Neural mechanisms underlying selective attention to threat
Neural mechanisms underlying selective attention to threat
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DOI：
10.1196/annals.1417.016
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发表时间：
2008-01-01
期刊：
影响因子：
--
通讯作者：
Bishop, Sonia J.
中科院分区：
文献类型：
--
作者：
Bishop, Sonia J.
选择性注意的有偏竞争模型表明，注意竞争既受到自下而上对刺激突显敏感的感觉机制的影响，也受到支持任务相关刺激加工的自上而下控制机制的影响。这为研究选择性注意威胁的神经机制提供了一个框架。与威胁检测有关的皮质下区域--特别是杏仁核--和涉及自上而下注意控制的前额叶皮质区域，都会在任务无关的威胁刺激下被激活。一些问题，包括杏仁核对威胁分心物反应的自动性，杏仁核焦虑的调制和对这些刺激的前额叶反应，以及遗传和环境因素对这一回路的影响。经验性文献是在选择性注意和有意识意识的神经基础的理论描述的背景下被考虑的。结果表明，特定视觉刺激引起的神经活动受自下而上轨迹强度(如呈现时间、后向掩蔽)、刺激突显性(包括威胁相关)、与其他视觉刺激对知觉加工资源的竞争以及通过自上而下分配注意资源来扩大刺激轨迹的因素的影响。特质和状态焦虑以及基因构成的个体差异被认为通过影响杏仁核和前额叶功能来调节刺激效价和自上而下注意力的影响。
Biased competition models of selective attention suggest that attentional competition is influenced both by bottom-up sensory mechanisms sensitive to stimulus salience and top-down control mechanisms that support the processing of task-relevant stimuli. This provides a framework for investigating the neural mechanisms underlying selective attention to threat. Both subcortical regions implicated in threat detection-specifically the amygdala-and prefrontal cortical regions implicated in top-down attentional control are activated in response to task-irrelevant threat stimuli. A number of questions including the automaticity of the amygdala response to threat distractors, the modulation by anxiety of the amygdala and prefrontal response to these stimuli, and the impact of genetic and environmental factors upon this circuitry are addressed. The empirical literature is considered in the context of theoretical accounts of the neural substrate of selective attention and conscious awareness. It is suggested that the neural activity provoked by a given visual stimulus is influenced by factors impacting upon the strength of the bottom-up trace (e.g., presentation time, backward masking), stimulus salience (including threat relatedness), competition with other visual stimuli for perceptual processing resources, and the augmentation of the stimulus trace by allocation of top-down attentional resources. Individual differences in trait and state anxiety, and in genetic makeup, are thought to modulate the influence of stimulus valence and top-down attention through their impact upon amygdala and prefrontal function.