Datensatz

Zusammenfassung

Background: Individuals with autism spectrum disorders (ASD) have difficulties in perceiving moving faces and extracting social cues from them such as identity, emotion and speech (O’Brien et al., 2014; Sato et al., 2013; Foxe et al., 2015). Here, we investigated how facial motion-sensitive regions are functionally connected to facial form-sensitive regions during recognition of facial speech in ASD. Methods: Seventeen adults with high-functioning ASD and seventeen typically developed pair - wise matched controls participated. The experiment included a combined functional magnetic resonance imaging (fMRI) and eye-tracking experiment on facial-speech recognition and a functional localizer. In the facial-speech recognition experiment, participants viewed blocks of muted videos of speakers articulating syllables. We asked them to recognize either the articu- lated syllable (facial-speech task), or the identity of the articulating person (face-identity task). The functional localizer included viewing of moving and static faces and objects. Functional connectivity was assessed with psycho-physiological interaction analysis (PPI) based on the contrast „facial-speech task > face-identity task“. Seed regions were defined in the motion- sensitive STS/STG and V5/MT. We combined functional localizer approach with anatomical maps to define regions of interest (ROI) in the form-sensitive bilateral fusiform face area (FFA) and the bilateral occipital face area (OFA). Results: Compared to the control group, the ASD group had decreased functional connectivity between the motion-sensitive regions V5/MT and STS/STG, and the group differences were related to autistic traits (p< .0125 FWE-corrected for ROI). Functional connectivity between motion-sensitive and form-sensitive regions (FFA, OFA) was similar in the control and in the ASD group. Conclusions: Fast and accurate perception of moving faces is one of the prerequisites for successful face-to-face communication (O’Toole et al., 2002), and its impairments likely con- tribute to communication deficits typical for ASD. We provide evidence that difficulties in facial-speech recognition in ASD are related to dysfunctional mechanisms for facial-motion rather than facial-form perception.