Dynamique des coordinations sensorimotrices interpersonnelles chez les patients schizophrènes : introduction d'un nouveau paradigme

We therefore designed a study where healthy individuals and schizophrenic patients were asked to intentionally track the oscillations of visual targets of various social relevance using hand movements. Four different rhythmic visual stimuli varying in degree of biological relevance (form and motion) are used : [1] an oscillating dot; [2] a computer generated hand moving up and down continuously driven by a sine function; [3] pre-recorded oscillatory movements of a real hand; and [4] the hand of a real individual (behind a curtain that occluded vision of the rest of the body). Two distinct dependent variables are computed to quantify the coordination between the movements of the participants and the visual stimuli : the relative phase and the power spectrum overlap between their own movements. In this preliminary study, analyses of kinematic data revealed that schizophrenic patients had trouble synchronizing to (the more) “biological” target unlike control healthy individuals. These results suggest that patients with schizophrenia may suffer from sensorimotor coordination disabilities with socially relevant visual stimuli. The novel paradigm we introduce in research on schizophrenia should allow for a better understanding of the troubles these patients encounter when interacting with other people thanks to an approach rooted and building on social coordination dynamics as well as motor and social cognition.