Psychophysiology Laboratory, Institute of Psychology, Jagiellonian University, Cracow, Poland.
Int J Psychophysiol. 2012 Jul;85(1):93-105. doi: 10.1016/j.ijpsycho.2011.05.007. Epub 2011 Jun 12.
The Stop-Signal Task (SST) is a procedure that can provide a measure of inhibitory control of an ongoing motor response. We used the stop-signal paradigm to determine whether deficient inhibitory control distinguishes children with a diagnosis of attention deficit hyperactivity disorder combined type (ADHD-Com) from normally developing children, matched on age and sex. Participants performed a standard visual two-choice task with an auditory stop-signal stimulus, while an EEG was recorded. The behavioral results indicated that the ADHD group had significantly impaired inhibitory control compared to the performance of normal children. Relative to controls, the go stimulus reaction time (RT) and the stop-signal reaction time (SSRT) were prolonged in children with ADHD. The amplitudes of P2 and P3 components to the auditory stop-signal were more pronounced for successful than for unsuccessful stop-signal trials in both groups. However, the successful-unsuccessful difference was larger in control subjects. In contrast, the amplitude of the N2 component to auditory stop-signal was more pronounced for unsuccessful than for successful stop-signal trials in both groups. The comparison of the N2 component between control and ADHD groups revealed a greater amplitude and longer latency in the latter group, in successful stop-signal trials only. Additionally, the amplitude of response-locked ERPs, containing the ERN-Pe complex related to error-detection, was smaller in ADHD children. These results support the hypothesis of a complex deficit of inhibitory control, conflict monitoring, and error recognition mechanisms in ADHD and corroborate the utility of the stop-signal task in distinguishing hyperactive from normal children.
停止信号任务（SST）是一种可以衡量正在进行的运动反应抑制控制能力的程序。我们使用停止信号范式来确定抑制控制不足是否可以区分患有注意力缺陷多动障碍混合型（ADHD-Com）的儿童和具有年龄和性别匹配的正常发育儿童。参与者执行带有听觉停止信号刺激的标准视觉二选一任务，同时记录 EEG。行为结果表明，与正常儿童相比，ADHD 组的抑制控制能力明显受损。与对照组相比，ADHD 儿童的 Go 刺激反应时间（RT）和停止信号反应时间（SSRT）延长。在两组中，成功和不成功的停止信号试验的 P2 和 P3 成分的振幅对于成功的停止信号试验比对不成功的停止信号试验更为明显。然而，在对照组中，成功-不成功差异更大。相比之下，在两组中，不成功的停止信号试验的 N2 成分的振幅对于成功的停止信号试验比对不成功的停止信号试验更为明显。对对照组和 ADHD 组的 N2 成分进行比较，发现只有在成功的停止信号试验中，后者组的振幅更大，潜伏期更长。此外，与错误检测相关的 ERN-Pe 复合反应锁定 ERP 的振幅在 ADHD 儿童中较小。这些结果支持 ADHD 中抑制控制、冲突监测和错误识别机制的复杂缺陷假说，并证实了停止信号任务在区分多动儿童和正常儿童方面的有效性。
