Biomedical subjects

Hanna Swaab-Barneveld

Publications and source records attributed to Hanna Swaab-Barneveld.

5 recordsLinked to original sources

PubMed2005

Motor flexibility problems as a marker for genetic susceptibility to attention-deficit/hyperactivity disorder.

BACKGROUND: Since many children with attention-deficit/hyperactivity disorder (ADHD) have fine visuomotor problems that are already evident at a young age, motor dysfunctioning is investigated in family-genetic perspective. We hypothesized that if fine motor problems may be a marker for genetic susceptibility to ADHD, nonaffected siblings of ADHD probands would experience motor problems similar to those of their ADHD siblings. METHODS: Twenty-five carefully phenotyped ADHD probands with a family history of ADHD, their nonaffected siblings (n = 25), and 48 normal control subjects (aged 6 to 17) completed a motor fluency task and a motor flexibility task. The motor fluency task involved completion of a familiar, automatized trajectory, whereas the motor flexibility task required continuous adjustment of movement to complete an unpredictable random trajectory. RESULTS: On the motor fluency task, the performance of the nonaffected children was significantly better than that of the ADHD probands; strikingly, on the motor flexibility task, they performed as well as their ADHD siblings. CONCLUSIONS: Nonaffected siblings experience complex motor problems similar to their ADHD siblings but only in nonautomatized movements that require controlled processing. The results suggest that higher-order controlled motor deficits in ADHD may be associated with genetic susceptibility for ADHD.

Adolescent↗

PubMed2005

Sustained attention and executive functioning performance in attention-deficit/hyperactivity disorder.

The aim of this study was to further refine the cognitive phenotype of attention-deficit/hyperactivity disorder (ADHD), with respect to the ability to sustain attention and executive functioning. Participants were 34 boys with ADHD (combined type) and 28 normal controls. The groups were closely matched for age and IQ. All participants were 12 years of age. Both groups performed a computerized sustained attention task and a response interference task. Measures related to speed, accuracy, and time on task were collected. We found that children with ADHD performed slower, less accurately, more impulsively, and with less stability than controls. Both groups produced more errors with increasing time on task, reflecting reduced vigilance. Importantly, no interaction with time on task was found. The overall pattern of results suggests that measures related to accuracy are more informative than measures related to speed of responding in refining the cognitive phenotype of ADHD.

Attention↗

PubMed2005

Familial clustering of executive functioning in affected sibling pair families with ADHD.

OBJECTIVE: To investigate familial clustering of executive functioning (i.e., response inhibition, fine visuomotor functioning, and attentional control) in attention-deficit/hyperactivity disorder (ADHD)-affected sibling pairs. METHOD: Fifty-two affected sibling pairs aged 6 to 18 years and diagnosed with ADHD according to DSM-IV performed the Stroop test, go/no-go task, two different fine visuomotor tracking tasks, and a sustained-, divided-, and focused attention task. RESULTS: Significant correlations (r = 0.4) were found between siblings for response inhibition and attentional control and for fine visuomotor skills that made high demands on executive functioning. CONCLUSIONS: Response inhibition, higher order controlled fine visuomotor functioning, and attentional control seem to cluster in ADHD-affected siblings. This suggests that these aspects of executive dysfunctioning may reflect an endophenotype of ADHD. Measurement of these executive functions may facilitate the identification of genes involved in ADHD by forming more homogeneous subgroups.

Adolescent↗

PubMed2004

Executive functioning in children: a comparison of hospitalised ODD and ODD/ADHD children and normal controls.

BACKGROUND: Deficits in executive functioning are supposed to have a predisposing influence on impulsive or aggressive behaviour. We tested the hypothesis that oppositional-defiant disorder (ODD) children with or without attention deficit hyperactivity disorder (ADHD) have problems in executive functioning. METHOD: Seventy-seven 7- to 12-year-old children (15 ODD, 26 ODD/ADHD, and 36 normal controls), all with normal IQ, completed 7 neuropsychological measures of executive functioning, assessing the abilities of set shifting, planning, working memory, inhibition/attention, and impulsivity. Some of these tasks involved the possibility of monetary rewards with a view to testing the prediction of a specific motivational inhibitory deficit. RESULTS: We found no evidence of deficits in working memory, planning, inhibition, or impulsivity. However, the ODD/ADHD group was worse than the normal control (NC) group in set shifting, and both the ODD and ODD/ADHD groups performed worse on a response perseveration task. Moreover, on the basis of one variable derived from a motivational inhibition task, 77% of the children could be correctly classified as ODD or NC. CONCLUSIONS: The findings do not support the hypothesis that ODD and ODD/ADHD children have a deficit in executive inhibitory control; rather, they emphasise that they have problems in regulating their behaviour under motivational inhibitory conditions.

Attention↗

PubMed2003

Deficient response inhibition as a cognitive endophenotype of ADHD.

OBJECTIVE: To investigate whether a deficient response inhibition is a cognitive endophenotype of attention-deficit/hyperactivity disorder (ADHD). The authors hypothesized that nonaffected siblings of ADHD probands would have a response inhibition between that of ADHD probands and normal controls, although they resembled the controls at a behavioral level. METHOD: Participants were 25 ADHD probands with a family history of ADHD, their nonaffected siblings (n = 25), and 48 normal controls matched for age and IQ. All participants were between 6 and 17 years of age. The nonaffected siblings were compared with their ADHD siblings and with controls on measures reflecting different types of response inhibition. RESULTS: The nonaffected siblings had results similar to those of the ADHD probands, who differed from the controls on all inhibition measures (p <.05). CONCLUSIONS: Siblings of ADHD probands, while not behaviorally expressing the disorder, have ADHD-associated deficits in response inhibition. This suggests that subtyping based on measures of response inhibition can help identify genetic susceptibility to ADHD. Children with a genetic vulnerability to ADHD may have hidden cognitive deficits in the absence of manifest behavioral symptoms. Therefore, they should be monitored to detect possible learning problems.

Adolescent↗