Choon Guan Lim

A brain-computer interface based attention training program for treating attention deficit hyperactivity disorder.

Attention deficit hyperactivity disorder (ADHD) symptoms can be difficult to treat. We previously reported that a 20-session brain-computer interface (BCI) attention training programme improved ADHD symptoms. Here, we investigated a new more intensive BCI-based attention training game system on 20 unmedicated ADHD children (16 males, 4 females) with significant inattentive symptoms (combined and inattentive ADHD subtypes). This new system monitored attention through a head band with dry EEG sensors, which was used to drive a feed forward game. The system was calibrated for each user by measuring the EEG parameters during a Stroop task. Treatment consisted of an 8-week training comprising 24 sessions followed by 3 once-monthly booster training sessions. Following intervention, both parent-rated inattentive and hyperactive-impulsive symptoms on the ADHD Rating Scale showed significant improvement. At week 8, the mean improvement was −4.6 (5.9) and −4.7 (5.6) respectively for inattentive symptoms and hyperactive-impulsive symptoms (both p<0.01). Cohen’s d effect size for inattentive symptoms was large at 0.78 at week 8 and 0.84 at week 24 (post-boosters). Further analysis showed that the change in the EEG based BCI ADHD severity measure correlated with the change ADHD Rating Scale scores. The BCI-based attention training game system is a potential new treatment for ADHD. Trial Registration ClinicalTrials.gov NCT01344044

Intrinsic Affective Network Is Impaired in Children with Attention-Deficit/Hyperactivity Disorder

Deficits in impulsivity and affect dysregulation are key features of attention-deficit/hyperactivity disorder (ADHD) besides impairing levels of hyperactivity and/or inattention. However, the neural substrates underlying these traits are relatively under-investigated. In this study, we use resting-state functional magnetic resonance imaging to test the hypothesis of diminished functional integration within the affective/limbic network (which includes the amygdala, hippocampus, subgenual cingulate cortex, orbitofrontal cortex and nucleus accumbens) of children with ADHD, which is associated with their behavioral measures of emotional control deficits. Resting state-fMRI data were obtained from 12 healthy control subjects and 15 children with ADHD, all who had a minimum one-month washout period for medications and supplements. Children with ADHD demonstrated less integrated affective network, evidenced by increased bilateral amygdalar and decreased left orbitofrontal connectivity within the affective network compared to healthy controls. The hyper-connectivity at the left amygdalar within the affective network was associated with increased aggressiveness and conduct problems, as well as decline in functioning in children with ADHD. Similar findings in affective network dysconnectivity were replicated in a subset of children with ADHD three months later. Our findings of divergent changes in amygdala and orbitofrontal intrinsic connectivity support the hypothesis of an impaired functional integration within the affective network in childhood ADHD. Larger prospective studies of the intrinsic affective network in ADHD are required, which may provide further insight on the biological mechanisms of emotional control deficits observed in ADHD.

Brain-computer-interface-based intervention re-normalizes brain functional network topology in children with attention deficit/hyperactivity disorder

A brain-computer-interface (BCI)-based attention training game system has shown promise for treating attention deficit/hyperactivity disorder (ADHD) children with inattentive symptoms. However, little is known about brain network organizational changes underlying behavior improvement following BCI-based training. To cover this gap, we aimed to examine the topological alterations of large-scale brain functional networks induced by the 8-week BCI-based attention intervention in ADHD boys using resting-state functional magnetic resonance imaging method. Compared to the non-intervention (ADHD-NI) group, the intervention group (ADHD-I) showed greater reduction of inattention symptoms accompanied with differential brain network reorganizations after training. Specifically, the ADHD-NI group had increased functional connectivity (FC) within the salience/ventral attention network (SVN) and increased FC between task-positive networks (including the SVN, dorsal attention (DAN), somatomotor, and executive control network) and subcortical regions; in contrast ADHD-I group did not have this pattern. In parallel, ADHD-I group had reduced degree centrality and clustering coefficient as well as increased closeness in task-positive and the default mode networks (prefrontal regions) after the training. More importantly, these reduced local functional processing mainly in the SVN were associated with less inattentive/internalizing problems after 8-week BCI-based intervention across ADHD patients. Our findings suggest that the BCI-based attention training facilitates behavioral improvement in ADHD children by reorganizing brain functional network from more regular to more random configurations, particularly renormalizing salience network processing. Future long-term longitudinal neuroimaging studies are needed to develop the BCI-based intervention approach to promote brain maturation in ADHD.

Omega-3 ( ω -3) and social skills interventions for reactive aggression and childhood externalizing behavior problems: a randomized, stratified, double-blind, placebo-controlled, factorial trial

BACKGROUND While studies suggest that nutritional supplementation may reduce aggressive behavior in children, few have examined their effects on specific forms of aggression. This study tests the primary hypothesis that omega-3 (ω-3), both alone and in conjunction with social skills training, will have particular post-treatment efficacy for reducing childhood reactive aggression relative to baseline. METHODS In this randomized, double-blind, stratified, placebo-controlled, factorial trial, a clinical sample of 282 children with externalizing behavior aged 7-16 years was randomized into ω-3 only, social skills only, ω-3 + social skills, and placebo control groups. Treatment duration was 6 months. The primary outcome measure was reactive aggression collected at 0, 3, 6, 9, and 12 months, with antisocial behavior as a secondary outcome. RESULTS Children in the ω-3-only group showed a short-term reduction (at 3 and 6 months) in self-report reactive aggression, and also a short-term reduction in overall antisocial behavior. Sensitivity analyses and a robustness check replicated significant interaction effects. Effect sizes (d) were small, ranging from 0.17 to 0.31. CONCLUSIONS Findings provide some initial support for the efficacy of ω-3 in reducing reactive aggression over and above standard care (medication and parent training), but yield only preliminary and limited support for the efficacy of ω-3 in reducing overall externalizing behavior in children. Future studies could test further whether ω-3 shows promise in reducing more reactive, impulsive forms of aggression.

An ocular artefacts correction method for discriminative EEG analysis based on logistic regression

Electrooculogram (EOG) contamination is a common critical issue in general EEG studies as well as in building highperformance brain computer interfaces (BCI). Existing regression or independent component analysis based artefacts correction methods are usually not applicable when EOG is not available or when there are very few EEG channels. In this paper, we propose a novel ocular artefacts correction method for processing EEG without using dedicated EOG channels. The method constructs estimate of ocular components through artefacts detection in EEG. Then, an optimization based on logistic regression is introduced to remove the components from EEG. Specifically, the optimization ensures that the discriminative information is maintained in the corrected EEG signals. The proposed method is offline evaluated with a large EEG data set containing 68 subjects. Experimental results show that, through the artefacts removal correction by the proposed method, EEG classification accuracy can be improved with statistical significance.

Brain-computer interface and its applications in cognitive training

We investigated the use of Brain-Computer Interface (BCI) in cognitive training. We developed a BCI to quantify a persons attention level. Based on this algorithm, a feedforward mechanism is then used to build gaming interfaces for cognitive training. Several clinical trials have been conducted and significant improvement has been achieved in both children with ADHD and elderly with cognitive decline. Pivotal trials to demonstrate the efficacy of cognitive training are under way in both children and elderly subjects.

Can We Play with ADHD? An Alternative Game-Based Treatment for Inattentive Symptoms in Attention-Deficit/Hyperactivity Disorder

Attention-deficit/hyperactivity disorder (ADHD) is a neurodevelopmental disorder presenting in early childhood with persistent, pervasive and impairing symptoms. It is also associated with other problematic mental health issues and negative outcomes, such as aggression, difficulties forming relationships and academic and occupational problems. Current standard treatments for ADHD include pharmacological treatments with stimulants and other medications, psychosocial interventions such as behavioural modifications, or a combination of both approaches (multi-modal approach consisting of parent education, medication and behaviour management for the child). There is interest in understanding effective non-pharmacological treatments for ADHD, given the temporary effects of medication and recent controversies on over-medicating children with ADHD. The use of neurofeedback treatment and cognitive training offers a promising new area for clinicians. We present a brain–computer interface (BCI)-based neurofeedback and cognitive training programme targeting the inattentive symptoms of ADHD in this chapter. The concept of an individualized model of attention is one of the features of the BCI training system. Incorporating this attention model into an innovative game targeted at ADHD children is another unique feature of this system. Recognizing the importance of validating serious games for the use of therapy, we have conducted several trials testing out the validity and playability of the BCI game, including a pilot phase and a larger randomized controlled trial. Currently, the future of this BCI-based treatment for ADHD is promising and we hope that, through our research efforts, it may prove to be an effective and viable treatment option that also appeals to the game-playing nature of children.