Imitation: evaluating neurophysiological signatures and clinical significance

Imitation and its neural basis has been the subject of great interest, particularly for researchers interested in autism spectrum disorders (ASD). Research has reported imitation deficits in ASD, which have been theoretically linked to the condition’s sociocommunicative difficulties. Abnormalities in the mirror neuron system (MNS), as measured using EEG techniques, have also been reported in autism, and linked to imitation skills. In this thesis, I examine questions both around behavioural imitation deficits, and the validity of EEG techniques used to investigate the MNS. I consider whether children with other communication disorders show similar imitation deficits to children with autism, examining verbal and motor imitation. I report data from non-autistic children with and without language problems, and children with autism and normal language (ANL) and children with autism and language-impairment (ALI). In contrast to previous studies, I find similar verbal imitation performance in children with ALI and non-autistic language impaired children, but limited motor imitation impairments in the disorder groups. I also examine the evidence from mu suppression studies for the role of the MNS in language, social processes and the development of ASD. I present findings from a preregistered study that show that methodological factors such as baseline condition have important effects on mu suppression studies’ results, and question its validity as an MNS measure. I also examine how imitation skills, self-reported communication abilities and autistic traits relate to individual differences in mu suppression. I find limited support for the theory that mu suppression correlated with behaviours and traits proposed to be underpinned by the MNS. I discuss the implications of these two projects for future research and clinical interventions for children with communication disorders