The perception of a manipulable objects induces an evocation of motor representations associated to the visual object. This evocation results in a desynchronization of neural oscillations observed between 8-12hz in central regions (µ rhythm). However, a reduction of µ rhythm desynchronization has been reported when an object evoking several distinct motor representations is presented, reflecting a competition between the different motor representations evoked by a single object. We questioned whether this competition phenomenon would also occur in multi-object situations, when pairs of objects evoking distinct motor representations are presented. We also investigated the potential influence of thematic relations between objects (e.g., key-lock) on this competition. 30 Participants had to select a target object in 3D scenes displaying object pairs. Each object evoked a power/precision grasp so that the objects of a pair could evoke similar or dissimilar grasps. Objects could be thematically related or unrelated. Preliminary results indicate that µ rhythm desynchronization during object perception was sensitive to the similarity of motor representations evoked by the two objects. The relations between objects modulates the effect.