An FMRI auditory oddball study of combined-subtype attention deficit hyperactivity disorder.
An FMRI auditory oddball study of combined-subtype attention deficit hyperactivity disorder.
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DOI：
10.1176/appi.ajp.2007.06050876
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发表时间：
2007-11
期刊：
影响因子：
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通讯作者：
M. Stevens;G. Pearlson;K. Kiehl
中科院分区：
文献类型：
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作者：
M. Stevens;G. Pearlson;K. Kiehl
目的对注意缺陷多动障碍(ADHD)的研究可靠地发现，事件相关电位(ERPs)波幅降低，表明大脑对奇怪或新的环境刺激自动定向注意并在工作记忆中表示该信息的能力受损。然而，ADHD患者神经认知异常与特定脑区功能障碍之间的关系尚不清楚。方法利用功能磁共振成像(FMRI)技术，识别在靶点和吸引注意力的奇怪刺激处理过程中出现血流动力学异常的脑区。46名11-18岁的男孩参与了这项研究，其中23名被诊断为ADHD伴多动和冲动(混合型)，23名人口统计学上匹配的对照组受试者。在参与者执行三刺激听觉古怪任务时，收集了与事件相关的fMRI数据。研究人员比较了ADHD参与者和对照组受试者之前与P3事件相关脑区的血流动力学活动。结果ADHD受试者在与注意定向和工作记忆认知过程相关的区域中，表现出由不频繁的注意力参与刺激引起的大脑活动缺陷。这些缺陷与高度可变的任务表现和缓慢的任务表现同时出现。结论本研究将ADHD注意力定向和工作记忆缺陷与特定大脑皮质区域的功能障碍联系起来。结果表明，ADHD的病理生理学损害了大脑系统，这些系统对于分配注意力和使用认知表征来指导认知和行为是重要的。因此，注意力相关的神经功能障碍是ADHD神经生物学理论中需要考虑的重要因素。
OBJECTIVE Studies of attention deficit hyperactivity disorder (ADHD) have reliably found reduced amplitude event-related potentials (ERPs) measuring attention-related brain function, indicating impairment in the brain's ability to automatically orient attention to odd or novel environmental stimuli and to represent that information in working memory. However, the relationship between abnormal neurocognition and dysfunction in specific brain regions in ADHD remains unclear. METHOD The authors used functional magnetic resonance imaging (fMRI) to identify brain regions with abnormal hemodynamic activity during processing of target and novelty oddball stimuli that engage attention. Forty-six boys 11-18 years of age participated in the study, including 23 diagnosed as having ADHD with hyperactivity and impulsivity (combined type) and 23 demographically matched control subjects. Event-related fMRI data were collected while participants performed a three-stimulus auditory oddball task. Hemodynamic activity was compared between ADHD participants and control subjects in brain regions previously linked to P3 ERPs. RESULTS Participants with ADHD showed deficits in brain activity elicited by infrequent attentionally engaging stimuli in regions associated with attentional orienting and working-memory cognitive processes. These deficits co-occurred with highly variable and slow task performance. CONCLUSIONS This study links ADHD attentional orienting and working-memory deficits to dysfunction in specific cortical brain regions. The results indicate that ADHD pathophysiology impairs brain systems that are important for allocating attention and using cognitive representations to guide cognition and behavior. Attention-related neural dysfunction is thus an important factor to consider in neurobiological theories of ADHD.