Alerting deficits in children with attention deficit/hyperactivity disorder: event-related fMRI evidence
Qingjiu Cao1, Yufeng Zang, Chaozhe Zhu
1Institute of Mental Health, Peking University, Beijing 100083, China.
Insights
Children with Attention Deficit/Hyperactivity Disorder (ADHD) exhibit attentional alerting deficits. fMRI reveals reduced brain activity in frontal and parietal regions, impacting attention control.
Area of Science:
- Neuroscience
- Developmental Psychology
- Child Psychiatry
Background:
- Attention Deficit/Hyperactivity Disorder (ADHD) is a common childhood developmental disorder.
- Neuropsychological studies indicate attentional alerting deficits in children with ADHD.
- The neurobiological underpinnings of these deficits require further investigation.
Purpose of the Study:
- To explore the neural correlates of intrinsic and phasic alertness deficits in ADHD.
- To compare brain activity in boys with ADHD and age-matched controls during a cued target detection task.
- To identify specific brain regions associated with attention deficits in ADHD.
Main Methods:
- Functional magnetic resonance imaging (fMRI) was employed to examine brain activity.
- A cued target detection task was administered to assess alertness and attention.
- Twelve boys with ADHD and 13 healthy controls participated in the study.
Main Results:
- The ADHD group exhibited a higher error rate and greater reaction time variability.
- Children with ADHD showed reduced activation in frontal (middle and superior frontal gyrus) and parietal (inferior parietal lobe, precuneus) regions.
- Lower activation was also observed in the putamen in the ADHD group.
Conclusions:
- Children with ADHD demonstrate significant deficits in alerting functions.
- These deficits are associated with abnormal neural activity in frontal and parietal regions.
- These brain regions are crucial for top-down attention control processes.
Abstract:
Attention deficit/hyperactivity disorder (ADHD) is one of the most common but poorly understood developmental disorders in childhood. Although neuropsychological studies demonstrate that children with ADHD have attentional alerting deficits, the neurobiological bases of such deficits have not been examined extensively. In this study, by using functional magnetic resonance imaging (fMRI), we explored the neural correlates of intrinsic alertness and phasic alertness deficits in ADHD by comparing twelve boys with ADHD (13.4+/-1.7 years) with 13 age-matched normal controls (13.2+/-1.2 years) in a cued target detection task. Behaviorally, compared with the controls, the ADHD group showed a higher overall error rate and a larger reaction time variability in performing the task. At the neural level, children with ADHD showed less activation than the controls in frontal (middle and superior frontal gyrus), parietal (inferior parietal lobe, precuneus) and putamen regions. These results demonstrate that children with ADHD have deficits in alerting functions and these deficits are related to the abnormal activities in frontal and parietal regions subserving top-down attention control processes.
