Single Key Impulsivity Paradigm Research Articles

Impulsivity in Multiplayer Online Battle Arena Gamers: Preliminary Results on Experimental and Self-Report Measures

Background and aimsMultiplayer Online Battle Arena (MOBA) games have become the most popular type of video games played worldwide, superseding the playing of Massively Multiplayer Online Role-Playing Games and First-Person Shooter games. However, empirical studies focusing on the use and abuse of MOBA games are still very limited, particularly regarding impulsivity, which is an indicator of addictive states but has not yet been explored in MOBA games. In this context, the objective of the present study is to explore the associations between impulsivity and symptoms of addictive use of MOBA games in a sample of highly involved League of Legends (LoL, currently the most popular MOBA game) gamers.MethodsThirty-six LoL gamers were recruited and completed both experimental (Single Key Impulsivity Paradigm) and self-reported impulsivity assessments (s-UPPS-P Impulsive Behavior Scale, Barratt Impulsiveness Scale), in addition to an assessment of problematic video game use (Problematic Online Gaming Questionnaire).ResultsResults showed links between impulsivity-related constructs and signs of excessive MOBA game involvement. Findings indicated that impaired ability to postpone rewards in an experimental laboratory task was strongly related to problematic patterns of MOBA game involvement. Although less consistent, several associations were also found between self-reported impulsivity traits and signs of excessive MOBA game involvement.ConclusionsDespite these results are preliminary and based upon a small (self-selected) sample, the present study highlights potential psychological factors related to the addictive use of MOBA games.

One Week of Naltrexone Treatment Does Not Reduce Impulsivity During Inpatient Treatment of Alcohol-dependent Patients

Objectives: The opioid receptor antagonist naltrexone (NTX) is widely used in alcohol dependence. The mechanism underlying NTX’s efficacy in reducing alcohol intake has yet to be determined. NTX may reduce impulsivity in alcohol-dependent patients. The current study was designed to examine the effect of NTX (50 mg/d) 7 d/wk treatment on impulsivity in NTX-treated alcoholics (NTA) compared with NTX-naive alcoholics (NNA) and healthy controls. Materials and Methods: The study included 17 NTA, 17 NNA, and 17 healthy control subjects. Impulsivity was assessed using Immediate Memory Task (IMT), The Single-Key Impulsivity Paradigm (SKIP), and Barratt Impulsiveness Scale (BIS-11). Results: NNA and NTA groups did not differ on IMT performance, SKIP performance, and BIS scores. As expected, alcohol-dependent subjects showed higher scores on the BIS and higher IMT ratios on the IMT compared with controls. SKIP performance did not differ between alcohol-dependent subjects and healthy controls. There were also significant correlations between the IMT performance and BIS scores. Conclusion: These results indicate that alcohol-dependent subjects were more impulsive, however, NTX does not seem to reduce alcohol intake by modulating impulsivity.

Effects of tryptophan depletion and a simulated alcohol binge on impulsivity.

Researchers have suggested binge drinkers experience disproportionate increases in impulsivity during the initial period of drinking, leading to a loss of control over further drinking, and that serotonergic mechanisms may underlie such effects. We examined the effects of a simulated alcohol binge and tryptophan depletion on 3 types of impulsivity-response initiation (immediate memory task [IMT]), response inhibition (GoStop task), and delay discounting (single key impulsivity paradigm [SKIP])-and tested whether observed effects were related to real-world binging. Adults (N = 179) with diverse drinking histories completed a within-subject crossover design over 4 experimental days. Each day, participants underwent 1 of 4 test conditions: tryptophan depletion/alcohol, tryptophan depletion/placebo, tryptophan-balanced control/alcohol, or tryptophan-balanced control/placebo. The simulated binge involved consuming 0.3 g/kg of alcohol at 5, 6, and 7 hr after consuming the tryptophan-depletion/balanced mixture. Impulsivity was measured before and after each drink. Relative to the placebo beverage condition, when alcohol was consumed, impulsive responding was increased at moderate and high levels of intoxication on the IMT and the GoStop but only at high levels of intoxication on the SKIP. Tryptophan depletion had no effect on impulsivity. Effects of alcohol and tryptophan manipulations on impulsivity were unrelated to patterns of binge drinking outside the laboratory. The effects of alcohol consumption on impulsivity depend on the component of impulsivity and the dose of alcohol consumed. Such effects do not appear to be a result of reduced serotonin synthesis. In addition, real-world binge drinking behaviors were unrelated to behavioral changes observed in the laboratory.

Reward sensitivity and anger in euthymic bipolar disorder

According to the hypersensitive behavioral approach system (BAS) model of bipolar disorder (BP), hypersensitivity of the BAS is a trait that should be present even in the euthymic state. This would be expected to result in increased anger and reward sensitivity, both of which are related to the approach system. This study examined these predictions through the use of tasks that assess different aspects of the BAS: reward sensitivity, anger and impulsivity. These characteristics were assessed using the probabilistic classification task (PCT), ultimatum game (UG) and single key impulsivity paradigm (SKIP), respectively. Participants were euthymic adult bipolar disorder patients (BP; N=40) and healthy controls (HC; N=41). In the UG, all participants showed the standard pattern of rejecting overtly unfair offers and accepting clearly fair offers; however, BPs rejected more of the moderately unfair offers than did HCs. BP and HC participants did not differ on their ability to learn, but did show different patterns of learning from reward and punishment. Learning for reward and punishment were negatively correlated in the BP group, suggesting that individuals could learn well either from reward or punishment, but not both. No correlation was found between these forms of learning in the HC group. BP patients show signs of their disorder even in the euthymic state, as seen by the dysbalance between reward and punishment learning and their residual anger in the UG.

Inhibitory Control Contributes to “Motor”- but not “Cognitive”- Impulsivity

Literature on impulsivity regularly claims inhibitory control deficits underlie impulsive behavior. The current study investigated whether taxing inhibitory control will increase reflection (decision making under conditions of uncertainty), temporal (delay of gratification), and motor impulsivity (behavioral disinhibition). Inhibitory control was challenged, via a random letter generation task presented during responding to three impulsivity measures: the Information Sampling Task (IST), Single Key Impulsivity Paradigm, and the Stop Signal Task (SST). Participants (n = 33) were assigned to the inhibitory control challenging (experimental) condition, or to a control condition in which inhibitory control was not challenged. The SST was affected by the inhibitory control challenge: participants in the experimental condition displayed increased motor impulsivity, evidenced in longer stop signal reaction times (SSRTs) compared to the control group. The manipulation did not affect reflection- or temporal- impulsivity measures. These data support the suggestion that the mechanisms underlying the motor subtype of impulsivity are dissociable from the temporal and reflection subtypes, and that engagement of inhibitory control is not necessary to prevent impulsive decision making.

Investigation of impulsivity in a sample of treatment-seeking pathological gamblers: A multidimensional perspective

Numerous studies have shown that problem gambling is characterised by lack of impulse control. However, they have often been conducted without considering the multifaceted nature of impulsivity and related psychological mechanisms. The current study aims to disentangle which impulsivity facets are altered in pathological gambling. Twenty treatment-seeking pathological gamblers (PGs) and 20 matched control participants completed a self-reported questionnaire measuring the various facets of impulsive behaviours (UPPS Impulsive Behaviour Scale), as well as two laboratory tasks assessing inhibitory control (the go-stop task) and tolerance for delayed rewards (single key impulsivity paradigm). Compared with matched controls, PGs exhibited higher urgency, lower premeditation, impairment in prepotent inhibition, and lower tolerance towards delayed rewards. Nevertheless, complementary profile analyses showed that impulsivity-related deficits found in PGs are highly heterogeneous, and that some PGs are neither impulsive in the impulsivity facets assessed nor impaired in the cognitive mechanisms measured. These findings underscore (1) the necessity to disentangle the construct of impulsivity into lower-order components and (2) that further studies should take into account, in addition to impulsivity-related mechanisms, other psychological factors potentially involved in pathological gambling.

Adults with a family history of alcohol related problems are more impulsive on measures of response initiation and response inhibition

Background Previous studies have found individuals with family histories of alcohol use disorders are more impulsive on some but not all laboratory behavioral measures, suggesting deficits on specific forms of impulse control. However, drawing conclusions is tenuous because these different measures have not been administered together in the same group of participants. Methods In the present study, we compared healthy 21–35 year old adults with family histories of alcohol related problems (FHAP+) or without such histories (FHAP−) on behavioral measures of response inhibition, response initiation, and consequence sensitivity impulsivity. FHAP+ ( n = 36) and FHAP− ( n = 36) participants were compared on performance on the Immediate Memory Task (IMT, response initiation), GoStop Impulsivity Paradigm (GoStop, response inhibition), Two Choice Impulsivity Paradigm (TCIP, consequence sensitivity) and Single Key Impulsivity Paradigm (SKIP, consequence sensitivity). Results FHAP+ individuals were more impulsive on the IMT and GoStop but not on the TCIP or SKIP. Conclusions These results suggest that response initiation and response inhibition impulsivity are increased in individuals with family histories of alcohol related problems despite not having alcohol or drug use disorders themselves. In contrast, increased consequence sensitivity impulsivity may be associated with additional risk factors such as more severe family histories of alcohol use disorders, or it may be increased as a consequence of heavy drug or alcohol use.

Trait impulsivity and response inhibition in antisocial personality disorder

Background Impulsive behavior is a prominent characteristic of antisocial personality disorder. Impulsivity is a complex construct, however, representing distinct domains of cognition and action. Leading models refer to impulsivity as an inability to evaluate a stimulus fully before responding to it (rapid-response impulsivity), and as an inability to delay responding despite a larger reward (reward-delay impulsivity). We investigated these models in terms of the diagnosis and severity of antisocial personality disorder. Methods Thirty-four male subjects on probation/parole who met DSM-IV criteria for ASPD, and 30 male healthy comparison subjects, matched by ethnicity, were recruited from the community. The Barratt Impulsiveness Scale (BIS-11) provided an integrated measure of trait impulsivity. Rapid-response impulsivity was assessed using the Immediate Memory Task (IMT), a continuous performance test. Reward delay impulsivity was assessed using the Two-choice Impulsivity Paradigm (TCIP), where subjects had the choice of smaller-sooner or larger-delayed rewards, and the Single Key Impulsivity Paradigm (SKIP), a free-operant responding task. Results Compared to controls, subjects with ASPD had higher BIS-11 scores (Effect Size (E.S.) = 0.95). They had slower reaction times to IMT commission errors (E.S. = 0.45). Correct detections, a measure of attention, were identical to controls. On the SKIP, they had a shorter maximum delay for reward (E.S. = 0.76), but this was not significant after correction for age and education. The groups did not differ on impulsive choices on the TCIP (E.S. < 0.1). On probit analysis with age and education as additional independent variables, BIS-11 score, IMT reaction time to a commission error, and IMT positive response bias contributed significantly to diagnosis of ASPD; SKIP delay for reward did not. Severity of ASPD, assessed by the number of ASPD symptoms endorsed on the SCID-II, correlated significantly with commission errors (impulsive responses) on the IMT, and with liberal IMT response bias. This relationship persisted with correction for age and education. Discussion These results suggest that ASPD is characterized by increased rapid-response impulsivity. Aspects of impulsivity related to reward-delay or attention appear relatively intact.

Severity of bipolar disorder is associated with impairment of response inhibition

Background: Pathological impulsivity in bipolar disorder could be related to deficiencies in mechanisms involved in attention or response inhibition. We investigated these mechanisms in subjects with bipolar disorder and examined relationships to severity of course of illness, use of medication, affective state, age, education, and gender. We measured two complementary aspects of response inhibition: attention-based and reward-based. Methods: Subjects with bipolar disorder ( n = 112) and healthy controls ( n = 71) were recruited from the community. Diagnoses were rendered using the SCID for DSMIV. Impulsivity-related measures included the Immediate Memory Task (IMT), a form of the Continuous Performance Task, and the Single Key Impulsivity Paradigm (SKIP), an operant procedure measuring ability to delay responding for a reward. Results: Subjects with bipolar disorder had fewer correct detections (Effect Size (ES) = 0.5), prolonged reaction times (ES = 0.88), and decreased discriminability (ES = 0.57) on the IMT compared to controls. History of frequent episodes, substance use disorders, or suicide attempts predicted faster reaction times, especially to a commission error. Subjects with bipolar disorder who also met criteria for an Axis II disorder had fewer correct detections, more commission errors relative to correct detections, and poorer discriminability on the IMT than other subjects with bipolar disorder. Subjects with bipolar disorder made more responses on the SKIP than did controls (ES = 0.5), with a shorter maximum delay (ES = 0.62), consistent with inability to delay reward. Probit analysis showed that faster reaction time to a commission error on the IMT was associated with history of substance use disorder, suicide attempt, or many previous episodes. Effects of medication or affective state did not account for these differences. Discussion: Bipolar disorder was associated with impairment in attention and response inhibition, encompassing impaired inhibition of rapid responses and an inability to delay reward, and resulting in impulsivity. Response inhibition mechanisms are impaired further in subjects with more severe complications of illness.

Multidimensional assessments of impulsivity in subjects with history of suicidal attempts

Objective This study aimed to examine whether subjects with history of suicidal attempts had higher impulsivity as measured by neurocognitive tests and self-report questionnaires. The interrelationships among different impulsivity measures were also explored. Methods Fifty-four nonpsychotic psychiatric inpatients, including 24 subjects with previous history of suicidal attempts and 30 comparison subjects without previous suicidal attempts, completed the self-report Barratt Impulsiveness Scale–11–Chinese version (BIS-11-CH) and 2 neuropsychologic tests of impulsivity: the immediate memory task/delayed memory task (IMT/DMT) and the single key impulsivity paradigm (SKIP). Results The results indicated that subjects with previous suicidal attempts exhibited higher BIS-11-CH factor 2 (lack of self-control/attentional impulsivity) subscore ( P = .02) and more commission errors in IMT ( P = .03). However, BIS-11-CH scores and performance indices of IMT/DMT and of SKIP did not correlate with each other. Conclusions Our findings supported that subjects with previous suicidal attempts had higher impulsivity, which could be revealed by both self-report and neurocognitive measures. However, there is no correlation among self-report, IMT/DMT, and SKIP measures, indicating that they might be measuring different dimensions of impulsivity.

Laboratory behavioral measures of impulsivity

Previous research and theory have conceptualized impulsivity as a multifaceted construct that requires multiple modes of measurement for accurate assessment. This article describes a software package that includes four paradigms for measuring multiple and unique aspects of impulsivity. Specifically, four tasks are described: (1) the two choice impulsivity paradigm, (2) the single key impulsivity paradigm, (3) the GoStop impulsivity paradigm, and (4) the time paradigm. These tasks measure processes related to the capacity to tolerate delay for reward, to inhibit an already initiated response, and to estimate the passage of time. These processes have been found to be important to the understanding of impulsive behaviors. The programs are flexible and allow the experimenter to manipulate a number of parameters related to delay-reward contingencies, timing, performance feedback/payment, and data output variables. Manipulation of these parameters makes the paradigms scalable to a wide range of ability levels and appropriate for samples ranging from children to adults. The four paradigms in this software package are available at no cost and can be obtained by contacting the corresponding author.

Laboratory Measures of Impulsivity: A Comparison of Women with or Without Childhood Aggression

This study compared laboratory models of impulsive behavior in 60 women ages 18–40. Three groups (n = 20, each) were recruited: (1) normal controls, (2) women on probation/parole without childhood aggression (Fight-), and (3) women on probation/parole with childhood aggression (Fight+). Two types of impulsivity paradigms were compared: response-disinhibition/attentional [Immediate/Delayed Memory Task (IMT/DMT)] and delayed-reward [Single Key Impulsivity Paradigm (SKIP)] models. The Fight+ group performed more impulsively, responding with more commission errors (IMT/DMT) and shorter delay choices (SKIP) compared to either the Fight- or Control groups. Compared to the SKIP, the IMT and DMT tasks had larger effect sizes and a more orderly pattern of impulsive performance differences between groups. Women classified on the basis of childhood behavior (initiating physical aggression) are behaviorally distinct on laboratory measures of impulsiveness in adulthood.

Comparisons of women with high and low trait impulsivity using behavioral models of response-disinhibition and reward-choice

Two types of behavioral models of impulsive behavior, response-disinhibition/attentional and reward-choice response models, were used to compare women grouped by high (Impulse+, n=43) and low (Impulse−, n=43) self-reported impulsive behavior on the Eysenck I 7 Questionnaire. Two of the four different tasks tested were response-disinhibition/attentional models; these included the Immediate and Delayed Memory Task and the GoStop Task. The other two tasks were based on the reward-choice model of impulsivity and included the Single Key Impulsivity Paradigm and the Two-Choice Reward Task. Of particular interest was whether commission errors (response-disinhibition/attentional paradigms) or a preference for smaller–sooner rewards over larger–later rewards (reward-choice) would differ between the groups. Participants completed one session of each task in a single day. The most significant findings were that the Impulse+ group had: (1) elevated commission errors; (2) lower stimulus discriminability (between target and catch stimuli); and (3) poorer response inhibition to a stop signal. Responding on the response-disinhibition/attentional tasks distinguished between the impulsivity groups while the reward-choice tasks did not. These results demonstrate that women who report higher levels of trait impulsivity respond in a manner consistent with previous studies examining impulsive behavior.