Schmajuk Mariana, Liotti Mario, Busse Laura, Woldorff Marty G
Center for Cognitive Neuroscience, Duke University, Durham, Box 90999, NC 27708, USA.
Neuropsychologia. 2006;44(3):384-95. doi: 10.1016/j.neuropsychologia.2005.06.005. Epub 2005 Aug 10.
In a recent ERP study of inhibitory control using the Stop-Signal Task [Pliszka, S., Liotti, M., Woldorff, M. (2000). Inhibitory control in children with attention-deficit/hyperactivity disorder: Event-related potentials identify the processing component and timing of an impaired right-frontal response-inhibition mechanism. Biological Psychiatry, 48, 238-246], we showed that in normal children (age 10-12 years) the Stop Signals elicited a robust, right-frontal-maximal N200 (latency approximately 200 ms) that was strongly reduced in children with ADHD. To further investigate the mechanisms of response inhibition, this paradigm was applied to 11 healthy young adults. To better distinguish response-inhibition-related activity from early attentional effects, a "Stop-Signal-Irrelevant" condition was added, in which subjects performed the task while ignoring the Stop Signals. In the Stop-Signal-Relevant condition, the right frontal N200 to the Stop Signals was larger for Successful inhibition (SI) than for Failed inhibition (FI) trials. The timing and distribution of this effect was strikingly similar to that of the right-frontal ADHD deficit reported in Pliszka et al. (2000), supporting this activity being related to successful normal inhibitory control processes. In contrast, a posterior N200 was larger for Stop-Relevant than for Stop-Irrelevant trials, likely reflecting enhanced early sensory attention to the Stop Signals when relevant. Two longer-latency failure-specific ERP effects were also observed: a greater frontopolar negative wave (370-450 ms) to Failed than Successful inhibitions, and a greater parietal positive slow wave (450-650 ms) for Failed inhibitions than ignore-stop trials, likely reflecting differential recruitment of error detection and correction mechanisms following Failed attempts to inhibit a response.
在最近一项使用停止信号任务对抑制控制进行的事件相关电位（ERP）研究中[普利斯卡，S.，廖蒂，M.，沃尔多夫，M.（2000年）。注意缺陷多动障碍儿童的抑制控制：事件相关电位确定受损的右额叶反应抑制机制的加工成分和时间。《生物精神病学》，48，238 - 246]，我们发现，在正常儿童（10 - 12岁）中，停止信号引发了一个强大的、以右额叶为最大波幅的N200（潜伏期约200毫秒），而患有注意力缺陷多动障碍（ADHD）的儿童中该波幅则大幅降低。为了进一步研究反应抑制的机制，该范式被应用于11名健康的年轻成年人。为了更好地将与反应抑制相关的活动与早期注意力效应区分开来，增加了一种“停止信号 - 无关”条件，即受试者在忽略停止信号的情况下执行任务。在“停止信号 - 相关”条件下，成功抑制（SI）试验中对停止信号的右额叶N200比对失败抑制（FI）试验中的更大。这种效应的时间和分布与普利斯卡等人（2000年）报道的右额叶ADHD缺陷惊人地相似，支持这种活动与正常的成功抑制控制过程相关。相比之下，与停止信号相关试验中的后部N200比与停止信号无关试验中的更大，这可能反映了在相关时对停止信号的早期感觉注意力增强。还观察到了两种潜伏期更长的特定于失败的ERP效应：失败抑制比成功抑制引发更大的额极负波（370 - 450毫秒），以及失败抑制比忽略停止信号试验引发更大的顶叶正慢波（450 - 650毫秒），这可能反映了在抑制反应失败后错误检测和纠正机制的不同募集情况。
