Sonuga-Barke Edmund J S, Elgie Sarah, Hall Martin
School of Psychology, University of Southampton, Highfield, Southampton, SO17 1BJ, UK.
Behav Brain Funct. 2005 Jul 20;1(1):10. doi: 10.1186/1744-9081-1-10.
Children with Attention Deficit/Hyperactivity Disorder (ADHD) often perform poorly on tasks requiring sustained and systematic attention to stimuli for extended periods of time. The current paper tested the hypothesis that such deficits are the result of observable abnormalities in search behaviour (e.g., attention-onset, -duration and -sequencing), and therefore can be explained without reference to deficits in non-observable (i.e., cognitive) processes. Forty boys (20 ADHD and 20 controls) performed a computer-based complex discrimination task adapted from the Matching Familiar Figures Task with four different fixed search interval lengths (5-, 10-, 15- and 20-s). Children with ADHD identified fewer targets than controls (p < 0.001), initiated searches later, spent less time attending to stimuli, and searched in a less intensive and less systematic way (p's < 0.05). There were significant univariate associations between ADHD, task performance and search behaviour. However, there was no support for the hypothesis that abnormalities in search carried the effect of ADHD on performance. The pattern of results in fact suggested that abnormal attending during testing is a statistical marker, rather than a mediator, of ADHD performance deficits. The results confirm the importance of examining covert processes, as well as behavioural abnormalities when trying to understand the psychopathophyiology of ADHD.
患有注意力缺陷多动障碍（ADHD）的儿童在需要长时间持续且系统地关注刺激的任务上往往表现不佳。本文检验了这样一种假设，即此类缺陷是搜索行为中可观察到的异常（例如，注意力起始、持续时间和顺序）的结果，因此无需参考不可观察（即认知）过程中的缺陷即可得到解释。40名男孩（20名ADHD患儿和20名对照组）进行了一项基于计算机的复杂辨别任务，该任务改编自匹配熟悉图形任务，有四种不同的固定搜索间隔时长（5秒、10秒、15秒和20秒）。ADHD患儿识别出的目标比对照组少（p < 0.001），搜索起始时间更晚，关注刺激的时间更少，且搜索强度和系统性更低（p值均< 0.05）。ADHD、任务表现和搜索行为之间存在显著的单变量关联。然而，没有证据支持搜索异常承载了ADHD对表现的影响这一假设。事实上，结果模式表明测试期间的异常注意力是ADHD表现缺陷的一个统计标志，而非中介因素。这些结果证实了在试图理解ADHD的心理病理学时，检查隐蔽过程以及行为异常的重要性。
