How benign sensory events become aversive: Self-fulfilling expectations in affective experience

Do we experience benign sensory events as aversive if we expect them to be? We addressed this question with two preregistered studies (N=149) employing a two-phase paradigm. During the expectation acquisition phase, benign intensity noise bursts were repeatedly preceded by one conditioned stimulus (CSbenign) whereas aversively loud bursts were preceded by another (CSaversive). In the subsequent test phase, benign bursts were preceded by both, CSaversive and CSbenign. Results showed that identical benign bursts preceded by CSaversive vs. CSbenign were rated as more aversive and also evoked potentiated early sensory event-related potentials, cardiac acceleration, and behavioral avoidance. These findings suggest that aversive expectations bias the affective processing of benign events, propagating from intensified sensory encoding to heightened physiological responses and subjective aversiveness, resulting in costly avoidance. Among others, this pathway is relevant for understanding symptom persistence and nocebo phenomena by demonstrating how even benign events may perceptually confirm aversive expectations.