Neuroimaging Evidence of Facial Emotion Processing in Autism Spectrum Disorder: A Meta-Analysis of Functional Neuroimaging Studies.
Across 25 fMRI studies, autistic brains reliably under-activate the left inferior frontal gyrus when reading facial emotions.
01Research in Context
What this study did
The team pooled 25 brain-scan studies that watched autistic people look at emotional faces.
All scans used fMRI. They ran the pictures through one big math model to find spots that lit up less in the autism group.
What they found
One area stood out: the left inferior frontal gyrus. It was quieter in autistic brains across studies.
A strip of ventral stream areas also showed lower activity. Only the left IFG spot survived strict correction for chance.
How this fits with other research
O'Connor et al. (2008) first saw weaker face-area signals in adults. The new meta-analysis widens the map to frontal and ventral regions.
Lee et al. (2024) adds kids to the story. They show real faces, not cartoons, trip up inhibitory circuits and early ERPs, matching the fMRI hypo-activation pattern.
Van der Donck et al. (2023) seems to disagree. They found no neural gap in adult males during fast expression changes. The gap is likely method: EEG speed tests tap different pathways than slow fMRI blocks mixed with younger participants.
Why it matters
You now have a clear brain target: the left inferior frontal gyrus. When social skills stall, check if the task taxes this area. Try breaking facial emotion drills into short, repeated trials with real faces and give extra feedback to wake up that sluggish frontal spot.
Want CEUs on This Topic?
The ABA Clubhouse has 60+ free CEUs — live every Wednesday. Ethics, supervision & clinical topics.
Join Free →Use real faces, not cartoons, in emotion drills and provide quick, explicit feedback to boost frontal engagement.
02At a glance
03Original abstract
PURPOSE: The neural mechanisms underlying facial emotion processing (FEP) difficulties in autistic people remain unclear. This Seed-based d Mapping with Permutation of Subject Images (SDM-PSI) meta-analysis examined brain activity during FEP in autistic people. METHOD: We systematically searched three databases (PubMed, Web of Science, PsycINFO) for fMRI studies (published up to September 2, 2025) comparing DSM-diagnosed autistic people with non-autistic people (NAP) during FEP, and eligible studies reported whole-brain coordinates. A convergence analysis of the contrasts between the ASD and NAP groups was performed. Subgroup analyses and meta-regressions were conducted to explore potential sources of heterogeneity. RESULTS: A total of 25 fMRI studies, comprising 632 autistic people and 568 non-autistic people, were included in this meta-analysis. The results revealed a widespread convergence of decreased activation in the inferior frontal gyrus (IFG), middle temporal gyrus (MTG), fusiform gyrus (FG), cerebellum (Cb), and insula during FEP in autistic people at an uncorrected threshold level with P < 0.005. Among these, only the IFG passed FWE correction with P < 0.05. Subgroup exploratory analyses based on task type suggested that both explicit and implicit tasks may elicit a convergence of decreased activation along the ventral stream (IFG, FG, MTG), while explicit tasks may additionally involve convergence of increased activation in visual processing regions (lingual gyrus and inferior longitudinal fasciculus) at an uncorrected threshold level with P < 0.005. In addition, subgroup exploratory analysis of age showed autistic minors may recruit more visual resources compared to adults at an uncorrected threshold level with P < 0.005, and the exploratory regression analysis showed that higher IQ may be associated with decreased neural activity in the superior occipital gyrus (SOG) at an uncorrected threshold level with P < 0.005. CONCLUSION: Dysfunctional brain activity during facial emotion processing in autistic people was most robustly reflected in the convergence of decreased activation in the IFG, particularly the left IFG-op. Exploratory analyses further suggested that other aberrant brain activations may be focused on the ventral stream. In addition, exploratory subgroup analyses indicated that explicit tasks and minors might recruit multiple visual systems, potentially as a compensatory strategy.
Journal of autism and developmental disorders, 2025 · doi:10.1371/journal.pone.0081206