Mathews Andrew, Yiend Jenny, Lawrence Andrew D
MRC Cognition and Brain Sciences Unit, Cambridge, UK.
J Cogn Neurosci. 2004 Dec;16(10):1683-94. doi: 10.1162/0898929042947810.
In this article, we consider the extent to which variations in the neural activation associated with fear-related stimuli are obligatory or optional. More specifically, we investigated modulation of activation according to type of encoding operation, and how this relates to individual differences in fearfulness and attentional control. In an fMRI study, fear-related (relative to neutral) pictures preferentially activated many of the regions involved in a hierarchical system responsible for organizing defensive behavior, and differential activation in some of these areas was related to self-reported individual variations in fearfulness. Preferential activation according to type of stimulus persisted to a limited extent even when attention was diverted from its emotional aspects. Importantly, however, encoding tasks involving attention to emotional versus nonemotional attributes of the same pictures revealed a pattern of greater activation during emotional encoding, similar to that differentiating fear-related from neutral stimuli. Again, the degree of modulation varied according to individual differences. We conclude that fear-related pictures can recruit activation in the defensive system even when attention is directed elsewhere, but that the extent of this activation is modulated by attentional control mechanisms. More critically, both differential activation and its modulation by attentional control are related to individual variations in emotional vulnerability, in a manner that conforms to predictions derived from existing theoretical accounts.
在本文中，我们探讨了与恐惧相关刺激相关的神经激活变化在何种程度上是必然的或可选择的。更具体地说，我们研究了根据编码操作类型对激活的调节，以及这与恐惧程度和注意力控制方面的个体差异有何关联。在一项功能磁共振成像（fMRI）研究中，与恐惧相关（相对于中性）的图片优先激活了负责组织防御行为的分层系统中涉及的许多区域，并且这些区域中某些区域的差异激活与自我报告的恐惧程度个体差异有关。即使注意力从刺激的情感方面转移，根据刺激类型的优先激活仍在一定程度上持续存在。然而，重要的是，涉及关注同一图片的情感与非情感属性的编码任务显示，在情感编码期间有更大的激活模式，类似于区分与恐惧相关刺激和中性刺激的模式。同样，调节程度因个体差异而异。我们得出结论，即使注意力指向其他地方，与恐惧相关的图片也能在防御系统中引发激活，但这种激活的程度受注意力控制机制调节。更关键的是，差异激活及其由注意力控制的调节都与情绪易感性的个体差异有关，其方式符合从现有理论解释得出的预测。
