Bodily self-consciousness in Autism Spectrum Disorder: investigating the relationship between interoception, self-representation and empathy

Recent theories of the self propose that interoception - the conscious and unconscious processing of signals originating from within the body – has an essential role in bodily self-consciousness, the basic sense of self that is rooted in the body. Furthermore, the processing of signals from within the body is thought to affect emotion, behaviour, cognition and social cognition. The aim of this thesis was to investigate if individuals with autism, a developmental condition historically described as a disorder of self, show differences in interoceptive processing and an altered bodily self, and investigated if these are related to deficits in the understanding of self and others. Experiment one investigated interoceptive processing on three dimensions, and found that participants with autism had lower interoceptive sensibility, lower interoceptive accuracy and a less pronounced heartbeat evoked potential. Experiments two and three investigated the relationship of interoceptive processing with alexithymia and empathy, and differences in automatic mimicry. These experiments found that autistic traits, interoceptive sensibility, alexithymia and empathy were associated, and that alexithymia played a mediating role in the relationship between interoception and empathy. This could explain why participants with autism and alexithymia had lower empathy than participants without autism, and lower than autistic participants without alexithymia. Experiment four investigated bodily self-consciousness with two multisensory paradigms – the full body illusion and an audio-tactile peripersonal space task. This experiment found that in contrast to neurotypical participants, participants with autism were not susceptible to the full body illusion, and that their peripersonal space was smaller with a sharper boundary. In conclusion, these results show that participants with autism show reduced interoceptive processing and altered bodily self-consciousness. There was additional evidence that bodily self-consciousness underlies deficits in the understanding of own emotions and the emotions of others. How this furthers our understanding of core characteristics of autism at a theoretical level is discussed