Objectives: We aim to outline the neural correlates of atypical emotional face processing in individuals with ASD.
Methods: A comprehensive literature search was conducted through electronic databases to identify functional magnetic resonance imaging (fMRI) studies of whole brain analysis with emotional-face processing tasks in individuals with ASD. The Signed Differential Mapping with random effects model was used to conduct meta-analyses. Identified fMRI studies were further divided into sub-groups based on contrast ("emotional-face vs. non-emotional-face" or "emotional-face vs. non-face") to confirm the results of a meta-analysis of the whole studies.
Results: Thirteen studies with 226 individuals with ASD and 251 typically developing people were identified. We found ASD-related hyperactivation in subcortical structures, including bilateral thalamus, bilateral caudate, and right precuneus, and ASD-related hypoactivation in the hypothalamus during emotional-face processing. Sub-analyses with more homogeneous contrasts preserved the findings of the main analysis such as hyperactivation in sub-cortical structure. Jackknife analyses showed that hyperactivation of the left caudate was the most robust finding.
Conclusions: Abnormalities in the subcortical structures, such as amygdala, hypothalamus and basal ganglia, are associated with atypical emotional-face processing in individuals with ASD.
Keywords: Asperger's syndrome; autistic disorder; functional magnetic resonance imaging; human; pervasive developmental disorders.