Interval timing predicts impulsivity in intertemporal choice: combined behavioral and drift-diffusion model evidence

ABSTRACT

This study investigated the relationship between interval timing and impulsivity in intertemporal choice in a healthy population. A duration production task was used to assess interval timing. Choice impulsivity was assessed using a hypothetical money choice task. Results from 134 participants indicated that faster internal clock significantly predicted lower choice impulsivity. A subsequent drift-diffusion model analysis of the behavioural data revealed that in the sub-group of relatively farsighted participants, faster internal clock predicted consideration of more information before making a choice, which in turn was associated with lower choice impulsivity. In the sub-group of relatively impatient participants too, faster internal clock predicted consideration of more information, but which in turn was associated with higher choice impulsivity. It is concluded that among relatively farsighted individuals in a normal population, faster internal clock favours a more deliberate processing of the options at hand, thus eliciting less impulsive choices.     

The role of impulsivity in the Dark Triad of personality

Among the Dark Triad of personality, both narcissism and psychopathy have been linked to impulsivity. What remains unclear is the pattern of associations that the Dark Triad have with functional and dysfunctional types of impulsivity. Using both student (N = 142) and adult samples (N = 329), we investigated the association of the Dark Triad variables with Dickman’s measures of functional and dysfunctional impulsivity. Based on regression analyses, psychopathy was most closely associated with dysfunctional impulsivity whereas narcissism was associated with functional impulsivity. It appears that narcissistic impulsivity involves venturesome social engagement whereas psychopathic impulsivity stems from poor self-regulation. As expected, Machiavellianism had no consistent association with either type of impulsivity. In short, the Dark Triad members show a coherent pattern of relations with impulsivity.     

Spanish adaptation of Dickman's impulsivity inventory: its relationship to Eysenck's personality questionnaire

We used exploratory factor analysis to determine the factorial structure of the Spanish adaptation of Dickman's impulsivity inventory in a sample of 355 university students. Our results showed the two impulsivity factors, functional and dysfunctional, described by Dickman (1990). We applied consensus direct oblimin rotation to the Spanish, American and Dutch versions of the inventory and obtained a high congruence between the three factorial solutions which seems to suggest that they are quite stable across languages and populations. Both kinds of impulsivity showed relationships to the extraversion and psychoticism dimensions of the EPQ-R although extraversion was more related to functional impulsivity and psychoticism was more related to dysfunctional impulsivity.     

Impulsivity and speed-accuracy tradeoffs in information processing

Despite its theoretical importance for such areas of research as reflection-impulsivity (Kagan, 1966), there is little evidence to support the assumption that individual differences in the personality trait of impulsivity are associated with differences in the willingness to sacrifice accuracy for speed of information processing. The present studies explored this association further. In Experiment 1, high, medium, and low impulsives (identified by self-report) performed a visual-comparison task under conditions differing in the monetary payoff for speed relative to accuracy. High impulsives were consistently faster and less accurate than other subjects. However, an analysis based on Sternberg's (1969) additive-factor method indicated that high impulsives performed at least one stage of information processing as slowly and accurately as other subjects. In Experiment 2, it was found that high impulsives were actually more accurate than low impulsives when all subjects were required to process information extremely rapidly. Experiment 3 identified the response execution stage as one that high impulsives carry out just as slowly and accurately as other individuals. The data from these experiments pose problems for a simple speed-accuracy tradeoff model of impulsive cognitive functioning.     

内侧前额皮层-伏隔核环路在决策冲动中的作用：基于动物模型的研究

注意缺陷多动障碍(attentiondeficit/hyperactivitydisorder,ADHD)行为控制不足与决策冲动密切相关,后者受内侧前额皮层(medial prefrontal cortex, mPFC)与伏隔核(nucleus accumbens, NAc)调节。为调查ADHD决策冲动与m PFC-NAc间功能耦合的关系,研究采用ADHD模型SHR (spontaneously hypertensive rat, SHR)大鼠,结合延迟折扣任务和在体电生理,研究发现,与对照Wistar (WIS)大鼠相比, SHR大鼠对延迟大奖赏的选择百分比降低; WIS大鼠m PFC-NAc的Theta频段相干值表现为延迟选择时显著大于立即选择时、首次选择时大于连续选择时、转换试次时大于连续试次时,而SHR大鼠在上述条件均低于WIS大鼠。回归分析发现m PFC-NAc的相干差值与延迟大奖赏选择率显著正相关。结果表明m PFC-NAc间功能联系减弱是ADHD决策冲动缺陷的重要环路基础,该缺陷与其深度信息加工以及策略转换能力受损有关,扩展了ADHD决策冲动的认知和神经机制的认识。     

Functional and dysfunctional impulsivity, depression, and suicidal ideation in a prison population

D. Lester (1993) was not able to show any association between dysfunctional impulsivity and suicidal ideation, but he did find a negative correlation between suicidal ideation and functional impulsivity. The correlation was weak and was not significant when depression was controlled for. Given the fact that college students were the participants in that study, the low correlations may have resulted from insufficient variance in the data. In the current study, data were collected from prisoners (half of whom had recently attempted suicide); correlations among the variables were stronger (but still quite low) than the correlations found in Lester's study. As expected, the association between dysfunctional impulsivity and suicidal ideation was stronger than that between functional impulsivity and suicidal ideation. However, consistent with Lester's study, these correlations were not significant when depression was controlled for. Results indicate that a direct association between impulsivity and suicidal ideation is unlikely.     

Psychometric adaption of the impulsive driver behavior scale in a Chinese sample

Impulsivity plays an important role in aberrant driving behavior and crash involvement. The purpose of this study was to evaluate the reliability and validity of the Impulsive Driver Behavior Scale (IDBS, Bıçaksız & Özkan, 2016a) with a Chinese sample. Two hundred and ninety-nine drivers completed the Chinese version of the Impulsive Driver Behavior Scale, the Driver Behavior Questionnaire, the Big Five Inventory and some social-demographic and traffic violation items. A confirmatory factor analysis indicated that a four-factor solution with 20 items yielded a better fit to the data than other solutions. The reduced IDBS showed good reliability and a stable structure. Drivers’ functional impulsivity was positively correlated with positive driver behavior and some ordinary violations. Meanwhile, the other three dimensions of dysfunctional impulsivity showed negative correlations with positive driver behavior and positive associations with aberrant driving behavior and penalty points and fines. Impulsive driver behavior is also associated with agreeableness and conscientiousness. These results provide evidence supporting the IDBS as a reliable and valuable instrument for measuring driving impulsivity in the Chinese traffic environment.     

Mental ability,P300, and mismatch negativity: Analysis of frequency and duration discrimination

Individual differences in mental ability (MA) were examined with event-related potentials (ERP). In addition to using an auditory frequency discrimination task, a duration discrimination task was used to elicit P300 and mismatch negativity (MMN) components of the ERP. Frequency and duration P300 latencies explained 9% and 10% of variance of MAB performance scores independently of each other and commonly 28% of variance. The finding that duration P300 latency explained variance of MA independent of that explained by frequency P300 latency, suggests that temporal information processing is partly dissociable from processing of frequency information in its prediction of MA. Duration and frequency MMNs were shown to be indices of discrimination ability and predicted 11% of variance of MAB performance scores. The outcome of the present study not only emphasizes the importance of both mental speed and discrimination ability for MA but also points to the significance of duration- and frequency-related ERP measures for the understanding of underlying brain mechanisms.     

Psychological refractory period in introverts and extraverts

The present study was designed to explore extraversion-related differences in the psychological refractory period (PRP). PRP refers to a bottleneck of information processing that becomes evident when participants are required to respond to two signals (S1 and S2) presented in rapid succession. If this capacity limit of premotor information processing is essential for differences in speed of information processing between introverts and extraverts, magnitude of the PRP effect should vary as a function of extraversion. Due to the failure of previous attempts to establish extraversion-related differences in the PRP effect, we also obtained lateralized readiness potentials (LRPs). For this purpose, 63 introverted and 63 extraverted female participants were tested with a standard PRP design. Extraverts responded faster to S2 and exhibited shorter stimulus-locked LRP latencies compared to introverts. Although a general PRP effect could be shown at the behavioral and psychophysiological level, there was no indication for any extraversion-related differences in PRP. Thus, extraversion-related differences in speed of information processing at the premotor level appear unlikely to originate from individual differences in the capacity limits underlying the PRP phenomenon. Furthermore, our findings provide converging evidence for the notion that extraversion-related individual differences in processing speed depend on specific task demands.     

A new approach to cerebral asymmetry: RT differences in simultaneous bimanual finger movement during verbal and nonverbal tasks

This study was aimed at testing a new approach for examination of functional laterality based on hemispheric specialization. The subjects had to perform verbal (words/nonwords) and nonverbal (similar/different patterns) discrimination. The separation of the two hemispheres during information processing was realized by requiring a simultaneous response of both index fingers. The obtained over-all reaction times (RT) were faster for verbal than for pattern tasks. Considering the RTs for solely the particular, faster response of one or the other index finger, the right index finger turned out to be faster on verbal tasks whereas the left one dominated on pattern tasks. According to the hypothesis that the faster hand indicates the more active (contralateral) hemisphere, it can be assumed that words are responded to more quickly when processed in the left hemisphere. On the other hand, patterns are responded to more quickly when the right hemisphere is active. These results suggest that each hemisphere may be capable of processing verbal and nonverbal material; the speed of information processing, however, is faster in the more adept one.     

The relationship between impulsivity and suicide among rural youths aged 15–35 years: a case–control psychological autopsy study

In China, the gender ratio of suicide rates did not match the Western patterns, which was higher for females than males. However, the rural men were at relatively high risk of suicide in Liaoning province. Impulsivity was an important factor of suicide behaviors, but there was a lack of studies in China. This research aimed to study the relationship between impulsive personality traits and suicidal behavior among Chinese rural youths. Suicides were consecutively sampled from six randomly selected counties in Liaoning Province in China. Between 2005 and 2007, a total of 162 suicide victims were enrolled in the study along with 162 community controls matched for age, gender, and location. The psychological autopsy method was used to collect data from informants knowledgeable about the selected suicide victims and controls. The results showed the suicide victims in the study were more likely to demonstrate dysfunctional impulsivity and less likely to demonstrate functional impulsivity compared with the controls. Mental disorders, acute negative life events, and dysfunctional impulsivity contributed to the risk of suicide; educational and functional impulsivity were protective factors. Suicide prevention efforts in rural China may address impulsivity.     

Sensorimotor Impairment of Speech and Hand Movement Timing Processing in Parkinson’s Disease

Models of motor control have highlighted the role of temporal predictive mechanisms in sensorimotor processing of speech and limb movement timing. We investigated how these mechanisms are affected in Parkinson’s disease (PD) while patients performed speech and hand motor reaction time tasks in response to sensory stimuli with predictable and unpredictable temporal dynamics. Results showed slower motor reaction times in PD vs. control in response to temporally predictable, but not unpredictable stimuli. This effect was driven by faster motor responses to predictable stimuli in control subjects; however, no such effect was observed in the PD group. These findings indicated the relationship between PD pathology and sensorimotor deficits in temporal predictive mechanisms of timing processing during speech production and hand movement.     

Personality traits associated with problematic and non-problematic massively multiplayer online role playing game use

This research investigated the associations between personality traits and both normal and problematic massively multiplayer online role playing game (MMORPGs) play, as measured by a self report scale. A total of 225 participants completed the online questionnaire, 66 of whom played MMORPGs. Correlational analyses indicated that low levels of functional impulsivity and agreeableness alongside high levels of verbal aggression and video game dependency were associated with greater amount of time spent playing MMORPGs. When comparing problematic and non-problematic MMORPG players directly, problematic players were found to be lower in self regulation, dysfunctional impulsivity and agreeableness, suggesting that these traits may be important in the development and maintenance of problematic MMORPG use.     

局部表象产生中行为性别差异的神经基础

行为研究发现女性具有更好的局部表象产生能力, 但其神经基础尚不清楚。研究采用事件相关电位技术以及小世界网络分析方法, 探索局部表象产生中性别差异的大脑信息加工基础。结果显示在局部表象产生中, 女性行为反应较男性更快, 表象产生诱发的P300-650平均波幅更小, 且大脑功能网络的平均路径长度更短。深入分析发现, 反应时与脑网络的平均路径长度之间成正相关。该结果意味着低耗高效的大脑信息加工模式是女性具有更好的局部表象能力的神经基础。     

Impulsivity, caffeine, and proofreading: a test of the Easterbrook hypothesis

Easterbrook's (1959) suggestion that arousal is inversely related to the range of cue utilization has been frequently cited as an explanation for the curvilinear relationship between arousal and performance. There is very little empirical support for this position, however. As a test of the Easterbrook hypothesis, 60 undergraduates who varied in their impulsivity level were given caffeine or placebo and then asked to proofread several passages. Estimates of sensitivity were calculated using signal detection techniques. It was predicted that high arousal would reduce sensitivity to interword errors, which require a broad range of cue utilization, but that the observed levels of arousal would not affect sensitivity to intraword errors, which require a minimal range of cue utilization. A significant crossover interaction between impulsivity and drug for interword errors indicated that caffeine increased the error detection rate of the (less aroused) more impulsive subjects but lowered the error detection rate of the (more aroused) less impulsive subjects. The results of this study support the suggestion that arousal has direct effects on the capacity for simultaneous information processing, independent of its effects on performance speed.     

Speed of processing of the visual-orthographic and auditory-phonological systems in adult dyslexics: the contribution of "asynchrony" to word recognition deficits

This study investigated whether "asynchrony" in speed of processing (SOP) between the visual-orthographic and auditory-phonological modalities contributes to word recognition deficits among adult dyslexics. Male university students with a history of diagnosed dyslexia were compared to age-matched normal readers on a variety of experimental measures while event-related potentials and reaction time data were collected. Measures were designed to evaluate auditory and visual processing for non-linguistic (tones and shapes) and linguistic (phonemes and graphemes) low-level stimuli as well as higher-level orthographic and phonological processing (in a lexical decision task). Data indicated that adult dyslexic readers had significantly slower reaction times and longer P300 latencies than control readers in most of the experimental tasks and delayed P200 latencies for the lexical decision task. Moreover, adult dyslexics revealed a systematic SOP gap in P300 latency between the auditory/phonological and visual/orthographic processing measures. Our data support and extend previous work that found SOP asynchrony to be an underlying factor of childhood dyslexia. The present data suggests, however, that among adult dyslexics the between modalities asynchrony occurs at later processing stages than in children.     

正念训练对冲动性不同要素的影响：基于双加工理论

正念是指对当下身心体验不带有评判地觉察。基于双加工理论,以正念为核心的训练对个体冲动性不同要素均具有明显干预效果。一方面,有助于降低因情感系统引发的冲动驱力：通过调整个体的奖赏评估与预期,缓和诱发冲动的压力与负性情绪反应,减弱自动化反应的联结和强度;另一方面,提升个体由认知控制系统调节的冲动控制力：增强个体的认知控制和行为抑制能力。由于冲动性驱动因素和控制因素二者加工时序的先后差异和作用方向对抗性特点,正念训练促进两类要素的积极交互影响,缩小冲动性“驱动”与“控制”力量之间的不平衡,为个体更好地回应自身反应与外界刺激提供了有利缓冲,是降低个体冲动性的有效干预手段。     

Evidence for mental ability related individual differences in the attentional blink obtained by an analysis of the P300 component

Attentional blink (AB) refers to impaired identification of a target (T2) when this target follows a preceding target (T1) after about 150-450 ms within a stream of rapidly presented stimuli. Previous research on a possible relation between AB and mental ability (MA) turned out to be highly ambiguous. The present study investigated MA-related individual differences in consolidation of T2 in working memory during the AB as indicated by the P300 component of the event-related potential. Thirty high (HA) and 30 low MA (LA) female participants performed an AB task while their brain activity was recorded. The AB did not differ between the two groups. HA individuals exhibited a larger P300 amplitude and longer P300 latencies during the AB suggesting higher mental effort. This higher mental effort, however, did not result in better performance presumably because of more competition between target and distractor stimuli in HA than LA individuals.     

A re-examination of the impact of object processing on shifts of spatial attention

When two targets are presented in rapid succession at the same spatial location, processing of the first is highly efficient, while processing of the second is often profoundly impaired at brief inter-target intervals (attentional blink; AB). While the AB has been shown to impact many processes, it is still unclear whether this includes the ability to shift spatial attention. The present study examined this question using a more sensitive dependent measure than past studies; namely, response times. It also evaluated whether masking of the cue stimulus modulated the effect of the AB on spatial shifts. The results showed significant cueing effects on T2 response times that were strongly modulated by the AB. This supports suggested links between mechanisms underlying object processing and spatial shifts of attention.     

Electrophysiological evidence reveals affective evaluation deficits early in stimulus processing in patients with panic disorder

Cognitive and neurobiological accounts of clinical anxiety and depression were examined via event-related brain potentials (ERPs) recorded from patients with panic disorder and healthy controls as they performed an old/new recognition memory task with emotionally negative and neutral words. The emotive connotation of words systematically influenced control subjects' - but not patients' - ERP effects at prefrontal sites in a latency range (to approximately 300-500 ms) generally assumed to reflect greater contribution of automatic than controlled memory processes. This provides evidence for dysfunctional inhibitory modulation of affective information processing in panic disorder. The ERP effects after 700 ms, however, suggest that some patients may adopt conscious strategies to minimize the impact of these early processing abnormalities on overt behaviors.