BACKGROUND Altered brain activity that has been observed in attention deficit hyperactivity disorder (ADHD) while performing cognitive control tasks like the stop signal task (SST) has generally been interpreted as reflecting either weak (under-active) or compensatory (over-active) versions of the same functions as in healthy controls. If so, then regional activities that correlate with the efficiency of inhibitory control (i.e. stop signal reaction time, SSRT) in healthy subjects should also correlate with SSRT in ADHD. Here we test the alternate hypothesis that BOLD (blood-oxygen-level-dependent) differences might instead reflect the redirection of neural processing resources normally used for task-directed inhibitory control, towards actively managing symptomatic behaviour. If so, then activities that correlate with SSRT in TD should instead correlate with inattentive and hyperactive symptoms in ADHD. METHODS We used fMRI (functional magnetic resonance imaging) in 14 typically developing (TD) and 14 ADHD adolescents performing the SST, and in a replication sample of 14 healthy adults. First, we identified significant group BOLD differences during all phases of activity in the SST (i.e. warning, response, reactive inhibition, error detection and post-error slowing). Next, we correlated these phases of activity with SSRT in TD and with SSRT, inattentive and hyperactive symptom scores in ADHD. We then identified whole brain significant correlations in regions of significant group difference in activity. RESULTS Only three regions of significant group difference were correlated with SSRT in TD and replication groups (left and right inferior frontal gyri (IFG) during error detection and hypothalamus during post-error slowing). Consistent with regions of altered activity managing symptomatic behaviour instead of task-directed behaviour, left IFG correlated with greater inattentive score, right IFG correlated with lower hyperactive score and hypothalamus correlated with greater inattentive score and oppositely correlated with SSRT compared to TD. CONCLUSIONS Stimuli that elicit task-directed integration of neural processing in healthy subjects instead appear to be directing integrated function towards managing symptomatic behaviour in ADHD. The ability of the current approach to determine whether altered neural activities reflect comparable functions in ADHD and control groups has broad implications for the development and monitoring of therapeutic interventions.

中文翻译：

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通常归因于抑制控制的粗体差异会预测症状，而不是ADHD中任务导向的抑制控制。

背景技术在执行认知控制任务（如停止信号任务（SST））时，在注意力缺陷多动障碍（ADHD）中观察到的大脑活动变化通常被解释为反映了弱（活动不足）或代偿性（活动过度）两种形式具有与健康对照相同的功能。如果是这样，那么与健康受试者中抑制控制效率（即停止信号反应时间，SSRT）相关的区域活动也应与ADHD中的SSRT相关。在这里，我们测试了另一种假设，即粗体（依赖于血氧水平）的差异可能反映了通常用于任务导向抑制控制的神经处理资源向积极管理症状行为的重定向。如果是这样，那么与TD中的SSRT相关的活动应与ADHD中的注意力不集中和活动过度的症状相关。方法我们在14名典型发育（TD）和14名进行SST的ADHD青少年中以及在14名健康成年人的复制样本中使用fMRI（功能磁共振成像）。首先，我们在SST活动的所有阶段（即警告，响应，反应性抑制，错误检测和错误后减慢）中识别出显着的BOLD组差异。接下来，我们将这些活动阶段与TD的SSRT和ADHD的SSRT，注意力不集中和过度活跃的症状评分相关联。然后，我们在活动的显着组差异区域中确定了全脑的显着相关性。结果在TD组和复制组中，只有三个显着组差异的区域与SSRT相关（错误检测期间左和右下额回（IFG）和错误后减慢期间下丘脑）。与管理症状行为而不是任务指导行为的活动改变区域一致，左IFG与注意力不集中评分较高相关，右IFG与多动症评分较低相关，下丘脑与无意识评分较高相关，与TD相比与SSRT相反。结论在健康受试者中引发任务导向的神经加工整合的刺激似乎正在将整合的功能导向对多动症的症状行为进行管理。