ability to tell a convincing lie in a later task. Consequently, it was hypothesized that a manipulation of ego depletion would enhance behavioral differences between liars and truth-tellers. To manipulate ego depletion, participants worked (vs. did not work) on a task in which they had to suppress dominant responses while copying a text. Subsequently, they talked in a simulated job interview about a job they had previously held (vs. not held). In the sample of 164 participants, there was no evidence to support the hypothesis; the expected Ego Depletion x Veracity interaction was not significant for any of the 15 behavioral cues coded in the videotaped interviews. Although the main effect of ego depletion was significant at the multivariate level for the first of two parts of the interview, none of the univariate main effects reached the significance level corrected for multiple testing. Bayesian analyses rendered moderate to strong evidence in favor of the null hypothesis. Possible implications of the results are discussed, also those related to ego depletion theory.

The Effect of Task-Irrelevant Emotional Valence on Limited Attentional Resources During Deception: An ERPs Study

Deception is a complex and cognitively draining dyadic process that simultaneously involves cognitive and emotional processes, both of which demand/capture attentional resources. However, few studies have investigated the allocation of attentional resources between cognitive and emotional processes during deception. The current study presented facial expressions of different valences to 36 participants. While an electroencephalogram was recording, they were asked to make either truthful or deceptive gender judgments according to preceding cues. The results showed that deceptive responses induced smaller P300 amplitudes than did truthful responses. Task-irrelevant negative emotional information (TiN) elicited larger P300 amplitudes than did task-irrelevant positive emotional information (TiP). Furthermore, the results showed that TiN elicited larger LPP amplitudes than did TiP in deceptive responses, but not in truthful ones. The results suggested that attentional resources were directed away to deception-related cognitive processes and TiN, but not TiP, was consistently able to compete for and obtain attentional resources during deception. The results indicated that TiN could disrupt with deception and may facilitate deception detection.

Little pranksters: Inhibitory control mediates the association between false belief understanding and practical joking in young children

To successfully pull a practical joke on someone, children need to understand that their victims do not know what they themselves know, be able to intentionally manipulate others’ beliefs, and maintain a straight face to safeguard the integrity of the joke. This study examined the relationship between children’s developing theory of mind (ToM), inhibitory control, and their ability to pull a practical joke. Ninety-five children between ages 2 and 6 participated in, among other measures, a practical joke task that required them to knowingly give one of the experimenters a gift box containing a rubber insect. Results showed that children’s ability to pull a practical joke was significantly related to their age, false belief understanding (FBU), inhibitory control, and verbal ability. Children with more siblings were more likely to successfully pull a practical joke. Most importantly, inhibitory control was shown to mediate the relation between FBU and practical joking. The findings provide evidence that practical joking as an example of ToM use is effortful.

Higher Self-Control, Less Deception: The Effect of Self-Control on Deception Behaviors

The self-control ability and self-control resources have a different influence on deception, but the cognition mechanism of this different influence has not been described yet. In this study, the event-related potentials (ERPs) technique was utilized to conduct two experiments exploring the effects of self-control ability and self-control resources on deception from two approaches. In Experiment 1, participants with different levels of self-control ability performed a visual perception task to measure deception and deception tendencies. The results revealed that individuals with low self-control ability exhibited more deceptive behaviors than did individuals with high self-control ability. Furthermore, individuals with high self-control ability evoked larger N2 and smaller P3 amplitudes than did individuals with low self-control ability. Experiment 2 involved selecting individuals with medium self-control ability. The Stroop task and a visual perception task were employed to investigate the influence of self-control resources on deception. The results showed that the depletion of self-control resources facilitated smaller N2 and larger P3 amplitudes than did non-depletion of self-control resources. In conclusion, these results suggest that individuals with high self-control ability are less likely to deceive others in order to obtain more benefits. When individuals have sufficient self-control resources, they resist temptation and reduce deception behaviors. Deception and deception tendencies may be more likely in people with low of self-control and whose self-control resources are depleted. In people with moderate self-control, deception was still regulated by self-depletion.

The effect of statement type and repetition on deception detection

Background

Deception is a prevalent component of human interaction. However, meta-analyses suggest that discriminating between truthful and deceptive statements is a very arduous task and accuracy on these judgments is at chance levels. To complicate matters further, individuals tell different types of lies. The current studies examined how an individual’s ability to accurately discriminate between truthful and deceptive statements is affected by the way truths and lies are conveyed. Participants judged the veracity of statements given by speakers who told truths or lies about a performed action by describing that action or denying that it had occurred. Additionally, these statements also differed with regard to how often the lie had been repeated (i.e., practiced), either once or thrice.

Results

The results were largely in line with the prevailing notion that it is difficult to successfully differentiate between truthful and deceptive statements, but also showed that performance was moderated by statement type and repetition. The results revealed that participants were more accurate in discriminating unrepeated descriptions than repeated descriptions, but this difference was not seen for denial statements. Additionally, participants were more likely to believe practiced (repeated) statements, both truthful and deceptive.

Conclusion

The results show that repeated statements as well as shorter denials can increase the difficulty of differentiating truthful from deceptive statements. Additionally, these findings suggest that truthful statements also benefit from repetition with regard to enhancing their believability.

The language of lies: a preregistered direct replication of Suchotzki and Gamer (2018; Experiment 2)

Is lying in a different language easier or more difficult? The Emotional Distance and the Cognitive Load hypothesis give competing answers. Suchotzki and Gamer measured the time native German speakers needed to initiate honest and deceptive answers to German and English questions. Lie-truth differences in RTs were much smaller for the foreign compared to the native language. In our preregistered replication study in native Dutch speakers, we found that lie-truth differences in RTs were moderately smaller when participants were tested in English than when tested in Dutch. These findings indicate that people struggle with quickly retrieving the truth in another language, and that foreign language use may diminish lie-truth differences.

Altruistic and self-serving goals modulate behavioral and neural responses in deception

People tell lies not only for their own self-interests but sometimes also to help others. Little is known about the ways in which different types of goals modulate behaviors and neural responses in deception. The present study investigated the neural processes associated with spontaneous deception that occurs with altruistic reasons (i.e. the money would be donated to charity), self-serving reasons (i.e. the participant receives all of the money) and mixed goals (i.e. the money would be equally split between the participant and the charity). Altruistic motivation for deception reduced the intensity of moral conflict and the subsequent mental cost of resolving this conflict, reflected by a smaller N2–P3 effect in the purely altruistic condition. When making decisions about whether to lie, self-interest was a stronger motivator than others’ interests, and the participants tended to lie more for themselves than for others. When the lie could be mutually beneficial for both of the self and others, the participants tended to lie even when they knew that they could be easily caught, but they actually lied for their own self-interest rather than for altruistic reasons. These findings shed light on the neural basis of ‘good lies’ and decision-making in mutually beneficial situations.

Verbal Deception and the Model Statement as a Lie Detection Tool

We have been reliably informed by practitioners that police officers and intelligence officers across the world have started to use the Model Statement lie detection technique. In this article we introduce this technique. We describe why it works, report the empirical evidence that it works, and outline how to use it. Research examining the Model Statement only started recently and more research is required. We give suggestions for future research with the technique. The Model Statement technique is one of many recently developed verbal lie detection methods. We start this article with a short overview of the-in our view- most promising recent developments in verbal lie detection before turning our attention to the Model Statement technique.

Stop in the name of lies: The cost of blocking the truth to deceive

Most researchers assume that deception involves a conflict between a predominant truth response and a deliberate deceptive response. Such a view is consistent with dual process theories that state that high-order cognition operates through fast-automatic processes that may conflict with slow-deliberate ones. In the present study, we tested whether one must inhibit the truth to deceive in light of inconsistent findings in the literature. One hundred and eighty-nine participants were tested across two Negative Priming paradigms that rest on the logic that the activation of a fast-automatic process will be hampered on a given display if it is inhibited on the previous display. Our findings suggest that truthful responses are predominant in healthy adults, which is why inhibitory control is required to activate a deliberate deceptive mode. We argue that the findings from deception studies could be best accounted for by dual process theories.

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.

Honesty Speaks a Second Language

Theories of dishonest behavior implicitly assume language independence. Here, we investigated this assumption by comparing lying by people using a foreign language versus their native tongue. Participants rolled a die and were paid according to the outcome they reported. Because the outcome was private, they could lie to inflate their profit without risk of repercussions. Participants performed the task either in their native language or in a foreign language. With native speakers of Hebrew, Korean, Spanish, and English, we discovered that, on average, people inflate their earnings less when they use a foreign language. The outcome is explained by a dual system account that suggests that self-serving dishonesty is an automatic tendency, which is supported by a fast and intuitive system. Because using a foreign language is less intuitive and automatic, it might engage more deliberation and reduce the temptation to lie. These findings challenge theories of ethical behavior to account for the role of the language in shaping ethical behavior.

Memory-Based Deception Detection: Extending the Cognitive Signature of Lying From Instructed to Self-Initiated Cheating

From a cognitive perspective, lying can be regarded as a complex cognitive process requiring the interplay of several executive functions. Meta‐analytic research on 114 studies encompassing 3,307 participants (Suchotzki, Verschuere, Van Bockstaele, Ben‐Shakhar, & Crombez, 2017) suggests that computerized paradigms can reliably assess the cognitive burden of lying, with large reaction time differences between lying and truth telling. These studies, however, lack a key ingredient of real‐life deception, namely self‐initiated behavior. Research participants have typically been instructed to commit a mock crime and conceal critical information, whereas in real life, people freely choose whether or not to engage in antisocial behavior. In this study, participants (n = 433) engaged in a trivia quiz and were provided with a monetary incentive for high accuracy performance. Participants were randomly allocated to either a condition where they were instructed to cheat on the quiz (mimicking the typical laboratory set‐up) or to a condition in which they were provided with the opportunity to cheat, yet without explicit instructions to do so. Assessments of their response times in a subsequent Concealed Information Test (CIT) revealed that both instructed cheaters (n = 107) and self‐initiated cheaters (n = 142) showed the expected RT‐slowing for concealed information. The data indicate that the cognitive signature of lying is not restricted to explicitly instructed cheating, but it can also be observed for self‐initiated cheating. These findings are highly encouraging from an ecological validity perspective.

Geven, Ben‐Shakhar, Kindt and Verschuere point out that research on deception detection usually employs instructed cheating. They experimentally demonstrate that participants show slower reaction times for concealed information than for other information, regardless of whether they are explicitly instructed to cheat or whether they can freely choose to cheat or not. Finding this ‘cognitive signature of lying’ with self‐initiated cheating too is argued by the authors to strengthen the external validity of deception detection research. [75]

Learning to Detect Deception from Evasive Answers and Inconsistencies across Repeated Interviews: A Study with Lay Respondents and Police Officers

Previous research has shown that inconsistencies across repeated interviews do not indicate deception because liars deliberately tend to repeat the same story. However, when a strategic interview approach that makes it difficult for liars to use the repeat strategy is used, both consistency and evasive answers differ significantly between truth tellers and liars, and statistical software (binary logistic regression analyses) can reach high classification rates (Masip et al., 2016b). Yet, if the interview procedure is to be used in applied settings the decision process will be made by humans, not statistical software. To address this issue, in the current study, 475 college students (Experiment 1) and 142 police officers (Experiment 2) were instructed to code and use consistency, evasive answers, or a combination or both before judging the veracity of Masip et al.'s (2016b) interview transcripts. Accuracy rates were high (60% to over 90%). Evasive answers yielded higher rates than consistency, and the combination of both these cues produced the highest accuracy rates in identifying both truthful and deceptive statements. Uninstructed participants performed fairly well (around 75% accuracy), apparently because they spontaneously used consistency and evasive answers. The pattern of results was the same among students, all officers, and veteran officers only, and shows that inconsistencies between interviews and evasive answers reveal deception when a strategic interview approach that hinders the repeat strategy is used.

Psychological Perspectives on Interrogation

Proponents of “enhanced interrogation techniques” in the United States have claimed that such methods are necessary for obtaining information from uncooperative terrorism subjects. In the present article, we offer an informed, academic perspective on such claims. Psychological theory and research shows that harsh interrogation methods are ineffective. First, they are likely to increase resistance by the subject rather than facilitate cooperation. Second, the threatening and adversarial nature of harsh interrogation is often inimical to the goal of facilitating the retrieval of information from memory and therefore reduces the likelihood that a subject will provide reports that are extensive, detailed, and accurate. Third, harsh interrogation methods make lie detection difficult. Analyzing speech content and eliciting verifiable details are the most reliable cues to assessing credibility; however, to elicit such cues subjects must be encouraged to provide extensive narratives, something that does not occur in harsh interrogations. Evidence is accumulating for the effectiveness of rapport-based information-gathering approaches as an alternative to harsh interrogations. Such approaches promote cooperation, enhance recall of relevant and reliable information, and facilitate assessments of credibility. Given the available evidence that torture is ineffective, why might some laypersons, policymakers, and interrogation personnel support the use of torture? We conclude our review by offering a psychological perspective on this important question.

Strategic Interviewing to Detect Deception: Cues to Deception across Repeated Interviews

Previous deception research on repeated interviews found that liars are not less consistent than truth tellers, presumably because liars use a “repeat strategy” to be consistent across interviews. The goal of this study was to design an interview procedure to overcome this strategy. Innocent participants (truth tellers) and guilty participants (liars) had to convince an interviewer that they had performed several innocent activities rather than committing a mock crime. The interview focused on the innocent activities (alibi), contained specific central and peripheral questions, and was repeated after 1 week without forewarning. Cognitive load was increased by asking participants to reply quickly. The liars’ answers in replying to both central and peripheral questions were significantly less accurate, less consistent, and more evasive than the truth tellers’ answers. Logistic regression analyses yielded classification rates ranging from around 70% (with consistency as the predictor variable), 85% (with evasive answers as the predictor variable), to over 90% (with an improved measure of consistency that incorporated evasive answers as the predictor variable, as well as with response accuracy as the predictor variable). These classification rates were higher than the interviewers’ accuracy rate (54%).

An empirical test of the decision to lie component of the Activation-Decision-Construction-Action Theory (ADCAT)

Meta-analyses reveal that behavioral differences between liars and truth tellers are small. To facilitate lie detection, researchers are currently developing interviewing approaches to increase these differences. Some of these approaches assume that lying is cognitively more difficult than truth telling; however, they are not based on specific cognitive theories of lie production, which are rare. Here we examined one existing theory, Walczyk et al.'s (2014) Activation-Decision-Construction-Action Theory (ADCAT). We tested the Decision component. According to ADCAT, people decide whether to lie or tell the truth as if they were using a specific mathematical formula to calculate the motivation to lie from (a) the probability of a number of outcomes derived from lying vs. telling the truth, and (b) the costs/benefits associated with each outcome. In this study, participants read several hypothetical scenarios and indicated whether they would lie or tell the truth in each scenario (Questionnaire 1). Next, they answered several questions about the consequences of lying vs. telling the truth in each scenario, and rated the probability and valence of each consequence (Questionnaire 2). Significant associations were found between the participants' dichotomous decision to lie/tell the truth in Questionnaire 1 and their motivation to lie scores calculated from the Questionnaire 2 data. However, interestingly, whereas the expected consequences of truth telling were associated with the decision to lie vs. tell the truth, the expected consequences of lying were not. Suggestions are made to refine ADCAT, which can be a useful theoretical framework to guide deception research.

Psychopathic Traits and Their Relationship with the Cognitive Costs and Compulsive Nature of Lying in Offenders

The cognitive view on deception holds that lying typically requires additional mental effort as compared to truth telling. Psychopathy, however, has been associated with swift and even compulsive lying, leading us to explore the ease and compulsive nature of lying in psychopathic offenders. We explored the costs of instructed lying versus truth telling through RTs and error rates in 52 violent male offenders, who were assessed with the Youth Psychopathic Traits Inventory (YPI). Our deception paradigm also included trials with the free choice to lie or tell the truth. By coupling monetary loss to slow and erroneous responding, we hypothesized that the frequency of lying despite likely negative consequences, would provide an index of compulsive lying. Offenders were slower and erred more often when lying than when telling the truth, and there was no robust association between psychopathy and the cognitive cost of lying. From an applied perspective, this suggests that psychopathy may not threaten the validity of computerized cognition-based lie detection. In the face of probable negative consequences, high grandiose-manipulative offenders chose to lie three times as often as low grandiose-manipulative offenders. Our new lying frequency index is a first attempt to create a much needed tool to empirically examine compulsive lying, and provides preliminary support for the compulsive nature of lying in grandiose-manipulative offenders. Alternative interpretation of the findings are discussed.

Explicit Instructions Increase Cognitive Costs of Deception in Predictable Social Context

Convincing participants to deceive remains one of the biggest and most important challenges of laboratory-based deception research. The simplest and most prevalent method involves explicitly instructing participants to lie or tell the truth before presenting each task item. The usual finding of such experiments is increased cognitive load associated with deceptive responses, explained by necessity to inhibit default and automatic honest responses. However, explicit instructions are usually coupled with the absence of social context in the experimental task. Context plays a key role in social cognition by activating prior knowledge, which facilitates behaviors consistent with the latter. We hypothesized that in the presence of social context, both honest and deceptive responses can be produced on the basis of prior knowledge, without reliance on truth and without additional cognitive load during deceptive responses. In order to test the hypothesis, we have developed Speed-Dating Task (SDT), which is based on a real-life social event. In SDT, participants respond both honestly and deceptively to questions in order to appear similar to each of the dates. The dates are predictable and represent well-known categories (i.e., atheist or conservative). In one condition participants rely on explicit instructions preceding each question (external cue). In the second condition no explicit instructions are present, so the participants need to adapt based on prior knowledge about the category the dates belong to (internal cue). With internal cues, reaction times (RTs) are similar for both honest and deceptive responses. However, in the presence of external cues (EC), RTs are longer for deceptive than honest responses, suggesting that deceptive responses are associated with increased cognitive load. Compared to internal cues, deception costs were higher when EC were present. However, the effect was limited to the first part of the experiment, only partially confirming our initial hypothesis. The results suggest that the presence of social context in deception tasks might have a significant influence on cognitive processes associated with deception.

The inhibitory spillover effect: Controlling the bladder makes better liars

The Inhibitory-Spillover-Effect (ISE) on a deception task was investigated. The ISE occurs when performance in one self-control task facilitates performance in another (simultaneously conducted) self-control task. Deceiving requires increased access to inhibitory control. We hypothesized that inducing liars to control urination urgency (physical inhibition) would facilitate control during deceptive interviews (cognitive inhibition). Participants drank small (low-control) or large (high-control) amounts of water. Next, they lied or told the truth to an interviewer. Third-party observers assessed the presence of behavioral cues and made true/lie judgments. In the high-control, but not the low-control condition, liars displayed significantly fewer behavioral cues to deception, more behavioral cues signaling truth, and provided longer and more complex accounts than truth-tellers. Accuracy detecting liars in the high-control condition was significantly impaired; observers revealed bias toward perceiving liars as truth-tellers. The ISE can operate in complex behaviors. Acts of deception can be facilitated by covert manipulations of self-control.

When deception becomes easy: the effects of task switching and goal neglect on the truth proportion effect

Lying is typically more cognitively demanding than truth telling. Yet, recent cognitive models of lying propose that lying can be just as easy as truth telling, depending on contextual factors. In line with this idea, research has shown that the cognitive cost of deception decreases when people frequently respond deceptively, while it increases when people rarely respond deceptively (i.e., the truth proportion effect). In the present study, we investigated two possible underlying mechanisms of the truth proportion effect. In Experiment 1 (N = 121), we controlled for the impact of switch costs by keeping the number of switches between deceptive and truthful responses constant. We found that people who often responded deceptively made fewer errors when responding deceptively than people who only occasionally responded deceptively, replicating the truth proportion effect. Thus, while the truth proportion effect in earlier studies may be partially driven by the cost of switching between truthful and deceptive responses, we still found evidence for the truth proportion effect while controlling for switch costs. In Experiment 2 (N = 68), we assessed whether the truth proportion effect is influenced by goal neglect. According to this view, the truth proportion effect should be reduced if participants are cued to maintain the task goals, while it should be larger when participants are allowed to neglect the task goals. In line with this hypothesis, we found a smaller truth proportion effect when participants were cued with the task goals compared to when they were not cued. This study shows that the truth proportion effect is influenced by goal neglect, implying that frequent deceptive responding strengthens the goal of responding deceptively. Our findings imply that the accuracy of lie detection tests could be increased by using a majority of truth-items (i.e., induce the truth proportion effect), and that the truth proportion effect should be maximized by (1) increasing the number of truth-lie task switches and (2) inducing goal neglect.

Being asked to tell an unpleasant truth about another person activates anterior insula and medial prefrontal cortex

"Truth" has been used as a baseline condition in several functional magnetic resonance imaging (fMRI) studies of deception. However, like deception, telling the truth is an inherently social construct, which requires consideration of another person's mental state, a phenomenon known as Theory of Mind. Using a novel ecological paradigm, we examined blood oxygenation level dependent (BOLD) responses during social and simple truth telling. Participants (n = 27) were randomly divided into two competing teams. Post-competition, each participant was scanned while evaluating performances from in-group and out-group members. Participants were asked to be honest and were told that their evaluations would be made public. We found increased BOLD responses in the medial prefrontal cortex, bilateral anterior insula and precuneus when participants were asked to tell social truths compared to simple truths about another person. At the behavioral level, participants were slower at responding to social compared to simple questions about another person. These findings suggest that telling the truth is a nuanced cognitive operation that is dependent on the degree of mentalizing. Importantly, we show that the cortical regions engaged by truth telling show a distinct pattern when the task requires social reasoning.

A reverse order interview does not aid deception detection regarding intentions

Promising recent research suggests that more cognitively demanding interviews improve deception detection accuracy. Would these cognitively demanding techniques work in the same way when discriminating between true and false future intentions? In Experiment 1 participants planned to complete a task, but instead were intercepted and interviewed about their intentions. Participants lied or told the truth, and were subjected to high (reverse order) or low (sequential order) cognitive load interviews. Third-party observers watched these interviews and indicated whether they thought the person was lying or telling the truth. Subjecting participants to a reverse compared to sequential interview increased the misidentification rate and the appearance of cognitive load in truth tellers. People lying about false intentions were not better identified. In Experiment 2, a second set of third-party observers rated behavioral cues. Consistent with Experiment 1, truth tellers, but not liars, exhibited more behaviors associated with lying and fewer behaviors associated with truth telling in the reverse than sequential interview. Together these results suggest that certain cognitively demanding interviews may be less useful when interviewing to detect false intentions. Explaining a true intention while under higher cognitive demand places truth tellers at risk of being misclassified. There may be such a thing as too much cognitive load induced by certain techniques

Measuring the cognitive resources consumed per second for real-time lie-production and recollection: a dual-tasking paradigm

This research report presents a novel method of dual-tasking lie-detection. Novel software "Follow Me" was invented for a concurrent eye-hand coordination task during truth-telling/lying. Undergraduate participants were instructed to tell truths on questions about undergraduate school whereas they were instructed to tell lies on interview questions about graduate school, pretending they were graduate students. Throughout the experiment, they operated the "Follow Me" software: moving the mouse pointer to follow a randomly-moving dot on a computer screen. The distance between the mouse pointer tip and the dot center was measured by the software every 50 ms. Frequency of distance fluctuation was analyzed as the index of cognitive effort consumed per second (i.e., "degree of cognitive effort"). The results revealed that the dominant frequency of distance fluctuation was significantly lower during encoding than during retrieving responses; and lower during lying than truth-telling. Thus, dominant frequency of distance fluctuation may be an effective index of cognitive effort. Moreover, both encoding and retrieving bald-faced lies were more cognitively effortful than truth-telling. This novel definition and measurement of degree of cognitive effort may contribute to the research field of deception as well as to many other fields in social cognition.

Can individuals with schizophrenia be instructed to deliberately feign memory deficits?

INTRODUCTION

Neuropsychological tests are increasingly applied in research studies and clinical practice in psychiatry. In this context, the detection of poor effort is crucial to adequately interpret data. We measured schizophrenia patients' performance on a memory test designed to detect excessive malingering (the "21-Item Test"), before examining whether a second group of schizophrenia patients would excessively malinger on this test when given an incentive to feign memory impairment.

METHODS

Two independent studies including respectively 49 schizophrenia patients and 100 controls (study 1) and 25 schizophrenia patients and 25 controls (study 2) were conducted. In study 1, participants were asked to complete the 21-Item Test to the best of their ability. In study 2, participants were given a hypothetical scenario in which having a memory impairment would be financially advantageous for them, before completing the 21-Item Test.

RESULTS

In study 1, no participant scored at levels indicative of excessive malingering. In study 2, 84% of controls but only 36% of patients scored at excessive levels of malingering, and these patients had higher executive functioning than patients who did not excessively malinger, although it should be noted that a significantly greater proportion of patients excessively malingered in study 2 compared to study 1.

CONCLUSIONS

These results indicate that schizophrenia patients do not normally feign excessive memory impairment during psychological testing. Furthermore, they are less able and/or less inclined to excessively malinger than controls in situations where a memory impairment would be advantageous, perhaps indicating a better ability to malinger without detection. Potential clinical implications are discussed.

The "good cop, bad cop" effect in the RT-based concealed information test: exploring the effect of emotional expressions displayed by a virtual investigator

Concealing the possession of relevant information represents a complex cognitive process, shaped by contextual demands and individual differences in cognitive and socio-emotional functioning. The Reaction Time-based Concealed Information Test (RT-CIT) is used to detect concealed knowledge based on the difference in RTs between denying recognition of critical (probes) and newly encountered (irrelevant) information. Several research questions were addressed in this scenario implemented after a mock crime. First, we were interested whether the introduction of a social stimulus (facial identity) simulating a virtual investigator would facilitate the process of deception detection. Next, we explored whether his emotional displays (friendly, hostile or neutral) would have a differential impact on speed of responses to probe versus irrelevant items. We also compared the impact of introducing similar stimuli in a working memory (WM) updating context without requirements to conceal information. Finally, we explored the association between deceptive behavior and individual differences in WM updating proficiency or in internalizing problems (state / trait anxiety and depression). Results indicated that the mere presence of a neutral virtual investigator slowed down participants' responses, but not the appended lie-specific time (difference between probes and irrelevants). Emotional expression was shown to differentially affect speed of responses to critical items, with positive displays from the virtual examiner enhancing lie-specific time, compared to negative facial expressions, which had an opposite impact. This valence-specific effect was not visible in the WM updating context. Higher levels of trait / state anxiety were related to faster responses to probes in the negative condition (hostile facial expression) of the RT-CIT. These preliminary findings further emphasize the need to take into account motivational and emotional factors when considering the transfer of deception detection techniques from the laboratory to real-life settings.

Are Computers Effective Lie Detectors? A Meta-Analysis of Linguistic Cues to Deception

This meta-analysis investigates linguistic cues to deception and whether these cues can be detected with computer programs. We integrated operational definitions for 79 cues from 44 studies where software had been used to identify linguistic deception cues. These cues were allocated to six research questions. As expected, the meta-analyses demonstrated that, relative to truth-tellers, liars experienced greater cognitive load, expressed more negative emotions, distanced themselves more from events, expressed fewer sensory–perceptual words, and referred less often to cognitive processes. However, liars were not more uncertain than truth-tellers. These effects were moderated by event type, involvement, emotional valence, intensity of interaction, motivation, and other moderators. Although the overall effect size was small, theory-driven predictions for certain cues received support. These findings not only further our knowledge about the usefulness of linguistic cues to detect deception with computers in applied settings but also elucidate the relationship between language and deception.

Manipulating item proportion and deception reveals crucial dissociation between behavioral, autonomic, and neural indices of concealed information

Developed as an alternative to traditional deception detection methods, the concealed information test (CIT) assesses recognition of critical (e.g., crime-relevant) "probes." Most often, recognition has been measured as enhanced skin conductance responses (SCRs) to probes compared to irrelevant foils (CIT effect). More recently, also differentially enlarged reaction times (RTs) and increased neural activity in the bilateral inferior frontal gyrus, the right middle frontal gyrus, and the right temporo-parietal junction have been observed. The aims of the current functional magnetic resonance imaging (fMRI) study were to (1) investigate the boundary conditions of the CIT effects in all three measures and thereby (2) gain more insight into the relative contribution of two mechanisms underlying enhanced responding to concealed information (i.e., orienting versus response inhibition). Therefore, we manipulated the proportion of probe versus irrelevant items, and whether suspects were instructed to actively deny recognition of probe knowledge (i.e., deceive) during the test. Results revealed that whereas overt deception was not necessary for the SCR CIT effect, it was crucial for the RT and the fMRI-based CIT effects. The proportion manipulation enhanced the CIT effect in all three measures. The results indicate that different mental processes might underlie the response pattern in the CIT. While skin conductance responding to concealed information may best be explained by orienting theory, it seems that response inhibition drives RT and blood oxygen level dependent responding to concealed information.

Deception rate in a "lying game": different effects of excitatory repetitive transcranial magnetic stimulation of right and left dorsolateral prefrontal cortex not found with inhibitory stimulation

Knowing the brain processes involved in lying is the key point in today's deception detection studies. We have previously found that stimulating the dorsolateral prefrontal cortex (DLPFC) with repetitive transcranial magnetic stimulation (rTMS) affects the rate of spontaneous lying in simple behavioural tasks. The main idea of this study was to examine the role of rTMS applied to the DLPFC in the behavioural conditions where subjects were better motivated to lie compared to our earlier studies and where all possible conditions (inhibition of left and right DLPFC with 1-Hz and sham; excitation of left and right DLPFC with 10-Hz and sham) were administered to the same subjects. It was expected that excitation of the left DLPFC with rTMS decreases and excitation of the right DLPFC increases the rate of lying and that inhibitory stimulation reverses the effects. As was expected, excitation of the left DLPFC decreased lying compared to excitation of the right DLPFC, but contrary to the expectation, inhibition had no different effects. These findings suggest that propensity to lie can be manipulated by non-invasive excitatory brain stimulation by TMS targeted at DLPFC and the direction of the effect depends on the cortical target locus.

Pants on fire: the electrophysiological signature of telling a lie

Even though electroencephalography has played a prominent role for lie detection via personally relevant information, the electrophysiological signature of active lying is still elusive. We addressed this signature with two experiments in which participants helped a virtual police officer to locate a knife. Crucially, before this response, they announced whether they would lie or tell the truth about the knife's location. This design allowed us to study the signature of lie-telling in the absence of rare and personally significant oddball stimuli that are typically used for lie detection via electrophysiological markers, especially the P300 component. Our results indicate that active lying attenuated P300 amplitudes as well as N200 amplitudes for such non-oddball stimuli. These results support accounts that stress the high cognitive demand of lie-telling, including the need to suppress the truthful response and to generate a lie.

Lying in neuropsychology

The issue of lying occurs in neuropsychology especially when examinations are conducted in a forensic context. When a subject intentionally either presents non-existent deficits or exaggerates their severity to obtain financial or material compensation, this behaviour is termed malingering. Malingering is discussed in the general framework of lying in psychology, and the different procedures used by neuropsychologists to evidence a lack of collaboration at examination are briefly presented and discussed. When a lack of collaboration is observed, specific emphasis is placed on the difficulty in unambiguously establishing that this results from the patient's voluntary decision.

Limited capacity to lie: Cognitive load interferes with being dishonest

The current study tested the boundary conditions of ethical decision-making by increasing cognitive load. This manipulation is believed to hinder deliberation, and, as we argue, reduces the cognitive capacity needed for a self-serving bias to occur. As telling a lie is believed to be more cognitively taxing than telling the truth, we hypothesized that participants would be more honest under high cognitive load than low cognitive load. 173 participants anonymously rolled a die three times and reported their outcomes — of which one of the rolls would be paid out — while either under high or low cognitive load. For the roll that determined pay, participants under low cognitive load, but not under high cognitive load, reported die rolls that were significantly different from a uniform (honest) distribution. The reported outcome of this roll was also significantly higher in the low load condition than in the high load condition, suggesting that participants in the low load condition lied to get higher pay. This pattern was not observed for the second and third roll where participants knew the rolls were not going to be paid out and where therefore lying would not serve self-interest. Results thus indicate that having limited cognitive capacity will unveil a tendency to be honest in a situation where having more cognitive capacity would have enabled one to serve self-interest by lying.

Interviewing to Detect Deception

DePaulo et al.’s (2003) meta-analysis of verbal and nonverbal cues to deception showed that cues to deception are faint and unreliable. If liars do not spontaneously display diagnostic cues to deceit, a logical step is to make sure that investigators elicit or enhance such cues in interviews through specific interview technique. Such interview techniques were scarce in the nonverbal and verbal cues to deception domain, but recently researchers have developed alternative protocols that have their roots in cognition and are based on the assumption that questions can be asked that are more difficult for liars to answer than for truth tellers. They will be discussed in the first part of this article. Traditionally, lie detection in a forensic context concentrated on police-suspect interview settings. However, in the wake of high-profile international terrorist attacks, the importance of identifying terrorist networks and gathering intelligence about the activities of such groups has become paramount. Deception detection in intelligence interviews differs in several ways from deception detection in traditional police-suspect interviews and requires innovative deception research. In the second part of this article we discuss the emerging literature in this domain.

Mind Reading Using Neuroimaging

Traditional lie detection tools, such as the polygraph, voice stress analysis, or special interrogation techniques, rely on behavioral or psychophysiological manifestations of deception. With the advent of neuroimaging techniques, the question emerged whether it would be possible to directly identify deceit in the part of the body where it is generated: the brain. After a few promising studies, these techniques became soon commercially available and there have been attempts to use such results in the court in recent years. The current article reviews the development of neuroimaging techniques in the field of deception detection and critically discusses the potential but also the shortcomings of such methods. Unfortunately, the majority of research in this field was rather unsystematic and neglected the accumulated knowledge regarding methodological pitfalls that were extensively discussed in the scientific community in conjunction with the polygraph. Therefore, neuroimaging studies on deception largely differ with respect to the experimental paradigm (the interrogation technique), the methods for analyzing the data, and the procedures to obtain individual diagnoses. Moreover, most studies used artificial laboratory settings that differ considerably from real-life applications. As a consequence, neuroimaging techniques are not applicable for detecting deception in individual field cases at the moment. However, recent advantages such as multivariate pattern analysis might yield novel neuroimaging applications in the near future that are capable of improving established techniques for detecting deception or concealed knowledge.

Reaction time measures in deception research: comparing the effects of irrelevant and relevant stimulus-response compatibility

Evidence regarding the validity of reaction time (RT) measures in deception research is mixed. One possible reason for this inconsistency is that structurally different RT paradigms have been used. The aim of this study was to experimentally investigate whether structural differences between RT tasks are related to how effective those tasks are for capturing deception. We achieved this aim by comparing the effectiveness of relevant and irrelevant stimulus-response compatibility (SRC) tasks. We also investigated whether an intended but not yet completed mock crime could be assessed with both tasks. Results showed (1) a larger compatibility effect in the relevant SRC task compared to the irrelevant SRC task, (2) for both the completed and the intended crime. These results were replicated in a second experiment in which a semantic feature (instead of color) was used as critical response feature in the irrelevant SRC task. The findings support the idea that a structural analysis of deception tasks helps to identify RT measures that produce robust group effects, and that strong compatibility effects for both enacted crimes as well as merely intended crimes can be found with RT measures that are based on the manipulation of relevant SRC.