The influence of repetitive thoughts of CS-US pairing on expectancy learning and evaluative conditioning: a fundamental study

Repetitive thinking is a common phenomenon, also implicated in a variety of mental disorders. The content of repetitive thoughts can take the form of prediction of aversive events (in worry) or evoking negatively valenced information (in rumination), for instance. Investigating the influence of repetitive thinking through the lens of associative learning could help deepen our understanding of the mechanisms involved in its effects.In two experiments, non-clinical participants were exposed to CS-US pairings with the aim of creating non-threatening expectancy learning (Experiment 1) or evaluative conditioning (Experiment 2). After each conditioning trial, participants were instructed to initiate repetitive thoughts about the pairing (i.e. rehearse) or follow control instructions.Experiment 1 (N = 64) showed that such intervention strengthen the association between the mental representations of the CS and the US, leading to a stronger US expectancy in response to the CS. In Experiment 2 (N = 107), an evaluative conditioning effect was observed; however, it was not influenced by instructions.The study demonstrated that simulated repetitive thinking strengthens the CS-US association and leads to greater US expectancy in expectancy learning, despite appearing not to influence the evaluative conditioning effect. The potential implications of these findings on repetitive thinking are discussed.