Spontaneous facial mimicry is a biological marker of affective empathy. Individuals with Autistic Spectrum Conditions (AS C), known to be weak empathisers, show reduced spontaneous facial mimicry compared with typically developed individuals. However, evidence that deliberate facial mimicry in ASC is intact refutes the notion of a deficit in the ASC mimicry system per se, and instead raises two interesting questions; (I) What drives spontaneous facial mimicry in the general population? (2) Why do individuals with ASC not engage in spontaneous facial mimicry to the same extent as typically developed individuals? In this thesis I test the hypothesis that a connection exists between the brain's reward and mimicry systems and that this reward-mimicry link is dysfunctional in individuals diagnosed with ASC. In addressing the first question, this thesis integrates findings from two techniques; electromyography (chapter 3) and fMRI (chapter 4 and 5). Furthermore, a meta-analysis of previous imaging studies explores whether overlap exists between the neural correlates reported III fMRI studies of reward and empathy (chapter 2). The results described in chapters 3, 4, and 5 confirm the hypothesis of a reward-mimicry link in the general population, whilst the meta-analysis indicates that the link might extend beyond mimicry to other components of empathy. In addressing the second question, the autism quotient (AQ) was used to measure autistic traits in participants in the EMG and fMRI studies. In each case there was evidence that the reward-mimicry link was weaker in individuals with high autistic traits compared to those with low autistic traits. In the final study (chapter 6) EMG was used to examine the reward mimicry link in individuals diagnosed with ASC. Partial evidence of a dysfunctional reward mimicry link was found in individuals diagnosed with ASC who possessed AQ scores at the extreme high end of the spectrum. However, based on the current evidence, the possibility that this finding resulted from a regionally specific deficit in the ASC mimicry system - and not from a deficit in the reward-mimicry link - cannot be ruled out.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:632858 |
| Date | January 2013 |
| Creators | Sims, Thomas B. |
| Publisher | University of Reading |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
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