Fig. 7. Responses of a type I medial octavolateralis nucleus (MON) unit to a 50 Hz vibrating sphere stimulus in still (left) and running (15.5 cm s^-1; right) water. Raster plots and level-response functions are as in Fig. 4. Displacement amplitudes were 3770, 2300 and 59 µm. In still water, this unit responded to the vibrating sphere with a decrease in discharge rate. Ongoing discharge rate was comparable in still and running water. Consequently, the response to the vibrating sphere was not masked.