Self-motion perception involves various sensory systems (primarily visual, vestibular and somatosensory). Sensory information is processed by the central nervous system to acquire a representation of the three-dimensional movements of the head and body in space, allowing spatial orientation, travelled distance perception, control of balance and posture. Perception at the sensory receptor reflects only very rarely conscious sensation of movement. The study of motion perception has to deal the interactions between different sensory modalities, more than the study of each sensory channel separately. Signals from different sensory systems may not be congruent, thus generating illusions and sensory conflicts studied by cognitive ergonomics.
