Neuroimaging techniques have been used to identify the neurological bases of phobias.
ObjectiveThis meta-review examines functional magnetic resonance imaging studies of individuals with specific animal phobia compared to healthy controls.
MethodSearches on Medline, Psycinfo, Academic Search Complete, PubMed, PsycARTICLES, Redalyc, Scopus, and Cochrane databases were conducted. Twenty high quality studies were selected. The effect size estimation was calculated.
ResultsThe random-effects model showed a high overall effect size for both limbic and frontal sites. Data analyses showed greater brain activity in the left amygdala and insular cortex in phobic individuals. We also observed an activation of the fusiform gyrus, the dorsolateral prefrontal cortex left, and the left cingulate cortex, although these areas were less frequently involved. Healthy controls showed high heterogeneity in the brain areas activated by phobic stimuli.
ConclusionsThese findings suggest the possible existence of a double processing pathway in phobic stimuli: a rapid processing pathway involving limbic areas and a slow pathway involving both limbic and frontal areas.