Behavioral Measures Of Impulsivity Research Articles

Predicting delay discounting from heterogeneous social media data

Delay discounting, a behavioral measure of impulsivity, is often used to quantify the human tendency to choose a smaller, sooner reward (e.g., $1 today) over a larger, later reward ($2 tomorrow). Delay discounting and its relation to human decision-making is a hot topic in economics and behavior science since pitting the demands of long-term goals against short-term desires is among the most difficult tasks in human decision-making (Hirsh et al. in J Res Personal 42:1646, 2008). Previously, questionnaire-based surveys were used to assess someone’s delay discounting rate (DDR). In this research, we develop a computational model to automatically predict DDR from diverse types of social media data such as likes and posts. We explore different unsupervised feature learning methods to take advantage of a large amount of unsupervised social media data. Based on our evaluation, the best model learned from social media likes achieved 0.634 ROC AUC, which 18% better than the baseline model that did not use unsupervised feature learning. The best model learned from social media posts achieved 0.641 ROC AUC, which is 24% better than the baseline that did not use unsupervised feature learning. We also employed unsupervised feature fusion to combine heterogeneous user data such as likes and posts together to further improve system performance. The final combined model outperformed the baseline that did not use unsupervised feature learning by 30%. Finally, we conducted additional analysis to uncover interesting correlation patterns between a person’s social media behavior and his/her DDR.

Obtaining quality data using behavioral measures of impulsivity in gambling research with Amazon's Mechanical Turk.

Background and aimsTo date, no research has examined the viability of using behavioral tasks typical of cognitive and neuropsychology within addiction populations through online recruitment methods. Therefore, we examined the reliability and validity of three behavioral tasks of impulsivity common in addiction research in a sample of individuals with a current or past history of problem gambling recruited online.MethodsUsing a two-stage recruitment process, a final sample of 110 participants with a history of problem or disordered gambling were recruited through MTurk and completed self-report questionnaires of gambling involvement symptomology, a Delay Discounting Task (DDT), Balloon Analogue Risk Task (BART), Cued Go/No-Go Task, and the UPPS-P.ResultsParticipants demonstrated logically consistent responding on the DDT. The area under the empirical discounting curve (AUC) ranged from 0.02 to 0.88 (M = 0.23). The BART demonstrated good split-third reliability (ρs = 0.67 to 0.78). The tasks generally showed small correlations with each other (ρs = ±0.06 to 0.19) and with UPPS-P subscales (ρs = ±0.01 to 0.20).Discussion and conclusionsThe behavioral tasks demonstrated good divergent validity. Correlation magnitudes between behavioral tasks and UPPS-P scales and mean scores on these measures were generally consistent with the existing literature. Behavioral tasks of impulsivity appear to have utility for use with problem and disordered gambling samples collected online, allowing researchers a cost efficient and rapid avenue for conducting behavioral research with gamblers. We conclude with best-practice recommendations for using behavioral tasks using crowdsourcing samples.

Reliability of triggering inhibitory process is a better predictor of impulsivity than SSRT

The ability to control behaviour is thought to rely at least partly on adequately suppressing impulsive responses to external stimuli. However, the evidence for a relationship between response inhibition ability and impulse control is weak and inconsistent. This study investigates the relationship between response inhibition and both self-report and behavioural measures of impulsivity as well as engagement in risky behaviours in a large community sample (N = 174) of healthy adolescents and young adults (15–35 years). Using a stop-signal paradigm with a number parity go task, we implemented a novel hierarchical Bayesian model of response inhibition that estimates stop-signal reaction time (SSRT) as a distribution and also accounts for failures to react to the stop-signal (i.e., “trigger failure”), and failure to react to the choice stimulus (i.e., “go failure” or omission errors). In line with previous studies, the model reduced estimates of SSRT by approximately 100 ms compared with traditional non-parametric SSRT estimation techniques. We found significant relationships between behavioural and self-report measures of impulsivity and traditionally estimated SSRT, that did not hold for the model-based SSRT estimates. Instead, behavioural impulsivity measures were correlated with rate of trigger failure. The relationship between trigger failure and impulsivity suggests that the former may index a higher order inhibition process, whereas SSRT may index a more automatic inhibition process. We suggest that the existence of distinct response inhibition processes that may be associated with different levels of cognitive control.

What Predicts What? Self-Reported and Behavioral Impulsivity and High-Risk Patterns of Alcohol Use in Spanish Early Adolescents: A 2-Year Longitudinal Study.

The directionality of the relationship between impulsivity and heavy drinking patterns remains unclear. Recent research suggests it could be reciprocal and depends on different facets of impulsivity and different patterns of drinking. The aim of this study was to analyze this potential reciprocal relationship between self-reported and behavioral measures of impulsivity and sensation seeking with specific patterns of heavy drinking in a sample of Spanish adolescents across 2years. The study has a cross-lagged prospective design in which participants were evaluated 3 times over 2years (once a year). Participants were 1,430 adolescents (53.9% male; mean age at study commencement=13.02, SD=0.51) from 22 secondary schools in Spain. Computerized versions of the following instruments were used: 2 subscales of Impulsive Sensation Seeking, 2 behavioral measures (Stroop Test and Delay Discounting [DD] task), frequency of intoxication episodes (IE), and the Rutgers Alcohol Problem Index to evaluate alcohol-related problems (ARP). Random intercepts cross-lagged panel models of reciprocal relationships between impulsivity measures and alcohol use outcomes were used. Individual levels of self-reported impulsivity and sensation seeking significantly predicted prospective involvement in IE and ARP. Performance in behavioral measures (Stroop Test and DD) did not predict subsequent heavy drinking or alcohol problems. No measure of drinking was found to be a significant predictor of prospective changes in impulsivity. Within-person levels of self-reported impulsivity and sensation seeking significantly predicted further heavy drinking from as early as 13years old, whereas behavioral measures were not predictive. In our study, neither IE nor ARP predicted prospective changes in impulsivity. Further studies should address additional specific relationships between facets of impulsivity and specific outcomes of heavy drinking.

Methodological factors as a potential source of discordance between self-report and behavioral measures of impulsivity and related constructs

There is a consistent but poorly understood finding that self-report and behavioral measures of impulsivity are weakly correlated or uncorrelated. There are many possible explanations for this observation, including differences in how these instruments are administered and scored. The present study examined the utility of alternative scoring algorithms for self-report measures that aim to identify participants' peak impulsivity (or self-control), informed by estimates of item difficulty from Item Response Theory (IRT) analyses. College students were administered self-report questionnaires (Zuckerman Sensation Seeking Scale [ZSS], Barratt Impulsiveness Scale [BIS-11], behavioral measures related to risk-taking and impulsivity (Balloon Analog Risk Task [BART], Experiential Discounting Task [EDT]), and the substance use module of a clinical interview (past-six-month alcohol and marijuana use). IRT analyses were conducted on self-report measures to estimate item difficulty. Scoring algorithms ranked items by difficulty and scored items based on consecutive items endorsed or denied. A maximal scoring algorithm increased the concordance between the BIS-11 and BART (r = 0.08 vs. −0.07), but there was no evidence of increased incremental validity for substance-use. Findings suggest that methodological factors may help explain the poor concordance of self-report and behavioral measures of impulsivity, but the magnitude of these correlations remained quite small. Further, alternative scoring algorithms were correlated with substance use but did not explain any variance that was distinct from typical algorithms. Future directions are discussed for elucidating the discrepancy between self-report and behavioral measures of impulsivity-related constructs, such as using large self-report item pools to develop computer adaptive tests.

The relationship between impulsivity and methamphetamine use severity in a community sample

BackgroundAbuse of psychostimulants, including methamphetamine (MA), has been linked to heightened impulsivity. While previous research has demonstrated differences in impulsivity between MA users and non-substance users, less is known about variability in impulsivity within MA users and whether the severity of MA use related problems predicts impulsivity within individuals who regularly use MA. This study aims to elucidate the relationship between impulsivity and MA use severity. MethodNon-treatment seeking individuals who reported regular MA use (n = 177) completed an impulsivity battery comprising self-report and behavioral measures. A structural equation modeling (SEM) approach was used to test the relationship between the MA use related problem severity and measures of impulsivity. ResultsThe final SEM model of impulsivity and MA use related problems (CFI = 0.897, RMSEA = 0.059, S-B scaled χ2 [260,n = 103] = 406.86) revealed that greater MA use severity was associated with greater self-reported impulsiveness, but no relationship was found between MA use severity and behavioral measures of impulsivity. ConclusionsThe current findings extend previous research by providing additional evidence that MA use is associated with increased self-reported impulsivity and highlights the importance of evaluating impulsivity as a multidimensional construct.

Excitatory repetitive transcranial magnetic stimulation applied to the right inferior frontal gyrus has no effect on motor or cognitive impulsivity in healthy adults

BackgroundImpulsivity is a multi-faceted concept. It is a crucial feature of many neuropsychiatric disorders. Three subtypes of impulsivity have been identified: motor, temporal, and cognitive impulsivity. Existing evidence suggests that the right inferior frontal gyrus (rIFG) plays a crucial role in impulsivity, and such a role has been elucidated using inhibitory repetitive transcranial magnetic stimulation (rTMS). There is a dearth of studies using excitatory rTMS at the rIFG, an important gap in the literature this study aimed to address. MethodsTwenty healthy male adults completed a single-blind sham-controlled randomised crossover study aimed at assessing the efficacy of rTMS in the neuromodulation of impulsivity. This involved delivering 10-Hz excitatory rTMS to the rIFG at the intensity of 100% motor threshold with 900 pulses per session. Trait impulsivity was measured at baseline using the Barrett Impulsiveness Scale and UPPS-P Impulsiveness Scale. The Stop Signal Task (SST) and Information Sampling Task (IST), administered before and after rTMS sessions, were used as behavioural measures of impulsivity. ResultsNo significant changes on any measures from either SST or IST after active rTMS at the rIFG compared to the sham-controlled condition were found. ConclusionsExcitatory rTMS applied to the rIFG did not have a statistically significant effect on response inhibition and reflective/cognitive impulsivity. Further research is required before drawing firm conclusions. This may involve a larger sample of highly impulsive individuals, a different stimulation site or a different TMS modality such as theta burst stimulation.

Grandiose narcissism versus vulnerable narcissism and impulsivity

Correlations between the grandiose narcissism and vulnerable narcissism with two self-report personality measures (i.e., BIS-11 and I7) and two behavioral tasks (i.e., Stop-Signal Task and Delay-Discounting task) of impulsivity in 338 students were examined. As one of the first studies to apply a two-dimensional approach to narcissism (i.e. grandiose narcissism and vulnerable narcissism) in different self-report and behavioral impulsivity measures, the present results have reported that both grandiose and vulnerable narcissism showed a significant positive correlations with the self-reported impulsivity. Moreover, the grandiose narcissism has shown significant associations with both behavioral tasks of impulsivity. Contrary, vulnerable narcissism was negatively related to the stop reaction time – people high in vulnerable narcissism scored shorter stop reaction time values and, consequently, presented less impulsive responding.

Relationship between measures of impulsivity in opioid-dependent individuals

BackgroundImpulsivity is implicated as a contributing factor to ongoing heroin use. This study aimed to determine the inter-relatedness of a battery of self-reported and performance-based behavioural measures of impulsivity in opioid-dependent individuals. MethodsSeventy-two participants on opioid substitution pharmacotherapy completed a battery of impulsivity measures. We analysed the correlations and factor structure of the impulsivity tasks. ResultsWe observed correlations between self-report measures, but self-report measures were unrelated to the performance-based tasks. For the performance-based tasks, correlations were only observed between outcome measures of the same task, and between outcome measures of the impulsive decision-making tasks. Principal components analysis revealed five components that we labelled self-reported impulsivity, impulsive decision-making with learning, impulsive decision-making without learning, sensitivity index, and responding without consideration of consequences. DiscussionThis study reinforces the distinction between multiple facets of impulsivity. This may assist with comparisons between studies that use different measures of impulsivity, and to design improved treatment interventions that target specific aspects of impulsivity.

Increased reward-oriented impulsivity in older bipolar patients: A preliminary study

ObjectiveImpulsivity is a well-established trait of bipolar disorder (BD) that persists across mood phases. It is, however, still unknown whether, in BD, impulsivity remains stable or varies in intensity over the lifespan. This cross-sectional study compared impulsive behavior in older euthymic BD patients and healthy individuals using a range of self-rating and behavioral measures of impulsivity. Methods28 BD patients (56.07 ± 4.08 years, 16 women) and 15 healthy controls (HC; 55.1 ± 3.95 years, 6 women) were administered the Barratt Impulsivity Scale (BIS) and selected tasks of the Cambridge Neuropsychological Test Automated Batter (CANTAB) reflecting impulsivity. Multivariate analysis of variance controlled for age compared impulsivity measures across BD and HC. ResultsBD patients displayed poor decision making, risk taking, and increased delay aversion. Other measures of impulsivity such as response inhibition, sustained cognitive control, and BIS scores were, overall, comparable between BD and HC. ConclusionsThese preliminary findings suggest that, in BD, aspects of impulsivity related to reward-based decision making persist into late adulthood. Large scale, longitudinal studies are needed to evaluate the relationship of age to impulsivity over time, and explore the link between impulsivity and illness progression in elderly individuals with BD.

Delay Discounting and Probability Discounting, But Not Response Inhibition, Are Associated With Sexual Risk Taking in Adults

Sexual risk behavior (SRB) is associated with impulsivity, but it is not clear whether different aspects of impulsivity are uniquely related to SRBs in adults. Unmarried adults ages 18 to 30 (N = 296; 41.0% male) recruited from the community reported their frequency of SRBs over the past six months using the Sexual Risk Survey (SRS; Turchik & Garske, 2009) and completed three behavioral measures of impulsivity: insensitivity to delayed consequences (delay discounting [DD]), insensitivity to probabilistic consequences (probability discounting [PD]) and response inhibition (stop signal task [SST]). SRS total scores were significantly related to both DD and PD but not SST. These findings suggest that insensitivity to delayed and probabilistic consequences, but not response inhibition, are meaningfully associated with SRBs in young adults. This may be important for the development of strategies to prevent or reduce sexual risk behaviors.

Social rejection magnifies impulsive behavior among individuals with greater negative urgency: An experimental test of urgency theory.

Impulsivity is a multifaceted trait with substantial implications for human well-being. One facet of impulsivity is negative urgency, the tendency to act impulsively in response to negative affect. Correlational evidence suggests that negative affect magnifies impulsive behavior among individuals with greater negative urgency, yet causal evidence for this core pillar of urgency theory is lacking. To fill this gap in the literature, participants (N = 363) were randomly assigned to experience social rejection (a situation shown to induce negative affect) or acceptance. Participants then reported their subjective negative affect, completed a behavioral measure of impulsivity, and reported their negative urgency. Among individuals with relatively high and average negative urgency, social rejection increased their impulsive behavior through greater experiences of negative affect. These indirect effects were not observed among individuals relatively low in negative urgency. These findings suggest that negative urgency exists at the nexus of urgent dispositions and situations that elicit negative affect, which offers novel support for urgency theory. (PsycINFO Database Record

Expectancy of impairment attenuates marijuana-induced risk taking

BackgroundMarijuana use has been associated with increased risk-taking and impulsive behavior. While pharmacologic effects of marijuana can lead to inhibitory impairment, expectancy of potential impairment may result in compensatory behavioral response by decreasing impulsive decisions and risky behaviors. With the increases in marijuana use and related problems, a better understanding of the individual characteristics associated with marijuana intoxication and risky behavior is needed. This study examined the role of impairment expectancies in marijuana's acute effects on behavioral measures of impulsivity and risk-taking. MethodsParticipants (N=136) were regular marijuana users. A balanced placebo design (BPD) was used crossing marijuana administration (i.e., 0% Tetrahydrocannabinol (THC) vs. 2.8% THC) with stimulus expectancy (i.e., Told Placebo vs. Told THC). Marijuana outcome expectancies were measured by self-report and dependent measures included a number of behavioral impulsivity tasks and the balloon analogue risk task (BART). ResultsAmong participants who received THC, higher expectancies for cognitive-behavioral impairment (CBI) were related to lower risk-taking on the BART. Among those who received placebo, there was no association between CBI expectancies and BART performance. CBI expectancies did not moderate the stimulus expectancy effect on the BART nor drug or stimulus expectancy effects on impulsivity measures. ConclusionsResults provide initial evidence that expectancies of greater impairment are associated with compensatory behavior on a risk-taking task under acute marijuana intoxication. Future studies should examine the role of impairment expectancies on risk behaviors of substantial public health concern, such as driving while under the influence of marijuana.

Are self-rated and behavioural measures of impulsivity in bipolar disorder mainly related to comorbid substance use problems?

ABSTRACTIntroduction: Impulsivity is a multidimensional feature observed in bipolar disorder (BD) and substance use disorder (SUD). We previously found a relationship between SUD and risk taking in BD. It is still unclear whether self-rated and behavioral impulsivity measures differ between BD with and without comorbid SUD, or are specific to BD.Methods: 93 adults with BD with comorbid SUD, 91 BD without SUD, and 93 healthy controls (HC) were administered the Barratt Impulsivity Scale (BIS), the Behavioral Inhibition/Behavioral Activation System Scale (BIS/BAS), and the Cambridge Neuropsychological Test Automated Battery. Analyses compared impulsivity measures across groups controlling for age. Discriminant function analyses (DFA) assessed the combination of variables effectively predicting group membership.Results: BD displayed increased BIS, BIS/BAS scores, reduced performance on the Cambridge Gambling and Rapid Visual Processing, and Affective Go/No-Go tasks compared to HC. Comparisons between BD with and without SUD showed increased BIS Motor impulsiveness. The overall predictive power of DFA was weak.Conclusions: Some facets of impulsivity are a core trait of BD and are partially independent from the presence of SUD. Motor impulsiveness may be distinctive of BD+SUD. More research is needed to understand the role of impulsive behaviors as risk factors for relapse in SUD.

Effects of Serotonin Transporter Gene Variation on Impulsivity Mediated by Default Mode Network: A Family Study of Depression.

Serotonergic neurotransmission, potentially through effects on the brain's default mode network (DMN), may regulate aspects of attention including impulse control. Indeed, genetic variants of the serotonin transporter (5-HTT) have been implicated in impulsivity and related psychopathology. Yet it remains unclear the mechanism by which the 5-HTT genetic variants contribute to individual variability in impulse control. Here, we tested whether DMN connectivity mediates an association between the 5-HTT genetic variants and impulsivity. Participants (N = 92) were from a family cohort study of depression in which we have previously shown a broad distribution of 5-HTT variants. We genotyped for 5-HTTLPR and rs25531 (stratified by transcriptional efficiency: 8 low/low, 53 low/high, and 31 high/high), estimated DMN structural connectivity using diffusion probabilistic tractography, and assessed behavioral measures of impulsivity (from 12 low/low, 48 low/high, and 31 high/high) using the Continuous Performance Task. We found that low transcriptional efficiency genotypes were associated with decreased connection strength between the posterior DMN and the superior frontal gyrus (SFG). Path modeling demonstrated that decreased DMN-SFG connectivity mediated the association between low-efficiency genotypes and increased impulsivity. Taken together, this study suggests a gene-brain-behavior pathway that perhaps underlies the role of the serotonergic neuromodulation in impulse control.

Self-report and behavioural measures of impulsivity as predictors of impulsive behaviour and psychopathology in male prisoners

Impulsivity is an important factor in adverse outcomes such as substance use, problem gambling and psychopathology. Extensive research has shown these negative outcomes are associated with both self-report and behavioural measures of impulsivity but these two measurement domains are not themselves associated. There has been limited research in prison samples. This is surprising given the high variability in impulsive behaviours that should make them ideal for investigating the convergence of impulsivity measures. Using a cross sectional design we investigated the associations of impulsivity – measured by self-report and two behavioural indices - with substance misuse and psychopathology in a sample of 72 male prisoners. We found higher self-reported impulsivity was associated with crack/cocaine use, problem gambling and a positive screen for personality disorder. Behavioural measures of impulsivity showed fewer associations with problematic behaviours; they were also not independent predictors of impulsive behaviour in multivariate analyses. These data suggest that self-reported impulsivity is a more consistent predictor of problematic behaviours than behavioural measures in a sample of people with significant levels of substance use and psychopathology. This difference could reflect relevance of self-reported measures to emotionally charged decision-making in daily life compared to more neutral behavioural measures.

Texting while driving, executive function, and impulsivity in college students

The purpose of the present study was to investigate the cognitive processes underlying texting while driving. A sample of 120 college students completed a survey to assess how frequently they send and read a text message while driving. Based on this information, students were assigned to one of two groups: 20 students who frequently text while driving and 20 matched-control students who infrequently text while driving but were similar in gender, age, years of education, and years driving. The groups were compared on the extent to which they differed in self-reported measures of executive function and impulsivity. The groups were also compared on a behavioral measure of impulsivity: the extent to which they discounted hypothetical monetary rewards as a function of the delay. For this measure, the students made repeated choices between smaller monetary rewards available immediately and larger rewards available after delays ranging from 1 week to 6 months. The results show that the group of students who frequently text while driving showed (a) significantly lower levels of executive function and (b) higher levels of self-reported impulsivity, although the groups did not differ significantly on the behavioral measure of impulsivity. These results support a general conclusion that drivers with lower levels of executive function and higher levels of impulsivity are more likely to text while driving.

Impulsivity predicts weight loss after obesity surgery

ObjectiveThere is evidence that executive function, and specifically inhibitory control, is related to obesity and eating behavior. The goal of this study was to determine whether personality traits and inhibitory control predict weight loss after bariatric procedures. Although the impressive weight reduction after bariatric surgery has been shown in short- and medium-term studies, the effect of personality traits on this reduction is uncertain. Specifically, the effect of impulsivity is still largely unknown. SettingPatients attending either a multidisciplinary information session or outpatient clinic at the Imperial Weight Management Centre were recruited with informed consent into the trial over a 4-month period from January to April 2013. Participants were invited to attend behavioral testing on an outpatient basis in a silent room invigilated by a single researcher. MethodsForty-five bariatric patients participated in the study (25 patients had a gastric bypass, with a mean BMI of 41.8 and age of 39.0 years; 20 had a sleeve gastrectomy, with a mean BMI of 47.2 and age of 49.0 years). All patients completed personality measures of impulsivity—Barratt’s Impulsivity Scale, as well as behavioral measures of impulsivity—the stop-signal reaction-time (SSRT) task measuring inhibitory control and the temporal discounting task measuring reward processing. Those measures were examined in relation to weight loss 6 months after surgery. ResultsThe surgical procedure and changes in the behavioral measure of inhibitory control (SSRT) were found to be significant predictors of reduction in body mass index (BMI) in patients undergoing bariatric surgery. The sleeve gastrectomy group found a reduction in BMI of 14.1%, which was significantly less than the 25% reduction in BMI in the gastric bypass group. The direction (parameter estimate) of the significant effect was positive for SSRT change, which indicates that pre- and postreduction in impulsivity predicts reduction in BMI. ConclusionImpulsivity measures predict weight reduction in patients undergoing bariatric surgery. This result has implications for predicting outcomes from surgical treatments of obesity.

Genetic and Modeling Approaches Reveal Distinct Components of Impulsive Behavior.

Impulsivity is an endophenotype found in many psychiatric disorders including substance use disorders, pathological gambling, and attention deficit hyperactivity disorder. Two behavioral features often considered in impulsive behavior are behavioral inhibition (impulsive action) and delayed gratification (impulsive choice). However, the extent to which these behavioral constructs represent distinct facets of behavior with discrete biological bases is unclear. To test the hypothesis that impulsive action and impulsive choice represent statistically independent behavioral constructs in mice, we collected behavioral measures of impulsivity in a single cohort of mice using well-validated operant behavioral paradigms. Mice with manipulation of serotonin 1B receptor (5-HT1BR) expression were included as a model of disordered impulsivity. A factor analysis was used to characterize correlations between the measures of impulsivity and to identify covariates. Using two approaches, we dissociated impulsive action from impulsive choice. First, the absence of 5-HT1BRs caused increased impulsive action, but not impulsive choice. Second, based on an exploratory factor analysis, a two-factor model described the data well, with measures of impulsive action and choice separating into two independent factors. A multiple-indicator multiple-causes analysis showed that 5-HT1BR expression and sex were significant covariates of impulsivity. Males displayed increased impulsivity in both dimensions, whereas 5-HT1BR expression was a predictor of increased impulsive action only. These data support the conclusion that impulsive action and impulsive choice are distinct behavioral phenotypes with dissociable biological influences that can be modeled in mice. Our work may help inform better classification, diagnosis, and treatment of psychiatric disorders, which present with disordered impulsivity.

26. Relationship between impulsivity traits and awareness of motor intention

Deficient voluntary control of behaviour and impulsivity are key aspects of impulse control disorders. The objective of the present study was to evaluate the relationship between behavioural measures of impulsivity and awareness of voluntary action. Seventy-four healthy volunteers completed the Barratt Impulsiveness Scale (BIS), a questionnaire used to measure impulsive personality traits, and a go/no-go task. Moreover, all participants performed a task in which, using the Libet’s clock, they were requested to report the time of a self-initiated movement (M-judgment) or the time they first felt intention to move (W-judgment). A positive relationship between W-judgment and impulsivity measures emerged. Namely, high scores in the attentional and motor impulsivity subscales of BIS and in the number of inhibitory failure responses in the go/no-go task, were related to a low difference between the W-judgment and the actual movement (i.e. the awareness of intention to move was closer to the voluntary movement execution). In contrast no relationship emerged with M-judgment. Findings suggest that impulsivity may be related to a delayed awareness of voluntary action. We hypothesize that in impulse control disorders the interval between conscious intention and actual movement could be insufficient to allow a conscious ‘veto’ of the impending action.