Extinction, avoidance, and generalization: Fear learning processes and their relations with anxious and depressive traits

Research shows anxious individuals exhibit slower extinction (EXT), more avoidance (AVO), and broader generalization (GEN) in Pavlovian fear conditioning, potentially contributing to maladaptive anxiety (chronic, avoidant, overgeneralized). However, studies typically focused on one of these processes, it remains unclear (1) whether the deficits in each process reflect separate or the same vulnerability factors; (2) whether deficits in any of these processes is more detrimental; (3) whether deficits in these processes cluster into distinct profiles that form an unique detrimental factor. Additionally, despite the high comorbidity rate with anxiety, the role of depression in these processes is surprisingly understudied. The current study tested EXT-AVO-GEN processes in the same individuals measuring both anxiety and depressive traits. To avoid the arbitrary selection of any indices for EXT-AVO-GEN processes, multiple index operationalizations were employed to ensure robust findings. Results showed small to no correlations, both among EXT-AVO-GEN processes and their correlations with personality characteristics. Cluster analysis identified no distinct profiles, and if such profiles were nonetheless forced to emerge, they were not associated with the anxious or depressive traits. According to these findings, EXT-AVO-GEN are likely to be independent processes and their deficits seem to have different underlying drivers. Therefore, studying EXT-AVO-GEN processes in combination may not offer additional comprehension about pathological fear development. Linear mixed-effects models, however, revealed stronger correlations between EXT-AVO-GEN and anxiety/depression, suggesting that they may be more sensitive in detecting individual differences compared to indices, as they capture trial-by-trial dynamics, which indices often fail to fully account for.