At least three sensory systems and a collective fourth integrative system are involved: Vestibular, visual and somatosensory sensory impulses are centrally integrated, adjusted by the primitive, subconscious parts of our brain – the medulla, midbrain and cerebellum -- and these signals are transmitted to the cortex (i.e., when we become aware of them) when they are important such as to form our spatial awareness, or during acceleration, or when there is a mismatch between the signals – such as with disorientation and motion sickness.