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Abstract:
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
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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.