Imitation of transitive and intransitive actions in healthy individuals.

A handful of patients have been described as being impaired in performing transitive gestures, despite being still able to perform intransitive gestures. This impairment need not be explained by assuming different mechanisms; rather, it can be due to transitive actions being more difficult. In this study we tested whether neurologically healthy participants had greater difficulties in imitating transitive actions with respect to intransitive actions. Consistent with the prediction, subjects imitated intransitive better than transitive gestures. The ease of imitation of intransitive actions supports the complexity account of apraxic impairments.