Inner speech impairments in autism

Background:  Three experiments investigated the role of inner speech deficit in cognitive performances of children with autism. Methods:  Experiment 1 compared children with autism with ability‐matched controls on a verbal recall task presenting pictures and words. Experiment 2 used pictures for which the typical names were either single syllable or multisyllable. Two encoding conditions manipulated the use of verbal encoding. Experiment 3 employed a task‐switching paradigm for which performance has been shown to be contingent upon inner speech. Results:  In Experiment 1, children with autism demonstrated a lower picture‐superiority effect compared to controls. In Experiment 2, the children with autism showed a lower word‐length effect when pictures were presented alone, but a more substantial word‐length effect in a condition requiring overt labelling. In Experiment 3, articulatory suppression affected the task‐switching performance of the control participants only. Conclusions:  Individuals with autism have limitations in their use of inner speech.