The Relationship Between Neural Correlates of Face Processing and Social Communication in Individuals with ASD and Schizophrenia

Background: Difficulty interpreting facial expressions is a common feature of both autism spectrum disorder (ASD) and schizophrenia (SCZ), a disorder with many genetic, neurobiological, and phenotypic similarities to ASD. Consistent with the NIMH’s Research Domain Criteria (RDoC) initiative, we sought to understand the neural correlates of face processing across these disorders. This study applied interactive neuroscience methods to study electrophysiological (EEG) brain response during a gaze-contingent paradigm that simulated face-to-face interactions. We aimed to explore the relationship between clinician-rated social communication and neural components of face processing across diagnostic categories.

Objectives: To examine the relationship between face-processing event related brain potential (ERP) components and social communication in ASD and SCZ.

Methods: ERPs were recorded from 14 adults with ASD and 12 adults with SCZ using a 128 electrode Geodesic Net; data collection is ongoing. Participants were presented with 80 distinct photorealistic, animated faces matched for low-level visual features. Utilizing gaze-contingent eye tracking technology, stimuli responded to a participant’s direct fixation to the face by exhibiting happy or fearful emotions. P1 and N250 amplitudes were extracted from selected electrodes. All participants were administered the Autism Diagnostic Observation Schedule, 2^nd Edition (ADOS-2), a gold-standard diagnostic measure of ASD. ANCOVAs were conducted to investigate the relationship between ADOS severity or item scores and amplitude of the P1 and N250 components.

Results: There were no significant main effects or interactions involving diagnostic group (ASD, SCZ); thus, the following results collapse across diagnostic group. Preliminary analyses revealed a significant interaction between hemisphere, emotion, and ADOS Social Affect (SA) severity score, the covariate, on the mean amplitude of the N250 component (p=.037). Post-hoc correlational analyses showed that as SA severity increases, the N250 component in the right hemisphere is significantly attenuated when viewing happy faces (r= -.479, p=.013). There were no significant correlations between the N250 mean amplitude and SA severity in the left hemisphere or for fearful faces. An additional ANCOVA revealed a significant interaction between hemisphere, emotion, and the ADOS Unusual Eye Contact item score (p=.026) on the peak amplitude of the P1 component. Within-group follow-up t-tests revealed a trend toward more right lateralized P1 when viewing fearful faces for those with normative eye contact (p=.071); in contrast, those with more atypical eye contact showed increased right lateralization when viewing happy faces (p=.012). Between group follow-up t-tests did not reveal significant differences between the P1 peak amplitude of those with atypical eye contact and those with typical eye contact (p>.10).

Conclusions: Our results indicate that clinician ratings of social function are associated with neural response to emotional faces. Distinct patterns of responsivity were observed for different facial expressions, and eye contact during in vivo social interactions was associated with lateralization of brain responses to emotional expressions. These findings reveal relationships between social communication and neural sensitivity to facial expressions that span diagnostic categories, suggesting the importance of examining social communicative biomarkers in transdiagnostic samples.