Fear and safety learning in anxiety- and stress-related disorders: An updated meta-analysis.

Fear learning processes are believed to play a crucial role in the development and maintenance of anxiety and stress-related disorders. To integrate results across different studies, we conducted a systematic meta-analysis following PRISMA guidelines to examine differences in fear conditioning during fear acquisition, extinction, and extinction recall between individuals with anxiety-related or stress-related disorders and healthy participants. This analysis updates the work of Duits et al.

Early hypervigilance and later avoidance: Event-related potentials track the processing of threatening stimuli in anxiety.

Avoidance behavior is a core symptom of anxiety disorders that may hinder adaptation. Anxiety disorders are heterogeneous and previous research suggests to decompose anxiety into two dimensions: anxious apprehension and anxious arousal. How these two dimensions are associated with avoidance of and exposure to threatening stimuli, as well as their accompanying neural processes, is barely understood.

Neural signature of delayed fear generalization under stress.

Although the generalization of fear to stimuli resembling a threatening stimulus is an adaptive mechanism, fear overgeneralization is maladaptive and thought to play a key role in anxiety-related disorders. Since there is typically a delay between an initial fear experience and a situation in which fear (over)generalization may occur, we assessed delayed fear generalization and its neural signature. Moreover, as stress is known to affect fear learning, we further tested whether acute stress modulates fear generalization.

Acute stress leaves fear generalization in healthy individuals intact.

Because threatening situations often occur in a similar manner, the generalization of fear to similar situations is adaptive and can avoid harm to the organism. However, the overgeneralization of fear to harmless stimuli is maladaptive and assumed to contribute to anxiety disorders. Thus, elucidating factors that may modulate fear (over)generalization is important.