ABSTRACT

Fear-generalization is a critical function for survival, in which an organism extracts information from a specific instantiation of a threat (e.g., the western diamondback rattlesnake in my front yard on Sunday) and learns to fear – and accordingly respond to – pertinent higher-order information (e.g., snakes live in my yard). Previous work investigating fear-conditioning in humans has used functional magnetic resonance imaging (fMRI) to demonstrate that activity patterns representing stimuli from an aversively-conditioned category (CS+) are more similar to each other than those of a neutral category (CS-). Here we used fMRI and multiple aversively-conditioned categories to ask whether we would find only similarity increases within the CS+ categories or also similarity increases between the CS+ categories. Using representational similarity analysis, we correlated several models to activity patterns underlying different brain regions and found that, following fear-conditioning, between-category and within-category similarity increased for the CS+ categories in the insula, superior frontal gyrus (SFG), and the right temporal pole. When specifically investigating fear-generalization, these between- and within-category effects were detected in the SFG. These results advance prior pattern-based neuroimaging work by exploring the effect of aversively-conditioning multiple categories and indicate an extended role for such regions in potentially representing supracategorical information during fear-learning.

摘要

恐惧泛化是生存的关键功能，其中有机体从威胁的特定实例中提取信息（例如，周日在我前院的西部小菜响尾蛇）并学会恐惧——并相应地应对——相关的更高——订单信息（例如，蛇住在我的院子里）。先前研究人类恐惧条件的工作已经使用功能磁共振成像 (fMRI) 来证明代表来自厌恶条件类别 (CS+) 的刺激的活动模式比中性类别 (CS-) 的活动模式更相似。在这里，我们使用功能磁共振成像和多aversively空调的类别来问我们是否会发现唯一的相似之处增加内的CS +类别或相似度也增大在CS+ 类别之间。使用表征相似性分析，我们将几个模型与不同大脑区域下的活动模式相关联，发现在恐惧条件反射后，脑岛、额上回 (SFG) 和 CS+ 类别的类别间和类别内相似性增加右颞极。在专门研究恐惧泛化时，在 SFG 中检测到了这些类别间和类别内的影响。这些结果通过探索厌恶调节多个类别的影响来推进先前基于模式的神经成像工作，并表明这些区域在恐惧学习期间可能代表超类别信息方面的扩展作用。