Department of Psychiatry, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan.
Eur Arch Psychiatry Clin Neurosci. 2013 Oct;263(7):561-73. doi: 10.1007/s00406-013-0407-2. Epub 2013 May 5.
Working memory (WM) is impaired among adults with attention-deficit hyperactivity disorder (ADHD). This study aimed to investigate the brain activation deficit for low-level or increased-load WM among adults with ADHD. A total of 20 adults with ADHD and controls were recruited according to diagnostic interviewing by a psychiatrist. Phonological and visual-spatial 2-back and 3-back tasks were performed under functional magnetic resonance scanning. The results demonstrated that both the adults with ADHD and the controls exhibited activation of the fronto-parietal network for WM, and the intensity was greater in the adult ADHD group. The ADHD group had higher brain activation over the bilateral anterior cingulate, left inferior frontal lobe, hippocampus, and supplementary motor area (SMA) for phonological WM than the control group. When the task loading increased from 2-back to 3-back tasks, the adults with ADHD perceived greater difficulty. The control group exhibited increased brain activation over the frontal-parietal network in response to increased phonological WM load. However, the ADHD group showed decreased brain activation over the left precuneus, insula, and SMA. Further analysis demonstrated that the ADHD group exhibited a greater decrease in brain activation over the left fronto-parietal network, including the precuneus, SMA, insula/inferior frontal lobe, and dorsolateral prefrontal cortex, than the control group. These results suggest that adults with ADHD pay more effort to low demanding phonological WM. On the other hand, brain activation of the left fronto-parietal network is impaired when the demands of WM exceed the capacity of adults with ADHD.
工作记忆（WM）在患有注意力缺陷多动障碍（ADHD）的成年人中受损。本研究旨在探讨 ADHD 成年人在低水平或高负荷 WM 时的大脑激活缺陷。根据精神科医生的诊断访谈，共招募了 20 名 ADHD 成年患者和对照组。在功能磁共振扫描下进行语音和视觉空间 2 回和 3 回任务。结果表明，ADHD 成年患者和对照组均表现出 WM 的额顶叶网络激活，ADHD 成年患者组的强度更大。与对照组相比，ADHD 组在语音 WM 时双侧前扣带回、左额下回、海马体和补充运动区（SMA）的大脑激活更高。当任务负荷从 2 回增加到 3 回时，ADHD 成年患者感到更困难。对照组表现出额顶叶网络的大脑激活增加，以响应增加的语音 WM 负荷。然而，ADHD 组表现出左楔前叶、岛叶和 SMA 的大脑激活减少。进一步的分析表明，与对照组相比，ADHD 组在左额顶叶网络（包括楔前叶、SMA、岛叶/额下回和背外侧前额叶皮质）的大脑激活减少更大。这些结果表明，ADHD 成年患者在进行低要求的语音 WM 时需要付出更多的努力。另一方面，当 WM 的需求超过 ADHD 成年患者的能力时，左额顶叶网络的大脑激活会受损。
