Heinrich H, Moll G H, Dickhaus H, Kolev V, Yordanova J, Rothenberger A
Child and Adolescent Psychiatry, University of Göttingen, v. Siebold-Strasse 5, D-37075 Göttingen, Germany.
Clin Neurophysiol. 2001 Jul;112(7):1280-7. doi: 10.1016/s1388-2457(01)00541-7.
The aim of this event-related potential (ERP) study was to test time-on-task analysis at the level of single sweeps in a clinical trial. Since inattentiveness is one of the main symptoms of attention-deficit hyperactivity disorder (ADHD), this child psychiatric disorder was chosen as an exemplary application.
Twenty-four healthy and 24 ADHD boys, aged 9--15 years, performed an auditory selective attention task for about 5 min. ERP single trials were analyzed using wavelet networks. Time-on-task analysis was applied to omission errors, reaction time and slow ERP components (frontal negativity, parietal positivity), represented by a low-frequency wavelet component.
Both performance and ERP measures showed distinct temporal dynamics. Time-on-task effects were not only linear, but also of higher order and started after less than 1 min. For ADHD children, earlier time-on-task effects, i.e. an earlier increase of omission errors and frontal negativity, resulted. Healthy children could allocate more attentional resources during the course of the experiment.
Time-on-task analysis at the level of single trials revealed phenomena probably reflecting ADHD children's attentional deficits. Thus, a more differentiated ERP analysis may provide a better understanding of the pathophysiological background in neuropsychiatric disorders.
本事件相关电位（ERP）研究旨在测试一项临床试验中单次扫描水平上的任务执行时间分析。由于注意力不集中是注意力缺陷多动障碍（ADHD）的主要症状之一，因此选择这种儿童精神疾病作为一个典型应用。
24名9至15岁的健康男孩和24名患有ADHD的男孩进行了约5分钟的听觉选择性注意任务。使用小波网络分析ERP单次试验。任务执行时间分析应用于遗漏错误、反应时间和由低频小波成分表示的缓慢ERP成分（额叶负波、顶叶正波）。
行为表现和ERP测量均显示出明显的时间动态变化。任务执行时间效应不仅呈线性，还具有更高阶性，且在不到1分钟后就开始出现。对于ADHD儿童，出现了更早的任务执行时间效应，即遗漏错误和额叶负波更早增加。健康儿童在实验过程中能够分配更多的注意力资源。
单次试验水平上的任务执行时间分析揭示了可能反映ADHD儿童注意力缺陷的现象。因此，更具区分性的ERP分析可能有助于更好地理解神经精神疾病的病理生理背景。
