División de Neurociencia, Centro de Investigación en Complejidad Social (neuroCICS), Facultad de Gobierno, Universidad del Desarrollo, Santiago, Chile.
Unidad de Imágenes Cuantitativas Avanzadas, Departamento de Imágenes, Clínica Alemana de Santiago, Santiago, Chile.
Sci Rep. 2017 Aug 3;7(1):7181. doi: 10.1038/s41598-017-07681-z.
Attention Deficit Hyperactivity Disorder (ADHD) is the most common neuropsychiatric disorder in childhood and is characterized by a delay of cortical maturation in frontal regions. In order to investigate interference control, which is a key function of frontal areas, a functional MRI study was conducted on 17 ADHD boys and 17 typically developing (TD) boys, while solving the multi source interference task (MSIT). This task consists of two conditions, a "congruent condition" and an "incongruent condition". The latter requires to inhibit information that interferes with task-relevant stimuli. Behavioral results showed that ADHD subjects committed more errors than TD children. In addition, TD children presented a larger MSIT effect -a greater difference in reaction times between the incongruent and the congruent conditions- than ADHD children. Associated to the MSIT effect, neuroimaging results showed a significant enhancement in the activation of the right lateral prefrontal cortex (rlPFC) in ADHD than in TD subjects. Finally, ADHD subjects presented greater functional connectivity between rlPFC and bilateral orbitofrontal cortex than the TD group. This difference in connectivity correlated with worse performance in both groups. Our results could reflect a compensatory strategy of ADHD children resulting from their effort to maintain an adequate performance during MSIT.
注意缺陷多动障碍(ADHD)是儿童期最常见的神经精神疾病,其特征是前额区域皮质成熟延迟。为了研究干扰控制,这是前额区域的关键功能,我们对 17 名 ADHD 男孩和 17 名典型发育(TD)男孩进行了功能磁共振成像研究,同时解决了多源干扰任务(MSIT)。这个任务包括两种情况,“一致条件”和“不一致条件”。后者需要抑制与任务相关的刺激相干扰的信息。行为学结果表明,ADHD 患者比 TD 儿童犯更多的错误。此外,TD 儿童在 MSIT 效应上表现出更大的差异——在不一致条件和一致条件之间的反应时间差异更大——比 ADHD 儿童更大。与 MSIT 效应相关的是,神经影像学结果显示,ADHD 患者右侧外侧前额叶皮层(rlPFC)的激活显著增强,而 TD 患者则没有。最后,ADHD 患者的 rlPFC 与双侧眶额皮层之间的功能连接比 TD 组更强。这种连接上的差异与两组的表现都较差相关。我们的结果可能反映了 ADHD 儿童的一种补偿策略,他们在进行 MSIT 时努力保持足够的表现。