Fig. 5.

Grand mean responses (n = 11) from the extraocular, cerebellar, sternocleidomastoid and tibialis anterior (TA) electrodes. Traces are shown for left (black traces) and right (grey traces) mastoid stimulation. Cerebellar responses (CEPs) are largest for both directions of perturbation from the electrode opposite to the direction of head rotation. The oVEMPs show little change in response to head rotation, while the cVEMP in SCM shows enhancement by head rotation to the opposite side, after allowing for tonic changes in activation. Postural reflexes shown for TA demonstrate clear changes with well-formed responses with head rotation to the side opposite stimulation and attenuation of the effect with rotation back to the midline and beyond, but with corresponding changes in tonic activity. *Responses from the SCM have been divided by pre-stimulus SCM activation levels and therefore reflect the corrected ratio