Increased generalisation in trait anxiety is driven by aversive value transfer not reduced perceptual discrimination

Anxiety has been linked to increased generalisation of threat expectations to perceptually similar stimuli. Such generalisation can arise either from a failure to distinguish threatening from non-threatening stimuli (perceptual mechanism) or from the transfer of learned values between stimuli (value-based mechanism). Yet, how these mechanisms contribute to generalisation remains unclear. Here we assess how participants (n = 140) generalise outcome expectancies to perceptually similar stimuli, using personalised stimulus spaces. We show that perceptual and value-based contributions to generalisation can be dissociated based on response distributions. Our computational modelling results indicate that generalisation in some participants can be explained by perceptual mechanisms alone but that stronger generalisation in trait anxiety is driven by greater reliance on value transfer. In this work we dissociate perceptual and value-based contributions to generalisation and link trait anxiety to preferential reliance on value-transfer.