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Title: LYING AND EXECUTIVE CONTROL: AN EXPERIMENTAL INVESTIGATION USING EGO DEPLETION AND GOAL NEGLECT Authors: Evelyne Debey¹, Bruno Verschuere2, & Geert Crombez3 1. MSc, Department of Experimental Clinical and Health Psychology, Ghent University, Henri Dunantlaan 2, 9000 Ghent, Belgium 2. Ph.D, Department of Clinical Psychology, University of Amsterdam, Weesperplein 4, 1018 XA Amsterdam, The Netherlands; Department of Experimental Clinical and Health Psychology, Ghent University, Henri Dunantlaan 2, 9000 Ghent, Belgium; and Faculty of Psychology and Neuroscience, Maastricht University, Universiteitssingel 5, 6229 ES Maastricht, The Netherlands;
[email protected] 3. Prof, Dr., Department of Experimental Clinical and Health Psychology, Ghent University, Henri Dunantlaan 2, 9000 Ghent, Belgium
Corresponding author:
[email protected]
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Abstract 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65
This study investigated whether lying requires executive control using a reaction-time based lie test. We hypothesized that (1) goal neglect induced by a long response stimulus interval (RSI; 5-8 s) would make lying harder relative to a short RSI (.2 s) that promoted attentional focus, and (2) participants whose executive control resources were depleted by an initial executive control task would experience more difficulty to lie than control participants who performed a task that required little executive control. Across two experiments, the ego depletion manipulation did not reliably affect lying. Both experiments revealed that the cognitive cost associated with lying was larger for the long compared to the short RSI. This finding supports the idea that lying requires more executive control than truth telling. The manipulation of RSI may provide a simple, yet effective means to improve lie detection accuracy.
Keywords: Deception; Lie detection; Executive control; Goal neglect; Ego depletion
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1. Introduction 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65
Lying is a complex cognitive activity. Liars have to deal with the coordination of one or more of following tasks: to make the decision to deceive, to suppress the truth and activate a lie, to infer what others already know, to keep their story straight, to monitor their own behavior as well as the reactions of the listener, and if necessary to adjust the lie to make it more believable. Zuckerman, DePaulo and Rosenthal (1981) were among the first to recognize the mentally taxing properties of lying. They introduced a cognitive view on deception, which essentially holds that lying is cognitively more demanding than telling the truth. A number of studies have found support for the cognitive view on deception. First, lying is accompanied by behaviors that are also typically observed in cognitively taxing tasks (Ekman and Friesen, 1972; Goldman-Eisler, 1968; Veltman and Gaillard, 1998), such as less hand and arm movements, reduced eye blinking and more pauses when speaking (DePaulo et al., 2003; Leal and Vrij, 2008, 2010; Sporer and Swandt, 2007). Second, in deception studies participants report that lying requires more mental effort compared to truth telling (Vrij et al., 1996). Third, police officers who see interviews from a high realistic forensic setting judge their suspects think harder when they lie than when they tell the truth (Mann and Vrij, 2006). Fourth, lying is associated with more errors and increased response latencies compared to truth telling, which is assumed to reflect increased cognitive effort (Seymour and Kerlin, 2008; Sheridan and Flowers, 2010; Spence et al., 2001; Verschuere et al., 2009, 2011). Finally, a growing number of brain imaging studies have found stronger activation of frontal regions for deception compared to truth telling – regions that are typically linked with cognitive, or executive, control (for recent reviews see Christ et al., 2009; Gamer, 2011). Miyake et al. (2000) differentiated three major components of executive control: working
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memory, task switching, and response inhibition. All three components are likely to play a 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65
role in deception. Working memory may enable to keep the truth active while constructing the lie, response inhibition may be required to inhibit the truth response from leaking, and task switching may allow to switch between being honest and being deceptive (Johnson et al., 2004; Spence et al., 2004; Visu-Petra et al., in press). The meta-analysis by Christ and colleagues indeed showed that ten of the thirteen brain regions activated during lying have also been associated with executive functions such as working memory, inhibitory control, and/or task switching. In sum, research has indicated that lying requires more cognitive effort and executive control than truth telling. However, most of the studies conducted so far are observational or correlational. Here we test the hypothesis that lying requires executive control by experimentally manipulating executive control. We selected two manipulations that are known to undermine executive control: (1) goal neglect and (2) ego depletion. Our first manipulation was based on Duncan‟s goal neglect theory (Duncan, 1995; Duncan et al., 1996; for similar views see e.g., De Jong et al., 1999; Engle and Kane, 2004; Kane and Engle, 2003). Duncan has argued that human behavior is goal-directed and therefore, task goals need to be formed that guide the selection of responses. Keeping task goals active (goal maintenance) is accomplished by means of an attentional goal-weighting process that relies on prefrontal cortex function. This implies that responses will be fast and accurate when attention is sharply focused on the task goal. When, however, attention to the task goal is loose, lapses of attention will occur and lead to goal neglect, i.e. “disregard of a task requirement even though it has been understood and remembered” (Duncan, 1995, p. 257). Goal maintenance is important in executive control tasks such as the Stroop task (Stroop, 1935), in which the required response is opposite to the prepotent response. In the Stroop task, the task goal entails naming the ink color in which color words are printed, while inhibiting the prepotent response of saying the word. The Stroop effect refers to the cost in
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response latency and accuracy on incongruent trials (e.g., RED in blue ink) compared to 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65
congruent trials (e.g., RED in red ink). Because on incongruent trials the prepotent response conflicts with the task goal, situations that promote goal neglect should result in more prepotency based behavior, and hence larger Stroop effects. To verify this prediction, De Jong, Berendsen and Cools (1999) asked participants to perform a Stroop task either with a short (200 ms) or long (2000 ms) response-stimulus interval (RSI; the period between the response and the appearance of the next stimulus). The authors argued that the fast pace, induced by the short RSI, would help participants to remain focused on the task and hence effectively inhibit the word‟s meaning. A long RSI, on the other hand, would lead to attentional lapses and a failure to fully deploy the ability to inhibit. Their results indeed showed that the Stroop effect was affected by the RSI. With a long RSI, the Stroop effect was significant (47 ms), whereas the effect was small and non-significant (11 ms) when the RSI was short. Here, we manipulated RSI to induce goal neglect in a deception task. Our second manipulation is grounded in the self-control and ego depletion literature. Self-control can be defined as “the overriding or inhibiting of automatic, habitual, or innate behaviors, urges, emotions, or desires that would otherwise interfere with goal directedbehavior” (Muraven et al., 2006, p. 524). Ego depletion is the well-studied phenomenon that the performance on a self-control task is significantly worse when another self-control task was executed before. This finding is usually explained by the limited resource model of Baumeister and colleagues (Baumeister et al., 1998, 2006). According to this model, selfcontrol depends on a limited resource that can be temporarily depleted, thereby hampering the efficacy of a subsequent self-control attempt. In a prototypical ego depletion study hungry participants were asked to eat radishes, while a plate of freshly baked cookies was placed in front of them (Baumeister et al., 1998). Afterwards, they were asked to solve a puzzle that unbeknownst to them was actually not solvable. It was found that participants who previously
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had to resist eating the cookies, quit earlier than the control group who had been allowed to 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65
eat cookies. Apparently, resisting the cookies depleted self-control resources that could no longer be used in the subsequent puzzle task. Recent work on ego depletion tried to connect the limited resource view of self-control to executive functioning. Conceptually, self-control has a large degree of overlap with executive control: in order to succeed in self-controlled behavior, one has to keep the goal active in working memory, refrain from any goal-irrelevant behavior, and switch goals if needed (Ilkowska and Engle, 2010; Robinson et al., 2010). In a series of studies, Schmeichel (2007) showed that participants who initially engaged in executive control tasks (e.g., inhibiting predominant writing tendencies) performed worse in subsequent executive control tasks (e.g., reverse digit span task), relative to a control group that performed initial tasks that did not require executive control. Other support for the effects of ego depletion of executive control comes from a study with the Autobiographic Memory Task (AMT; Neshat-Doost et al., 2008). In this study, participants were asked to recall specific autobiographical memories (e.g.., “I remember the day we went to Disneyland”) in response to word cues (e.g., “holiday”). Most of the times a word primes over-general, prepotent memories (e.g., “I enjoyed all of my holidays as a teenager”). Therefore, working memory capacity is needed to set these unspecific memories aside and maintain the search through the autobiographic knowledge base (Conway and Pleydell-Pearce, 2000). NeshatDoost et al. showed that the depletion of working memory resources through a color Stroop task that consisted of only incongruent trials led to reduced autobiographic memory specificity in comparison to a control Stroop that required to name color names printed in black. Here, we implemented an ego depletion manipulation before participants engaged into the deception task. Goal neglect and ego depletion were manipulated in the Sheffield lie test (Spence et al., 2001), a well-established variant of the Differentiation-of-Deception Paradigm (Furedy et al.,
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1988). In the Sheffield lie test, participants were required to give speeded yes or no responses 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65
to questions about simple daily activities (e.g., “Drunk coffee?”). Depending on the color of the response labels that appeared under the questions, they were instructed to answer truthfully in the presence of one color, whereas the other color indicated to lie. Using this paradigm, it has been repeatedly shown that lying leads to greater response times – sometimes accompanied by more errors – than truth telling (i.e., lie effects; Spence et al., 2001, 2008; Verschuere et al., 2011). In the present study, RSI was manipulated within subjects. A long RSI preceded the questions on half of the trials, whereas the RSI was short on the other half of the trials. We hypothesized that a long RSI would disturb the ability for goal maintenance, which would have the strongest effect on trials that require most executive control (i.e., lie trials). This would result in larger lie effects on long RSI trials compared to trials with a short RSI. Prior to the Sheffield lie test, ego depletion was manipulated between subjects using the e-hunting task (Baumeister et al., 1998; DeWall et al., 2008). A meta-analysis on ego depletion showed that this task produces the largest effect size (Hagger et al., 2010). In the ehunting task, participants first form the habit of crossing out every instance of the letter e in a text. Whereas the control group afterwards applies the same rules in a second text, the depletion group receives additional rules that prohibit crossing out every e. These rules may bring along a state of ego depletion, as participants have to override their acquired habit. Following the idea that executive control is crucially involved in lying, we predicted that the depletion group would have difficulties to efficiently suppress the truth in the Sheffield lie test, as expressed in larger lie effects compared to the control group. In order to maximize the effect of ego depletion, several other manipulations from the meta-analysis of Hagger et al. (2010) were implemented in our design: (1) as previous studies have shown that motivation can diminish ego depletion effects (Stewart et al., 2009), the experiment was not announced as a lie detection study, thereby trying to prevent that
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participants would spare resources for the Sheffield lie test, (2) we presented the e-hunting 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65
task and the lie test as two independent experiments, (3) developed by different experimenters, (4) we used an interim period between the self-control tasks by letting participants fill out questionnaires, including the Self-Monitoring Scale (SMS; Snyder, 1974) and the Consideration of Future Consequences Scale (CFCS; Strathman et al., 1994), and (5) before the start of the Sheffield lie test, we informed participants about a third self-control task (Experiment 1: White bear suppression task; Experiment 2: hand grip task) that would follow subsequently, thereby promoting conservation of resources. Especially the depletion group would be prone not to allocate their remaining resources in the lie test. As a result, the depletion effect would further be exacerbated. The performance on the third self-control task also served as an extra manipulation check of ego depletion. It was predicted that both manipulations – goal neglect induced by a long RSI, and ego depletion induced by the e-hunting task – would hinder deception, thereby increasing the difference in reaction times and error rates between lying and truth telling (i.e., lie effects).
2. Experiment 1
2.1. Method
2.1.1. Participants
Sixty-nine participants (15 men; Mage = 20.17 years, SD = 2.91) were assigned to either the ego depletion group (n = 35) or the control group (n = 34), using a randomization method in which every following tested pair of participants was assigned to the same group. Groups did not differ for age, sex, and hand preference. Participants gave their informed consent and
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received course credits or a financial reimbursement (8 Euro) for their participation. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65
2.1.2. Apparatus
The Sheffield lie test was run on a ASUS A2500H Pentium IV laptop (2.8 GHz Pentium 4 processor; 60 Hz 15-inch color monitor), using the Inquisit Millisecond software package (Inquisit 1.33, 2002), which records reaction times with 1 ms accuracy (De Clercq et al., 2003).
2.1.3. Procedure
The experiment was announced as a reaction time study, and we presented the depletion task and the lie test as two separate experiments, developed by different experimenters (Hagger et al., 2010).
2.1.3.1. E-hunting task and ego depletion. The e-hunting task consisted of two parts, each lasting three minutes. In the first part, all participants received a one page text on cosmic radiation, in which they were asked to cross out all instances of the letter e. In the second part, they received another one page text, which was the continuation of the first text. The control group was again instructed to cross out all the e‟s. The depletion group performed the task with additional rules: Participants were no longer allowed to cross out e‟s that were adjacent or two letters away from another vowel.
2.1.3.2. Interim phase. After completing the e-hunting task, participants were asked to fill out three questionnaires. First, participants filled out an autobiographical questionnaire (Spence et
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al., 2001), in which they had to indicate which of 36 simple daily activities they had 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65
performed on the day of the experiment (e.g., “Did you take a bath?”, “Did you buy a paper?”). Next, they completed the 25-item Self-Monitoring Scale (Snyder, 1974), and the 12item Consideration of Future Consequences Scale (Strathman et al., 1994), both of which are not further reported upon in this paper1. Before the start of the Sheffield lie test, participants were informed about another selfcontrol task, in which they would be asked to suppress their thoughts: the White bear thought suppression task (Wegner & Schneider, 2003). Participants were informed that they would perform this task after the Sheffield lie test.
2.1.3.3. Sheffield lie test. In the Sheffield lie test (Spence et al., 2001; Verschuere et al., 2011), statements of the autobiographic questionnaire were presented in white in the centre of a black screen. Participants were instructed to respond yes or no as quickly and accurately as possible by pressing the “4” or the “6” key on the numerical keyboard. When no response was recorded within 5000 ms, the next trial started automatically. Below the questions, the yes and no response labels were presented according to their response mapping. Crucially, the color of the response labels varied across trials. Participants were instructed to answer truthfully in the presence of one color (e.g., blue), and to lie in the presence of the other color (e.g., yellow). The assignment of the response mapping and color rule was counterbalanced across participants. After a practice phase (12 trials; 6 truthful, 6 deceptive), all 36 questions were presented four times (144 trials in total), so that each question was presented once in each of the 2 (Deception: Truth vs. Lie) x 2 (RSI: Short vs. Long) conditions. The short RSI was 200 ms, the long RSI was 5000 ms. Mean reaction times and error percentages were assessed as the dependent variables.
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2.1.3.4. White bear thought suppression task. In the White bear thought suppression task 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65
(Wegner & Schneider, 2003), participants went through three phases, each lasting three minutes. The task started with a baseline phase, in which participants were allowed to think about anything, for example a white bear. In the following „thought suppression‟ phase, participants had to suppress thoughts of a white bear. To examine possible rebound effects, a third phase was conducted in which participants were again allowed to think about anything, for example a white bear. In each phase, participants were instructed to place a mark whenever they thought about a white bear. The total number of marks within each phase served as the outcome variable. Based on previous research, we expected the white bear thought frequency to be smaller in the thought suppression phase and higher in the rebound phase, compared to baseline (Abramowitz et al., 2001). In addition, we hypothesized that participants from the the depleted group would have more difficulty to suppress thoughts than those from the control group, resulting in a relatively higher frequency of white bear thoughts in the suppression phase and a larger rebound effect in the third phase.
2.1.3.5. Manipulation checks. Both after the e-hunting task and the Sheffield lie test, and as well following the White bear thought suppression task, participants completed a manipulation check in which they were asked to mark on a line scale from 0 to 100 how difficult the task was (0 = not difficult at all, 100 = very difficult), how much effort it took to complete the task (0 = no effort at all, 100 = very much effort) , and how tired (0 = not tired at all, 100 = very tired) they felt. As ego depletion may induce negative affect (Hagger et al., 2010), they additionally indicated how happy they were on the 9-point affect scale of the SelfAssessment-Manikin (SAM; Lang et al., 1993). To check for baseline differences, we also asked participants at the beginning of the experiment to rate how tired and happy they were.
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2.2. Results 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65
Cohen‟s d was calculated as a measure of effect size. A d of .20, .50 and .80 was used as a threshold to define small, medium and large effects, respectively (Cohen, 1988). Two participants from the depletion group were excluded from further analyses: one whose mean error rate in the Sheffield lie test (36.11 %) exceeded the group mean (M = 5.93 %, SD = 3.74) by 2.5 standard deviations (SDs) and one whose mean reaction time in the lie test (M = 2262 ms) surpassed the group mean by 2.5 SDs (M = 1552 ms, SD = 287).
2.2.1. Manipulation check
At the beginning of the experiment, participants in the depletion group reported to be more happy (M = 7.21, SD = .82) than participants in the control group (M = 6.50, SD = 1.38), t(65) = 2.56, p = .01 . As affect did not correlate with any of the dependent variables, we did not control for this factor in our analyses. No baseline differences were found for tiredness, t(65) = 1.16, p = .25. The depletion group rated their version of the e-hunting task as more difficult (M = 46.27, SD = 24.50) than the control group (M = 28.26, SD = 19.55), t(65) = 3.33, p < .01. Surprisingly however, the participants in the control group reported to be more tired (M = 54.15, SD = 22.34) than the depleted participants (M = 41.97, SD = 19.16), t(65) = 2.39, p = .02. Moreover, performing the e-hunting task had a different impact on affect in the control and depletion group, F(2,64) = 7.47, p < .001. In the control group, affect became marginally more negative compared to baseline (M = -.24, SD = .70), F(1,33) = 3.85, p = .06, whereas it remained stable in the depletion group (M = .06, SD = .35), F(1,33) = 1.00, p = .33.
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To analyze the performance in the White bear thought suppression task, a 3 (Phase: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65
Baseline, Inhibition, Rebound) x 2 (Group: Control, Depletion) repeated measures ANOVA was conducted. The analysis revealed a main effect of Phase, F(2,64) = 28.66, p < .001. Follow-up comparisons showed that participants thought less about a white bear in the Inhibition phase (M = 5.31, SD = 6.06) than in the Baseline phase (M = 7.58, SD = 5.09), t(66) = 28.66, p < .001. The white bear thought frequency in the Rebound phase (M = 4.18, SD = 4.18) was lower than in the Inhibition phase, t(66)= 2.06, p = .04, and also lower compared to baseline frequency, t(66) = 7.48, p < .001. The crucial interaction of Phase and Group was not significant, F(2,64) = 1.23, p = .30.
2.2.2. Sheffield lie test
Both error rates (Table 1) and reaction times (Table 2) were analyzed by means of a 2 x 2 x 2 repeated measures ANOVA with Deception (Truth vs. Lie) and RSI (Short vs. Long) as within-subjects variables, and Group (Control vs. Depletion) as the between-subjects variable. For the reaction time analysis, trials in which an error occurred (6.36 %) were discarded. In an outlier analysis, response latencies exceeding the individual‟s mean by 2.5 SDs were also excluded from the reaction time analysis (2.55 %).
2.2.2.1. Error percentages. The analysis showed a main effect of Deception, F(1,65) = 16.17, p < .001, d = .49, indicating that participants made more errors when lying (M = 7.11 %, SD = .03) than telling the truth (M = 4.90 %, SD = 3.51). The interaction of Deception and RSI also proved significant, F(1,65) = 12.06, p < .01, d = .42, with a larger lie effect (i.e., % errors lie minus % errors truth) in long RSI trials (M = 3.90 %, SD = 6.39) compared to short RSI trials (M = .53 %, SD = 5.54). Additional analyses showed that errors decreased from short to long
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RSI trials when participants told the truth (M = -1.52 %, SD = 6.23), t(66) = 1.99, p = .05, d = 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65
.24, but increased from short to long RSI trials when participants lied (M = 1.90 %, SD = 5.83), t(66) = 2.66, p = .01, d = .33. The error increase on lie trials contributed significantly more to the difference between short and long RSI lie effects than the error decrease when on truth trials, t(66) = 3.50, p < .01, d = .38. None of the within- and between-subjects effects with Group were significant [Group, F(1,65) = 1.12, p = .29; Deception x Group, F < 1; RSI x Group, F(1,65) = 1.48, p = .23; Deception x RSI x Group, F(1,65) = 1.48, p = .23].
– INSERT TABLE 1 ABOUT HERE –
2.2.2.2. Reaction times. The analysis yielded a main effect of Deception, F(1,65) = 112.39, p < .001, d = 1.28, with longer reaction times when lying (M = 1626 ms, SD = 290) than telling the truth (M = 1476 ms, SD = 265). The main effect of RSI, F(1,65) = 143.10, p < .001, d = 1.46, indicated that reaction times were overall slower when the RSI was long (M = 1668 ms, SD = 315) than when it was short (M = 1431 ms, SD = 247). The significant interaction of Deception and RSI, F(1,65) = 4.58, p = .04, d = .26, revealed that the lie effect (i.e., RT lie minus RT truth) was larger when the RSI was long (M = 171 ms, SD = 143) than when it was short (M = 132 ms, SD = 136). Follow-up analyses showed that the increase in reaction times from short to long RSI trials was present in both truth telling (M = 222 ms, SD = 174), t(66) = 1.65, p < .001, d = 1.42, and in lying (M = 261 ms, SD = 184), t(66) = 10.45, p < .001, d = 1.28. However, the increase was significantly larger in lie trials, t(66) = 2.05, p = .04, d = .25, thereby creating a larger lie effect in long RSI trials than in short RSI trials. Again, none of the effects involving Group were significant [Group, F < 1; Deception x Group, F < 1; RSI x Group, F < 1; Deception x RSI x Group, F(1,65) = 1.33, p = .25].
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– INSERT TABLE 2 ABOUT HERE – 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65
2.3. Discussion
The results can be readily summarized. First, lying is reliably associated with increased response latencies and more errors than truth telling (see also Spence et al., 2001, 2008; Verschuere et al., 2011). Second, manipulating the RSI affected the process of lying. In both errors and reaction times, the lie effect were larger in long RSI trials than in short RSI trials. These effects were caused by a larger increase in errors and reaction times from short to long RSI trials when participants had to lie compared to when they had to tell the truth. This observation suggests that lying is more sensitive than truth telling for situations that promote attentional lapses, which is in line with the idea that goal maintenance is crucial to cope with cognitive demands of lying, such as inhibiting the goal-irrelevant truth response. Third, despite our efforts to optimize ego depletion effects based upon the moderators reported in the meta-analysis of Hagger et al. (2010), we found no effect of ego depletion on lying. The manipulation checks indicated that our depletion manipulation may not have been successful. Although the depletion task was rated as more difficult than the control task, participants felt more tired and less happy after the control task than after the depletion task. Furthermore, depletion had no effect on the White bear thought suppression task. In sum, it is not clear whether our depletion manipulation was successful, and it seems premature to dismiss possible effects of ego depletion on deception. In Experiment 2 we therefore used another ego depletion manipulation that has repeatedly and successfully been used in the ego depletion literature. With regard to the Sheffield lie test, a drawback of using the questions from the original questionnaire of Spence et al. (2001) was that participants tend to perform an unequal number
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of activities (i.e., ca. 40 % yes versus 60 % no answers). As a result, the yes/no ratio varied 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65
across participants. To maximize experimental control in Experiment 2, we used a balanced yes/no response ratio in the Sheffield lie test.
3. Experiment 2
Experiment 1 showed that manipulating the RSI resulted in greater lie effects in the long RSI trials compared to the short RSI trials. Experiment 2 sought to replicate and extend this finding, now using a balanced yes/no response ratio in the Sheffield lie test. Participants executed a number of activities in the lab, allowing a 50 % proportion of yes and no answers. As our depletion manipulation may not have been successful in Experiment 1, in Experiment 2 we used another, often used depletion manipulation: the color Stroop task (Stroop, 1935; see Introduction). Several studies have shown that the Stroop task can effectively deplete inhibition resources (Bray et al., 2008; Govorun & Payne, 2006; NeshatDoost et al., 2008; Wallace and Baumeister, 2002). Furthermore, we opted for the hand grip task as an extra manipulation check of ego depletion because we failed to obtain rebound effects in the White bear thought suppression task (see also Rassin, 2005). In the hand grip task, participants are required to squeeze a spring-loaded handgrip as long as possible. Although squeezing a handgrip seems to measure muscular strength, prior research has shown that it is a valid measure of self-control (Rethlingshafei, 1942; Thornton, 1939). As squeezing a handgrip becomes fatiguing after a short period of time, one must exert self-control to override the urge to quit. In several studies on ego depletion, the task has been successfully used as a measure of self-control (Ciarocco, et al., 2001; Martijn et al., 2007; Muraven et al., 1998; Tice et al., 2007).
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3.1. Method 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65
3.1.1. Participants
Forty-seven students (8 men; Mage = 19.96 years, SD = 1.73) were rewarded with 8 Euro for their participation. The control (n = 22) and depletion group (n = 23) did not differ for age, sex, and hand preference.
3.1.2. Procedure
The procedure was the same as in Experiment 1, except for the following changes:
(1) A pre-test of handgrip stamina allowed to control for within-subjects variation in hand strength. Participants placed the handgrip in their dominant hand and as soon as they squeezed it, the experimenter inserted a matchstick between the handles and started a stopwatch. Time was stopped when the match fell out (Martijn et al., 2007; Muraven, et al., 1998). After completing the lie test, participants performed the post-test of the handgrip task. (2) Ego depletion was manipulated using a verbal Stroop task. The Stroop task was presented on five sheets with 60 color words per sheet. The sheets were identical in both groups, except for ink color. In the control group, the ink color (red, green, blue or yellow) of 80 % of the words was congruent with the semantic meaning of the word (Control Stroop). In the depletion group, the ink color of only 20 % of the words was congruent (Conflict Stroop). Participants were asked to name the ink color of the words as accurate and quick as possible, within a time frame of three minutes. The number of errors and the total time to complete the task were registered by the experimenter.
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(3) In the period between the Stroop task and Sheffield lie test, participants first 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65
performed ten out of twenty simple activities (e.g., ripping a sheet of paper, walking on a line, throwing a ball, etc.). Participants were randomly assigned to one of four combinations of activities. To be sure that they remembered which activities they had performed, participants afterwards received a questionnaire in which they had to indicate which of the twenty activities they had performed. Next, they filled in the SMS and CFCS (see Experiment 1). (4) To boost the RSI effect on lying, the long RSI in the Sheffield lie test was increased from 5000 ms to 8000 ms.
3.2. Results
We excluded one participant (depletion group) from further analyses because the number of errors he made in the Stroop task (M = 27) was 2.5 SDs above the group mean (M = 3.68, SD = 5.28), and one participant (control group) whose error percentage (23.13 %) in the Sheffield lie test exceeded the group mean (M = 4.30 %, SD = 3.85) by 2.5 SDs.
3.2.1. Manipulation check
Participants who performed the Conflict Stroop made significantly more errors (M = 5.38, SD = 4.19) and needed more time (M = 289 s, SD = 59) to complete the task than participants who performed the Control Stroop (errors: M = .50, SD = .96; RT: M = 161 s, SD = 32), t(65) = 5.82, p < .001, and t(65) = 9.01, p < .001, respectively. The Conflict Stroop was also rated as more difficult (M = 69.17, SD = 8.55) than the Control Stroop (M = 39.45, SD = 21.95), t(65) = 4.91, p < .001. No group differences in ratings on effort or tiredness were found, t‟s ≤ 1.22. When comparing the difference between the pre-test and post-test of
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handgrip endurance, a trend for difficulty was found, F(1,43) = 3.22, p = .08, showing that the 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65
increase in rated difficulty from pre-test to post-test was more evident in the depletion group (M = 19.78, SD = 22.48) than in the control group (M = 8.73, SD = 8.55).
3.2.2. Sheffield lie test
A 2 (Deception: Truth vs. Lie) x 2 (RSI: Short vs. Long) x 2 (Group: Control vs. Depletion) repeated measures ANOVA was conducted to analyze error rates (Table 3) and reaction times (Table 4). For the reaction time analysis, errors (4.29 %) were discarded. In an outlier analysis, response latencies that were more than 2.5 SDs away from the individual‟s mean (2.47 %) were excluded.
3.2.2.1. Error percentages. The analysis revealed a significant main effect of Deception, F(1,43) = 45.62, p < .001, d = .98, with more errors made when lying (M = 5.60 %, SD = 3.92) than telling the truth (M = 2.11 %, SD = 2.21). The interaction between Deception and RSI was not significant, F < 1. Likewise, the interaction between Deception and Group did not reach significance, F(1,43) = 1.06, p = .31. There was, however, a trend towards a significant three-way interaction of Deception, RSI and Group, F(1,43) = 3.11, p = .09, d = .52. A follow-up analysis showed that the lie effect did not differ between groups when the RSI was short, t < 1. The lie effect was marginally larger in the depletion group (M = 4.45 %, SD = 3.96) than in the control group (M = 1.94 %, SD = 4.62) in long RSI trials, t(43) = 1.96, p = .06, d = .70.
– INSERT TABLE 3 ABOUT HERE –
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3.2.2.2. Reaction times. Again, a main effect of Deception was obtained, F(1,43) = 130.12, 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65
p < .001, d = 1.71, with longer reaction times in lie trials (M = 1649 ms, SD = 282) than in truth trials (M = 1479 ms, SD = 279). The main effect of RSI, F(1,43) = 143.82, p < .001, d = 1.89, showed that overall reaction times were faster in short RSI trials (M = 1397 ms, SD = 227) compared to long RSI trials (M = 1731 ms, SD = 346). Follow-up analyses showed that the increase in reaction times from short to long RSI trials was significant both for truth telling (M = 298 ms, SD = 193), t(45) = 10.47, p < .001, d = 1.48, and for lying (M = 374 ms, SD = 202), t(45) = 12.56, p < .001, d = 1.85. The increase on lie trials was however significantly larger than on truth trials, t(45) = 3.66, p < .001, d = .54, and as such accounts for the RSI effect on lying. The significant interaction between Deception and RSI, F(1,43) = 16.12, p < .001, d = 1.25, indicated that the lie effect was larger in long RSI trials (M = 213 ms, SD = 133) than in short RSI trials (M = 130 ms, SD = 109). Effects involving Group were not significant, F’s < 1.
– INSERT TABLE 4 ABOUT HERE –
3.3. Discussion
Experiment 2 replicated the main findings of Experiment 1. Although the RSI manipulation had no longer an effect on error percentages, we again found a robust RSI effect on lying in reaction times, with a larger RT lie effect in long RSI trials compared to short RSI trials. These findings indicate that the RSI effect in Experiment 1 was not due to artifacts, such as an unbalanced yes/no response ratio. As in Experiment 1, the effect was caused by a larger increase in reaction times from short to long RSI trials when participants had to lie compared to when they had to tell the truth. As such, the second experiment further
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strengthens the idea that lying requires executive control, thereby increasing the need for 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65
attentional focus to maintain the task goal. The manipulation checks indicate that the depletion manipulation in Experiment 2 was more successful than in Experiment 1. There were more pronounced and consistent selfreported and behavioral differences between the depleted and the control group. Despite the indications that depletion was successful, lying appeared unaffected by ego depletion. Only in the error data, and only in the long RSI trials, there was a trend for a larger lie effect in the depletion group than in the control group, but this effect failed to reach statistical significance.
4. General discussion
In two experiments we investigated the hypothesis that lying requires executive control by experimentally manipulating executive control before (ego depletion) and while (goal neglect) executing the Sheffield lie test. We hypothesized that (1) compared to short RSI trials that are thought to promote attentional focus, a long RSI would promote neglect of task goals, making it harder to lie, and (2) participants whose executive control resources were depleted by an initial executive control task would overall experience more difficulty to lie than control participants who performed a task that required little executive control. The lie effect (lie minus truth) in errors and reaction times was expected to increase for long compared to short RSI and for depleted compared to non-depleted participants. In Experiment 1, we demonstrated that both the error and RT lie effect were larger in trials following a long RSI than in short RSI trials. In Experiment 2, we again found a robust RSI effect on lying in reaction times, but not in errors. In both experiments, the increase in the RT lie effect from short to long RSI trials was due to a larger increase in time to lie than in time to tell the truth. Lying was thus more affected by a context that promoted lapses of
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attention than truth telling. This finding is in line with the idea that lying requires executive 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65
control, such as suppressing the dominant truth response, and that therefore attention is needed to maintain the goal-relevant representation of inhibiting the truth. In the literature on goal neglect, several theories have been proposed that differ in the degree to which goal neglect is considered as the cause of effects in a range of complex cognitive tasks. De Jong et al. (1999), for example, reasoned that interference effects, such as the Stroop effect, can be fully attributed to goal neglect. As such, the authors distanced themselves from the view that interference effects would stem from fundamental limitations in competition resolution. In line with their hypothesis, they indeed found that the Stroop effect was eliminated with a short RSI (see Introduction). Although in our experiments the short RSI resulted in smaller lie effects than the long RSI, the lie effect was still substantial. Therefore, our results fit better with the dual-process theory of Engle and Kane (2003, 2004). This theory states that interference effects are determined by two mechanisms: competition resolution and goalmaintenance. Hence, even if attention is tightly focused on the task goal of resolving the conflict, the time-consuming process of resolving the conflict itself would still contribute to the effect. De Jong et al.‟s (1999) assumption that manipulating the response-stimulus interval would tap into attentional processes, is in line with previous findings. In the research domain of attention, it has repeatedly been shown that task performance decreases as the interval length between stimuli increases (Niemi and Näätänen, 1981; Posner, 2011; Sanders, 1983). Posner has attributed this finding to a difficulty in maintaining the alertness state as the interval becomes longer (Posner, 1978). A related idea has been put forward in Sanders‟ cognitive-energetic model (1983, 1998). Sanders has argued that the efficiency with which a task is performed depends on one‟s state of arousal (i.e., the time-locked phasic physiological response to input) and activation (i.e., a long-lasting voluntary readiness for action), two
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concepts that are closely related to attention. According to the model, the state of 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65
arousal/activation increases as a function of event rate. Slow event rates would create underactivation, resulting in a decline in task performance. Several findings have supported these attentional accounts. First, it has been shown that the presentation of a warning signal (i.e., neutral stimuli in the interval between stimuli) results in a better performance compared to trials in which no such warning signal was presented. Warning signals would increase the alert state and the expectancy of the upcoming stimulus, thereby improving goal representation and task preparation (Hackley, 2009; Hackley and Valle-Inclán, 2003; Meiran and Chorev, 2005; Posner and Boies, 1971). Second, research on mind wandering has shown that longer intervals between the presentation of stimuli yields greater thoughts that are unrelated to the task (Antrobus, 1968; Giambra, 1995; Grodsky and Giambra, 1990; Smallwood et al., 2004). As a final point of support, we refer to patient studies. It has been found that patients with a frontal lobe syndrome – a syndrome characterized by disturbed attention – are more easily distracted by irrelevant stimuli presented during long interstimulus intervals than during short intervals (Woods and Knight, 1986; Woods et al., 1993). In a similar vein, patients with Attention Deficit Hyperactivity Disorder (ADHD) perform worse when the event rate is slow. This finding has often been explained in terms of Sanders‟ cognitive-energetic model (1983), by stating that patients with ADHD would have trouble regulating the suboptimal arousal/activation state, induced by long interstimulus intervals (Kooistra et al., 2010; Sergeant, 2005; Wiersema et al., 2006). Although these studies support an attentional explanation of the RSI effect on lying, it may be appropriate in future research to further strengthen the idea that attentional lapses mediate the relationship between the RSI manipulation and the lie effect(s). In studies investigating mind wandering, thought sampling has been the most common used method to obtain an online measure of attentional lapses (Smallwood and Schooler, 2006). This method consists of asking participants at various
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points during the task whether their thoughts were off-task or focused on the task. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65
Interestingly, task-unrelated thoughts have found to be a good predictor of task performance (McVay and Kane, 2009; McVay et al., 2009; Schooler et al., 2004). Another, more experimental way to demonstrate the mediating role of attentional lapses/goal neglect, may consist of adding trials in which a warning signal (e.g., fixation cross) is presented during the response stimulus interval. If attentional lapses account for the larger lie effects in long RSI trials, a warning signal would recover alertness and help to focus again on the task goal (Hackley and Valle-Inclán, 2003; Posner and Boies, 1971). The above follow-up studies would justify further research on goal neglect in deception. It would be interesting to find out which RSI induces the optimal state of goal neglect. We may expect that the chance of attentional lapses to occur will increase linearly as the RSI becomes longer. Although the present experiments do not allow a direct comparison, the effect sizes of the RT lie effects are suggestive of such a trend, with a larger effect size when the RSI was 8000 ms (d = 1.71; Experiment 2) than when it was 5000 ms (d = 1.28; Experiment 1). Furthermore, in future research, it may be appropriate to take into account individual differences in susceptibility for goal neglect. Several studies have supported the hypothesis that individuals with a high working memory capacity differ primarily from participants with a low working memory capacity in a better control of actively maintaining goal-relevant information (Kane et al., 2007; Kane and Engle, 2003; McVay and Kane, 2009; Unsworth et al., 2010). Consequently, we can expect that individuals with a low working memory capacity would have more difficulty to lie on long RSI trials than high working memory capacity individuals. Our results may also provide an explanation for the effects of truth proportion on deception. Verschuere and colleagues (2011) found that increasing the amount of lie trials in the Sheffield lie test decreased the error and RT lie effect, whereas increasing the amount of truth trials enhanced them. The authors explained this finding by a
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shift in the dominance of the truth response. However, in the light of the present study, an 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65
explanation in terms of goal neglect might also be plausible. A large proportion of lie trials would make it easy to maintain the goal of inhibiting the truth, whereas a small number of lie trials would encourage naming the prepotent, truth response. Indeed, in conflict tasks, such as the Stroop task, it has repeatedly been shown that increasing the relative proportion of congruent trials produces larger Stroop effects, whereas the Stroop effect is reduced with increased incongruency (Kane and Engle, 2003; Logan and Zbrodoff, 1979; Lowe and Mitterer, 1982; West and Baylis, 1998). From a goal neglect perspective, a relatively large number of congruent trials makes it difficult to maintain the goal of color naming, since prepotency guided responding (word naming) also leads to the right answer on these trials. On the contrary, goal maintenance becomes fairly easy when the goal to inhibit word naming is reinforced by a large number of incongruent trials (Kane and Engle, 2003). Despite our efforts to maximize the effect of depletion based upon the meta-analysis of Hagger et al. (2010), our manipulation did not affect lying. In Experiment 1, the e-hunting task seemed to be unsuccessful to manipulate ego depletion. After completion of the task, the depletion group reported to be more tired and less happy than the control group. It is possible that the control group was more prone to perceive the application of the same rules as boring, due to their relatively less positive affective state. Boredom may have caused the increase in negative affect. Moreover, engaging in boring tasks requires self-control resources to enable task persistence and may consequently induce ego depletion (Vohs and Heatherton, 2000). This would explain why participants felt more tired. The development of ego depletion might have been further strengthened by the increased negative affect, as attempts to repair negative affect have shown to drain self-control resources (Bruyneel et al., 2009). In sum, boredom might also have brought the control group into a state of ego depletion, which would explain why our depletion manipulation was not effective. Another factor that may have rendered our
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depletion manipulation unsuccessful, is related to the time participants spent on the e-hunting 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65
task. The meta-analysis of Hagger et al. tested the hypothesis, consistent with the conceptualization of self-control as a limited resource, that spending longer on the depletion tasks would be accompanied by a larger ego depletion effect. The results showed that the length of time spent on a depletion task only accounted for relatively little variance in the ego depletion effect. It was therefore suggested that task duration should be a minor consideration when designing and evaluating ego depletion experiments. Based on this finding, our manipulation was relatively brief (i.e., three minutes to cross out e‟s in each text). The ehunting task in several ego depletion studies was somewhat longer (i.e., five minutes; e.g., DeWall et al., 2011; Job et al., 2010). Perhaps our manipulation was too short to induce a state of ego depletion. Irrespective of the reasons for the failed manipulation, the data of Experiment 1 emphasize the importance of administering self-reported measures such as effort, fatigue, difficulty and mood in ego depletion research. As previous studies on ego depletion did not always include such measures (Hagger et al., 2010), the current data should encourage researchers to consistently assess manipulation checks in the future. The manipulation check of Experiment 2 indicated that the Stroop task was more successful to manipulate ego depletion. Still, there was no robust ego depletion effect on lying. The only indication for a depletion effect was revealed in a marginally larger error lie effect on long RSI trials in the depletion group than in the control group. However, the lack of a significant difference between groups in self-reported effort and fatigue may suggest that the ego depletion manipulation was not strong enough to affect lying. The meta-analysis of Hagger et al. showed that the degree of ego depletion evoked by cognitive processing tasks is dependent on task complexity. In future research, more complex tasks, such as the Operation Span (Unsworth et al., 2005), may be preferable. In follow-up studies, it may also be appropriate to control for individual differences in self-control, by e.g. the Self-Control Scale
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(Tangney et al., 2004). Furthermore, it might be worthwhile to assess people‟s beliefs about 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65
the availability of self-control. In a recent study, Job and colleagues found that depletion effects only occurred in people who believed that the ability to exert self-control is limited (Job et al., 2010). This might suggest that the depletion effect after executing a self-control task may reflect people‟s beliefs about the availability of self-control resources, rather than true resource depletion. By assessing beliefs about self-control, it would be possible to verify whether the depletion effect on lying only (or more strongly) occurs in participants who hold a limited-resource view. Previous research mainly supported the cognitive view on lying using observational and correlational techniques (see e.g., Christ et al., 2009; Farrow et al., 2010, Vrij et al., 2006). Notable exceptions are recent neuroimaging studies that experimentally manipulated neural activity in brain regions that have been associated with executive control (Karim et al., 2010; Karton and Bachmann, 2011; Mameli et al., 2010; Priori et al., 2008). Priori et al. (2008) and Mameli et al. (2010) demonstrated that increasing the excitability of the dorsolateral prefrontal cortex (DLPFC) using anodal transcranial direct current stimulation (tDCS) slowed down deceptive responding relative to truthful responding. In contrast, inhibiting activity of the anterior prefrontal cortex by cathodal tDCS was shown to result in faster deceptive responding (Karim et al., 2010). Karton and Bachmann (2011) used transcranial magnetic stimulation (TMS) to temporarily disturb activation in the DLPFC. Their results showed that stimulation of the right hemisphere decreased the choice to lie, whereas stimulation of the left hemisphere increased lying. Our study extended these findings to a behavioral level and as such, supported the idea that executive control is a prerequisite for deception. The present study found that lying was more negatively affected in situations that promoted attentional lapses than truth telling. This finding supports the hypothesis that lying requires more executive control than truth telling, thereby increasing the need to maintain the
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focus on tasks goals. The manipulation of RSI may also have practical implications. Our 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65
findings suggest that lie detection accuracy might be improved by using relatively long RSIs in lie tests. Investigating whether the RSI effect generalizes to other lie paradigms that are applied in practice (e.g., Concealed Information Test; Lykken, 1959) might be a first step in that direction.
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Footnote 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65
1. The Self-Monitoring Scale (SMS) measures to what extent individuals can and do regulate their self-presentation. The Consideration of Future Consequences Scale (CFCS) is a measure of the extent to which individuals consider and are influenced by the potential distant outcomes of their current behavior. Ego depletion has shown to be positively associated with low self-monitoring (Seeley and Gardner, 2003; Wan and Sternthal, 2008) and higher levels of consideration of future consequences (Joireman et al., 2008). In the present study, however, these individual traits did not moderate effects of ego depletion.
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References 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65
Aarts, E., Roelofs, A., van Turennout, M., 2008. Anticipatory activity in anterior cingulate cortex can be independent of conflict and error likelihood. J. Neurosci. 28, 4671–4678. Abramowitz, J.S., Tolin, D.F., Street, G.P., 2001. Paradoxical effects of thought suppression: A meta-analysis of controlled studies. Clin. Psychol. Rev. 21, 683‒ 703. Antrobus, J.S., 1968. Information theory and stimulus-independent thought. Brit. J. Psychol. 59, 423–430. Baumeister, R.F., Bratslavsky, E., Muraven, M., Tice, D.M., 1998. Self-control depletion: Is the active self a limited resource? J. Pers. Soc. Psychol. 74, 1252‒ 1265. Baumeister, R.F., Gailliot, M.T., DeWall, C.N., Oaten, M., 2006. Self-regulation and personality: Strength-boosting interventions and trait moderators of ego depletion. J. Pers. 74, 1773–1802. Brass, M., von Cramon, D.Y., 2002. The role of the frontal cortex in task preparation. Cereb. Cortex 12, 908–914. Bray, S.R., Ginis, K.A.M., Hicks, A.L., Woodgate, J. (2008). Effects of self-regulatory strength depletion on muscular performance and EMG activation. Psychophysiology 45, 337–343. Bruyneel, S.D., Dewitte, S., Franses, P.H., Dekimpe, M.G., 2009. I felt low and my purse feels light: Depleting mood regulation attempts affect risk decision making. J. Behav. Decis. Making 22, 153–170. Christ, S.E., Van Essen, D.C., Watson, J.M., Brubaker, L.E., McDermott, K.B., 2009. The contributions of prefrontal cortex and executive control to deception: evidence from activation likelihood estimate meta-analysis. Cereb. Cortex 19, 1557–1566.
31
Ciarocco, N.J., Sommer, K.L., Baumeister, R.F., 2001. Ostracism and ego depletion: The 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65
strains of silence. Pers. Soc. Psychol. B. 27, 1156–1163. Cohen, J., 1988. Statistical power analysis for the behavioural sciences. Lawrence Erlbaum, Hillsdale. Conway, M.A., Pleydell-Pearce, C.W., 2000. The construction of autobiographical memories in the self memory system. Psychol. Rev. 107, 261‒ 288. De Clercq, A., Crombez, G., Buysse, A., Roeyers, H., 2003. A simple and sensitive method to measure timing accuracy. Beh. Res. Meth. Ins. C. 35, 109–115. De Jong, R.D., Berendsen, E., Cools, R., 1999. Goal neglect and inhibitory limitations: Dissociable causes of interference effects in conflict situations. Acta Psychol. 101, 379–394. DePaulo, B.M., Lindsay, J.J., Malone, B.E., Muhlenbruck, L., Charlton, K., Cooper, H., 2003. Cues to deception. Psychol. Bull. 129, 74–118. DeWall, C.N., Baumeister, R.F., Gailliot, M.T., Maner, J.K., 2008. Depletion makes the heart grow less helpful: Helping as a function of self-regulatory energy and genetic relatedness. Pers. Soc. Psychol. B. 34, 1653–1662. DeWall, C.N., Baumeister, R.F., Mead, N.L., & Vohs, K.D., 2011. How leaders self-regulate their task performance: evidence that power promotes diligence, depletion, and disdain. J. Pers. Soc. Psychol. 100, 47–65. Duncan, J., 1995. Attention, intelligence, and the frontal lobes, in: Gazzaniga, M.S. (Ed.), The cognitive neurosciences. MIT Press, Cambridge, pp. 721–733. Duncan, J., Emslie, H., Williams, P., Johnson, R., Freer, C., 1996. Intelligence and the frontal lobe: The organization of goal-directed behavior. Cognitive Psychol. 30, 257–303. Ekman, P., Friesen, W.V., 1972. Hand movements. J. Commun. 22, 353–374.
32
Engle, R.W., Kane, M.J., 2004. Executive attention, working memory capacity, and a two1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65
factor theory of cognitive control, in: Ross, B. (Ed.), The psychology of learning and motivation. Academic Press, New York, pp. 145‒ 199. Farrow, T.F.D., Hopwood, M.C., Parks, R.W., Hunter, M.D., Spence, S.A., 2010. Evidence of mnemonic ability selectively affecting truthful and deceptive response dynamics. Am. J. Psychol. 123, 447‒ 453. Furedy, J.J., Davis, C., Gurevich, M., 1988. Differentiation of deception as a psychological process – a psychophysiological approach. Psychophysiology 25, 683‒ 688. Gamer, M., 2011. Detecting of deception and concealed information using neuroimaging techniques, in: Verschuere, B., Ben-Shakhar, G., Meijer, E.H. (Eds.), Memory detection: Theory and application of the concealed information test. Cambridge University Press, Cambridge, pp. 90‒ 113. Giambra, L.M., 1995. A laboratory based method for investigating influences on switching attention to task unrelated imagery and thought. Conscious Cogn. 4, 1–21. Govorun, O., Payne, B.K., 2006. Ego depletion and prejudice: Separating automatic and controlled components. Social Cogn. 24, 111‒ 136. Goldman-Eisler, F., 1968. Psycholinguistics: Experiments in spontaneous speech. Double day, New York. Grodsky, A., Giambra, L., 1990. The consistency across vigilance and reading tasks of individual differences in the occurrence of task unrelated and task related images and words. Imagin. Cogn. Pers. 10, 39–52. Hackley, S.A., 2009. The speeding of voluntary reaction by a warning signal. Psychophysiology 46, 225–233. Hackley, S.A., Valle-Inclán, F., 2003. Which stages of processing are speeded by a warning signal? Biol. Psychol. 64, 27–45.
33
Hagger, M.S., Wood, C., Stiff, C., Chatzisarantis, N.L.D., 2010. Ego depletion and the 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65
strength model of self-control: A meta-analysis. Psychol. Bull. 136, 495–525. Ilkowska, M., Engle, R.W., 2010. Working memory capacity and self-regulation, in: Hoyle, R.H. (Ed.), Handbook of personality and self-regulation. Willey-Blackwell, Oxford, pp. 265‒ 290. Job, V., Dweck, C.S., Walton, G.M., 2010. Ego Depletion -- Is it all in your head?: Implicit theories about willpower affect self-regulation. Psychol. Sci. 21, 1686–1693. Joireman, J., Balliet, D., Sprott, D., Spangenberg, E., Schultz, J., 2008. Consideration of future consequences, ego-depletion, and self-control: Support for distinguishing between CFC-Immediate and CFC-Future sub-scales. Pers. Indiv. Differ. 45, 15–21. Kane, M.J., Conway, A.R.A., Hambrick, D.Z., Engle, R.W., 2007. Variation in working memory capacity as variation in executive attention and control, in: Conway, A.R.A., Jarrold, C., Kane, M.J., Miyake, A., Towse, J.N. (Eds.), Variation in working memory. Oxford University Press, New York, pp. 21–48. Kane, M.J., Engle, R.W., 2003. Working memory capacity and the control of attention: The contributions of goal neglect, response competition, and task set to Stroop interference. J. Exp. Psych. Gen. 132, 47‒ 70. Karim, A.A., Schneider, M., Lotze, M., Veit, R., Sauseng, P., Braun, C., Birbaumer, N., 2010. The truth about lying: Inhibition of the anterior prefrontal cortex improves deceptive behavior. Cereb. Cortex 20, 205–213. Karton, I., Bachmann, T., 2011. Effect of prefrontal transcranial magnetic stimulation on spontaneous truth-telling. Behav. Brain Res. 225, 209–214. Kooistra, L., van der Meere, J.J., Edwards, J.D., Kaplan, B.J., Crawford, S., Goodyear, B.G., 2010. Preliminary fMRI findings on the effects of event rate in adults with ADHD. J. Neural Transm. 117, 655–662.
34
Lang, P.J., Greenwald, M.K., Bradley, M.M., Hamm, A.O., 1993. Looking at pictures: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65
affective, facial, visceral, and behavioral reactions. Psychophysiology 30, 261‒ 273. Leal, S., Vrij, A., 2008. Blinking during and after lying. J. Nonverbal Behav. 32, 187‒ 194. Leal, S., Vrij, A., 2010. The occurrence of eye blinks during a guilty knowledge test. Psychol. Crime Law 16, 349‒ 357. Logan, G.D., Zbrodoff, N.J., 1979. When it helps to be misled: Facilitative effects of increasing the frequency of conflicting stimuli in a Stroop-like task. Mem. Cognition 7, 166‒ 174. Lowe, D., Mitterer, J.O., 1982. Selective and divided attention in a Stroop task. Can. J. Psychology 36, 684‒ 700. Lykken, D., 1959. The GSR in the detection of guilt. J. Appl. Psychol. 43, 385‒ 388. Mameli, F., Mrakic-Sposta, S., Vergari, M., Fumagalli, M., Macis, M., Ferrucci, R., Nordio, F., Consonni, D., Sartori, G., Priori, A., 2010. Dorsolateral prefrontal cortex specifically processes general - but not personal - knowledge deception: Multiple brain networks for lying. Behav. Brain Res. 21, 164‒ 168. Mann, S., Vrij, A., 2006. Police officers‟ judgements of veracity, tenseness, cognitive load and attempted behavioural control in real life police interviews. Psychol. Crime Law, 12, 307‒ 319. Martijn, C., Alberts, H., Merckelbach, H., Havermans, R., Huijts, A., De Vries, N.K., 2007. Overcoming ego depletion: The influence of exemplar priming on self-control performance. Eur. J. Soc. Psychol. 37, 231–238. McVay, J.C., Kane, M.J., 2009. Conducting the train of thought: Working memory capacity, goal neglect, and mind wandering in an executive-control task. J. Exp. Psychol. Learn. 35, 196–204.
35
McVay, J.C., Kane, M.J., Kwawpil, T.R., 2009. Tracking the train of thought from the 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65
laboratory into everyday life: An experience-sampling study of mind wandering across controlled and ecological contexts. Psychon. B. Rev. 16, 857–863. Meiran, N., Chorev, Z., 2005. Phasic Alertness and the Residual Task Switching Cost. Exp. Psychol. 52, 109–124. Muraven, M., Shmueli, D., Burkley, E., 2006. Conserving self-control strength. J. Pers. Soc. Psychol. 91, 524–537. Muraven, M., Tice, D.M., Baumeister, R.F., 1998. Self-control as a limited resource: Regulatory depletion patterns. J. Pers. Soc. Psychol. 74, 774–789. Neshat-Doost, H.T., Dalgleish, T., Golden, A.M.J., 2008. Reduced Specificity of Emotional Autobiographical Memories Following Self-Regulation Depletion. Emotion 8, 731‒ 736. Niemi, P., Näätänen, R., 1981. Foreperiod and simple reaction time. Psychol. Bull. 89, 133– 162. Posner, M.I., 1978. Chronometric explorations of mind. Erlbaum, Hillsdale. Posner, M.I., 2011. Cognitive neuroscience of attention, second ed. Guilford Press, New York. Posner, M.I., Boies, S.J., 1971. Components of Attention. Psychol. Rev. 78, 391–408. Priori, A., Mameli, F., Cogiamanian, F., Marceglia, S., Tiriticco, M., Mrakic-Sposta, S., Ferrucci, R., Zago, S., Polezzi, D., Sartori, G., 2008. Lie-specific involvement of dorsolateral prefrontal cortex in deception. Cereb. Cortex 18, 451–455. Rassin, E., 2005. Thought suppression. Elsevier, Oxford. Rethlingshafer, D., 1942. Relationship of tests of persistence to other measures of continuance of activities. J. Abnorm. Soc. Psych. 37, 71–82.
36
Robinson, M.D., Schmeichel, B. J., Inzlicht, M., 2010. A cognitive control perspective of 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65
self-control strength and its depletion. Soc. Personal. Psychol. Compass 4, 189–200. Sanders, A.F., 1983. Towards a model of stress and performance. Acta Psychol. 53, 61–97. Sanders, A.F., 1998. Elements of Human Performance: Reaction Processes and Attention in Human Skill. Lawrence Erlbaum Associates, Mahwah. Schmeichel, B.J., 2007. Attention control, memory updating, and emotion regulation temporarily reduce the capacity for executive control. J. Exp. Psychol. Gen. 136, 241‒ 255. Schooler, J.W., Reichle, E.D., Halpern, D.V., 2004. Zoning out while reading: Evidence for dissociations between experience and metaconsciousness, in: Levin, D. (Ed.), Thinking and seeing: Visual metacognition in adults and children. MIT Press, Cambridge, pp. 203–226. Seeley, E.A., Gardner, W.I., 2003. The “selfless” and self-regulation: The role of chronic other-orientation in averting self-regulatory depletion. Self Identity 2, 103–117. Sergeant, J.A., 2005. Modeling attention-deficit/hyperactivity disorder: a critical appraisal of the cognitive-energetic model. Biol. Psychiat. 57, 1248–1255. Seymour, T.L., Kerlin, J.R., 2008. Successful detection of verbal and visual concealed knowledge using an RT-based paradigm. Appl. Cognitive Psych. 22, 475‒ 490. Sheridan, M.R., Flowers, K.A., 2010. Reaction times and deception: the lying constant. Int. J. Psychol. Stud. 2, 41‒ 51. Smallwood, J., Davies, J.B., Heim, D., Finnigan, F., Sudberry, M.V., O‟Connor, R.C., Obonsawain,. M.C., 2004. Subjective experience and the attentional lapse. Task engagement and disengagement during sustained attention. Conscious Cogn. 4, 657– 690.
37
Smallwood, J., Schooler, J.W., 2006. The restless mind. Psychol. Bull. 132, 946–958. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65
Snyder, M., 1974. Self-monitoring of expressive behavior. J. Pers. Soc. Psychol. 30, 526–537. Spence, S. A., Farrow, T.F.D., Herford, A.E., Wilkinson, I.D., Zheng, Y., Woodruff, P.W.R., 2001. Behavioural and functional anatomical correlates of deception in humans. Neuroreport 12, 2849‒ 2853. Spence, S.A., Hunter, M.D., Farrow, T.F., Green, R.D., Leung, D.H., Hughes, C.J., Ganesan V. (2004). A cognitive neurobiological account of deception: evidence from functional neuroimaging. Philos. Trans. R. Soc. Lond. B. Biol. Sci. 359, 1755‒ 1762. Spence, S.A., Kaylor-Hughes, C.J., Farrow, T.F.D., Wilkinson, I.D., 2008. Looking for truth and finding lies: the prospects for a nascent neuroimaging of deception. Neurocase 14, 68‒ 81. Sporer, L., Schwandt, B., 2007. Moderators of nonverbal indicators of deception. Psychol. Public Pol. L. 13, 1‒ 34. Stewart, C.C., Wright, R.A., Hui, S.-K.A., Simmons, A., 2009. Outcome expectancy as a moderator of mental fatigue influence on cardiovascular response. Psychophysiology 46, 1141–1149. Strathman, A., Boninger, D.S., Gleicher, F., Baker, S.M., 1994. Constructing the future with present behavior: an individual difference approach, in: Zaleski, Z. (Ed.), Psychology of future orientation. Catholic University of Lublin Press, Lublin, pp. 107‒ 120. Stroop, J.R., 1935. Studies of inference in serial verbal reactions. J. Exp. Psychol. 18, 643‒ 662. Tangney, J.P., Baumeister, R.F., Boone, A.L., 2004. High self-control predicts good adjustment, less pathology, better grades, and interpersonal success. J. Pers. 72, 271– 322.
38
Tice, D.M., Baumeister, R.F., Shmueli, D., Muraven, M., 2007. Restoring the self: Positive 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65
affect helps improve self-regulation following ego depletion. J. Exp. Soc. Psychol. 43, 379–384. Thornton, G.R., 1939. A factor analysis of tests designed to measure persistence. Psychol. Monogr. 51, 1–42. Unsworth, N., Heitz, R.P., Schrock, J.C., Engle, R.W., 2005. An automated version of the operation span task. Behav. Res. Methods 37, 498–505. Unsworth, N., Redick, T.S., Lakey, C.E., & Young, D.L., 2010. Lapses in sustained attention and their relation to executive control and fluid abilities: An individual differences investigation. Intelligence 38, 111–122. Veltman, J.A., Gaillard, A.W.K., 1998. Physiological workload reactions to increasing levels of task difficulty. Ergonomics 41, 656‒ 669. Verschuere, B., Crombez, G., Degrootte, T., Rosseel, Y., 2009. Detecting concealed information with reaction times: Validity and comparison with the polygraph. Appl. Cognitive Psych. 23, 1‒ 11. Verschuere, B., Spruyt, A., Meijer, E.H., Otgaar, H., 2011. The ease of lying. Conscious Cogn. 20, 908‒ 911. Visu-Petra, G., Miclea, M., Visu-Petra, L., in press. RT-based detection of concealed information in relation to individual differences in executive functioning. Appl. Cognit. Psychol. DOI: 10.1002/acp.1827 Vohs, K.D., Heatherton, T.F., 2000. Self-regulatory failure: A resource-depletion approach. Psychol. Sci. 11, 249‒ 254. Vrij, A., Fisher, R., Mann, S., Leal, S., 2006. Detecting deception by manipulating cognitive load. Trends Cogn. Sci. 10, 141–142.
39
Vrij, A., Semin, G.R., Bull, R., 1996. Insight into behavior displayed during deception. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65
Hum. Commun. Res. 22, 544–562. Wallace, H.M., Baumeister, R.F., 2002. The effects of success versus failure feedback on further self-control. Self Identity 1, 35–41. Wan, E.W., Sternthal, B., 2008. Regulating the effects of depletion through monitoring. Pers. Soc. Psychol. B. 34, 32–46. Wegner, D.M., Schneider, D.J., 2003. The White Bear Story, Psychol. Inq. 14, 326–329. West, R., Baylis, G.C., 1998. Effects of increased response dominance and contextual disintegration on the Stroop interference effect in older adults. Psychol. Aging 13, 206‒ 217. Wiersema, R., van der Meere, J., Roeyers, H., Van Coster, R., Baeyens, D., 2006. Event rate and event-related potentials in ADHD. J. Child Psychol. Psyc. 47, 560–567. Woods, D.L., Knight, R.T., 1986. Electrophysiological evidence of increased distractibility after dorsolateral prefrontal lesions. Neurology 36, 212–216. Woods, D.L., Knight, R.T., Scabini, D., 1993. Anatomical substrates of auditory selective attention: behavioral and electrophysiological effects of temporal and parietal lesions. Cognitive Brain Res. 1, 227–240. Zuckerman, M., DePaulo, B.M., Rosenthal, R., 1981. Verbal and nonverbal communication of deception, in: Berkowitz, L. (Ed.), Advances in experimental social psychology, Volume 14. Academic Press, New York, pp. 1‒ 57.
Table 1. Error percentages (%) in the Sheffield lie test of Experiment 1. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65
Depletion
Control
Short RSI M (SD)
Long RSI M (SD)
Short RSI M (SD)
Long RSI M (SD)
Truth
5.13 (4.87)
3.54 (4.07)
6.13 (5.17)
4.76 (4.11)
Lie
6.41 (4.00)
7.00 (5.39)
5.93 (4.61)
9.09 (8.30)
Lie – truth
1.28 (5.89)
3.46 (5.28)
-.20 (5.16)
4.33 (7.37)
41
Table 2. Mean reaction times (ms) in the Sheffield lie test of Experiment 1. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65
Depletion
Control
Short RSI M (SD)
Long RSI M (SD)
Short RSI M (SD)
Long RSI M (SD)
Truth
1403 (225)
1603 (308)
1332 (245)
1569 (326)
Lie
1509 (226)
1771 (327)
1488 (319)
1743 (337)
Lie – truth
106 (140)
168 (145)
156 (128)
174 (143)
42
Table 3. Error percentages (%) in the Sheffield lie test of Experiment 2. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65
Depletion
Control
Short RSI M (SD)
Long RSI M (SD)
Short RSI M (SD)
Long RSI M (SD)
Truth
1.71 (1.84)
1.60 (2.23)
2.40 (4.05)
2.78 (2.71)
Lie
5.26 (4.43)
6.04 (3.88)
6.35 (5.31)
4.72 (5.33)
Lie – truth
3.55 (4.81)
4.44 (3.96)
3.95 (4.21)
1.94 (4.62)
43
Table 4. Mean reaction times (ms) in the Sheffield lie test of Experiment 2. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65
Depletion
Control
Short RSI M (SD)
Long RSI M (SD)
Short RSI M (SD)
Long RSI M (SD)
Truth
1362 (217)
1655 (316)
1303 (236)
1601 (396)
Lie
1504 (237)
1882 (303)
1421 (242)
1799 (396)
Lie – truth
142 (114)
227 (133)
118 (106)
198 (127)
*Abstract
Abstract
This study investigated whether lying requires executive control using a reaction-time based lie test. We hypothesized that (1) goal neglect induced by a long response stimulus interval (RSI; 5-8 s) would make lying harder relative to a short RSI (.2 s) that promoted attentional focus, and (2) participants whose executive control resources were depleted by an initial executive control task would experience more difficulty to lie than control participants who performed a task that required little executive control. Across two experiments, the ego depletion manipulation did not reliably affect lying. Both experiments revealed that the cognitive cost associated with lying was larger for the long compared to the short RSI. This finding supports the idea that lying requires more executive control than truth telling. The manipulation of RSI may provide a simple, yet effective means to improve lie detection accuracy.
Keywords: Deception; Lie detection; Executive control; Goal neglect; Ego depletion
