Weissman D H, Giesbrecht B, Song A W, Mangun G R, Woldorff M G
Center for Cognitive Neuroscience and Department of Psychological and Brain Sciences, Duke University, Box 90999, Durham, NC 27708, USA.
Neuroimage. 2003 Aug;19(4):1361-8. doi: 10.1016/s1053-8119(03)00167-8.
Parallel processing affords the brain many advantages, but processing multiple bits of information simultaneously presents formidable challenges. For example, while one is listening to a speaker at a noisy social gathering, processing irrelevant conversations may lead to the activation of irrelevant perceptual, semantic, and response representations that conflict with those evoked by the speaker. In these situations, specialized brain systems may be recruited to detect and resolve conflict before it leads to incorrect perception and/or behavior. Consistent with this view, recent findings indicate that dorsal/caudal anterior cingulate cortex (dACC), on the medial walls of the frontal lobes, detects conflict between competing motor responses primed by relevant versus irrelevant stimuli. Here, we used a cued global/local selective attention task to investigate whether the dACC plays a general role in conflict detection that includes monitoring for conflicting perceptual or semantic representations. Using event-related functional magnetic resonance imaging (fMRI), we found that the dACC was activated by response conflict in both the global and the local task, consistent with results from prior studies. However, dACC was also activated by perceptual and semantic conflict arising from global distracters during the local task. The results from the local task have implications for recent theories of attentional control in which the dACC's contribution to conflict monitoring is limited to response stages of processing, as well as for our understanding of clinical disorders in which disruptions of attention are associated with dACC dysfunction.
并行处理赋予大脑许多优势，但同时处理多条信息也带来了巨大挑战。例如，当一个人在嘈杂的社交聚会上听演讲者讲话时，处理无关的对话可能会导致激活与演讲者引发的感知、语义和反应表征相冲突的无关表征。在这些情况下，专门的大脑系统可能会被征募来在冲突导致错误感知和/或行为之前检测并解决冲突。与此观点一致，最近的研究结果表明，位于额叶内侧壁的背侧/尾侧前扣带皮层（dACC）能检测由相关与无关刺激引发的竞争性运动反应之间的冲突。在此，我们使用了一个线索化全局/局部选择性注意任务来研究dACC是否在冲突检测中发挥普遍作用，包括监测冲突的感知或语义表征。使用事件相关功能磁共振成像（fMRI），我们发现dACC在全局任务和局部任务中均被反应冲突激活，这与先前研究结果一致。然而，在局部任务中，dACC也被全局干扰物引发的感知和语义冲突激活。局部任务的结果对最近的注意力控制理论有影响，在这些理论中，dACC对冲突监测的贡献仅限于加工的反应阶段，同时也影响我们对临床疾病的理解，在这些疾病中，注意力的干扰与dACC功能障碍有关。
