Background: Anecdotal evidence has noted that individuals with autism spectrum conditions (ASC) frequently exhibit heightened spontaneous imitative behavior, with symptoms of echolalia and echopraxia. This is contrasted by empiric reports that ASC results in decreased imitation and an underlying deficit in the mirror system, leading to impaired social understanding. Thus, it remains unclear whether automatic imitation is enhanced in ASC and how this is related to poorer social abilities.
Methods: This study investigated spontaneous imitation in 18 high-functioning adults with ASC and 18 age- and IQ-matched control participants during a simple imitation inhibition task. Mentalizing was experimentally assessed in the same participants using both behavioral and functional magnetic resonance imaging measures, as was social interaction using an observational measure.
Results: Individuals with ASC showed increased imitation of hand actions compared with control participants and this was associated with reduced mentalizing and poorer reciprocal social interaction abilities. In the functional magnetic resonance imaging mentalizing paradigm, ASC participants with increased imitation scores showed less brain activation in areas often found to be active in mental state attribution, namely the medial prefrontal cortex and temporoparietal junction.
Conclusions: The results confirm the presence of hyperimitation in ASC, which is accompanied by reduced social cognition, suggesting that a general imitation impairment and a global mirror system deficit are absent. These findings offer an explanation for echopractic features based on theories of atypical functioning of top-down modulation processes in autism.
Copyright © 2010 Society of Biological Psychiatry. Published by Elsevier Inc. All rights reserved.