5. Discussion

The present study aimed to investigate whether schizophrenic patients’ impaired ability in appreciating others’ intentions is confined, rather than generalized, to a particular type of intention. To test this hypothesis, we designed a series of tasks requiring to identify different types of intentions, varying according to either their scope or target. Our second hypothesis was that a deficit in intention attribution, if established, should be accounted for by an abnormal interplay of the two types of information which usually contribute to this ability. In a previous study, we indeed showed that appreciating others’ intentions relied on an interaction between visual information – derived from the agent’s kinematics – and prior knowledge that participants progressively gained about the most likely causes of what they observed (Chambon et al., xxxx).

The results revealed that patients’ performance accounts for this interaction whatever the type of intention considered. First, patients better recognized the underlying intentions when the visual information conveyed by the action scene increased; second, they provided a greater number of correct responses and faster RTs for preferred intentions than for non-preferred ones; finally, in both groups, performances exhibited a strong bias effect which progressively increased as the amount of visual information decreased, and vice versa.