Jacob van der Meere

Developmental changes in error monitoring: An event-related potential study

The aim of the study was to investigate the developmental trajectory of error monitoring. For this purpose, children (age 7-8), young adolescents (age 13-14) and adults (age 23-24) performed a Go/No-Go task and were compared on overt reaction time (RT) performance and on event-related potentials (ERPs), thought to reflect error detection (error-related negativity: ERN) and conscious evaluation (error positivity: Pe) of the error. RT on correct trials, variability of responding and percentage of errors decreased with age. The latencies of incorrect responses, compared to correct responses, were shorter in children and adolescents than in adults, indicative of developmental changes in impulsive response style. Groups did not differ in the ability to adjust response strategies after making an error (post-error slowing). The ERN amplitude increased with age, the Pe amplitude did not change with age. Possible explanations for the developmental changes in ERN are discussed.

Context-dependent Dynamic Processes in Attention Deficit/Hyperactivity Disorder: Differentiating Common and Unique Effects of State Regulation Deficits and Delay Aversion

The ability to specify differential predictions is a mark of a scientific models’ value. State regulation deficits (SRD) and delay aversion (DAv) have both been hypothesized as context-dependent dynamic dysfunctions in ADHD. However, to date there has been no systematic comparison of their common and unique elements. Here we review these hypotheses—and describe the core and secondary manifestations of the two constructs and review evidence in support of them. Second, we focus on what are seen as the hallmark indicators of the two deficits—preference of small immediate over large delayed rewards for DAv and the slow event rate effect for SRD. We describe the overlap between these two manifestations and then explore how experimental manipulations and the analysis of neuropsychological and physiological mediators of effects can allow us to differentiate these two patterns of neuropsychological dysfunction on the basis of specific predictions. Finally, we highlight the implications of neuropsychological heterogeneity for the practical implementation of tests of DAv and SRD.

State Regulation in Adult ADHD : An Event-related Potential Study

The state regulation hypothesis postulates that poor task performance of children with ADHD is related to poor energetical state control. The current study aimed to investigate whether such a deficit persists in adult ADHD. Event-related potentials (ERPs) were recorded during administration of a Go/No-Go task that incorporated the stressor presentation rate of stimuli. It was found that males with ADHD responded slower than control males in the slow condition, which was accompanied by smaller parietal P3s, suggesting less effort allocation. No group differences were found with respect to the response inhibition measures (errors of commission and the N2 effect). In conclusion, problems in state regulation seem to persist in male adults with ADHD.

Dysfunctional modulation of default mode network activity in attention-deficit/hyperactivity disorder.

The state regulation deficit model posits that individuals with attention-deficit/hyperactivity disorder (ADHD) have difficulty applying mental effort effectively under suboptimal conditions such as very fast and very slow event rates (ERs). ADHD is also associated with diminished suppression of default mode network (DMN) activity and related performance deficits on tasks requiring effortful engagement. The current study builds on these 2 literatures to test the hypothesis that failure to modulate DMN activity in ADHD might be especially pronounced at ER extremes. Nineteen adults with ADHD and 20 individuals without any neuropsychiatric condition successfully completed a simple target detection task under 3 ER conditions (2-, 4-, and 8-s interstimulus intervals) inside the scanner. Task-related DMN deactivations were compared between 2 groups. There was a differential effect of ER on DMN activity for individuals with ADHD compared to controls. Individuals with ADHD displayed excessive DMN activity at the fast and slow, but not at the moderate ER. The results indicate that DMN attenuation in ADHD is disrupted in suboptimal energetic states where additional effort is required to optimize task engagement. DMN dysregulation may be an important element of the neurobiological underpinnings of state regulation deficits in ADHD.

Response Inhibition and Immediate Arousal in Children with High-Functioning Autism

The current study compared high-functioning children with autism (HFA) and a peer control group on an immediate arousal task measuring response inhibition. In one condition go stimuli were presented whereas in another condition a tone preceded the go stimulus. The tone caused an immediate arousal effect, which resulted in a reaction time decrease and an error rate increase. It was expected that children with HFA would produce a higher error rate in comparison with normal peers, since they might be less able to suppress immediate arousal. However, the HFA group outperformed the control group, indicating neither arousal regulation deficit nor response inhibition deficit.

Event rate and reaction time performance in ADHD: testing predictions from the state regulation deficit hypothesis using an ex-Gaussian model

According to the state regulation deficit (SRD) account, ADHD is associated with a problem using effort to maintain an optimal activation state under demanding task settings such as very fast or very slow event rates. This leads to a prediction of disrupted performance at event rate extremes reflected in higher Gaussian response variability that is a putative marker of activation during motor preparation. In the current study, we tested this hypothesis using ex-Gaussian modeling, which distinguishes Gaussian from non-Gaussian variability. Twenty-five children with ADHD and 29 typically developing controls performed a simple Go/No-Go task under four different event-rate conditions. There was an accentuated quadratic relationship between event rate and Gaussian variability in the ADHD group compared to the controls. The children with ADHD had greater Gaussian variability at very fast and very slow event rates but not at moderate event rates. The results provide evidence for the SRD account of ADHD. However, given that this effect did not explain all group differences (some of which were independent of event rate) other cognitive and/or motivational processes are also likely implicated in ADHD performance deficits.

Visual orientation in hospitalized boys with early onset conduct disorder and borderline intellectual functioning

The aim of the present study is to investigate visual orientation in hospitalized boys with severe early onset conduct disorder and borderline intellectual functioning. It is tested whether boys with the dual diagnosis have a stronger action-oriented response style to visual-cued go signals than the norm. To this end, boys with the dual diagnosis were compared with a peer control group on Posners (1980) visual-spatial detection test. Here, on each trial, a visual cue points either in the direction of the location of a subsequent go signal (valid cue), or points in the opposite direction away from the location of the subsequent go signal (invalid cue). Findings indicated superior orientation (a strong action-oriented response style) of children with the dual diagnosis in valid-cued trials as well as in invalid-cued trials in both the left and the right visual hemifield. Findings were controlled for attention scores on the Child Behavior Checklist -Teacher Form and IQ scores.