Schachar Russell, Logan Gordon D, Robaey Philippe, Chen Shirley, Ickowicz Abel, Barr Cathy
Psychiatry Research Unit, Department of Psychiatry, Brain and Behavior Programme, Research Institute, The Hospital for Sick Children, University of Toronto, 555 University Avenue, Toronto, Ontario, Canada.
J Abnorm Child Psychol. 2007 Apr;35(2):229-38. doi: 10.1007/s10802-006-9075-2. Epub 2007 Mar 10.
We used variations of the stop signal task to study two components of motor response inhibition-the ability to withhold a strong response tendency (restraint) and the ability to cancel an ongoing action (cancellation)-in children with a diagnosis of attention deficit hyperactivity disorder (ADHD) and in non-ADHD controls of similar age (ages 7-14 years). The goal was to determine if restraint and cancellation were related and if both were deficient in ADHD. The stop signal task involved a choice reaction time task (go task) which required a rapid response. The demand for inhibitory control was invoked through the presentation of a stop signal on a subset of go trials which required that the ongoing response be suspended. The stop signal was presented either concurrently with the go signal (restraint version) or after a variable delay (cancellation version). In Study 1, we compared ADHD and control children on the cancellation version of the stop task; in Study 2, we compared ADHD and controls on the restraint version. In Study 3, a subset of ADHD and control participants completed both tasks so that we could examine convergence of these dimensions of inhibition. Compared to control participants, ADHD participants showed a deficit both in the ability to cancel and to restrain a speeded motor response. Performance on the restraint version was significantly correlated with performance on the cancellation version in controls, but not in ADHD participants. We conclude that ADHD is associated with deficits in both restraint and cancellation subcomponents of inhibition.
我们使用停止信号任务的变体，来研究运动反应抑制的两个组成部分——抑制强烈反应倾向的能力（克制）和取消正在进行动作的能力（取消），研究对象为被诊断患有注意力缺陷多动障碍（ADHD）的儿童以及年龄相仿（7至14岁）的非ADHD对照组儿童。目的是确定克制和取消这两种能力是否相关，以及在ADHD中这两种能力是否都存在缺陷。停止信号任务包括一个选择反应时任务（执行任务），该任务需要快速做出反应。通过在一部分执行试验中呈现停止信号来引发对抑制控制的需求，这要求暂停正在进行的反应。停止信号要么与执行信号同时呈现（克制版本），要么在可变延迟后呈现（取消版本）。在研究1中，我们在停止任务的取消版本上比较了ADHD儿童和对照组儿童；在研究2中，我们在克制版本上比较了ADHD儿童和对照组。在研究3中，一部分ADHD参与者和对照组参与者完成了这两项任务，以便我们能够检验这些抑制维度的趋同性。与对照组参与者相比，ADHD参与者在取消和克制快速运动反应的能力上均表现出缺陷。在对照组中，克制版本的表现与取消版本的表现显著相关，但在ADHD参与者中并非如此。我们得出结论，ADHD与抑制的克制和取消子成分的缺陷有关。
