Fear extinction in the human brain: A meta-analysis of fMRI studies in healthy participants

The study of fear extinction represents an important example of translational neuroscience in psychiatry and promises to improve the understanding and treatment of anxiety and fear-related disorders. We present the results of a set of meta-analyses of human fear extinction studies in healthy participants, conducted with functional magnetic resonance imaging (fMRI) and reporting whole-brain results. Meta-analyses of fear extinction learning primarily implicate consistent activation of brain regions linked to threat appraisal and experience, including the dorsal anterior cingulate and anterior insular cortices. An overlapping anatomical result was obtained from the meta-analysis of extinction recall studies, except when studies directly compared an extinguished threat stimulus to an unextinguished threat stimulus (instead of a safety stimulus). In this latter instance, more consistent activation was observed in dorsolateral and ventromedial prefrontal cortex regions, together with other areas including the hippocampus. While our results partially support the notion of a shared neuroanatomy between human and rodent models of extinction processes, they also encourage an expanded account of the neural basis of human fear extinction.