Inhibitory deficits and symptoms of attention-deficit hyperactivity disorder: How are they related to effortful control?

Separate studies with clinical and community-based samples have identified an association between symptoms of attention-deficit hyperactivity disorder (ADHD) and inhibitory control deficits and ADHD and weak effortful control. We tested whether differences in effortful control explained the associations between ADHD symptoms and inhibitory control deficits, controlling for conduct problems. In a community sample, parents rated ADHD symptoms, conduct problems, effortful control, surgency and negative affect in 77 4-7-year-olds (47 girls), who performed an inhibitory control task. ADHD symptoms, deficient inhibitory control and low effortful control were correlated. Controlling for conduct problems, path analysis showed the ADHD symptoms – inhibitory control link was mediated statistically by effortful control. This focuses attention on cognitive-energetic factors associated with ADHD-related executive deficits.     

Does comorbid attention-deficit/hyperactivity disorder impact the clinical expression of pediatric obsessive-compulsive disorder?

What is the impact of attention-deficit/hyperactivity disorder (ADHD) on the phenotypic expression of pediatric obsessive-compulsive disorder (OCD). We examined phenotypic features, and functional and clinical correlates in youths with OCD, with and without comorbid ADHD, from a large sample of consecutively referred pediatric psychiatry patients. Although comorbid ADHD had no meaningful impact on the phenotypic expression or clinical correlates of OCD, it was associated with higher rates of compromised educational functioning compared with other OCD youths. Our findings suggest that the OCD phenotype runs true and is not impacted by comorbid ADHD in youths diagnosed with both OCD and ADHD. In such affected youths, both disorders contribute to morbid dysfunction and require treatment. More work is needed to determine whether OCD plus ADHD represents a developmentally and etiologically distinct form of the OCD syndrome.     

Does attention-deficit/hyperactivity disorder have a dimensional latent structure? A taxometric analysis

An understanding of the latent structure of attention-deficit/hyperactivity disorder (ADHD) is essential for developing causal models of this disorder. Although some researchers have presumed that ADHD is dimensional and others have assumed that it is taxonic, there has been relatively little research directly examining the latent structure of ADHD. The authors conducted a set of taxometric analyses using data from the NICHD Study of Early Child Care and Youth Development (ns between 667 and 1,078). The results revealed a dimensional latent structure across a variety of different analyses and sets of indicators for inattention, hyperactivity/impulsivity, and ADHD. Furthermore, analyses of correlations with associated features indicated that dimensional models demonstrated stronger validity coefficients with these criterion measures than dichotomous models. These findings jibe with recent research on the genetic basis of ADHD and with contemporary models of ADHD.     

A multi-dimensional model of the origins of attitude certainty: teachers’ attitudes toward attention-deficit/hyperactivity disorder

This research tested and extended a laboratory-derived model of the origins of attitude certainty using a real attitude object: Teaching children with attention-deficit/hyperactivity disorder (ADHD). In Study 1, an experiment manipulated the amount of information, thought, and consistency of information delivered to pre-service teachers ( $n = 224$ ) with no prior experience with ADHD. Structural equation modelling (SEM) of Study 1 did not support the original model, in which relationships between attitude certainty and objective knowledge, thought, and consistency were mediated by perceived knowledge, thought, and ambivalence. Instead, objective amount of information, thought, and consistency interacted in their effect on attitude certainty. Study 2 ( $n = 368$ ) used a survey to test whether experiences with ADHD (personal, direct and indirect) among in-service and pre-service teachers were antecedents of attitude certainty, and to test perceived accessibility as a mediator. SEM supported both these hypotheses. Perceived accessibility and perceived knowledge mediated the relationship between attitude certainty and prior experiences with ADHD, and between attitude certainty and objective knowledge. Together, the results suggest that psychological processes underlying strong attitude certainty differ according to the familiarity and personal relevance of the attitude object, and the context and stage of attitude formation. The results have practical utility for teacher training at pre-service and in-service levels.     

Do boys with attention-deficit/hyperactivity disorder have positive illusory self-concepts?

One hundred ninety-five boys with attention-deficit/hyperactivity disorder (ADHD) were compared with 73 comparison boys (M = 9.83 years, SD = 1.30) on self-perceptions relative to a teacher-rated criterion. Emphasis was placed on ADHD subgroup comparisons according to level of aggression, academic achievement, and depression compared with control boys. Consistent with the authors' prediction, ADHD boys overestimated relative to teacher report, more than did controls, in the scholastic competence, social acceptance, and behavioral conduct domains. Examination of discrepancy scores (child rating - teacher rating) by comorbidity subgroups suggested that aggressive and low-achieving ADHD boys tended to overestimate their competence the most in the domains in which they were the most impaired. Results are discussed in terms of prior literature on "positive illusions" in ADHD children.     

Does response variability predict distractibility among adults with attention-deficit/hyperactivity disorder?

Increased intraindividual variability in response time (RTSD) has been observed reliably in attention-deficit/hyperactivity disorder (ADHD) and has often been used as a measure of inattention. RTSD is assumed to reflect attentional lapses and distractibility, though evidence for the validity of this connection is lacking. We assessed whether RTSD is an indicator of inattention by comparing RTSD on the stop-signal task (SST) with performance on the delayed oculomotor response (DOR) task, a measure of distractibility. Participants included 30 adults with ADHD and 28 controls. Participants completed the SST and the DOR task, which measured subjects' ability to maintain attention and avoid distraction by inhibiting reflexive saccades toward distractors. On the SST, the ADHD group was slower to inhibit than were controls, indicating poorer inhibitory control in ADHD. The ADHD group also displayed slower reaction times (RTs), greater RTSD, and more omission errors. On the DOR task, the ADHD group displayed more premature saccades (i.e., greater distractibility) than did controls. Greater variability in RT was associated with increased distraction on the DOR task, but only in ADHD participants. Results suggest that RTSD is linked to distractibility among adults with ADHD and support the use of RTSD as a valid measure of inattention in ADHD.     

Age-related changes in antisaccade task performance: inhibitory control or working-memory engagement?

In antisaccade tasks, subjects are required to generate a saccade in the direction opposite to the location of a sudden-onset target stimulus. Compared to young adults, older adults tend to make more reflex-like eye movements towards the target, and/or show longer saccadic onset latencies on correct direct antisaccades. To better understand the nature of these effects of aging on antisaccade performance, we examined the role of age-related deficiencies in inhibitory control vis-a-vis age changes in the engagement of working memory. Inhibitory demands were manipulated using fixation-offset conditions, while working-memory demands were manipulated by varying memory-updating requirements. The results indicate that inhibitory oculomotor functions remain largely intact with advancing age; older adults' performance breaks down only when their limited working-memory capacity is taxed by increasing updating demands.     

To do or not to do? Prospective memory versus response inhibition in autism spectrum disorder and attention-deficit/hyperactivity disorder

In the present research, event-based prospective memory and response inhibition (RI) abilities were investigated in children with ASD (Study 1), with ADHD (Study 2), and their matched neurotypical controls. Children engaged in a categorisation (ongoing) task and, concurrently, in either an event-based prospective memory (PM) or a Go/No-Go secondary task. Results showed that, as compared to their matched controls, ASD children's performance was more impaired in the PM task than in the Go/No-Go task, while the performance pattern of ADHD children was reversed. In the ongoing task, ASD children were as accurate as, but significantly slower than, controls, independently of conditions. ADHD children did not differ from controls in the presence of a concurrent PM task, while they were less accurate than controls in the presence of the go/no-go task. Overall, the two patterns of findings suggest important differences in the way ASD and ADHD children remember and realise intentions requiring opposite behaviours (acting vs stopping).     

To justify or excuse?: A meta-analytic review of the effects of explanations

The authors used R. Folger and R. Cropanzano's (1998, 2001) fairness theory to derive predictions about the effects of explanation provision and explanation adequacy on justice judgments and cooperation, retaliation, and withdrawal responses. The authors also used the theory to identify potential moderators of those effects, including the type of explanation (justification vs. excuse), outcome favorability, and study context. The authors' predictions were tested by using meta-analyses of 54 independent samples. The results showed strong effects of explanations on both the justice and response variables. Moreover, explanations were more beneficial when they took the form of excuses rather than justifications, when they were given after unfavorable outcomes, and when they were given in contexts with instrumental, relational, and moral implications.     

Multiple causal pathways in attention-deficit/hyperactivity disorder – Do emerging executive and motivational deviations precede symptom development?

The multiple causal pathways model on the etiology of attention-deficit/hyperactivity disorder (ADHD) is well established. However, developmental implications of the model are not yet sufficiently analyzed. The model implies that critical neural and neuropsychological deviations from normative development precede secondarily developing ADHD symptoms. Cognitive, “cool” inhibitory control (CIC) and reward-related, “hot” functions (RRF) are regarded as neuropsychological basic deficits that indicate independent causal pathways. Both functions involve top-down control networks that undergo major normative developmental changes in the preschool period. We formalized the following assumptions in a path model: (a) CIC and RRF predict change in ADHD symptoms in the preschool period, (b) the reverse is not true, and (c) CIC and RRF independently contribute to this prediction. A community-based sample of 125 (71 boys) preschoolers was assessed at at age 4 and 5 years. At each assessment wave, CIC and RRF were measured by a battery of age-appropriate valid tasks. ADHD symptoms were measured by a clinical parent interview. Evaluation of model fit using manifest maximum likelihood parameter estimation clearly supported the hypothesized path model while controlling for gender of child and maternal education level. Thus, regarding the basic deficits of CIC and RRF, the results add evidence on the developmental implications of the multiple causal pathways model. Our findings point to the potential significance of these early emerging characteristics as indicators of risk and as targets for preventive interventions.     

Does stimulant medication decrease the lower extremity response times of children with and without attention-deficit/hyperactivity disorder?

In 2005 Pedersen and Surburg reported that stimulant medications reduced the lower extremity response times of 16 boys with Attention-Deficit/Hyperactivity Disorder. However, as boys without ADHD and girls with and without ADHD were not studied, one cannot conclude that reported effects represent a medication effect unique to children with ADHD. An alternative hypothesis is presented: that stimulant medications produce an excitatory effect in the central nervous system by increased occupancy of postsynaptic dopamine receptors to reduce the lower extremity response times of children in general. Well-designed controlled clinical trials are needed to evaluate this hypothesis.     

Maxims or myths of beauty? A meta-analytic and theoretical review

Common maxims about beauty suggest that attractiveness is not important in life. In contrast, both fitness-related evolutionary theory and socialization theory suggest that attractiveness influences development and interaction. In 11 meta-analyses, the authors evaluate these contradictory claims, demonstrating that (a) raters agree about who is and is not attractive, both within and across cultures; (b) attractive children and adults are judged more positively than unattractive children and adults, even by those who know them; (c) attractive children and adults are treated more positively than unattractive children and adults, even by those who know them; and (d) attractive children and adults exhibit more positive behaviors and traits than unattractive children and adults. Results are used to evaluate social and fitness-related evolutionary theories and the veracity of maxims about beauty.     

Timing variations in music performance: musical communication, perceptual compensation, and/or motor control?

A perceptual performance paradigm was designed to disentangle the timing variations in music performance that are due to perceptual compensation, motor control, and musical communication. First, pianists perceptually adjusted the interonset intervals of three excerpts so that they sounded regular. These adjustments deviated systematically from regularity, highlighting two sources of perceptual biases in time perception: rhythmic grouping and a psychoacoustic intensity effect. Then the participants performed the excerpts on the piano in the same regular way. The intensity effect disappeared, and some variations due to motor constraints were observed in relation to rhythmic groups. Finally, the participants performed the excerpts musically. Variations due to musical communication involved additional group-final lengthening that reflected the hierarchical grouping structure of the excerpts. These results underline the nuclear role of grouping in musical time perception and production.     

Sex differences in motor performance of young children: Fact or fiction?

Prepubescent boys and girls who had participated for one or more years in a coeducational physical education program were classified by grade (3, 4, and 5) and year (1977, 1978, and 1979). Scores from the AAHPER Youth Fitness Test were analyzed for differences. Results indicated that females at prepubescent ages may be expected to perform at similar levels to boys of the same age on most test items. While differences were not significant, girls in 1979 were actually better than boys of the same age from the two previous years.     

Gender differences in social representations of aggression: The phenomenological experience of differences in inhibitory control?

Women are more likely than men to experience acts of aggression as expressive (a loss of self‐control) than as instrumental (control over others). We propose that this might arise from differences in behavioural restraint. If women have better inhibitory control, aggressive behaviour should occur less frequently yet should be experienced as more emotionally ‘out of control’ because women can tolerate higher levels of anger before inhibitory control is breached. Participants (N =606) aged 13–24 completed the Multidimensional Personality Questionnaire (MPQ), the State‐Trait Anger Expression Inventory‐2 (STAXI‐2) and Expagg. A more expressive view of aggression was associated with higher levels of STAXI anger control and higher levels of MPQ constraint. However, it was the harm avoidance component of constraint, rather than control versus impulsivity, that was the stronger predictor. While behavioural inhibition is built on an infrastructure of fear, the latter may be more important in explaining gender differences in social representations of aggression.     

Severity of childhood attention-deficit hyperactivity disorder--a risk factor for personality disorders in adult life?

Some evidence points to an increased rate of cluster B and C personality disorders (PDs) in adult ADHD patients. In order to assess axis II disorders comprehensively we used the diagnostic instrument of the WHO. In sixty adult out-patients with ADHD according to DSM-IV criteria PDs were assessed with the International PD Examination (IPDE) and severity of childhood ADHD with the Wender-Utah-Rating Scale (WURS). We found at least one PD in 25% of cases. Cluster C PDs were most common (36.6%) followed by Cluster B (23.3%) and A (8.3%). Avoidant (21.7%) and borderline (18.3%) were the most frequent single PD entities. ADHD patients with PD suffered from significantly more severe childhood ADHD compared to those without co-occurring PD. Applying the IPDE we confirmed a high number of PDs among adult ADHD patients. Our findings point to a higher vulnerability for the development of PDs in patients with severe childhood ADHD.     

Priming of disability and elderly stereotype in motor performance: similar or specific effects?

In three experimental studies, the effects of priming participants with the disability stereotype were investigated with respect to their subsequent motor performance. Also explored were effects of activating two similar stereotypes, persons with a disability and elderly people. In Study 1, participants were primed with the disability stereotype versus with a neutral prime, and then asked to perform on a motor coordination task. In Studies 2 and 3, a third condition was introduced: priming participants with the elderly stereotype. Results indicated that priming participants with the disability stereotype altered their motor performance: they showed decreased manual dexterity and performed slower than the non-primed participants. Priming with the elderly stereotype decreased only performance speed. These findings underline that prime-to-behavior effects may depend on activation of specific stereotype content.     

A meta-analytic study of the effects of goal setting on task performance: 1966–1984

A meta-analytic study was conducted involving primarily published research from 1966 to 1984 and focusing on the relationship between goal-setting variables and task performance. Two major sets of studies were analyzed, those contrasting hard goals (goal difficulty) versus easy goals, and those comparing specific hard goals (goal specificity/difficulty) versus general goals, “do best” instructions, or no goal. As expected, strong support was obtained for the goal difficulty and goal specificity/difficulty components of E. A. Locke's (1968a, Organizational Behavior and Human Performance, 3, 157–189) theory. A two-stage approach was employed to identify potential moderators of the goal difficulty and goal specificity/difficulty—performance relationships. Setting (laboratory versus field) was identified as a moderator of the relationship between goal specificity/difficulty and task performance. Two supplemental meta-analyses yielded support for the efficacy of combining specific hard goals with feedback versus specific hard goals without feedback and for participatively set goals versus assigned goal setting (when goal level is held constant), although this latter finding was interpreted as inconclusive based on the limited studies available. Implications for future research are addressed.