Brain Correlates of Self-Other Distinction Centred on Touch and Actions in Adults with High-Functioning Autism

Background:  It has been argued that patients with autism spectrum disorder (ASD) have problems to distinguish self from other when observing other people’s behavior (Spengler et al., 2010). While there is some behavioral evidence that ASD patients slow down more strongly when performing an action while observing an incongruent action, this evidence is however far from being conclusive. When centred on tactile consequences of observed actions and felt touch, neural evidence for self-other distinction problems in ASD was recently provided (Deschrijver et al., 2016a). So far however, neural evidence for self-other distinction problems centred on actions per se does not exists in ASD.

Objectives: By means of EEG, we assessed whether self-other distinction centred on actions was neurally disturbed in the group of adults with ASD that had shown impaired self-other distinction centred on tactile consequences of observed actions and felt touch in an earlier study (Deschrijver et al., 2016a). If so, we reasoned that their brain should not adequately signal when an observed action does not match an own action.

Methods: We employed the imitation-inhibition paradigm (Brass et al., 2000), in which participants observe a human hand lifting the index or middle finger while they are instructed to perform the same (congruent) or the opposite (incongruent) movement. Following our earlier EEG-studies (Deschrijver et al., 2016ab), we hypothesized that if self-other distinction centred on actions is impaired in ASD, we should observe a smaller congruency difference within the P3 in adults with ASD as compared to a matched control group.

Results: The ASD group did not show diminished neural signaling of observed actions that do not match own actions, as reflected in an intact P3- congruency effect within the imitation-inhibition task. As such, we did not find evidence for disturbed self-other distinction centred on actions in our group with ASD. Instead, we found evidence for disturbed motor preparation processes within the readiness potential.

Conclusions: Self-other distinction centred on actions may be preserved in individuals with ASD, while self-other distinction centred on tactile consequences of observed actions and own touch may not. The sense of touch and motor preparation processes may play a more crucial role for social cognition in ASD than previously thought.