‘Episodic Threat Conditioning’: a novel approach to simultaneously measure Pavlovian threat conditioning and episodic memory

The powerful ways future behavior and cognition can be affected by emotional events are typically studied either by means of Pavlovian conditioning or episodic memory paradigms, which both rest on the idea that associations are formed between distinct stimuli experienced closely together in space or time. However, due to their incompatible methods, little is known about how physiological read-outs of Pavlovian conditioning and episodic memory work in concert to affect behavior and other cognitive processes, how they relate to each other, or whether they reflect the activity of distinct associative processes in the first place. To shed light on such questions, a paradigm is needed that can assess both conditioned psychophysiology and episodic memory. We reasoned that multimodal stimuli, consisting of congruent image-sound combinations, have the potential to serve as potent unconditioned stimuli in a paradigm where participants encode a large number ‘mini-conditioning events’. Measuring both pupil dilation and facial electromyography, we found that psychophysiological responses to 20 unique aversive USs – but not positive USs - transferred to arbitrary predictors already after a single paired presentation in this novel paradigm. Real-life emotional aversive and stressful events are likely to involve both Pavlovian conditioning and episodic memory processes. The ‘Episodic Threat Conditioning’ paradigm enables their simultaneous assessment, thereby providing an opportunity to gain more holistic insight into how different expressions of memory interact in mental health and disease.