Figure 1: A participant performing the four mirroring tasks in random order: A) The iCub robot mirroring facial expressions; B) The Pepper robot affectively signaling through LED color changes; C) The iCub robot mirroring head movement based on an inertial measurement unit (IMU) readings. The red circle shows the IMU; D) The iCub robot mirroring head movement according to a vision-based model. The red circle shows the camera.