The neural correlates of deficient error awareness in attention-deficit hyperactivity disorder (ADHD)

Neural and Behavioral Measures of Stress-induced Impairment in Error Awareness and Post-error Adjustment

Exposure to stress negatively affects error processing, but the impact of stress on error awareness remains to be determined. In the present study, we examined the temporal dynamics of error awareness and post-error adjustment following acute stress. Forty-nine healthy men were randomly assigned to the control (n = 26) or stress group (n = 23). After stress induction, participants completed the error awareness task, and their brain activity was assessed by electroencephalography. Compared to the control group, the stress group demonstrated lower error awareness accuracy and smaller Pe (error positivity) and ΔPe amplitudes following aware error responses, which indicated impairment of error awareness following stress. Furthermore, the stress group had lower accuracy in post-aware error responses than in post-unaware error responses and the control group, which indicated poor post-error adjustment following stress. Our results showed a stress effect on sequential stages of error processing. Stress induces impaired error identification, which further generates maladaptive post-error performance.

To err is human- to understand error-processing is divine: Contributions of working memory and anxiety to error-related brain and pupil responses

Both anxiety and working memory capacity appear to predict increased (more negative) error-related negativity (ERN) amplitudes, despite being inversely related to one another. Until the interactive effects of these variables on the ERN are clarified, there may be challenges posed to our ability to use the ERN as an endophenotype for anxiety, as some have suggested. The compensatory error monitoring hypothesis suggests that high trait-anxiety individuals have larger ERN amplitudes because they must employ extra, compensatory efforts to override the working memory demands of their anxiety. Yet, to our knowledge, no ERN study has employed direct manipulation of working memory demands in conjunction with direct manipulations of induced (state) anxiety. Furthermore, little is known about how these manipulations affect other measures of error processing, such as the error-related pupil dilation response and post-error behavioral adjustments. Therefore, we manipulate working memory load and anxiety in a 2 × 2 within-subjects design to examine the interactive effects of working memory load and anxiety on ERN amplitude, error-related pupil dilation response amplitude, and post-error behavior. There were no effects of our manipulations on ERN amplitude, suggesting a strong interpretation of compensatory error-processing theory. However, our worry manipulation affected post-error behavior, such that worry caused a reduction in post-error accuracy. Additionally, our working memory manipulation affected error-related PDR magnitude and the amplitude of the error-related positivity (Pe), such that increased working memory load decreased the amplitude of these responses. Implications of these results within the context of the compensatory error processing framework are discussed.

Dysregulation of the autonomic nervous system in adult attention deficit hyperactivity disorder. A systematic review

Background: Adult Attention Deficit Hyperactivity Disorder (aADHD) is characterised by inattention, hyperactivity, impulsivity, and emotional instability, all of which were linked to altered modulation of the autonomic nervous system. This and the clinical effectiveness of sympathomimetic medication raised the question if autonomic modulation is altered in aADHD patients.Methods: We systematically searched PubMed, Cochrane Library, and Web Of Science for publications investigating autonomic modulation in aADHD and controls during resting-state and/or under task conditions.Results: We reviewed 15 studies involving 846 participants (424 aADHD and 422 controls), including 4 studies on sympathetic tone at rest, 13 studies on sympathetic modulation during tasks, 3 studies on resting state parasympathetic modulation and 3 papers on task-related parasympathetic modulation. Studies comprised measurements of electrodermal activity, heart rate variability, blood pressure variability, blood volume pulse, pre-ejection period, and baroreflex sensitivity. 2 studies reported reduced sympathetic tone in aADHD; 7 papers described lower sympathetic reactivity to task demands in this cohort. One study linked aADHD to impaired vagal tone, while no indications of altered tasks-related parasympathetic reactivity in aADHD patients were reported.Conclusion: The reviewed data revealed impaired cardiovascular autonomic modulation in aADHD patients, predominantly in sympathetic modulation and during stress exposure.

Abnormal functional asymmetry and its behavioural correlates in adults with ADHD: A TMS-EEG study

OBJECTIVES

Abnormal functional brain asymmetry and deficient response inhibition are two core symptoms of attention deficit hyperactivity disorder (ADHD). We investigated whether these symptoms are inter-related and whether they are underlined by altered frontal excitability and by compromised interhemispheric connectivity.

METHODS

We studied these issues in 52 ADHD and 43 non-clinical adults by comparing: (1) stop-signal reaction time (SSRT); (2) frontal asymmetry of the N200 event-related potential component, which is evoked during response inhibition and is lateralised to the right hemisphere; (3) TMS-evoked potential (TEP) in the right frontal hemisphere, which is indicative of local cortical excitability; and (4) frontal right-to-left interhemispheric TMS signal propagation (ISP), which is reversely indicative of interhemispheric connectivity.

RESULTS

Compared to controls, the ADHD group demonstrated elongated SSRT, reduced N200 right-frontal-asymmetry, weaker TEP, and stronger ISP. Moreover, in the ADHD group, N200 right-frontal-asymmetry correlated with SSRT, with TEP, and with symptoms severity. Conversely, no relationship was observed between ISP and N200 right-frontal-asymmetry, and both TEP and ISP were found to be unrelated to SSRT.

CONCLUSIONS

Our results indicate that abnormal frontal asymmetry is related to a key cognitive symptom in ADHD and suggest that it is underlined by reduced right-frontal excitability.

Young adults who improve performance during dual-task walking show more flexible reallocation of cognitive resources: a mobile brain-body imaging (MoBI) study

INTRODUCTION

In young adults, pairing a cognitive task with walking can have different effects on gait and cognitive task performance. In some cases, performance clearly declines whereas in others compensatory mechanisms maintain performance. This study investigates the preliminary finding of behavioral improvement in Go/NoGo response inhibition task performance during walking compared with sitting, which was observed at the piloting stage.

MATERIALS AND METHODS

Mobile brain/body imaging (MoBI) was used to record electroencephalographic (EEG) activity, 3-dimensional (3D) gait kinematics and behavioral responses in the cognitive task, during sitting or walking on a treadmill.

RESULTS

In a cohort of 26 young adults, 14 participants improved in measures of cognitive task performance while walking compared with sitting. These participants exhibited walking-related EEG amplitude reductions over frontal scalp regions during key stages of inhibitory control (conflict monitoring, control implementation, and pre-motor stages), accompanied by reduced stride-to-stride variability and faster responses to stimuli compared with those who did not improve. In contrast, 12 participants who did not improve exhibited no EEG amplitude differences across physical condition.

DISCUSSION

The neural activity changes associated with performance improvement during dual tasking hold promise as cognitive flexibility markers that can potentially help assess cognitive decline in aging and neurodegeneration.

Self-caught methodologies for measuring mind wandering with meta-awareness: A systematic review

Mind wandering, also known as task-unrelated thought, refers to the drift of attention from a focal task or train of thought. Because self-caught measures of mind wandering require participants to spontaneously indicate when they notice their attention drift, self-caught methodologies provide a way to measure mind wandering with meta-awareness. Given the proposed role of meta-awareness in mental health and psychological interventions, an overview of existing self-caught methodologies would help clinicians and researchers make informed decisions when choosing or adapting a mind wandering or meta-awareness measure. This systematic review included 39 studies after 790 studies were assessed for eligibility. All studies operationalised mind wandering as instances of attention drift from a primary task. Three types of primary task were identified: (1) tasks adapted from computerised continuous performance tests (CPT) of sustained attention, (2) tasks involving focusing on the breath or a stream of aural beats, akin to in-vivo mindfulness meditation, (3) tasks involving an everyday life activity such as reading. Although data on mind wandering without meta-awareness (e.g., measured with probe-caught measures) was also obtained in many studies, such data was not always used in conjunction with self-caught mind wandering data to determine level of mind wandering meta-awareness. Few studies reported both reliability and validity of the measures used. This review shows that considerable methodological heterogeneity exists in the literature. Methodological variants of self-caught mind wandering methodologies are documented and examined, and suggestions for future research and clinical work are suggested.

Methylphenidate significantly improves neurocognitive impairments in children with ADHD

This study aimed to investigate the effects of methylphenidate (MPH) on scores on a neurocognitive test battery for individuals with various presentations of attention deficit/hyperactivity disorder (ADHD) and the effect of comorbidities on executive function. This study included 861 children and adolescents aged 7-17 years who were diagnosed with ADHD according to DSM-V criteria. The CNS Vital Signs Battery was utilized to compare the neuropsychological characteristics and MPH treatment responses of patients with predominantly inattentive (ADHD-I) and combined (ADHD-C) presentations of ADHD. Before MPH administration, a statistically significant difference was observed between groups only for complex attention. In addition, the overall prevalence rate of psychiatric comorbidities was 45.5%, and no statistically significant differences were found in the ADHD-I group pre- versus post-MPH administration. Prior to the administration of MPH, statistically significant differences were observed within the ADHD-C group between those with or without comorbidities. However, after MPH administration, these differences between the groups disappeared. The effects of MPH on improving scores on neuropsychological subtests were similar between the groups with different presentations of ADHD. Additionally, MPH treatment was effective despite the presence of comorbidities.

Online and Intellectual Awareness of Executive Functioning in Daily Life among Adolescents with and without ADHD

OBJECTIVE

Executive function deficits (EFD) are a central mechanism underlying negative outcomes in ADHD. This study examined awareness of EFD manifested in "real-time" task performance (Online Awareness) and in general self-knowledge of daily activities, outside the context of a specific task (Intellectual Awareness) among adolescents with and without ADHD.

METHODS

102 adolescents with (n = 52) and without (n = 50) ADHD were administered Weekly Calendar Planning Activity (WCPA) and Behavior Rating Inventory of Executive Function (BRIEF). Parents completed the BRIEF parent version. Awareness was defined using the discrepancy paradigm: performance versus estimation on WCPA for online awareness; self versus parent report on the BRIEF for intellectual awareness.

RESULTS

Adolescents with ADHD overestimated their performance on the WCPA and underestimated their EFD on the BRIEF compared to parent's ratings. The discrepancy scores in both types of awareness were significantly larger among ADHD than controls (p < .005).

CONCLUSIONS

Adolescents with ADHD demonstrate significantly lower rates of online and intellectual awareness of EFD compared to controls.

Examining the neural correlates of error awareness in a large fMRI study

Goal-directed behavior is dependent upon the ability to detect errors and implement appropriate posterror adjustments. Accordingly, several studies have explored the neural activity underlying error-monitoring processes, identifying the insula cortex as crucial for error awareness and reporting mixed findings with respect to the anterior cingulate cortex (ACC). Variable patterns of activation have previously been attributed to insufficient statistical power. We therefore sought to clarify the neural correlates of error awareness in a large event-related functional magnetic resonance imaging (fMRI) study. Four hundred and two healthy participants undertook the error awareness task, a motor Go/No-Go response inhibition paradigm in which participants were required to indicate their awareness of commission errors. Compared to unaware errors, aware errors were accompanied by significantly greater activity in a network of regions, including the insula cortex, supramarginal gyrus (SMG), and midline structures, such as the ACC and supplementary motor area (SMA). Error awareness activity was related to indices of task performance and dimensional measures of psychopathology in selected regions, including the insula, SMG, and SMA. Taken together, we identified a robust and reliable neural network associated with error awareness.

Primary School Children’s Self-Reports of Attention Deficit Hyperactivity Disorder-Related Symptoms and Their Associations With Subjective and Objective Measures of Attention Deficit Hyperactivity Disorder

Background

The diagnosis of Attention deficit hyperactivity disorder (ADHD) is primarily dependent on parents’ and teachers’ reports, while children’s own perspectives on their difficulties and strengths are often overlooked.

Goal

To further increase our insight into children’s ability to reliably report about their ADHD-related symptoms, the current study examined the associations between children’s self-reports, parents’ and teachers’ reports, and standardized continuous performance test (CPT) data. We also examined whether the addition of children’s perceptions of ADHD-symptoms to parents’ and teachers’ reports would be reflected by objective and standardized data.

Methods

The study included 190 children with ADHD, aged 7–10 years, who were referred to a pediatric neurologic clinic. A retrospective analysis was conducted using records of a clinical database. Obtained data included children’s self-reports of their attention level and ADHD-related symptoms, parent, and teacher forms of the Conners ADHD rating scales, Child Behavior Checklist (CBCL), Teacher’s Report Form (TRF), and CPT scores.

Results

Children’s self-evaluations of their functioning were globally associated with their teachers’ and parents’ evaluations, but not uniquely. Children’s self-reports of ADHD symptoms were not uniquely linked to a specific CPT impairment index, but to a general likelihood of having an impaired CPT. The CPT performance successfully distinguished between the group of children who defined themselves as inattentive and those who did not.

Conclusion

Primary school children with ADHD are able to identify their limitations and needs difficulties and that their perspectives should inform clinical practice and research. The clinical and ethical imperative of taking children’s perspectives into account during ADHD diagnosis and treatment is highlighted.

HIV infection is linked with reduced error-related default mode network suppression and poorer medication management abilities

OBJECTIVE

Brain activity linked with error processing has rarely been examined among persons living with HIV (PLWH) despite importance for monitoring and modifying behaviors that could lead to adverse health outcomes (e.g., medication non-adherence, drug use, risky sexual practices). Given that cannabis (CB) use is prevalent among PLWH and impacts error processing, we assessed the influence of HIV serostatus and chronic CB use on error-related brain activity while also considering associated implications for everyday functioning and clinically-relevant disease management behaviors.

METHODS

A sample of 109 participants, stratified into four groups by HIV and CB (HIV+/CB+, n = 32; HIV+/CB-, n = 27; HIV-/CB+, n = 28; HIV-/CB-, n = 22), underwent fMRI scanning while completing a modified Go/NoGo paradigm called the Error Awareness Task (EAT). Participants also completed a battery of well-validated instruments including a subjective report of everyday cognitive failures and an objective measure of medication management abilities.

RESULTS

Across all participants, we observed expected error-related anterior insula (aI) activation which correlated with better task performance (i.e., less errors) and, among HIV- participants, fewer self-reported cognitive failures. Regarding awareness, greater insula activation as well as greater posterior cingulate cortex (PCC) deactivation were notably linked with aware (vs. unaware) errors. Regarding group effects, unlike HIV- participants, PLWH displayed a lack of error-related deactivation in two default mode network (DMN) regions (i.e., PCC, medial prefrontal cortex [mPFC]). No CB main or interaction effects were detected. Across all participants, reduced error-related PCC deactivation correlated with reduced medication management abilities and PCC deactivation mediated the effect of HIV on such abilities. More lifetime CB use was linked with reduced error-related mPFC deactivation among HIV- participants and poorer medication management across CB users.

CONCLUSIONS

These results demonstrate that insufficient error-related DMN suppression linked with HIV infection, as well as chronic CB use among HIV- participants, has real-world consequences for medication management behaviors. We speculate that insufficient DMN suppression may reflect an inability to disengage task irrelevant mental operations, ultimately hindering error monitoring and behavior modification.

A systematic review and meta-analysis of altered electrophysiological markers of performance monitoring in Obsessive-Compulsive Disorder (OCD), Gilles de la Tourette Syndrome (GTS), Attention-Deficit/Hyperactivity disorder (ADHD) and Autism

Altered performance monitoring is implicated in obsessive-compulsive disorder (OCD), Gilles de la Tourette syndrome (GTS), attention-deficit/hyperactivity disorder (ADHD) and autism. We conducted a systematic review and meta-analysis of electrophysiological correlates of performance monitoring (error-related negativity, ERN; error positivity, Pe; feedback-related negativity, FRN; feedback-P3) in individuals with OCD, GTS, ADHD or autism compared to control participants, or associations between correlates and symptoms/traits of these conditions. Meta-analyses on 97 studies (5890 participants) showed increased ERN in OCD (Hedge's g = 0.54[CIs:0.44,0.65]) and GTS (g = 0.99[CIs:0.05,1.93]). OCD also showed increased Pe (g = 0.51[CIs:0.21,0.81]) and FRN (g = 0.50[CIs:0.26,0.73]). ADHD and autism showed reduced ERN (ADHD: g=-0.47[CIs:-0.67,-0.26]; autism: g=-0.61[CIs:-1.10,-0.13]). ADHD also showed reduced Pe (g=-0.50[CIs:-0.69,-0.32]). These findings suggest overlap in electrophysiological markers of performance monitoring alterations in four common neurodevelopmental conditions, with increased amplitudes of the markers in OCD and GTS and decreased amplitudes in ADHD and autism. Implications of these findings in terms of shared and distinct performance monitoring alterations across these neurodevelopmental conditions are discussed. PROSPERO pre-registration code: CRD42019134612.

Adaptation following errors: Error awareness predicts future performance

The ability to detect an error in performance is critical to ongoing and future goal-directed behaviour. Diminished awareness of errors has been associated with a loss of insight and poor functional recovery in several clinical disorders (e.g., attention-deficit/hyperactivity disorder, addiction, schizophrenia). Despite the clear imperative to understand and remediate such deficits, error awareness and its instantiation in corrective behaviour remains to be fully elucidated. The present study investigated the relationship between error awareness and future performance in order to determine whether conscious recognition of errors facilitates adaptive behaviour. Fifty-one healthy participants completed a motor Go/No-Go error awareness task that afforded the opportunity to learn from errors. A mixed-effects model was specified wherein awareness of an error was used to predict inhibitory performance on the following No-Go trial. The model revealed a significant predictive effect of error awareness on future performance, such that aware errors were more frequently followed by correct inhibitory performance. Notably, improvement in performance accuracy was not due to a temporary increase in conservatism of responding, but appeared to be a context-specific adaptation. These results highlight the adaptive role of error awareness and the relationship between error awareness and learning from errors that has the potential to contribute to clinical symptomatology.

Conjoint fluctuations of PFC-mediated processes and behavior: An investigation of error-related neural mechanisms in relation to sustained attention

The ability to detect errors, which derives from the medial prefrontal cortex (mPFC), is crucial to maintain attention over a long period of time. While impairment of this ability has been reported in patients with sustained attention disruption, the role mPFC-mediated processes play in the intra-individual fluctuation of sustained attention remains an open question. In this context, we computed the variance time course of reaction time (RT) of 42 healthy individuals to distinguish intra-individual periods of low and high performance instability, assumed to represent optimal and suboptimal attentional states, when performing a sustained Go/NoGo task. Analysis of the neurophysiological mechanisms of response monitoring revealed a specific reduction in the error-related negativity (ERN) amplitude and frontal midline theta power during periods of high compared to low RT variability, but only in individuals with a higher standard deviation of reaction time (SD-RT). Concerning post-error adaptation, an increase in the correct-related negativity (CRN) amplitude as well as the frontal lateral theta power on trials following errors was observed in individuals with lower SD-RT but not in those with higher SD-RT. Our results thus show that individuals with poor sustained attention ability exhibit altered post-error adaptation and attentional state-dependent efficiency of error monitoring. Conversely, individuals with good sustained attention performances retained their post-error adaptation and response monitoring regardless of the attentional periods. These findings reveal the critical role of the action-monitoring system in intra-individual behavioral stability and highlight the importance of considering attentional states when studying mPFC-mediated processes, especially in subjects with low sustained attention ability.

What Event-Related Potential Tells Us about Brain Function: Child-Adolescent Psychiatric Perspectives

Electroencephalography (EEG) measures neural activation due to various cognitive processes. EEG and event-related potentials (ERPs) are widely used in studies investigating psychopathology and neural substrates of psychiatric diseases in children and adolescents. The present study aimed to review recent ERP studies in child and adolescent psychiatry. ERPs are non-invasive methods for studying synaptic functions in the brain. ERP might be a candidate biomarker in child-adolescent psychiatry, considering its ability to reflect cognitive and behavioral functions in humans. For the EEG study of psychiatric diseases in children and adolescents, several ERP components have been used, such as mismatch negativity, P300, error-related negativity (ERN), and reward positivity (RewP). Regarding executive functions and inhibition in patients with attention-deficit/hyperactivity disorder (ADHD), P300 latency, and ERN were significantly different in patients with ADHD compared to those in the healthy population. ERN showed meaningful changes in patients with anxiety disorders, such as generalized anxiety disorder, separation anxiety disorder, and obsessive-compulsive disorder. Patients with depression showed significantly attenuated RewP compared to the healthy population, which was related to the symptoms of anhedonia.

The Role of Motivation and Anxiety on Error Awareness in Younger and Older Adults

Aging is associated with several changes in cognitive functions, as well as in motivational and affective processes, which in turn interact with cognitive functions. The present study aimed to investigate error awareness (EA), which declines with aging, in relation to motivation and anxiety. Adopting an experimental task, we firstly tested the hypothesis that EA could be enhanced through reward motivation. Secondly, we explored the relation between state and trait anxiety and EA, investigating the hypothesis of an association between EA and anxiety, and between anxiety and the potential benefit of motivation on EA. Thirty healthy younger (age range: 19-35 years; mean age 25.4 ± 5.1; 10 M) and 30 healthy older adults (age range: 61-83 years; mean age 69.7 ± 5.5; 12 M) took part in the study and performed both the classic Error Awareness Task (EAT) and one experimental task, called the Motivational EAT. In this new task, motivational incentives were delivered after aware correct responses and aware errors. For every participant, standard measures of state and trait anxiety and cognitive functions were collected. Confirming the presence of a significant age-related EA decline, results did not reveal any influence of reward motivation on EA, nor any relation between EA and anxiety. However, both younger and older adults had longer response times (RTs) and made more errors during the Motivational EAT, with the more anxious participants showing the greater RT slowing. Findings suggest that reward motivation might not be always beneficial for cognitive performance, as well as that anxiety does not relate to EA capacity. Results also recommend further investigation, as well as the assessment of EA in patients with either motivational deficits like apathy, and/or with anxiety disorders.

Impaired error awareness in healthy older adults: an age group comparison study

Aging is associated with reduced conscious error detection but the brain regions mediating these changes have yet to be clarified. The present study examined the neural correlates of error awareness in healthy older adults. Sixteen older participants (mean age = 75.5 years) and sixteen younger controls (mean age = 27.9 years) were administered the error awareness task, a go/no-go response inhibition paradigm, in which participants were required to signal commission errors. Compared with young adults, older adults were significantly poorer at consciously detecting performance errors, despite both groups being matched for overall accuracy. This age-related behavioral effect was associated with differences in error-related dorsal anterior cingulate cortex and insula activation, with younger adults showing significant differences between errors made with versus without awareness compared with older adults. By contrast, an age-specific modulation in right inferior parietal lobule activation emerged, with increased right inferior parietal lobule activity occurring in older adults during errors made with awareness compared with younger adults. These findings are consistent with theories of age-related deterioration in error processing mechanisms.

Error and post-error processing in children with attention-deficit/hyperactivity disorder: An electrical neuroimaging study

OBJECTIVE

Inaccurate and inconsistent response styles in attention-deficit/hyperactivity disorder (ADHD) have been observed in a wide variety of cognitive tasks, in line with regulatory deficit models of ADHD. Event-related potential (ERP) studies of error processing have provided evidence for these models, but are limited in specificity. We aimed to improve the isolation, localization and identification of error (self-monitoring and adaptive control) and post-error (implementation of cognitive control) processing in ADHD.

METHODS

ERPs were obtained for 46 ADHD and 51 typically developing (TD) children using the stop-signal task. Response-locked error (Ne and Pe) and stimulus-locked post-error (N2) components were compared between groups. Ne/Pe were corrected for preceding stimulus overlap and group differences were localized.

RESULTS

Ne was intact, while Pe amplitude was markedly reduced in children with ADHD (ηp² = 0.14). Pe differences were localized in the dorsal posterior/midcingulate (BA31/24) cortex. While the TD group showed increased N2 amplitude in post-error trials (ηp² = 0.24), localized in the left ventrolateral prefrontal cortex (VLPFC) and angular gyrus, the ADHD group did not.

CONCLUSIONS

Self-regulation deficits in ADHD are associated with later stages of error processing and subsequent implementation of cognitive control.

SIGNIFICANCE

We contribute to the literature by further specifying error processing deficits in ADHD.

Error-Related Dynamics of Reaction Time and Frontal Midline Theta Activity in Attention Deficit Hyperactivity Disorder (ADHD) During a Subliminal Motor Priming Task

Post-error slowing (PES) is an established performance monitoring readout. Several previous studies have found that PES is reduced in children and adolescents with attention-deficit hyperactivity disorder (ADHD). We analyzed reaction time data, along with electroencephalography (EEG) data, from a response priming experiment in children and adolescents with ADHD (N = 28) and typically developing (TD) controls (N = 15) between 10 and 17 years of age. We report dynamic reaction time changes before and after errors: whereas TD controls readjusted their response speed to their individual average speed after committing an error, this reaction time adjustment appeared to be delayed and decreased in ADHD patients. In the EEG, error trials were accompanied by increased frontal midline theta activity, which was attenuated in ADHD compared to TD. We conclude that PES has a different time course rather than being fully absent in ADHD and discuss relationships with our EEG findings and potential implications for performance monitoring in ADHD.

Neural Correlates of Response Inhibition and Error Processing in Individuals with Mild Traumatic Brain Injury: An Event-Related Potential Study

Individuals with a mild traumatic brain injury (mTBI) often have executive control deficits; however, the underlying neural mechanisms of such deficits are yet to be clarified. Inhibitory control and cognitive monitoring are two fundamental aspects of executive control processes. This study investigated the executive control of mTBI by using the Stop-signal task. Eighteen adults with mTBI and 18 age-, sex-, and education level-matched controls were recruited. Behavioral performance and event-related potential correlates of response inhibition and error processing were compared between groups. The mTBI group tended to have a lower probability of inhibition and a longer stop signal reaction time. N1 amplitude was greater on successful trials. Also on successful trials, N2 and P3 peaked earlier than on failed trials. The N2 amplitude of the mTBI group tended to be smaller than that of the controls. The control group had larger P3 amplitude on successful trials than on failed trials, whereas the mTBI group exhibited no P3 amplitudes difference between the two trial types. In addition, the mTBI group showed significantly longer error positivity latency than did the controls. These results suggest that inhibitory control and error processing were inefficient in the mTB group even more than three months after injury. Electrophysiological markers of cognitive dysfunction can be used as a sensitive tool for determining executive control after mTBI.

Attenuated brain activity during error processing and punishment anticipation in procrastination - a monetary Go/No-go fMRI study

Procrastination is a self-regulatory failure in which people voluntarily but irrationally delay important tasks. Trait procrastination is estimated to affect 15-20% of the total population and leads to a significant decrease in performance, satisfaction with achievements, and quality of life. Procrastination is related to impulsivity and reduced executive control, especially in the domain of inhibition. Moreover, procrastinatory tendencies seem to increase with negative affect, suggesting impaired emotion regulation. The aim of this study was to investigate the neuronal mechanisms of inhibition, error processing, and behavioral control under pressure of punishment in procrastinators. Non-student subjects recruited to low (LP) and high procrastination (HP) groups performed an fMRI monetary Go/No-go task. HP showed significantly lower error-related activity in ACC than LP. There was also a significant group by condition interaction in the ACC and right DLPFC suggesting increase of control during the punishment condition in LP but not HP group. These results suggest that procrastinators have impaired error processing mechanisms which may add to the persistence of procrastination through difficulties in correction of faulty behaviors. Procrastination also seems to be related to a decreased ability to intensify self-control in more demanding situations and/or impaired coping in the context of negative situations.

An Event-related Potential Study of Error-monitoring Deficits in Female College Students Who Participate in Binge Drinking

Objective

This study investigated error-monitoring deficits in female college students with binge drinking (BD) using event-related potentials (ERPs) and the modified Flanker task.

Methods

Participants were categorized into BD (n=25) and non-BD (n=25) groups based on the scores of the Korean-version of the Alcohol Use Disorder Identification Test (AUDIT-K) and the Alcohol Use Questionnaire (AUQ). The modified Flanker task, consisting of congruent (target and flanker stimuli are the same) and incongruent (target and flanker stimuli are different) conditions, was used to evaluate error-monitoring abilities.

Results

The BD group exhibited significantly shorter response times and more error rates on the Flanker task, as well as reduced error-related negativity (ERN) amplitudes compared with the non-BD group. Additionally, ERN amplitudes measured at FCz and Cz were significantly correlated with scores on the AUDIT-K and AUQ in the whole participants. The BD and non-BD groups did not show any significant differences in error positivity amplitudes.

Conclusion

The present results indicate that college students with BD have deficits in error-monitoring, and that reduced ERN amplitudes may serve as a biological marker or risk factor of alcohol use disorder.

Overlaps and distinctions between attention deficit/hyperactivity disorder and autism spectrum disorder in young adulthood: Systematic review and guiding framework for EEG-imaging research

Attention deficit/hyperactivity disorders (ADHD) and autism spectrum disorders (ASD) frequently co-occur. However, we know little about the neural basis of the overlaps and distinctions between these disorders, particularly in young adulthood - a critical time window for brain plasticity across executive and socioemotional domains. Here, we systematically review 75 articles investigating ADHD and ASD in young adult samples (mean ages 16-26) using cognitive tasks, with neural activity concurrently measured via electroencephalography (EEG) - the most accessible neuroimaging technology. The majority of studies focused on event-related potentials (ERPs), with some beginning to capitalise on oscillatory approaches. Overlapping and specific profiles for ASD and ADHD were found mainly for four neurocognitive domains: attention processing, performance monitoring, face processing and sensory processing. No studies in this age group directly compared both disorders or considered dual diagnosis with both disorders. Moving forward, understanding of ADHD, ASD and their overlap in young adulthood would benefit from an increased focus on cross-disorder comparisons, using similar paradigms and in well-powered samples and longitudinal cohorts.

Interoceptive awareness in attention deficit hyperactivity disorder

ADHD is considered a disorder of self-regulation. Recent research has shown that awareness of bodily states, referred to as interoceptive awareness, crucially contributes to self-regulatory processes. Impaired self-regulation in ADHD has been explained in terms of arousal regulation deficits in ADHD (the state regulation deficit (SRD) account). There is now ample support for the SRD account, however the exact reason for arousal regulation difficulties is not yet known. The SRD account explicitly refers to the ability to monitor one's momentary bodily state as a prerequisite for effective state regulation. However, surprisingly, no study to date has tested the ability to become aware of bodily signals, i.e. interoceptive awareness, in ADHD. In the current study, we therefore compared interoceptive awareness between 24 adults with ADHD and 23 controls by means of both an objective (heartbeat perception task) and subjective measure (questionnaire) of interoceptive awareness. Results revealed a strikingly similar performance for both groups on both measures, suggesting preserved interoceptive awareness in adult ADHD.

The Significance of Impulsive Error in Children With ADHD

A deficit of inhibition ability is a neuropsychological problem in children with attention deficit hyperactivity disorder (ADHD). We investigated whether in children who made impulsive error (IE), less error-related negativity (ERN) would correlate with poorer executive attention functions (EAFs). Ninety children (49 with ADHD and 41 without ADHD) were investigated by a 4-minute simple reaction time task and simultaneous electroencephalogram. When they made IE, the ERN in response-locked event-related potential (ERP) was defined as error awareness. The average area under curve of ERN in the control group with IEs was used as the proper criterion for regrouping the children with ADHD into 2 groups: ADHD children with enough ERN (ADHD-enough ERN) and those with less ERN (ADHD-less ERN). EAFs from Comprehensive Nonverbal Attention Test were used as objective indices, and behavioral questionnaires were used as subjective indices and statistically analyzed within ADHD groups. Forty-eight percent of the children made IEs. ADHD(n = 31, 63%) was significantly more than in the control group (n = 12, 29%; P < .001). The ADHD group had significantly less ERN than did the control group while making IE, especially at frontal and central electrodes ( P < .01). Both ADHD-less ERN and ADHD-enough ERN groups had poorer subjective EAFs on questionnaires. Only the ADHD-less ERN group had significant poorer objective EAFs on the Comprehensive Nonverbal Attention Test than did the ADHD without IE. We conclude that investigating the IE and ERN of IE in children with ADHD might help to differentiate subtypes of ADHD with different neuropsychological abilities, and the possibility that ADHD-less ERN children might be confirmed a meaningful subgroup that needs close follow-up, treatments different from standard, or both.

Errors on a computer task and subclinical symptoms of attention-deficit/hyperactivity disorder (ADHD)

Previous reports have found increased error rate for children with attention-deficit/hyperactivity disorder (ADHD) on response time (RT) computer tasks. Here we attempt the conceptual replication and extension of two studies that examined error rate in a general population of children (N = 203). Study 1 followed Johnstone and Galletta but considered associations between scores on a dimensional measure of ADHD symptoms (rather than comparing those with or without an ADHD diagnosis) and the frequency of commission and omission errors. Study 2 followed Shiels, Tamm & Epstein and examined post-error adjustment in the same group of children as for Study 1. Study 1 did not replicate previous findings of no increase in errors of commission in those with higher ADHD symptoms (Johnstone & Galletta). Instead, we found that younger children with lower ADHD symptoms were more likely to make commission errors, while omission errors did not vary with age. Study 2 replicated the previous finding of less RT slowing in children with more ADHD symptoms, extending this finding to a general population of children. Namely, as ADHD symptoms increase, RT slowing is less likely, putting children with higher ADHD symptoms at risk of additional errors. Overall, we extend previous ADHD research to typically developing children with ADHD symptoms.

Intra-Individual Variability of Error Awareness and Post-error Slowing in Three Different Age-Groups

Background: Error awareness (EA) and post-error slowing (PES) are two crucial components of an adequate performance monitoring because, respectively, they allow being aware of an error and triggering performance adjustments following unexpected events. Objective: The purpose of the present study was to investigate the ontogenetic trajectories of EA and PES, as well as to examine how EA and PES interact with each other. Methods: The performance of three groups of participants (children, younger, and older adults) in a modified version of the Error Awareness task (EAT; Hester et al., 2005) was compared. In particular, in this study not only variations of the average performance were examined, but also intra-individual variability (IIV), considered in terms of variations of SD and ex-Gaussian parameters (mu, sigma, and tau). Results: Two distinct ontogenetic trajectories of EA and PES were observed. Regarding EA, we observe a U-shaped curve that describes an increase of the process from childhood to early adulthood and a progressive reduction advancing age in late adulthood. Furthermore, a greater IIV in older adults indicated a susceptibility of EA to the aging process. The ontogenetic trajectory of PES seems substantially different from the trajectory that describes EA since in PES we do not observe age-related differences. Conclusion: These results suggest that EA and PES are two independent processes. Furthermore, it appears that EA and PES are differently prone to short-term fluctuations in performance across the lifespan. While EA presents an increase in IIV in aging, PES seems to be immune to these changes.

Possible Role of Dorsolateral Prefrontal Cortex in Error Awareness: Single-Pulse TMS Evidence

Background: Error awareness is essential to maintain an adaptive and goal-directed behavior and is supposed to rely on the activity of the right dorsolateral prefrontal cortex (DLPFC). However, studies employing electrophysiological methods and functional resonance imaging (fMRI) do not allow to establish a causal relationship between error awareness and implicated brain structures.

Objective: The study examined the causal relationship between DLPFC activity and error awareness in order to confirm the involvement of the right DLPFC in error awareness and to obtain temporal information about this process, namely when the activity of the right DLPFC is involved in error awareness.

Methods: Three experiments with three different samples were conducted employing on-line Transcranial Magnetic Stimulation (TMS). A paired-pulse and a single-pulse on-line TMS paradigm were employed respectively in Experiments 1 and 3, whereas in Experiment 2 a control test was conducted without TMS. In TMS experiments, the right DLPFC was stimulated, considering the left DLPFC and the Vertex as control sites.

Results: Experiment 1 showed no effect of paired-pulse TMS over either right or left DLPFC on error awareness. In Experiment 3, independently from the time point during which TMS was delivered, results showed a significant effect of single-pulse TMS over the DLPFC on Stroop Awareness, without evidence for lateralization of the process.

Conclusions: Results of the present study partially demonstrate the involvement of the DLPFC in error awareness.

Probe-caught spontaneous and deliberate mind wandering in relation to self-reported inattentive, hyperactive and impulsive traits in adults

Research has revealed a positive relationship between types of mind wandering and ADHD at clinical and subclinical levels. However, this work did not consider the relationship between mind wandering and the core symptoms of ADHD: inattention, hyperactivity and impulsivity. Given that the DMS-V attributes mind wandering to inattention only, and that only inattention is thought to result from impairment to the executive function linked to mind wandering, the present research sought to examine this relationship in 80 undiagnosed adults. Using both standard and easy versions of the Sustained Attention to Response Task (SART) we measured both spontaneous and deliberate mind wandering. We found that spontaneous mind wandering was related to self-reported inattentive traits when the task was cognitively more challenging (standard SART). However, hyperactive and impulsive traits were related to spontaneous mind wandering independent of task difficulty. The results suggest inattentive traits are not uniquely related to mind wandering; indeed, adults with hyperactive/impulsive traits were more likely to experience mind wandering, suggesting that mind wandering might not be useful diagnostic criteria for inattention.

The Interaction between Interoceptive and Action States within a Framework of Predictive Coding

The notion of predictive coding assumes that perception is an iterative process between prior knowledge and sensory feedback. To date, this perspective has been primarily applied to exteroceptive perception as well as action and its associated phenomenological experiences such as agency. More recently, this predictive, inferential framework has been theoretically extended to interoception. This idea postulates that subjective feeling states are generated by top-down inferences made about internal and external causes of interoceptive afferents. While the processing of motor signals for action control and the emergence of selfhood have been studied extensively, the contributions of interoceptive input and especially the potential interaction of motor and interoceptive signals remain largely unaddressed. Here, we argue for a specific functional relation between motor and interoceptive awareness. Specifically, we implicate interoceptive predictions in the generation of subjective motor-related feeling states. Furthermore, we propose a distinction between reflexive and pre-reflexive modes of agentic action control and suggest that interoceptive input may affect each differently. Finally, we advocate the necessity of continuous interoceptive input for conscious forms of agentic action control. We conclude by discussing further research contributions that would allow for a fuller understanding of the interaction between agency and interoceptive awareness.

Impaired Behavioral Inhibition in Implicit Sequence Learning in Adult ADHD

OBJECTIVE

Deficits in explicit learning and memory have consistently been reported in adult ADHD, but it is less clear whether these deficits reflect deficient attentional processes or specific dysfunctions in memory processes. Studies on implicit learning and memory, which are less dependent on the allocation of attention, have rarely been conducted on adult ADHD.

METHOD

We implemented a modified serial reaction-time task that involves distracting stimuli to investigate implicit sequence learning in 32 adult participants with ADHD and in 32 matched healthy control participants.

RESULTS

The participants with ADHD revealed unimpaired implicit learning performance, but they made significantly more errors than the control participants. There was no evidence for impaired error monitoring in the participants with ADHD reflected by a comparable degree of double errors and post-error slowing in the two groups.

CONCLUSION

Reduced efficiency of the inhibition of incorrect responses in implicit sequence learning supports previous findings of impaired behavioral inhibition in adult ADHD.

The error-related negativity (ERN) is an electrophysiological marker of motor impulsiveness on the Barratt Impulsiveness Scale (BIS-11) during adolescence

Objectives

Previous studies have postulated that the error-related negativity (ERN) may reflect individual differences in impulsivity; however, none have used a longitudinal framework or evaluated impulsivity as a multidimensional construct. The current study evaluated whether ERN amplitude, measured in childhood and adolescence, is predictive of impulsiveness during adolescence.

Methods

Seventy-five children participated in this study, initially at ages 7–9 years and again at 12–18 years. The interval between testing sessions ranged from 5 to 9 years. The ERN was extracted in response to behavioural errors produced during a modified visual flanker task at both time points (i.e. childhood and adolescence). Participants also completed the Barratt Impulsiveness Scale − a measure that considers impulsiveness to comprise three core sub-traits − during adolescence.

Results

At adolescence, the ERN amplitude was significantly larger than during childhood. Additionally, ERN amplitude during adolescence significantly predicted motor impulsiveness at that time point, after controlling for age, gender, and the number of trials included in the ERN. In contrast, ERN amplitude during childhood did not uniquely predict impulsiveness during adolescence.

Conclusions

These findings provide preliminary evidence that ERN amplitude is an electrophysiological marker of self-reported motor impulsiveness (i.e. acting without thinking) during adolescence.

Error blindness and motivational significance: Shifts in networks centering on anterior insula co-vary with error awareness and pupil dilation

This investigation aims to further our understanding of the brain mechanisms underlying the awareness of one's erroneous actions. While all errors are registered as such in the rostral cingulate zone, errors enter awareness only when the anterior insula cortex is activated. Aware but not unaware errors elicit autonomic nervous system reactivity. Our aim is to investigate the hypothesis that activation in the insula during error awareness is related to autonomic arousal and to inter-regional interactions with other areas of the brain. To examine the role of the anterior insula in error awareness, we assessed its functional connectivity to other brain regions along with autonomic nervous system reactivity in young healthy participants who underwent simultaneous pupil-diameter and functional magnetic resonance imaging measurements while performing a complex and error-prone task. Error blindness was associated with failures to engage sufficient autonomic reactivity. During aware errors increased pupil-diameter along with increased task-related activation within, and increased connectivity between anterior insula and task-related networks suggested an increased capacity for action-control information transfer. Increased pupil-diameter during aware errors was furthermore associated with decreased activation of the default-mode network along with decreased insular connectivity with regions of the default mode system, possibly reflecting decreased task-irrelevant information processing. This shifting mechanism may be relevant to a better understanding of how the brain and the autonomic nervous system interact to enable efficient adaptive behavior during cognitive challenge.

Cue-dependent inhibition in posttraumatic stress disorder and attention-deficit/hyperactivity disorder

OBJECTIVE

Attention-deficit/hyperactivity disorder (ADHD) and posttraumatic stress disorder (PTSD) are common among military veterans, but the comorbidity of these two psychiatric disorders remains largely unstudied. Evaluating response inhibition and cue-dependent learning as behavioral and neurocognitive mechanisms underlying ADHD/PTSD can inform etiological models and development of tailored interventions.

METHOD

A cued go/no-go task evaluated response inhibition in 160 adult males. Participants were recruited from the community and a Veterans Administration medical center. Four diagnostic groups were identified: ADHD-only, PTSD-only, ADHD+PTSD, controls.

RESULTS

Group differences were observed across most indices of inhibitory functioning, reaction time, and reaction time variability, whereby PTSD-only and ADHD+PTSD participants demonstrated deficits relative to controls. No cue dependency effects were observed.

CONCLUSION

Finding complement prior work on neurocognitive mechanisms underlying ADHD, PTSD, and ADHD+PTSD. Lack of expected group differences for the ADHD-only group may be due to limited power. Additional work is needed to better characterize distinctions among clinical groups, as well as to test effects among women and youth.

Parsing the neural signatures of reduced error detection in older age

Recent work has demonstrated that explicit error detection relies on a neural evidence accumulation process that can be traced in the human electroencephalogram (EEG). Here, we sought to establish the impact of natural aging on this process by recording EEG from young (18-35 years) and older adults (65-88 years) during the performance of a Go/No-Go paradigm in which participants were required to overtly signal their errors. Despite performing the task with equivalent accuracy, older adults reported substantially fewer errors, and the timing of their reports were both slower and more variable. These behavioral differences were linked to three key neurophysiological changes reflecting distinct parameters of the error detection decision process: a reduction in medial frontal delta/theta (2-7 Hz) activity, indicating diminished top-down input to the decision process; a slower rate of evidence accumulation as indexed by the rate of rise of a centro-parietal signal, known as the error positivity; and a higher motor execution threshold as indexed by lateralized beta-band (16-30 Hz) activity. Our data provide novel insight into how the natural aging process affects the neural underpinnings of error detection.

Error detection across the adult lifespan: Electrophysiological evidence for age-related deficits

With increasing age, cognitive control processes steadily decline. Prior research suggests that healthy older adults have a generally intact performance monitoring system, but show specific deficits in error awareness, i.e., the ability to detect committed errors. We examined the neural processing of errors across the adult lifespan (69 participants; age range 20-72 years) by analysing the error (-related) negativity (Ne/ERN) and the error positivity (Pe) using an adapted version of the Go/Nogo task. At a stable overall error rate, higher age was associated with a greater proportion of undetected errors. While the Ne/ERN was associated with the processing of errors in general, the Pe amplitude was modulated by detected errors only. Furthermore, the Pe amplitude for detected errors was significantly smaller in older adults, in contrast to the Ne/ERN amplitude which did not show age-related changes. Structural path models suggested that through those age-related changes in Pe amplitude, an indirect effect on the performance was observed. Our results confirm and extend previous extreme-group based findings about specific deficits in error detection associated with higher age using age as a continuous predictor. Age-related reductions in Pe amplitude, associated with more undetected errors, are independent of early error processing, as evidenced by the preserved Ne/ERN.

Error detection and behavioural inhibition in young heavy drinkers

BACKGROUND

Increases in inhibitory errors in heavy drinkers are established; less well-studied is whether heavy drinkers are aware of these errors in performance. Reductions in error detection and awareness limit the possibility for remedial action to be taken, and have implications for substance abusers seeking to control use: failure to monitor and/or adjust ongoing behaviour may be linked to using more or more often than intended, and failing to adjust behaviour after a slip. Here we report the first study of both inhibitory control and error awareness in young heavy drinkers, using behavioural and psychophysiological measures.

METHODS

Heavy drinkers (n=25) and light- or non-drinking controls (n=35) completed a difficult inhibitory task which required signaling the awareness of inhibitory errors on the subsequent trial, while brain electrical activity was recorded.

RESULTS

Heavy drinkers made more inhibitory errors than controls, but we observed no difference in error awareness, both via overt signaling and with equivalent amplitude of the error positivity (Pe), indexing conscious error detection. Similarly, controls and heavy drinkers showed no difference in amplitude or latency of the error-related negativity (ERN), indexing early pre-conscious error detection.

CONCLUSIONS

This research suggests no significant difference in detection of errors in heavy drinkers, even as they are more prone to make these errors, a result seen in dependent drinkers reported elsewhere. Future research with larger sample sizes, and a more difficult task producing sufficient errors, should determine whether heavy drinkers employ sufficient post-error remedial action.

Deficits in Response Inhibition in Patients with Attention-Deficit/Hyperactivity Disorder: The Impaired Self-Protection System Hypothesis

Problems in inhibitory control are regarded in Psychology as a key problem associated with attention-deficit/hyperactivity disorder (ADHD). They, however, might not be primary deficits, but instead a consequence of inattention. At least two components have been identified and dissociated in studies in regards to inhibitory control: interference suppression, responsible for controlling interference by resisting irrelevant or misleading information, and response inhibition, referring to withholding a response or overriding an ongoing behavior. Poor error awareness and self-monitoring undermine an individual's ability to inhibit inadequate responses and change course of action. In non-social contexts, an individual depends on his own cognition to regulate his mistakes. In social contexts, however, there are many social cues that should help that individual to perceive his mistakes and inhibit inadequate responses. The processes involved in perceiving and interpreting those social cues are arguably part of a self-protection system (SPS). Individuals with ADHD not only present impulsive behaviors in social contexts, but also have difficulty perceiving their inadequate responses and overriding ongoing actions toward more appropriate ones. In this paper, we discuss that those difficulties are arguably a consequence of an impaired SPS, due to visual attention deficits and subsequent failure in perceiving and recognizing accurately negative emotions in facial expressions, especially anger. We discuss evidence that children with ADHD exhibit problems in a series of components involved in the activation of that system and advocate that the inability to identify the anger expressed by others, and thus, not experiencing the fear response that should follow, is, ultimately, what prevents them from inhibiting the ongoing inappropriate behavior, since a potential threat is not registered. Getting involved in high-risk situations, such as reckless driving, could also be a consequence of not registering a threat and thus, not experiencing fear.

Post-Error Slowing in Patients With ADHD: A Meta-Analysis

OBJECTIVE

Post-error slowing (PES) is a cognitive mechanism for adaptive responses to reduce the probability of error in subsequent trials after error. To date, no meta-analytic summary of individual studies has been conducted to assess whether ADHD patients differ from controls in PES.

METHOD

We identified 15 relevant publications, reporting 26 pairs of comparisons (ADHD, n = 1,053; healthy control, n = 614). Random-effect meta-analysis was used to determine the statistical effect size (ES) for PES.

RESULTS

PES was diminished in the ADHD group as compared with controls, with an ES in the medium range (Cohen's d = 0.42). Significant group difference was observed in relation to the inter-stimulus interval (ISI): While healthy participants slowed down after an error during long (3,500 ms) compared with short ISIs (1,500 ms), ADHD participants sustained or even increased their speed.

CONCLUSION

The pronounced group difference suggests that PES may be considered as a behavioral indicator for differentiating ADHD patients from healthy participants.

Performance monitoring mechanisms activated before and after a response: A comparison of aware and unaware errors

The main goal of the current study was to investigate whether correct withholds, aware errors and unaware errors could be distinguished in terms of performance monitoring mechanisms activated before and after the response. To this end, an error awareness task (explicit acknowledgment of a performance error, expressed by pressing a specific button) was combined with the event-related potential (ERP) technique. Results regarding the performance monitoring mechanisms triggered before a response revealed faster responses before an aware error than before an unaware error. Likewise, analysis of the error-preceding positivity (EPP) revealed specific modulation in frontal scalp regions according to error type. This result shows that transient disengagement and/or inefficiency of the performance monitoring system relates specifically to one type of error.

Post-error adjustments and ADHD symptoms in adults: The effect of laterality and state regulation

Evidence is accumulating that individuals with Attention-Deficit/Hyperactivity Disorder (ADHD) do not adjust their responses after committing errors. Post-error response adjustments are taken to reflect, among others, error monitoring that is essential for learning, flexible behavioural adaptation, and achieving future goals. Many behavioural studies have suggested that atypical lateral brain functions and difficulties in allocating effort to protect performance against stressors (i.e., state regulation) are key factors in ADHD. Whether these factors contribute to the absence of post-error response adjustments in ADHD is unknown. The aim of the present study is to investigate the contribution of the left and right hemispheres and the deficiency in effort allocation to deviant post-error processing in adults with high ADHD symptoms. From a pool of 87 university students, two groups were formed: a group with higher (n=30) and a group with lower (n=26) scores on the ADHD index subscale of the Conners' Adult ADHD Rating Scales. The groups performed a lateralized lexical decision task with a fast and slower stimulus presentation rate. Post-error slowing and post-error response accuracy to stimuli presented in the left and right visual field were measured in each stimulus presentation rate. Results indicated that subjects with the lower ADHD scores slowed down and improved their response accuracy after errors, especially when stimuli were presented in the right visual field at the slower rate. In contrast, subjects with the higher ADHD scores showed no post-error adjustments. Results suggest that during lexical decision performance, impaired error processing in adults with ADHD is associated with affected ability of the left hemisphere to compensate for errors, especially when extra effort allocation is needed to meet task demands.

Error-related brain activity and error awareness in an error classification paradigm

Error-related brain activity has been linked to error detection enabling adaptive behavioral adjustments. However, it is still unclear which role error awareness plays in this process. Here, we show that the error-related negativity (Ne/ERN), an event-related potential reflecting early error monitoring, is dissociable from the degree of error awareness. Participants responded to a target while ignoring two different incongruent distractors. After responding, they indicated whether they had committed an error, and if so, whether they had responded to one or to the other distractor. This error classification paradigm allowed distinguishing partially aware errors, (i.e., errors that were noticed but misclassified) and fully aware errors (i.e., errors that were correctly classified). The Ne/ERN was larger for partially aware errors than for fully aware errors. Whereas this speaks against the idea that the Ne/ERN foreshadows the degree of error awareness, it confirms the prediction of a computational model, which relates the Ne/ERN to post-response conflict. This model predicts that stronger distractor processing - a prerequisite of error classification in our paradigm - leads to lower post-response conflict and thus a smaller Ne/ERN. This implies that the relationship between Ne/ERN and error awareness depends on how error awareness is related to response conflict in a specific task. Our results further indicate that the Ne/ERN but not the degree of error awareness determines adaptive performance adjustments. Taken together, we conclude that the Ne/ERN is dissociable from error awareness and foreshadows adaptive performance adjustments. Our results suggest that the relationship between the Ne/ERN and error awareness is correlative and mediated by response conflict.

Altered response-preparation in patients with adult ADHD: A high-density ERP study

Aberrations in early-developing bottom-up processes, such as stimulus-driven response preparation, are thought to play a critical role in the onset of ADHD, and in its persistence over time. Electrophysiology offers a unique tool to gain insight into response preparation, since response preparation has been associated with distinctive ERP changes, including negative potential-shifts which occur predominantly over frontal brain areas. We examined response-preceding negative potential shifts (RPNS) as a probe of response-preparation in adult ADHD patients by obtaining high-density event-related potentials from 33 ADHD and 29 matched healthy subjects during a Go/Nogo task using a 128-channel BioSemi recording-system. Compared to controls, ADHD patients showed enhancement of the RPNS in fronto-central brain regions in the Go condition during correct responses. This change was associated with poor performance in the Stroop incongruency-task: the greater the enhancement, the higher the proportion of errors. Moreover, the ERP-enhancement showed association with the severity of ADHD-symptoms; and with heightened response-variability. Thus, ADHD patients demonstrate neurophysiological alterations in response-preparation and response-preceding brain activity, suggestive of excessive activation of prefrontal neural circuits. Given the correlation with neuropsychological and psychopathological measures, these changes may constitute a pathway for core symptoms of ADHD, including premature and impaired response-preparation and motor-hyperactivity.

Response Inhibition in Tic Disorders: Waiting to Respond Is Harder When ADHD Is Present

OBJECTIVE

Tic disorders such as Gilles-de-la-Tourette syndrome (TS) are associated with difficulties in withholding movements and sometimes inappropriate actions. The present study examined whether these disorders lead to a specific difficulty in withholding preprogrammed voluntary movements irrespective of decisions on whether or not to move.

METHOD

Children with TS with or without attention-deficit hyperactivity disorder (ADHD) and controls performed a fast-paced simple reaction time task involving responses to a target in a rapid letter stream (9 letters/s, average foreperiod 332 ms) with feedback on response speed.

RESULTS

The ADHD group showed more premature responses and more variable response time than other groups, whether the timing of the target was predictable or not.

CONCLUSION

The data indicate that in tic disorders, the presence of ADHD is associated with difficulties in waiting to initiate preprogrammed movements independently of response selection or response timing difficulties.