Abstract
Working memory (WM) dysfunction and increased within-subject variability are known issues in attention deficit/hyperactivity
disorder (ADHD) patients. Little is known about the electrophysiological characteristics of this variability. We evaluated
behavioral and electrophysiological within-subject variability taking developmental aspects into account in a group of ADHD
patients. Multichannel (n = 31) event-related potentials (ERP) were measured during a visuo-spatial backmatching task; 44 children (8–16 years old)
were tested: 22 children with ADHD, combined (n = 17) and inattentive (n = 5) type, and 22 age- and intelligence-matched control children. One-backmatching (BM1) and two-backmatching (BM2) tasks
were performed. Classical behavioral parameters and target and nontarget ERP were compared between groups. In addition, motor
response variability and ERP amplitude variability were studied. Age-related changes in both motor response and ERP amplitude
variability were analyzed in each group. Attention deficit/hyperactivity disorder children made more commission errors, which
was more pronounced in the difficult (BM2) task. No difference between groups was found in ERP amplitude and in motor response
variability. However, ADHD patients had higher ERP amplitude variability, which was again more pronounced in the difficult
WM task. A delayed maturation of amplitude variability was seen in ADHD patients with a slower than in controls decrease in
variability with age. This amplitude variability was correlated with the number of commissions, but in an opposite way for
ADHD and control children. Our findings indicate an impaired visuo-spatial WM processing in ADHD children with greater ERP
amplitude variability compared to controls. Our results also support the view of a delayed cortical development of visuo-spatial
WM circuits in this disorder.
disorder (ADHD) patients. Little is known about the electrophysiological characteristics of this variability. We evaluated
behavioral and electrophysiological within-subject variability taking developmental aspects into account in a group of ADHD
patients. Multichannel (n = 31) event-related potentials (ERP) were measured during a visuo-spatial backmatching task; 44 children (8–16 years old)
were tested: 22 children with ADHD, combined (n = 17) and inattentive (n = 5) type, and 22 age- and intelligence-matched control children. One-backmatching (BM1) and two-backmatching (BM2) tasks
were performed. Classical behavioral parameters and target and nontarget ERP were compared between groups. In addition, motor
response variability and ERP amplitude variability were studied. Age-related changes in both motor response and ERP amplitude
variability were analyzed in each group. Attention deficit/hyperactivity disorder children made more commission errors, which
was more pronounced in the difficult (BM2) task. No difference between groups was found in ERP amplitude and in motor response
variability. However, ADHD patients had higher ERP amplitude variability, which was again more pronounced in the difficult
WM task. A delayed maturation of amplitude variability was seen in ADHD patients with a slower than in controls decrease in
variability with age. This amplitude variability was correlated with the number of commissions, but in an opposite way for
ADHD and control children. Our findings indicate an impaired visuo-spatial WM processing in ADHD children with greater ERP
amplitude variability compared to controls. Our results also support the view of a delayed cortical development of visuo-spatial
WM circuits in this disorder.
- Content Type Journal Article
- Category Original Contribution
- Pages 1-12
- DOI 10.1007/s00787-012-0253-1
- Authors
- I. Myatchin, Department of Woman and Child, Section Paediatric Neurology, University Hospitals KULeuven, Herestraat 49, 3000 Leuven, Belgium
- J. Lemiere, Department of Child and Adolescent Psychiatry, UPC-KULeuven, Leuven, Belgium
- M. Danckaerts, Department of Child and Adolescent Psychiatry, UPC-KULeuven, Leuven, Belgium
- L. Lagae, Department of Woman and Child, Section Paediatric Neurology, University Hospitals KULeuven, Herestraat 49, 3000 Leuven, Belgium
- Journal European Child & Adolescent Psychiatry
- Online ISSN 1435-165X
- Print ISSN 1018-8827