Pavlovian bias instigates suboptimal choices

In daily life, decisions are often biased by Pavlovian (e.g., reward-associated) cues present in the environment. Here, we propose that Pavlovian bias can instigate suboptimal choices. Using a modified Pavlovian-to-Instrumental Transfer (PIT) paradigm, participants first learned an optimal decision-making strategy which consisted in preferring the rich option (70% reward probability) over the poor option (30% reward probability) to maximize rewards. Subsequently, Pavlovian cues predicting these outcomes were introduced during the decision-making process. Results confirmed our hypothesis, indicating that Pavlovian cues altered optimal decision-making strategy, even when this bias reduced overall reward income. Notably, this bias persisted both under extinction and when rewards were available, confirming its maladaptive nature. In a second experiment, when rewards were available, Pavlovian bias was abolished by reducing cue-outcome associations during Pavlovian learning, highlighting the pivotal role of the cue value in this bias. These findings have implications for understanding and potentially mitigating maladaptive behaviors, such as addiction and impulsivity.