State-related electroencephalographic deviances in attention deficit hyperactivity disorder

Objective: This study aimed to provide more insight into the functional significance of electroencephalographic (EEG) deviances in attention-deficit/hyperactivity disorder (ADHD) by evaluating quantitative EEG during performance on a task with a low activation level and a task tapping top-down executive control. Method: Behavioral performance and EEG activity were compared between 24 adults with ADHD and 20 typically developing adults during a simple slow-paced 2-choice reaction time (2-CRT) task and a moderately paced flanker task. Results: During the slow 2-CRT task, adults with ADHD responded slower, more variably, and tended to make more errors of commission. Although being slower, adults with ADHD showed equally large congruency effects during flanker task performance, indicating intact interference inhibition. In the slow 2-CRT task, (midline) theta and beta power were higher in the ADHD group than in the control group, whereas no significant EEG group differences were observed in the flanker task. A moderate positive correlation between theta power and errors of commission was found in the 2-CRT task for adults with ADHD. Conclusions: Adults with ADHD performed worse on a task inducing a low activation level but showed intact interference inhibition. The EEG findings are in accord with this, showing an abnormal EEG pattern in ADHD only when a low activation level was induced, not when top-down executive control load was high. Time-on-task effects could not explain the group deviances. The findings indicate that EEG deviances in ADHD are task-dependent and may be related to a suboptimal energetic state, rather than impaired top-down executive control

On a BSD-type formula for L-values of Artin twists of elliptic curves

This is an investigation into the possible existence and consequences of a Birch-Swinnerton-Dyer-type formula for L-functions of elliptic curves twisted by Artin representations. We translate expected properties of L-functions into purely arithmetic predictions for elliptic curves, and show that these force some peculiar properties of the Tate-Shafarevich group, which do not appear to be tractable by traditional Selmer group techniques. In particular we exhibit settings where the different p-primary components of the Tate-Shafarevich group do not behave independently of one another. We also give examples of "arithmetically identical" settings for elliptic curves twisted by Artin representations, where the associated L-values can nonetheless differ, in contrast to the classical Birch-Swinnerton-Dyer conjecture.Comment: 27 pages, new versio

No evidence for inhibitory deficits or altered reward processing in ADHD: data from a new integrated incentive delay go/no-go task

Objective: Cognitive and motivational factors differentially affect individuals with mental health problems such as ADHD. Here we introduce a new task to disentangle the relative contribution of inhibitory control and reward anticipation on task performance in children with ADHD and/or autism spectrum disorders (ASD). Method: Typically developing children, children with ADHD, ASD, or both disorders worked during separate sessions for monetary or social rewards in go/no-go tasks with varying inhibitory load levels. Participants also completed a monetary temporal discounting (TD) task. Results: As predicted, task performance was sensitive to both the effects of anticipated reward amount and inhibitory load. Reward amount had different effects depending on inhibitory load level. TD correlated with inhibitory control in the ADHD group. Conclusion: The integration of the monetary incentive delay and go/no-go paradigms was successful. Surprisingly, there was no evidence of inhibitory control deficits or altered reward anticipation in the clinical groups

Altered intrinsic organisation of brain networks implicated in attentional processes in adult attention-deficit/hyperactivity disorder: a resting state study of attention, default mode and salience network connectivity

Deficits in task-related attentional engagement in attention-deficit/hyperactivity disorder (ADHD) have been hypothesized to be due to altered interrelationships between attention, default mode and salience networks. We examined the intrinsic connectivity during rest within and between these networks. Six minutes resting state scans were obtained. Using a network-based approach, connectivity within and between the dorsal and ventral attention, the default mode and the salience networks was compared between the ADHD and control group. The ADHD group displayed hyperconnectivity between the two attention networks and within the default mode and ventral attention network. The salience network was hypoconnected to the dorsal attention network. There were trends towards hyperconnectivity within the dorsal attention network and between the salience and ventral attention network in ADHD. Connectivity within and between other networks was unrelated to ADHD. Our findings highlight the altered connectivity within and between attention networks, and between them and the salience network in ADHD. One hypothesis to be tested in future studies is that individuals with ADHD are affected by an imbalance between ventral and dorsal attention systems with the former playing a dominant role during task engagement making individuals with ADHD highly susceptible to distraction by salient task-irrelevant stimuli

ICT fans the flames of learning: University of Groningen introduces Nestor

In the spring of 2000, the University of Groningen (RUG) launched a university-wide ICT in Education programme: the electronic classroom (EC). In this case that means a kind of distributed learning in which IT-opportunities were mixed with traditional classroom management. Now the pilot year has ended successfully. In the academic year 2000-2001, more than 8,500 students (roughly half of the total number of students at the RUG), and 500 teaching staff made use of Nestor – as the EC has now been christened. This article describes how the EC was implemented. The article focusses on the project organisation, choosing the learning platform and the phases in the project. One of the main conclusions we can draw from the project is that the introduction of new ICT facilities for teachers is more successful if they can be involved in a hands-on capacity at an early stage. Another main conclusion is that the project is a costly one. Now it is completed almost Euro 1.5 million will have been spent over a period of eighteen months. The RUG has taken an important first step by introducing Nestor but there is still a great deal to be done

The influence of working memory load on response inhibition in children with attention-deficit/hyperactivity disorder or reading disorder

The aim of the present study was to examine the relationship between response inhibition and working memory in 8-12-year-old children with attention-deficit/hyperactivity disorder (ADHD; n = 19), reading disorder (RD; n = 17), ADHD + RD (n = 21), and control children (n = 19). For the first time a within-task methodology was used to study the combined effect of both executive functions on a common measure of task performance in two often comorbid childhood disorders, ADHD and RD. We found evidence of an interaction between both domains, suggesting that they rely on a common pool of resources. In addition, we found that children with ADHD or RD were not more seriously affected by the combined load of both executive functions than children without ADHD or RD