Threat learning impairs subsequent memory recombination with past episodes

To successfully predict important events, the representations in memory on which we rely need to be constantly updated and transformed to best reflect a complex and dynamic world. Here we employed a novel paradigm to investigate how memories of threat learning affect the flexible recombination across distinct but overlapping experiences, an ability referred to as relational memory. Participants (n=35) visited the lab to first encode neutral associations (A - B), which were reactivated and predictively associated with a new aversive or neutral element (B - C) on the following day, whilst pupil dilation was measured as an index of arousal. Then, again one day later, the accuracy of relational memory judgements (A - C?) was tested. Novel association to threat was found to impair relational memory. Unexpectedly, this effect was not moderated by arousal. We propose that compartmentalization of threat learning events could be a function of a healthy memory, preventing maladaptive ‘episodic overgeneralization’ of threat to previously encoded episodes.