Fig. 1.

Single-subject data showing changes in VsCEP responses to the left (black traces, upper) and right (grey traces, lower) mastoid stimulation. The effect of head position was qualitatively the same for both mastoid sites. Stimulation ipsilateral to the direction of head rotation (e.g. left, upper left trace) evoked a large VsCEP with a short latency in the electrode overlying the opposite cerebellar hemisphere (P12-N17; PO10). Stimulation over the opposite (right) mastoid (lower set of traces), with the head rotated to the left, evoked a large but later response in the same electrode. The opposite occurred with head rotation to the right; here, right mastoid stimulation evoked a large short-latency response in PO9, with left mastoid stimulation evoking a later response