Impulsive Response Style Research Articles

Attending at a Low Intensity Increases Impulsivity in an Auditory Sustained Attention to Response Task.

Why attention lapses during prolonged tasks is debated, specifically whether errors are a consequence of under-arousal or exerted effort. To explore this, we investigated whether increased impulsivity is associated with effortful processing by modifying the demand of a task by presenting it at a quiet intensity. Here, we consider whether attending at low but detectable levels affects impulsivity in a population with intact hearing. A modification of the Sustained Attention to Response Task was used with auditory stimuli at two levels: the participants' personal "lowest detectable" level and a "normal speaking" level. At the quiet intensity, we found that more impulsive responses were made compared with listening at a normal speaking level. These errors were not due to a failure in discrimination. The findings suggest an increase in processing time for auditory stimuli at low levels that exceeds the time needed to interrupt a planned habitual motor response. This leads to a more impulsive and erroneous response style. These findings have important implications for understanding the nature of impulsivity in relation to effortful processing. They may explain why a high proportion of individuals with hearing loss are also diagnosed with Attention Deficit Hyperactivity Disorder.

Real‐time hostile attribution measurement and aggression in children

Hostile attributions are an important predictor of aggression in children, but few studies have measured hostile attributions as they occur in real-time. The current study uses an interactive video racing game to measure hostile attributions while children played against a presumed peer. A sample of 75 children, ages 10-13, used nonverbal and verbal procedures to respond to ambiguous provocation by their opponent. Hostile attributions were significantly positively related to parent-rated reactive aggression, when controlling for proactive aggression. Hostile attributions using a nonverbal response procedure were negatively related to proactive aggression, when controlling for reactive aggression. Results suggest hostile attributions in real-time occur quickly and simultaneously with social interaction, which differs from the deliberative, controlled appraisals measured with vignette-based instruments. The relation between real-time hostile attributions and reactive aggression could be accounted for by the impulsive response style that is characteristic of reactive aggression, whereas children exhibiting proactive aggression may be more deliberate and intentional in their responding, resulting in a negative relation with real-time hostile attributions. These findings can be used both to identify children at risk for aggression and to enhance preventive interventions.

Specificity of basic information processing and inhibitory control in attention deficit hyperactivity disorder

Both inhibitory-based executive functioning (IB-EF) and basic information processing (BIP) deficits are found in clinic-referred attention deficit hyperactivity disorder (ADHD) samples. However, it remains to be determined whether: (1) such deficits occur in non-referred samples of ADHD; (2) they are specific to ADHD; (3) the co-morbidity between ADHD and oppositional defiant disorder/conduct disorder (ODD/CD) has additive or interactive effects; and (4) IB-EF deficits are primary in ADHD or are due to BIP deficits. We assessed 704 subjects (age 6-12 years) from a non-referred sample using the Development and Well-Being Assessment (DAWBA) and classified them into five groups: typical developing controls (TDC; n = 378), Fear disorders (n = 90), Distress disorders (n = 57), ADHD (n = 100), ODD/CD (n = 40) and ADHD+ODD/CD (n = 39). We evaluated neurocognitive performance with a Two-Choice Reaction Time Task (2C-RT), a Conflict Control Task (CCT) and a Go/No-Go (GNG) task. We used a diffusion model (DM) to decompose BIP into processing efficiency, speed-accuracy trade-off and encoding/motor function along with variability parameters. Poorer processing efficiency was found to be specific to ADHD. Faster encoding/motor function differentiated ADHD from TDC and from fear/distress whereas a more cautious (not impulsive) response style differentiated ADHD from both TDC and ODD/CD. The co-morbidity between ADHD and ODD/CD reflected only additive effects. All ADHD-related IB-EF classical effects were fully moderated by deficits in BIP. Our findings challenge the IB-EF hypothesis for ADHD and underscore the importance of processing efficiency as the key specific mechanism for ADHD pathophysiology.

The effects of acute tryptophan depletion on impulsivity and mood in adolescents engaging in non‐suicidal self‐injury

Non-suicidal self-injury (NSSI) is associated with impaired emotion regulation and impulsivity. Low serotonin (5-hydroxytryptamine) function is associated with NSSI, impaired emotion regulation and impulsivity. We investigated the effects of experimentally lowered 5-hydroxytryptamine activity, via acute tryptophan depletion (ATD), on impulsive action, reflection impulsivity and mood in female adolescents engaging in NSSI. Thirty-two female adolescents engaging in NSSI participated in a parallel group ATD study. Following ATD, impulsive action was assessed using the Continuous Performance Test, Identical Pairs Version. Reflection impulsivity was assessed using the Matching Familiar Figures Test. Mood-lowering was examined using the Profile of Mood States. Following ATD, the participants showed an impulsive response style (as reflected in their low β) and increased attentional capacity (as reflected in their elevated d'). ATD did not affect reflection impulsivity or mood. Acute tryptophan depletion caused an impulsive response style and increased attentional capacity. Importantly, the findings suggest that low serotonin function is a vulnerability among female adolescents for engaging in NSSI when in emotional distress.

Punishment promotes response control deficits in obsessive-compulsive disorder: evidence from a motivational go/no-go task

Obsessive-compulsive disorder (OCD) has been associated with response inhibition deficits under motivationally neutral contingencies. We examined response inhibition performance in the presence of reward and punishment. We further investigated whether the hypothesized difficulties in flexibly updating behaviour based on external feedback in OCD would also lead to a reduced ability to adjust to changes in the reward and punishment contingencies. Participants completed a go/no-go task that used punishments or rewards to promote response activation or suppression. The task was administered to OCD patients free of current Axis-I co-morbidities including major depression (n = 20) and a group of healthy controls (n = 32). Compared with controls, patients with OCD had increased commission errors in punishment conditions, and failed to slow down immediately after receiving punishment. The punishment-induced increase in commission errors correlated with self-report measures of OCD symptom severity. Additionally, patients did not differ from controls in adapting their overall response style to the changes in task contingencies. Individuals with OCD showed reduced response control selectively under punishment conditions, manifesting in an impulsive response style that was related to their current symptom severity. This stresses failures of cognitive control in OCD, particularly under negative motivational contingencies.

The short (S) allele of the serotonin transporter polymorphism and acute tryptophan depletion both increase impulsivity in men

Reduced serotonergic neurotransmission is implicated in impulsive behavior. We studied the triallelic system of the serotonin transporter gene linked polymorphic region (5-HTTLPR) and acute manipulation of serotonin together to further delineate the mechanisms by which serotonergic neurotransmission affects impulsivity. Fifty-two healthy participants (38 men and 14 women) underwent acute tryptophan depletion (ATD) or placebo in a randomized, double-blind, parallel group experiment. Impulsive response style was measured on two versions of the Continuous Performance Task (CPT), and calculated using signal detection theory. We observed a dose-dependent effect for the short (S′) allele of the 5-HTTLPR on impulsive response style. Individuals who had the S′/S′ genotype were more impulsive than individuals with the L/S′ genotype. Participants with the L/S′ genotype were more impulsive than those with the L/L genotype. ATD increased impulsivity in men, and decreased impulsivity in women. These data demonstrate for the first time that reduced serotonergic tone as a result of either 5-HTTLPR genotype, or experimental ATD, are both independently and additively, associated with elevated impulsive response style in Caucasian men.

Impulsiveness and ERP components in a Go/Nogo task

Impulsiveness has been linked to fast guesses and premature responses in reaction time tasks like the Eriksen flanker task or the Go/Nogo task. In the present study, healthy subjects without history of DSM-IV Axis I or II psychopathology were examined. Impulsiveness was determined by calculating individual reaction times (as a function of general response speed) in order to split the entire group (n = 26) in a subgroup with a more controlled response style (low impulsiveness [LI] group; n = 13) and a subgroup with a more impulsive response style (high impulsiveness [HI] group; n = 13). Subjects performed a Go/Nogo task while a multi-channel EEG was recorded. Two event-related potentials (ERP) were of special interest: the Nogo-N2 and -P3 component. HI subjects had significantly reduced (less positive) Nogo-P3 amplitudes compared to LI subjects whereas groups did not differ with regard to the Nogo-N2. These results corroborate previous findings of reduced Nogo-P3 amplitudes in samples with enhanced levels of impulsiveness. Moreover, present data suggest that there is a broader range of impulsiveness even in healthy subjects which might mask or pronounce between-group differences in clinical studies. Therefore, different levels of impulsiveness in control groups should be carefully taken into account in further ERP studies.

Impulsive Responses In Children with Conduct Disorder and Borderline Intellectual Functioning

The study is designed to investigate response inhibition in children with conduct disorder and borderline intellectual functioning. To this end, children are compared to a normal peer control group using the Alertness test. The test has two conditions. In one condition, children are instructed to push a response button after a visual “go” signal is presented on the screen. In a second condition the “go” signal is preceded by an auditory signal, telling the child that a target stimulus will occur soon. Compared to the control group, the group carrying the dual diagnosis made many preliminary responses (responses before the presentation of the “go” signal), especially in the condition with an auditory signal. This impulsive response style was controlled for attention deficit/hyperactivity disorder characteristics of the children.

Interactive Effects of Sex and 5-HTTLPR on Mood and Impulsivity During Tryptophan Depletion in Healthy People

Serotonin (5-HT) plays a central role in mood regulation and impulsivity. We studied whether healthy men and women react differently on mood and impulsivity measures during acute tryptophan depletion (ATD). We also studied the relative contribution of a functional length triallelic polymorphism in the promoter region of the serotonin transporter, designated 5-HTTLPR, to the behavioral responses to ATD. Thirty-nine men and 44 women participated in a randomized, double-blind, parallel group ATD study. Behavioral measures of impulsivity and mood were obtained. During ATD, women reported mood reduction and showed a cautious response style, which is commonly associated with depression. Men showed an impulsive response style and did not report mood reduction. The 5-HTTLPR influenced the mood response to ATD in women. Healthy men became more impulsive, whereas healthy women showed mood reduction in response to ATD. This suggests that 5-HT could be one mechanism contributing to the sex differences in the prevalence of mood and impulsivity disorders. The influence of 5-HTTLPR on mood responses in women further substantiates the relevance of this variant in the pathophysiology of at least a subgroup of patients with major depressive disorder.

Developmental changes in error monitoring: An event-related potential study

The aim of the study was to investigate the developmental trajectory of error monitoring. For this purpose, children (age 7–8), young adolescents (age 13–14) and adults (age 23–24) performed a Go/No-Go task and were compared on overt reaction time (RT) performance and on event-related potentials (ERPs), thought to reflect error detection (error-related negativity: ERN) and conscious evaluation (error positivity: Pe) of the error. RT on correct trials, variability of responding and percentage of errors decreased with age. The latencies of incorrect responses, compared to correct responses, were shorter in children and adolescents than in adults, indicative of developmental changes in impulsive response style. Groups did not differ in the ability to adjust response strategies after making an error (post-error slowing). The ERN amplitude increased with age, the Pe amplitude did not change with age. Possible explanations for the developmental changes in ERN are discussed.

Neural mechanisms underlying trait impulsivity in non-clinical adults: Stop-signal performance and event-related potentials

Impaired inhibitory processing has been implicated in clinical expressions of impulsivity, but it is unknown whether the same deficit underlies the personality trait in healthy, non-clinical populations. The present study examined performance and event-related potentials (ERPs) during a stop-signal task in non-clinical adults who scored in the top (“Low” n = 20) and bottom 15% (“High” n = 20) on Eysenck's Impulsiveness Questionnaire from a sample of 200 subjects. The stop-signal task consisted of a visual choice-RT task and auditory stop-signals presented on 30% of trials. While performance findings revealed no differences between groups, underlying ERPs revealed a number of quantitative differences. Lateralised readiness potential (LRP) amplitude on stop-signal trials was larger in the High than Low group, indicating greater response side-specific motor preparation in the primary motor cortex (PMC), while an N1/P3 complex was evoked on successful stop-signal trials and was also enhanced in the High than Low group. The centrally-maximal successful-stop P3 has previously been implicated as an index of inhibition in the PMC, suggesting enhanced inhibitory processing in the High group. Together these findings indicate that the High impulsivity group was able to counteract an impulsive response style on stop-signal trials with enhanced inhibitory activation, resulting in comparable overt performance to the Low group. These results provide a unique insight into the neural mechanisms underlying trait impulsivity in non-clinical adults.

Neural correlates of impulsive responding in borderline personality disorder: ERP evidence for reduced action monitoring

Patients with borderline personality disorder (BPD) are characterized by marked impulsive behaviour. The impulsive response style of patients with BPD may be associated with diminished action monitoring, which can be investigated by measuring the error-related negativity (ERN). The ERN is an ERP component generated in the anterior cingulate cortex (ACC) following erroneous responses. Behavioural and ERP measurements were obtained during performance on a speeded two-choice reaction task in a group of patients with BPD ( N = 12) and in a group of age-matched controls ( N = 12). The ERP results showed that ERN amplitudes were reduced for patients with BPD, as were the P300 amplitudes after late feedback. The behavioural results confirmed a more impulsive response style for the BPD group, reflected in larger RT differences between correct and incorrect responses and in an increase in erroneous responses to the easy congruent stimuli. Additionally, analyses on post-error congruency effects demonstrated that controls adjusted their behaviour following errors, but patients with BPD did not. The attenuated ERNs indicate reduced action monitoring in patients with BPD. This suggests that the ACC, or the action-monitoring network it is part of, is not functioning optimally. Due to this reduced action monitoring, patients with BPD do not learn from their errors as well as controls. Consequently, they do not adjust their behaviour when necessary and thus maintain their impulsive response style.

Impulsivity in depressed children and adolescents: A comparison between behavioral and neuropsychological data

Impulsivity at the neuropsychological and behavioral levels was investigated in a sample of drug-naive depressed children and adolescents. The performance of 21 patients with a current diagnosis of mood disorder was compared with that of 21 normal controls on tests of executive functions related to impulsivity (Matching Familiar Figures Test, Continuous Performance Test, Verbal Fluency, Stroop Test, and Walk–Don't Walk) and on impulsive/restless behavior on the Conners' Parent Rating Scale. Depressed children and adolescents showed a pattern of conservative response style, with slow reaction times and attentional problems, similar to that observed in adults, and a general delay/difficulty in response initiation on the Fluency Test. Depressed participants were rated by their parents as being significantly more impulsive/restless than controls. However, there was no evidence of an impulsive cognitive response style in more impulsive/restless patients. Symptom severity (Hamilton Rating Scale for Depression) and subjective mood state (Children's Depression Inventory) were also taken into account.

Association of the dopamine D4 receptor gene 7-repeat allele with neuropsychological test performance of children with ADHD.

Association between attention deficit hyperactivity disorder (ADHD) and the 7-repeat allele of a variant (a 48 bp variable number of tandem repeats) in the dopamine D4 receptor gene (DRD4) has been widely documented. A meta-analysis of 21 studies revealed evidence of significant association. In this article the authors examine whether the DRD4 7-repeat allele is associated with performance on a variety of neuropsychological tasks in children with ADHD. The presence or absence of the 7-repeat allele was determined in 133 drug-naive children 6 to 13 years of age who fulfilled diagnostic criteria for ADHD. These children were then assessed on several neuropsychological tests known to be associated with attention, impulse control, and response inhibition (the Continuous Performance Test, Matching Familiar Figures Test, Go/No Go Task, and Stop Task). Activity levels were assessed with an actigraph. Children with and without at least one 7-repeat allele were compared with each other and with children in a previous population-based study. Children who had the 7-repeat allele had significantly more incorrect responses on the Matching Familiar Figures Test (16.1 versus 14.3) than children who did not have the allele. Children with the allele also had shorter mean reaction times for incorrect responses on the Matching Familiar Figures Test (846.1 versus 1103.7 msec) and on the Stop Task (116.6 versus 134.1 msec) than children without the allele. Children with the allele also displayed higher activity levels. The children with and without the allele did not differ significantly in number of ADHD symptoms when the symptoms were split into the areas of inattention and hyperactivity/impulsivity. Both groups of children with ADHD were more neuropsychologically impaired than the nonpatient comparison group. In children with ADHD, possession of the DRD4 7-repeat allele appears to be associated with an inaccurate, impulsive response style on neuropsychological tasks that is not explained by ADHD symptom severity.

Neurodevelopmental status at eight years in children with dextro-transposition of the great arteries: The Boston Circulatory Arrest Trial

Objectives Our goal was to determine which of the two major methods of vital organ support used in infant cardiac surgery, total circulatory arrest and low-flow cardiopulmonary bypass, results in better neurodevelopmental outcomes at school age. Methods In a single-center trial, infants with dextrotransposition of the great arteries underwent the arterial switch operation after random assignment to either total circulatory arrest or low-flow cardiopulmonary bypass. Developmental, neurologic, and speech outcomes were assessed at 8 years of age in 155 of 160 eligible children (97%). Results Treatment groups did not differ in terms of most outcomes, including neurologic status, Full-Scale or Performance IQ score, academic achievement, memory, problem solving, and visual-motor integration. Children assigned to total circulatory arrest performed worse on tests of motor function including manual dexterity with the nondominant hand ( P = .003), apraxia of speech ( P = .01), visual-motor tracking ( P = .01), and phonologic awareness ( P = .003). Assignment to low-flow cardiopulmonary bypass was associated with a more impulsive response style on a continuous performance test of vigilance ( P < .01) and worse behavior as rated by teachers ( P = .05). Although mean scores on most outcomes were within normal limits, neurodevelopmental status in the cohort as a whole was below expectation in many respects, including academic achievement, fine motor function, visual-spatial skills, working memory, hypothesis generating and testing, sustained attention, and higher-order language skills. Conclusions Use of total circulatory arrest to support vital organs during heart surgery in infancy is generally associated with greater functional deficits than is use of low-flow cardiopulmonary bypass, although both strategies are associated with increased risk of neurodevelopmental vulnerabilities.

Psychological Meaning of Profile Elevation in the Vocational Preference Inventory

Correlates of profile elevation and two differentiation indices in the Vocational Preference Inventory (VPI), Self-Directed Search, and related inventories are examined to clarify the meaning of elevated and low profiles. The traditional differentiation index is not independent of profile elevation. Other results imply that profile elevation is also related to indicators of a tendency to endorse items in the positive direction and to independent measures of positive, energetic, or impulsive response style. The correlations with independent criteria are usually weak. The possibility that counselors may over-interpret profile elevation in the VPI and related inventories is discussed.

Attention styles of hyperactive and normal girls.

Behavioral characteristics and cognitive skills of teacher-identified hyperactive (n = 24) and normally active (n = 24) first- and second-grade girls were investigated. Teachers rated subjects on the Conners Teacher Rating Scale (TRS). Subjects were given several tasks measuring attentional styles and motor skills. Results suggested that hyperactive girls, like hyperactive boys, have short attention spans and poor concentration when compared with normals. Unlike hyperactive boys, hyperactive girls did not show an impulsive response style, and presented few conduct problems to their teachers. TRS profile patterns of the hyperactive girls were similar to those of hyperactive boys, but cutoff scores currently used for males may not be applicable to females. A direct comparison of hyperactive females and males is advocated.

The Effects of Visual Discrimination Training on Reading Readiness Test Performance of Impulsive First Grade Boys

An impulsive conceptual tempo has been shown to be a factor affecting performance on some learning tasks. The purpose of this study was to determine if a visual discrimination treatment could alter the effects of an impulsive response style on performance on a readiness measure. Thirty-two impulsive first grade boys were randomly assigned to either an experimental or a control group. Experimental Ss received 20 days of visual discrimination training. Posttest scores on a readiness measure showed significant differences between experimental and control Ss. It was concluded that visual discrimination training could compensate for impulsive response style.