The Significance of Impulsive Error in Children With ADHD

Effects of Twenty Hours of Neurofeedback-Based Neuropsychotherapy on the Executive Functions and Achievements among ADHD Children

Objective. Neurofeedback can reduce ADHD symptoms; however, current programs are relatively long, with fewer concerns about executive function (EF). The present study aimed to investigate a 20-hour combined computerized training neurofeedback program. Methods. Fifty ADHD children were randomly assigned to either the experimental group (EXP) or the wait-list control group (CON), who took training after the post-tests. The EF measures were the Tower of London (ToL), Wisconsin Card Sorting Test (WCST), and Comprehensive Nonverbal Attention Test (CNAT). SNAP-IV and questionnaires reported by parents constituted the behavioral measures. Two-way repeated-measures ANOVA and bootstrapping dependent t-tests were also used. Results. The F-tests revealed the interaction effects on ADHD symptoms and math scores. The EXP had increased the ToL scores, decreased the error and perseverative error rates on WCST, as well as the dysexecutive index on CNAT in the t-test. Conclusions. The training effects were related to behavioral symptoms and functions, EFs, and generalized achievement performances. We suggest that future studies could apply to different patients and examine the maintenance of the program.

Can electroencephalography (EEG) identify ADHD subtypes? A systematic review

Attention Deficit/Hyperactivity Disorder (ADHD) has been associated with atypical patterns of neural activity measured by electroencephalography (EEG). However, the identification of EEG diagnostic biomarkers has been complicated by the disorder's heterogeneity. The objective of this review was to synthesize the literature investigating EEG variation in patients diagnosed with ADHD, addressing the following questions: 1) Are the diagnostic ADHD subtypes associated with different EEG characteristics? 2) Are EEG measures correlated with ADHD traits and/or symptom severity? and 3) Do classification techniques using EEG measures reveal different clinical presentations of ADHD? Outcomes highlight the potential for electrophysiological measures to provide meaningful insights into the heterogeneity of ADHD, although direct translation of EEG biomarkers for diagnostic purposes is not yet supported. Key measures that show promise for the discrimination of existing ADHD subtypes and symptomatology include: resting state and task-related modulation of alpha, beta and theta power, and the event-related N2 and P3 components. Prescriptions are discussed for future studies that may help to bridge the gap between research and clinical application.

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.