Publications by authors named "Jaap J van der Meere"

As children with epilepsy may have a number of learning and behavioral problems, it is important that insight into the underlying neurocognitive differences in these children, which may underlie these areas of challenge is gained. Executive function (EF) problems particularly are associated with specific learning abilities as well as behavioral problems. We aim to review systematically the current status of empirical studies on the association between EF problems and behavior and socioemotional problems in children with epilepsy.

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Many studies have indicated a close relationship between ADHD and mood symptoms in university students. In the present study, we explore the role of daily functional impairments and executive functioning in the ADHD-mood relationship. A total of 343 adults (126 males) filled out (a) the Conners' Adult ADHD Rating Scale, (b) the Depression Anxiety and Stress Scale, (c) the Weiss Functional Impairment Rating Scale, and (d) the Executive Function Index Scale.

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Error monitoring during task execution is reflected in post-error slowing (PES), which refers to the tendency to slow down performance after making an error in order to prevent future mistakes. The key question of the present study is whether poor error monitoring (reduced magnitude of PES) has negative consequences for daily life executive function skills, as well as functioning in different life settings such as work, family, social, and academic settings. Eighty-five university students performed a lexical decision task and completed The Executive Function Index Scale (EFI), and the Weiss Functional Impairments Rating Scale (WFIRS).

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The aim of this study was to examine Health-Related Quality of Life (HRQoL) of patients with Phenylketonuria (PKU) in three different age groups and to investigate the impact of metabolic control and tetrahydrobiopterin (BH4) treatment on HRQoL of these patients. Participants were 90 early-treated patients aged 7 to 40 years (M = 21.0, SD = 10.

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Cognitive and mental health problems in individuals with the inherited metabolic disorder phenylketonuria (PKU) have often been associated with metabolic control and its history. For the present study executive functioning (EF) was assessed in 21 PKU patients during childhood (T1, mean age 10.4 years, SD = 2.

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Objective: Despite early dietary treatment phenylketonuria patients have lower IQ and poorer executive functions compared to healthy controls. Cognitive problems in phenylketonuria have often been associated with phenylalanine levels. The present study examined the cognitive profile and mental health in adult phenylketonuria, in relation to phenylalanine levels and tetrahydrobiopterin treatment.

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Article Synopsis
  • Individuals with ADHD often fail to adjust their responses after making errors, indicating possible issues with error monitoring and behavioral adaptation essential for learning and achieving goals.
  • A study involving university students with varying levels of ADHD symptoms found that those with lower ADHD scores were better at slowing down and improving accuracy following mistakes, particularly in tasks presented to the right visual field.
  • The results suggest that adults with higher ADHD symptoms struggle with error processing, potentially due to impaired functioning in the left hemisphere of the brain when increased effort is required for tasks.
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Introduction: Many clinical studies have shown that performance of subjects with attention-deficit/hyperactivity disorder (ADHD) is impaired when stimuli are presented at a slow rate compared to a medium or fast rate. According to the cognitive-energetic model, this finding may reflect difficulty in allocating sufficient effort to regulate the motor activation state. Other studies have shown that the left hemisphere is relatively responsible for keeping humans motivated, allocating sufficient effort to complete their tasks.

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Objective: Early treatment of phenylketonuria (ET-PKU) prevents mental retardation, but many patients still show cognitive and mood problems. In this study, it was investigated whether ET-PKU-patients have specific phenylalanine (Phe-)related problems with respect to social-cognitive functioning and social skills.

Methods: Ninety five PKU-patients (mean age 21.

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Many clinical studies reported a compromised brain lateralization in patients with Attention-Deficit/Hyperactivity Disorder (ADHD) without being conclusive about whether the deficit existed in the left or right hemisphere. It is well-recognized that studying ADHD dimensionally is more controlled for comorbid problems and medication effects, and provides more accurate assessment of the symptoms. Therefore, the present study applied the dimensional approach to test the relationship between brain lateralization and self-reported ADHD symptoms in a population sample.

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The present study applied the dimensional approach to test whether self-reported symptoms of Attention Deficit/Hyperactivity Disorder (ADHD) in adults are associated with the speed of interhemispheric interaction. A sample of first grade students (N = 112) completed Conners' Adult ADHD Rating Scales and letter matching reaction time tasks. In the tasks, participants had to match a single target letter displayed below the fixation cross, either on left or right visual field, with one of two letters displayed above the fixation cross, one letter on each visual field.

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In the present experiment, children with mild spastic cerebral palsy and a control group carried out a memory recognition task. The key question was if errors of the patient group are foreshadowed by attention lapses, by weak motor preparation, or by both. Reaction times together with event-related potentials associated with motor preparation (frontal late contingent negative variation), attention (parietal P300), and response evaluation (parietal error-preceding positivity) were investigated in instances where 3 subsequent correct trials preceded an error.

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Article Synopsis
  • The study investigates the effectiveness of the Behavior Rating Inventory of Executive Function (BRIEF) as a monitoring tool for executive functioning (EF) in adults with phenylketonuria (PKU).
  • Despite a significant percentage of PKU patients showing borderline or clinical BRIEF-A scores, these did not correlate with performance on objective neurocognitive tests.
  • The findings suggest that self-reported EF difficulties do not always align with actual EF deficits, indicating that BRIEF-A may not be a reliable method for monitoring EF in this population.
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Objectives: To compare the neurocognitive outcomes of patients with phenylketonuria (PKU) to determine whether decreasing phenylalanine (Phe) levels to <240 is preferable to the use of 360 μmol/L as an upper-target Phe level. An additional aim was to establish the influence of biochemical indices other than Phe on neurocognitive outcomes.

Study Design: Patients with PKU (n = 63; mean age 10.

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This article presents a new Dutch multicenter study ("PKU-COBESO") into cognitive and behavioral sequelae of early and continuously treated Phenylketonuria (PKU) patients. Part of the study sample will consist of young adult PKU patients who have participated in a large neuropsychological study approximately 10 years ago, when they were 7-to-15-year-olds (Huijbregts et al., 2002 [1]).

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Both shared and unique genetic risk factors underlie the two symptom domains of attention deficit hyperactivity disorder (ADHD): inattention and hyperactivity-impulsivity. The developmental course and relationship to co-occurring disorders differs across the two symptom domains, highlighting the importance of their partially distinct etiologies. Familial cognitive impairment factors have been identified in ADHD, but whether they show specificity in relation to the two ADHD symptom domains remains poorly understood.

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Article Synopsis
  • ADHD is linked to performance issues in various tasks, indicating potential general cognitive processing inefficiencies rather than just impulsivity.
  • A study with children diagnosed with ADHD and healthy controls analyzed their results on two cognitive tasks using a model that separates information processing efficiency from speed-accuracy tradeoffs.
  • Findings showed that children with ADHD had lower information processing efficiency, but their speed-accuracy tradeoff was similar to that of the control group, suggesting their cognitive challenges stem from inefficiency rather than impulsivity.
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Article Synopsis
  • Children with ADHD show a stronger tendency to choose immediate smaller rewards over larger delayed ones, highlighting impulsivity.
  • A study was conducted with 25 children with ADHD and 28 controls to see if background "pink noise" could reduce impulsive choices.
  • The results indicated that while children with ADHD made more impulsive choices than the control group, adding noise did not help alleviate this impulsivity, suggesting that the SRD model may not fully explain this behavior.
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This study evaluated the brain activation state during error making in youth with mild spastic cerebral palsy and a peer control group while carrying out a stimulus recognition task. The key question was whether patients were detecting their own errors and subsequently improving their performance in a future trial. Findings indicated that error responses of the group with cerebral palsy were associated with weak motor preparation, as indexed by the amplitude of the late contingent negative variation.

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Background: Emotional lability (EL) is commonly seen in patients with attention-deficit/hyperactivity disorder (ADHD). The reasons for this association remain currently unknown. To address this question, we examined the relationship between ADHD and EL symptoms, and performance on a range of neuropsychological tasks to clarify whether EL symptoms are predicted by particular cognitive and/or motivational dysfunctions and whether these associations are mediated by the presence of ADHD symptoms.

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The study investigated stimulus evaluation time, event preparation, and motor action planning of patients with mild spastic cerebral palsy and a peer control group in the age range of 9 to 18 years. To this end, participants were carrying out a stimulus recognition task. Findings indicated an overall slowness and inaccurate reaction time performance of the patient group.

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Youth with mild spastic cerebral palsy (n = 14) and a peer control group were compared on an oddball paradigm. Here, visual stimuli were presented with low and high probability and participants were instructed to count in silence the number of rare stimuli. The infrequent stimulus typically elicits an enhanced frontal central N2 and a centroparietal P300 event-related brain potential, reflecting orientation and evaluation of stimulus novelty.

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Dependent on criteria used, between 35% and 53% of the participants with cerebral palsy fulfilled the criteria of clinically relevant executive function problems as defined by Conners' (1994) Continuous Performance Test. Executive function problems were noticed mainly in participants with bilateral brain lesions and who had been born preterm. Findings highlight the need to check for attention problems in children with cerebral palsy.

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Context: Attention-deficit/hyperactivity disorder (ADHD) is associated with widespread cognitive impairments, but it is not known whether the apparent multiple impairments share etiological roots or separate etiological pathways exist. A better understanding of the etiological pathways is important for the development of targeted interventions and for identification of suitable intermediate phenotypes for molecular genetic investigations.

Objectives: To determine, by using a multivariate familial factor analysis approach, whether 1 or more familial factors underlie the slow and variable reaction times, impaired response inhibition, and choice impulsivity associated with ADHD.

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Inhibition problems in attention deficit hyperactivity disorder (ADHD) are sensitive to stimulus event rate. This pilot study explores the neural basis of this increased susceptibility to event rate in ADHD. Event-related functional magnetic resonance imaging was used in conjunction with the administration of a fast (1.

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