Page 120 - Demo

Chapter 4118Our hypothesis that higher autistic trait level would result in reduced facial mimicry responses was also not confirmed. Even though we did not explicitly instruct participants to mimic, individuals with higher autistic trait levels seemed to automatically show unaltered facial muscle activation patterns, contradicting findings in clinical populations (McIntosh et al., 2006) as well as in healthy individuals with high autistic traits (Hermans et al., 2009). Importantly, it has been suggested that mimicry in ASD might especially be reduced for shorter presentation durations (Mathersul et al., 2013) and occur with a delay rather than not at all (Oberman et al., 2009), which we did not examine in our study. We did, however, observe a modulation in the link between facial mimicry and emotion recognition by autistic traits. In the recognition of sad expressions, increased activity of the corrugator, indicating mimicry of sadness, was less predictive of accurate recognition whereas the same applied to stronger zygomaticus activity in the recognition of happiness. While a sole evaluation of the latter effect would be difficult due to the ceiling performance in happiness recognition (see previous paragraph) as well as to a lack of reproducibility of a result when using a relative accuracy score (see Supplemental Material), the robust results concerning sadness recognition support the presence of a meaningful modulation. It seems, thus, that facial mimicry plays a less informative role in emotion recognition, at least of sad expressions, in association with higher autistic trait levels. This observation is in line with past research that did not find an effect of automatic, intentional or externally induced mimicry on reports of the participant%u2019s own emotional experience in individuals on the autism spectrum, while neurotypical participants were considerably influenced by mimicry (Stel et al., 2008). According to the idea of the existence of two routes in emotion recognition, a fast one involving proprioceptive (bottom-up) information and a long one involving knowledge-based (top-down) information (Stel & van Knippenberg, 2008), the fast route might have been less employed in the recognition of sadness in participants with higher autistic traits. Since recognition performance of particularly sad expression was less negatively affected by higher autistic traits, judgments via the alternative, long route could have resulted in similarly successful judgments. Previous studies have already reported qualitative differences in the recognition of sadness compared to other emotion expressions related to ASD. For example,