Threat learning by proxy: Semantic structures facilitate emotional memory integration throughout the MTL and medial prefrontal cortex

This is the authors' abstract. We don't add key points for this paper.

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 experience in the past. Yet, how a new emotional experience infiltrates and spreads across pre-existing semantic categories is unknown. We used an 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-hours in the hippocampus and perirhinal cortex. During threat conditioning, reactivation of the semantic category interacted with hippocampal/medial prefrontal cortex activity to predict subsequent amygdala activity toward novel category members at test, providing evidence for online integration promoting 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 associative networks built up over time and stored in memory as conceptual knowledge.