Abstract
The effect of postrotatory vertical canal stimulation on nystagmus and apparent vertical was investigated as a function of the tilt position at stop in a vertical roll-plane. Nystagmus duration and number of beats as well as the effect on the apparent vertical increased with change of stop position from head-up to head-down. The results are interpreted in terms of a hypothesis which proposes a decline of effectiveness of the statolith organs with increasing degree of tilt. This is discussed with respect to related findings.