Aversive conditioning is impaired in impulsive individuals: A study on learning asymmetries

Background and objectives: Appetitive and aversive conditioning are thought to be involved in the development and maintenance of mental disorders including anxiety, mood, eating, and substance use disorders. However, few studies measure the relative strength of appetitive and aversive associations, and their relevance to the risk of mental disorders. This study aims to address this gap. Methods: We tested how readily healthy volunteers acquire appetitive vs. aversive associations. 150 participants associated complex 3D objects with either gain or loss and made decisions to gain or avoid losing points. We investigated the relationship of a learning asymmetry with neuroticism, impulsivity, and anhedonia, to test the hypothesis that a stronger learning asymmetry corresponds to more extreme scores on these traits. Results: Impulsivity was positively associated with the learning asymmetry (R2 = .10). This resulted from an inverse relation with the strength of aversive associations, indicating that impulsive individuals are worse at aversive learning. However, appetitive associations did not differ significantly. No correlations with neuroticism or anhedonia were found. Limitations: Conditioning studies typically use primary reinforcers and a CS-. Lacking these may make these results less comparable to other studies. Conclusions: We demonstrate that the learning asymmetry can measure individual differences linked to personality traits, and that impulsivity, normally linked with appetitive learning, also influences aversive learning. These results enable additional studies of learning asymmetry in relation to mental disorders, which could include measurements of mental health symptoms to provide further insight into how appetitive and aversive learning interacts with mental disorders.