Abstract:
Emotional experiences can profoundly impact our conceptual model of the world, modifying how we represent and remember a host of information even indirectly associated with that experienced in the past. Yet, how a new emotional experience infiltrates and spreads across pre-existing semantic knowledge structures (e.g., categories) is unknown. We used a modified aversive sensory preconditioning paradigm in fMRI (n = 35) to investigate whether threat memories integrate with a pre-established category to alter the representation of the entire category. We observed selective but transient changes in the representation of conceptually related items in the amygdala, medial prefrontal cortex, and occipitotemporal cortex following threat conditioning to a simple cue (geometric shape) pre-associated with a different, but related, set of category exemplars. These representational changes persisted beyond 24 h in the hippocampus and perirhinal cortex. Reactivation of the semantic category during threat conditioning, combined with activation of the hippocampus or medial prefrontal cortex, was predictive of subsequent amygdala reactivity toward novel category members at test. This provides evidence for online integration of emotional experiences into semantic categories, which then promotes threat generalization. Behaviorally, threat conditioning by proxy selectively and retroactively enhanced recognition memory and increased the perceived typicality of the semantic category indirectly associated with threat. These findings detail a complex route through which new emotional learning generalizes by modifying semantic structures built up over time and stored in memory as conceptual knowledge.
摘要:
情感体验可以深刻地影响我们对世界的概念模型,修改我们如何表示和记住许多信息,甚至间接地与过去所经历的信息相关联。然而,新的情感体验如何在预先存在的语义知识结构中渗透和传播(例如,类别)未知。我们在功能磁共振成像(n=35)中使用了改良的厌恶性感觉预处理范式,以调查威胁记忆是否与预先建立的类别相结合以改变整个类别的表示。我们观察到杏仁核中概念相关项目的代表性有选择性但短暂的变化,内侧前额叶皮质,和枕颞叶皮层后的威胁条件为一个简单的线索(几何形状)预先与不同的,但相关,一组类别样本。这些代表性的变化在海马和周围皮层中持续超过24小时。在威胁条件化期间重新激活语义类别,结合海马或内侧前额叶皮层的激活,在测试中可以预测随后的杏仁核对新类别成员的反应性。这为在线将情感体验整合到语义类别中提供了证据,然后促进威胁泛化。行为上,通过代理选择性和追溯性地增强了识别记忆,并增加了与威胁间接相关的语义类别的感知典型性。这些发现详细说明了一条复杂的路线,通过该路线,新的情感学习可以通过修改随着时间的推移而建立并作为概念知识存储在内存中的语义结构来推广。