Exploring preference and attention towards social mimicry in the broader autism phenotype

Autism has been the focus of intensive research for several decades, and we know a considerable amount about how it manifests on social and cognitive levels, but much less is known about the Broader Autism Phenotype (BAP). The concept of the BAP was originally used to describe the mild autism characteristics exhibited by family members of someone with autism spectrum disorder (ASD). Research has found that parents with autistic children often exhibit social tendencies that are like those found on autism spectrum but to a milder extent which does not impair their daily functioning. It is important that we study the BAP given that many parents of ASD children show features of the BAP, and it is likely that their own social difficulties could exacerbate those shown by their child. This thesis focuses on autistic traits in the general population and examines whether these traits predict mimicry and the sensitivity to observed mimicry. In recent years, autism has been viewed by some researchers as an alternate trajectory of human neural and behavioural development in which different factors could have led to the alternate pathway of autism. autism has been typically viewed from a “condition state” model in which its definition is frequently extended beyond the diagnostic behavioural phenotype, to an inferred lifelong brain or neurochemical pathology. Nevertheless, it should be reminded that “autism” specifically refers to a diagnosis based on overt behavioural symptoms which is the end of the developmental pathway, and not to an identified underlying pathology. The study in this thesis set out to explore the nature of the BAP in relation to social mimicry. Research suggests that social mimicry is deficit in autistic adults and children. Further social mimicry is linked to the development of features such as empathy and theory of mind in neurotypical children. Both of which are key features of autism. Study 1 in the thesis involved the use of electromyography (EMG) to investigate facial mimicry by recording muscle activation in the corrugator supercilia and zygomaticus major face muscles when viewing different kinds of emotions including happy, sad, neutral, angry, fearful, and disgusted states. A total of 42 participants took part in the study and it was found that there is a negative association between Autism Quotient (AQ) scores and peak activation for happy expressions and the Empathy Quotient (EQ) demonstrated a positive correlation for peak activation and onset for the happy condition. The study suggested an association between facial mimicry and autistic traits. Study 2 involved a novel paradigm in which participants rated rapidly seen images for their pleasantness. In this study, social mimicry was manipulated to further investigate responses to social mimicry. A total of 52 participants took part in the study and it was found that those who scored higher on the autism quotient rated images containing face-to-face mimicry as less pleasant when compared to those who score lower on the autism quotient. Study 3 investigated the attentional capture of social mimicry by using a Dot-Probe task. A total of 46 participants took part in the study and it was found that probes replacing face-to-face images were responded faster than back-to-back images regardless of the presence of mimicry. Specifically, high AQ group responded to faster towards probes that replaced mimicry images than low AQ group. The results demonstrated that AQ and social responsiveness (SRS) scores can predict whether people prefer face-to-face or back-to-back images in the mimicry condition. Finally, Study 4 replicated the Study 2 rating task with parents of either TD children or autistic children. A total of 57 participants took part. The key finding in the final study was that regardless of having ASD or TD children, the parents’ own levels of empathy and autistic traits were the main feature that influenced their preference for face-to-face mimicry. All the study’s findings supported the literature in BAP that autistic trait exist on a continuum in the general population and that high level of autistic traits, even if subclinical can produce impairments of social perception and social behaviour with particular reference to social mimicry.