Bishop Sonia, Duncan John, Brett Matthew, Lawrence Andrew D
Medical Research Council Cognition and Brain Sciences Unit, 15 Chaucer Road, Cambridge CB2 2EF, UK.
Nat Neurosci. 2004 Feb;7(2):184-8. doi: 10.1038/nn1173. Epub 2004 Jan 4.
Threat-related stimuli are strong competitors for attention, particularly in anxious individuals. We used functional magnetic resonance imaging (fMRI) with healthy human volunteers to study how the processing of threat-related distractors is controlled and whether this alters as anxiety levels increase. Our work builds upon prior analyses of the cognitive control functions of lateral prefrontal cortex (lateral PFC) and anterior cingulate cortex (ACC). We found that rostral ACC was strongly activated by infrequent threat-related distractors, consistent with a role for this area in responding to unexpected processing conflict caused by salient emotional stimuli. Participants with higher anxiety levels showed both less rostral ACC activity overall and reduced recruitment of lateral PFC as expectancy of threat-related distractors was established. This supports the proposal that anxiety is associated with reduced top-down control over threat-related distractors. Our results suggest distinct roles for rostral ACC and lateral PFC in governing the processing of task-irrelevant, threat-related stimuli, and indicate reduced recruitment of this circuitry in anxiety.
与威胁相关的刺激是注意力的强大竞争者，在焦虑个体中尤为如此。我们利用功能磁共振成像（fMRI）对健康人类志愿者进行研究，以探讨与威胁相关的干扰因素的处理是如何受到控制的，以及随着焦虑水平的增加这是否会发生变化。我们的研究建立在先前对外侧前额叶皮层（外侧PFC）和前扣带回皮层（ACC）认知控制功能的分析基础之上。我们发现，不常见的与威胁相关的干扰因素会强烈激活喙部ACC，这与该区域在应对由显著情绪刺激引起的意外加工冲突中所起的作用相一致。焦虑水平较高的参与者总体上喙部ACC活动较少，并且随着与威胁相关的干扰因素预期的建立，外侧PFC的募集也减少。这支持了焦虑与对与威胁相关的干扰因素自上而下控制减少有关的观点。我们的结果表明，喙部ACC和外侧PFC在控制与任务无关的、与威胁相关的刺激处理中具有不同作用，并表明焦虑状态下该神经回路的募集减少。
