The conflict adaptation is affected by attentional strategies: evidence from the arrow flanker task

Recently, several studies have considered factors affecting the occurrence of congruency sequence effect (CSE) in the arrow flanker task. In the present study, the influence of the following factors was examined: the presentation of a fixation and the intertrial interval (ITI) were considered. Results of the study showed that the CSE was significant when there was no fixation and when the ITI was long for response repetitions and response changes, but disappeared for response change trials in other conditions. These results showed that, even in the arrow flanker task, the conflict adaptation effect did contribute to the CSE. The current results suggested that the conflict adaptation effect in the arrow flanker task was based on the appropriate application of attention strategies.     

The Congruency Sequence Effect 3.0: A Critical Test of Conflict Adaptation

Over the last two decades, the congruency sequence effect (CSE) –the finding of a reduced congruency effect following incongruent trials in conflict tasks– has played a central role in advancing research on cognitive control. According to the influential conflict-monitoring account, the CSE reflects adjustments in selective attention that enhance task focus when needed, often termed conflict adaptation. However, this dominant interpretation of the CSE has been called into question by several alternative accounts that stress the role of episodic memory processes: feature binding and (stimulus-response) contingency learning. To evaluate the notion of conflict adaptation in accounting for the CSE, we construed versions of three widely used experimental paradigms (the colour-word Stroop, picture-word Stroop and flanker task) that effectively control for feature binding and contingency learning. Results revealed that a CSE can emerge in all three tasks. This strongly suggests a contribution of attentional control to the CSE and highlights the potential of these unprecedentedly clean paradigms for further examining cognitive control.     

Is high prevalence of vitamin D deficiency a correlate for attention deficit hyperactivity disorder?

The aim of the study was to determine the association between vitamin D and attention deficit hyperactivity disorder (ADHD), and difference in the level of vitamin D in ADHD children and control. This a case–control study carried out in school health and primary health care clinics. A total of 1,331 children and adolescents who were diagnosed with ADHD based on clinical criteria and standardized questionnaires were enrolled in this study and were matched with 1,331 controls, aged 5–18 years old. Data on body mass index (BMI), clinical biochemistry variables including serum 25-hydroxyvitamin D were collected. The study found significant association between ADHD and vitamin D deficiency after adjusting for BMI and sex (adj. OR 1.54; 95 % CI 1.32–1.81; P < 0.001). Majority of the ADHD children were in the age group 5–10 years (40.7 %), followed by 11–13 years (38.4 %). The proportion of BMI <85th percentile was significantly over represented in ADHD group as compared to healthy control (87.8 vs. 83 %; P < 0.001, respectively), while on the other hand, BMI >95th percentile was over represented in the control than ADHD group (7.6 vs. 4.6 %; P < 0.001, respectively). Mean values of vitamin D (ng/mL) were significantly lower in ADHD children (16.6 ± 7.8) than in healthy children (23.5 ± 9.0) (P < 0.001). There was significant correlation between vitamin D deficiency and age (r = ?0.191, P = 0.001); calcium (r = 0.272, P = 0.001); phosphorous (r = 0.284, P = 0.001); magnesium (r = 0.292, P = 0.001); and BMI (r = 0.498, P = 0.001) in ADHD children. The vitamin D deficiency was higher in ADHD children compared to healthy children.     

Attenuated Tonic and Enhanced Phasic Release of Dopamine in Attention Deficit Hyperactivity Disorder

It is unclear whether attention deficit hyperactive disorder (ADHD) is a hypodopaminergic or hyperdopaminergic condition. Different sets of data suggest either hyperactive or hypoactive dopamine system. Since indirect methods used in earlier studies have arrived at contradictory conclusions, we directly measured the tonic and phasic release of dopamine in ADHD volunteers. The tonic release in ADHD and healthy control volunteers was measured and compared using dynamic molecular imaging technique. The phasic release during performance of Eriksen’s flanker task was measured in the two groups using single scan dynamic molecular imaging technique. In these experiments volunteers were positioned in a positron emission tomography (PET) camera and administered a dopamine receptor ligand ¹¹C-raclopride intravenously. After the injection PET data were acquired dynamically while volunteers either stayed still (tonic release experiments) or performed the flanker task (phasic release experiments). PET data were analyzed to measure dynamic changes in ligand binding potential (BP) and other receptor kinetic parameters. The analysis revealed that at rest the ligand BP was significantly higher in the right caudate of ADHD volunteers suggesting reduced tonic release. During task performance significantly lower ligand BP was observed in the same area, indicating increased phasic release. In ADHD tonic release of dopamine is attenuated and the phasic release is enhanced in the right caudate. By characterizing the nature of dysregulated dopamine neurotransmission in ADHD, the results explain earlier findings of reduced or increased dopaminergic activity.     

Reduced emotional empathy in adults with subclinical ADHD: evidence from the empathy and systemizing quotient

Studies in children with ADHD suggest impairments in social cognitive functions, whereas studies in adults with ADHD are scarce and inconclusive. The aim of this study was to investigate the relationship between ADHD traits and self-reported social cognitive style in a sample of adults from the general population. For this purpose, a community sample of 685 adults filled out online self-report questionnaires about ADHD symptoms (ADHD Rating Scale, ARS), social cognitive functioning and friendships. The Empathy Quotient (EQ) with the subscales Cognitive Empathy (CE), Emotional Empathy (EE) and Social Skills (SS), and the Systemizing Quotient (SQ) were included for measuring social cognitive style and the Friendship Questionnaire (FQ) for the quality of friendships. Participants who met the DSM-5 criteria on the ARS (‘subclinical ADHD’; n = 56) were compared regarding their social cognitive functioning scores with a control group (n = 56) that was matched for age, sex and student status. With small effect sizes, the subclinical ADHD group showed reduced EE scores on the EQ and a more male social cognitive profile. This result was not influenced by sex or ADHD subtype. This study points to a relationship between traits of ADHD and the emotional aspect of empathy, whereas more complex aspects of empathy were unrelated. These findings should be corroborated in clinical patients with ADHD, employing neuropsychological tests rather than self-report questionnaires.     

Dissociable Patterns in the Control of Emotional Interference in Adults with Attention-Deficit/Hyperactivity Disorder (ADHD) and in Adults with Alcohol Dependence

Objectives

To effectively manage current task demands, attention must be focused on task-relevant information while task-irrelevant information is rejected. However, in everyday life, people must cope with emotions, which may interfere with actual task demands and may challenge functional attention allocation. Control of interfering emotions has been associated with the proper functioning of the dorsolateral prefrontal cortex (DLPFC). As DLPFC dysfunction is evident in subjects with ADHD and in subjects with alcohol dependence, the current study sought to examine the bottom-up effect of emotional distraction on task performance in both disorders.

Methods

Male adults with ADHD (n = 22), male adults with alcohol dependence (n = 16), and healthy controls (n = 30) performed an emotional working memory task (n-back task). In the background of the task, we presented neutral and negative stimuli that varied in emotional saliency.

Results

In both clinical groups, a working memory deficit was evident. Moreover, both clinical groups displayed deficient emotional interference control. The n-back performance of the controls was not affected by the emotional distractors, whereas that of subjects with ADHD deteriorated in the presence of low salient distractors, and that of alcoholics did not deteriorate until high salient distractors were presented. Subsequent to task performance, subjects with ADHD accurately recognized more distractors than did alcoholics and controls. In alcoholics, picture recognition accuracy was negatively associated with n-back performance, suggesting a functional association between the ability to suppress emotional distractors and successful task performance. In subjects with ADHD, performance accuracy was negatively associated with ADHD inattentive symptoms, suggesting that inattention contributes to the performance deficit.

Conclusions

Subjects with ADHD and alcoholics both display an emotional interference control deficit, which is especially pronounced in subjects with ADHD. Beyond dysfunctional attention allocation processes, a more general attention deficit seems to contribute to the more pronounced performance deficit pattern in ADHD.     

ERP Correlates of Proactive and Reactive Cognitive Control in Treatment-Na?ve Adult ADHD

This study investigated whether treatment naïve adults with Attention Deficit Hyperactivity Disorder (ADHD; n = 33; 19 female) differed from healthy controls (n = 31; 17 female) in behavioral performance, event-related potential (ERP) indices of preparatory attention (CueP3 and late CNV), and reactive response control (Go P3, NoGo N2, and NoGo P3) derived from a visual cued Go/NoGo task. On several critical measures, Cue P3, late CNV, and NoGo N2, there were no significant differences between the groups. This indicated normal preparatory processes and conflict monitoring in ADHD patients. However, the patients had attenuated Go P3 and NoGoP3 amplitudes relative to controls, suggesting reduced allocation of attentional resources to processes involved in response control. The patients also had a higher rate of Go signal omission errors, but no other performance decrements compared with controls. Reduced Go P3 and NoGo P3 amplitudes were associated with poorer task performance, particularly in the ADHD group. Notably, the ERPs were not associated with self-reported mood or anxiety. The results provide electrophysiological evidence for reduced effortful engagement of attentional resources to both Go and NoGo signals when reactive response control is needed. The absence of group differences in ERP components indexing proactive control points to impairments in specific aspects of cognitive processes in an untreated adult ADHD cohort. The associations between ERPs and task performance provided additional support for the altered electrophysiological responses.     

Alertness Modulates Conflict Adaptation and Feature Integration in an Opposite Way

Previous studies show that the congruency sequence effect can result from both the conflict adaptation effect (CAE) and feature integration effect which can be observed as the repetition priming effect (RPE) and feature overlap effect (FOE) depending on different experimental conditions. Evidence from neuroimaging studies suggests that a close correlation exists between the neural mechanisms of alertness-related modulations and the congruency sequence effect. However, little is known about whether and how alertness mediates the congruency sequence effect. In Experiment 1, the Attentional Networks Test (ANT) and a modified flanker task were used to evaluate whether the alertness of the attentional functions had a correlation with the CAE and RPE. In Experimental 2, the ANT and another modified flanker task were used to investigate whether alertness of the attentional functions correlate with the CAE and FOE. In Experiment 1, through the correlative analysis, we found a significant positive correlation between alertness and the CAE, and a negative correlation between the alertness and the RPE. Moreover, a significant negative correlation existed between CAE and RPE. In Experiment 2, we found a marginally significant negative correlation between the CAE and the RPE, but the correlation between alertness and FOE, CAE and FOE was not significant. These results suggest that alertness can modulate conflict adaptation and feature integration in an opposite way. Participants at the high alerting level group may tend to use the top-down cognitive processing strategy, whereas participants at the low alerting level group tend to use the bottom-up processing strategy.     

Unconsciously Triggered Conflict Adaptation

In conflict tasks such as the Stroop, the Eriksen flanker or the Simon task, it is generally observed that the detection of conflict in the current trial reduces the impact of conflicting information in the subsequent trial; a phenomenon termed conflict adaptation. This higher-order cognitive control function has been assumed to be restricted to cases where conflict is experienced consciously. In the present experiment we manipulated the awareness of conflict-inducing stimuli in a metacontrast masking paradigm to directly test this assumption. Conflicting response tendencies were elicited either consciously (through primes that were weakly masked) or unconsciously (strongly masked primes). We demonstrate trial-by-trial conflict adaptation effects after conscious as well as unconscious conflict, which could not be explained by direct stimulus/response repetitions. These findings show that unconscious information can have a longer-lasting influence on our behavior than previously thought and further stretch the functional boundaries of unconscious cognition.     

Short Term Integrative Meditation Improves Resting Alpha Activity and Stroop Performance

Our previous research showed that short term meditation training reduces the time to resolve conflict in the flanker task. Studies also show that resting alpha increases with long term meditation practice. The aim of this study is to determine whether short term meditation training both increases resting alpha activity and reduces the time to resolve conflict in the Stroop task and whether these two effects are related. Forty-three Chinese undergraduates were randomly assigned an experiment group given 5 days meditation training using integrative body-mind training (IBMT) and a relaxation training control. After training, only the IBMT group showed decreased conflict reaction time (RT), and increased resting mean alpha power. Moreover, the higher the enhancement of resting alpha power, the stronger the improvement of conflict RT. The results indicate that short term meditation diffusely enhances alpha and improves the ability to deal with conflict and moreover these two effects are positively related.     

Comorbidity and continuity of attention deficit hyperactivity disorder (ADHD) from childhood to adolescence in Turkey

The aim of this study was to examine clinical outcomes, psychiatric comorbidity and neuropsychological characteristics in Turkish adolescents with an attention deficit hyperactivity disorder (ADHD) diagnosis in childhood. A total of 45 children with ADHD diagnosis and 28 children with a psychiatric diagnosis other than ADHD in a 1-year cohort of 7–10-year-olds were reevaluated 6 years later using Schedule for Affective Disorders and Schizophrenia for School-Age Children Present and Lifetime version and Wechsler Intelligence Scale for Children-Revised and Stroop Test TBAG version. This study shows that the clinical outcomes and the comorbidity patterns for ADHD from childhood to adolescence in Turkey are similar to reported rates in the Western countries. In the ADHD group, 75.6 % still has impairing ADHD symptoms and 46.6 % has comorbid psychiatric disorders. The main difference is anxiety disorders being the most common comorbid disorders (37.8 %) in Turkish ADHD youth. These findings stress the high comorbidity associated with ADHD and support the importance of assessment and treatment for ADHD and comorbidities during adolescence.     

Separate and overlapping relationships of inattention and hyperactivity/impulsivity in children and adolescents with attention-deficit/hyperactivity disorder

There is debate regarding the dimensional versus categorical nature of attention-deficit/hyperactivity disorder (ADHD). This study utilized confirmatory factor analysis to examine this issue. ADHD symptoms rated on interviews and rating scales from a large sample of individuals (ages 3–17, 74 % male, 75 % Caucasian) with ADHD were examined (n = 242). Four potential factor structures were tested to replicate prior findings in a sample with a wide age range and included only participants who met DSM-IV-TR diagnostic criteria for ADHD. Correlations with executive function measures were performed to further assess the separability and validity of the derived factors. The data support a bifactor model with a general ADHD factor and two specific factors, inattention and hyperactivity/impulsivity. Importantly, the individual factors were also differentially correlated with executive functioning measures. This study adds to a growing literature suggesting both a general component to ADHD, as well as dimensional traits of inattention and hyperactivity/impulsivity, associated with distinct executive functioning profiles. The presence of a general underlying factor contraindicates separating the inattentive and combined subtypes of ADHD into distinct disorders.     

Long-Term Exposure to High Altitude Affects Conflict Control in the Conflict-Resolving Stage

The neurocognitive basis of the effect of long-term high altitude exposure on conflict control is unclear. Event related potentials (ERPs) were recorded in a flanker task to investigate the influence of high altitude on conflict control in the high-altitude group (who had lived at high altitude for three years but were born at low altitude) and the low-altitude group (living in low altitude only). Although altitude effect was not significant at the behavioral level, ERPs showed cognitive conflict modulation. The interaction between group and trial type was significant: P3 amplitude was greater in the low-altitude group than in the high-altitude group in the incongruent trial. This result suggests that long-term exposure to high altitude affects conflict control in the conflict-resolving stage, and that attentional resources are decreased to resist the conflict control in the high-altitude group.     

The Impact of Hypnotic Suggestions on Reaction Times in Continuous Performance Test in Adults with ADHD and Healthy Controls

Attention is one of the key factors in both hypnotic processes and patients with ADHD. In addition, the brain areas associated with hypnosis and ADHD overlap in many respects. However, the use of hypnosis in ADHD patients has still received only minor attention in research. The main purpose of the present work was to investigate whether hypnosis and hypnotic suggestions influence the performance of adult ADHD (n = 27) and control participants (n = 31) in the continuous performance test (CPT). The hypnotic susceptibility of the participants was measured by the Harvard Group Scale of Hypnotic Susceptibility (HGSHS:A) and the attentional task was a three minute long auditory version of the CPT. The CPT task was administered four times: before hypnosis (CPT1), after a hypnotic induction (CPT2), after suggestions about speed and accuracy (CPT3), and after the termination of hypnosis (CPT4). The susceptibility of the groups measured by HGSHS:A did not differ. There was a statistically significant decrease in reaction times in both ADHD and control groups between CPT2 and CPT3. The differences between CPT1 and CPT2, even though non-significant, were different in the two groups: in the ADHD group reaction times decreased whereas in the control group they increased. Both groups made very few errors in the short CPT. This study indicates that hypnotic suggestions have an effect on reaction times in the sustained attention task both in adult ADHD patients and control subjects. The theoretical and clinical implications are discussed.     

Symptom covariance accounts for behavioral approach associations across impulse control disorders

Behavioral approach system (BAS) dysfunction has been identified as a correlate of and a potential mechanism for attention-deficit/hyperactivity disorder (ADHD) and comorbid disorders. This study examined the role of symptom covariation in the relations among BAS dysfunction, ADHD symptoms, and comorbid impulsive personality disorder features. Undergraduates (N = 207) completed measures of BAS functioning, ADHD symptoms, and borderline and antisocial personality disorder symptoms, and associated features (i.e., relational aggression). Hierarchical regression suggested that age, impulsive ADHD symptoms, and relational aggression were associated with BAS functioning. Adding other ADHD symptom dimensions (inattention, hyperactivity) and antisocial and borderline scores to the model did not increase variance accounted for beyond that accounted for by ADHD impulsivity scores. Results highlight a role of symptom covariance in the previously demonstrated relation between BAS, impulsive presentations of ADHD, and comorbid impulsive personality pathology. Implications for etiological models of ADHD and its co-occurrence with other disorders are discussed.     

Understanding deficient emotional self-regulation in adults with attention deficit hyperactivity disorder: a controlled study

While symptoms of deficient emotional self-regulation (DESR) such as low frustration tolerance, temper outbursts, emotional impulsivity, and mood lability are commonly associated with attention deficit hyperactivity disorder (ADHD), little is known about their nature. The main aim of this post hoc study was to examine the correlates of DESR in a large sample of adults with and without ADHD. Subjects were 206 adults with ADHD and 123 adults without ADHD from a family study of ADHD. Emotional impulsivity was operationalized using items from the Barkley Current Behavior Scale. Subjects were comprehensively assessed for psychiatric comorbidity using structured diagnostic interview methodology. We used the Quality of Life, Enjoyment, and Satisfaction Questionnaire-Short Form (QLES-Q-SF) and Social Adjustment Scale-Self-report (SAS-SR) to assess quality of life and psychosocial functioning. DESR was more common among ADHD compared with non-ADHD adults, and 55 % of adults with ADHD reported extreme DESR of greater severity than 95 % of control subjects. The association of ADHD and DESR was not entirely accounted for by either current or lifetime comorbid disorders. DESR was also associated with significant functional impairment as evaluated by the QLES-Q-SF and SAS-SR, and with reduced marital status, as well as higher risk for traffic accidents and arrests. DESR adversely impacts quality of life in adults with ADHD. More work is needed to further evaluate DESR in clinical and investigational studies of subjects with ADHD.     

Methylphenidate and if-then plans are comparable in modulating the P300 and increasing response inhibition in children with ADHD

A disturbed functioning of the prefrontal cortex, the anterior cingulate cortex, and an accordingly reduced P300 presumably underlies executive function deficits of children with attention deficit hyperactivity disorder (ADHD). Using a combined classification and Go/NoGo task paradigm, the present study investigated whether medication with methylphenidate (MPH) modulates the P300 as measured by a high-density electroencephalogram (EEG) and facilitates response inhibition in children with ADHD. Further, effects of MPH were compared with effects of self-regulation by if-then plans (Gollwitzer in Am Psychol 54: 493-503, 1999). MPH as well as if-then plans modulated the P300 and improved inhibition of an unwanted response on a Go/NoGo task to the same level observed in children without ADHD. Importantly, self-regulation strategies might be a valuable alternative to medication with MPH in children with ADHD.     

Self-regulation strategies support children with ADHD to overcome symptom-related behavior in the classroom

Children with attention deficit hyperactivity disorder (ADHD) suffer from self-regulation deficits that cause inattention, impulsivity, and hyperactivity. Self-regulation interventions may address these deficits, but to date, only few empirical studies have examined their benefits for children with ADHD in everyday life. The present study investigated three classroom interventions to promote self-regulation and tested their benefit on self-regulatory competencies (assessed with an ADHD questionnaire) in children with ADHD. Students of a special education school for children with ADHD participated in the intervention study that included three sessions (Session 1: Goal Intention or Goal Intention + If–Then Plan; Session 2: Goal Intention + If–Then Plan; Session 3: Goal Intention + If–Then Plan + Self-Monitoring). Teacher-rated self-regulatory competencies were assessed both before and after the intervention sessions. Children with ADHD had better self-regulatory competencies after their first Goal Intention + If–Then Plan Session, but lasting intervention effects were found only when children started with a mere goal intention session.     

The Impact of Financial Reward Contingencies on Cognitive Function Profiles in Adult ADHD

Objectives

Although it is well established that cognitive performance in children with attention-deficit/hyperactivity disorder (ADHD) is affected by reward and that key deficits associated with the disorder may thereby be attenuated or even compensated, this phenomenon in adults with ADHD has thus far not been addressed. Therefore, the aim of the present study was to examine the motivating effect of financial reward on task performance in adults with ADHD by focusing on the domains of executive functioning, attention, time perception, and delay aversion.

Methods

We examined male and female adults aged 18–40 years with ADHD (n = 38) along with a matched control group (n = 40) using six well-established experimental paradigms.

Results

Impaired performance in the ADHD group was observed for stop-signal omission errors, n-back accuracy, reaction time variability in the continuous performance task, and time reproduction accuracy, and reward normalized time reproduction accuracy. Furthermore, when rewarded, subjects with ADHD exhibited longer reaction times and fewer false positives in the continuous performance task, which suggests the use of strategies to prevent impulsivity errors.

Conclusions

Taken together, our results support the existence of both cognitive and motivational mechanisms for the disorder, which is in line with current models of ADHD. Furthermore, our data suggest cognitive strategies of “stopping and thinking” as a possible underlying mechanism for task improvement that seems to be mediated by reward, which highlights the importance of the interaction between motivation and cognition in adult ADHD.