Acquisition of behavioral avoidance: task-irrelevant conditioned stimuli trigger costly decisions

Individuals avoid stimuli which are associated with aversive experience to preserve safety. However, behavioral avoidance also causes impairments and prevents the individual from attaining positive rewards. Little is known about the link between fear acquisition and the development of behavioral avoidance in the presence of potential rewards. Therefore, two experiments investigated the impact of fear conditioning on a subsequent gambling task. In an experimental group (n = 30) advantageous choices (higher reward probability) were linked to a fear-relevant stimulus that was associated with an aversive unconditioned stimulus (US) during fear conditioning (conditioned stimulus, CS+). A disadvantageous choice (lower reward probability) was, however, linked to a safe stimulus that was never associated with the US (CS-). In a control group (n = 25), fear conditioning was followed by a similar gambling task with novel stimuli. A second experiment focused on individual predictors of avoidant decisions (n = 81). Compared with the control group, individuals in the experimental groups avoided the advantageous CS + choice despite fewer gains. The predictor analysis further clarified that avoidant decisions were pronounced in highly trait anxious participants who exhibited higher fear responses. On the other hand, findings also indicated a reduction in absolute avoidance across the task. Combined, these findings demonstrate that fear conditioning can lead to avoidant decision making, especially in vulnerable individuals. The resulting costs parallel impairments caused by behavioral avoidance. Such an emotional decision-making style may be a link between aversive experience and the development of habitual pathological avoidance. Introducing rewards for approach, however, may counteract avoidant decisions.