Verbal mediation of theory of mind in verbal adolescents with autism spectrum disorder.

This study tests the role of verbal mediation during theory of mind processing in autism spectrum disorder (ASD). Adolescents with ASD or typical development completed a false belief task while simultaneously performing a verbal or nonverbal load task. There was no group difference in false belief accuracy; however, under verbal load, the ASD group was relatively less efficient, with slower reaction times, in false belief compared to true belief trials. Faster false belief task performance under verbal but not nonverbal load was associated with pragmatic language ability for the ASD group only. Results were consistent with the theory that there are two (implicit, nonverbal and explicit, verbal) processes that support cognitive reasoning about other people's minds (Apperly & Butterfill, 2009), and that people with ASD rely more on the explicit system. Verbal mediation may be critical for false belief understanding in individuals with ASD, but not typical development.