The mirror neuron hypothesis of autism is highly controversial, in part because there are conflicting reports as to whether putative indices of mirror system activity are actually deficient in autism spectrum disorder (ASD). Recent evidence suggests that a typical putative mirror system response may be seen in people with an ASD when there is a degree of social relevance to the visual stimuli used to elicit that response. Individuals with ASD (n = 32) and matched neurotypical controls (n = 32) completed a transcranial magnetic stimulation (TMS) experiment in which the left primary motor cortex (M1) was stimulated during the observation of static hands, individual (i.e., one person) hand actions, and interactive (i.e., two person) hand actions. Motor-evoked potentials (MEP) were recorded from the contralateral first dorsal interosseous, and used to generate an index of interpersonal motor resonance (IMR; a putative measure of mirror system activity) during action observation. There was no difference between ASD and NT groups in the level of IMR during the observation of these actions. These findings provide evidence against a global mirror system deficit in ASD, and this evidence appears to extend beyond stimuli that have social relevance. Attentional and visual processing influences may be important for understanding the apparent role of IMR in the pathophysiology of ASD.
Keywords: mirror neurons, interaction, transcranial magnetic stimulation, primary motor cortex, electromyography
Citation: Enticott PG, Kennedy HA, Rinehart NJ, Bradshaw JL, Tonge BJ, Daskalakis ZJ and Fitzgerald PB (2013) Interpersonal motor resonance in autism spectrum disorder: evidence against a global “mirror system” deficit. Front. Hum. Neurosci. 7:218. doi: 10.3389/fnhum.2013.00218
Received: 11 January 2013; Accepted: 07 May 2013;
Published online: 23 May 2013.
Edited by:Jamie Ward, University of Sussex, UK
Reviewed by:Jamie Ward, University of Sussex, UK
Copyright © 2013 Enticott, Kennedy, Rinehart, Bradshaw, Tonge, Daskalakis and Fitzgerald. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in other forums, provided the original authors and source are credited and subject to any copyright notices concerning any third-party graphics etc.
*Correspondence: Peter G. Enticott, Monash Alfred Psychiatry Research Centre, Level 4, 607 St. Kilda Road, Melbourne, VIC 3004, Australia. e-mail: firstname.lastname@example.org