Fig. 1 . Measures used to quantify medial octavolateralis nucleus (MON) unit
responses. (A) Sensitivity to running water. Discharge rate, mean ±
S.D. averaged across 60 s of constant water velocity (ongoing rate
subtracted), of a MON unit is plotted as function of flow velocity. A linear
regression was fitted to the data (broken line) and was used as a measure of
flow sensitivity. (B) Level-response function of a MON unit. Mean discharge
rate (ongoing rate subtracted) is plotted as function of sphere displacement
in still (filled circles, averaged across 20 stimulus presentations) and
running (open circles) water. (C) Strength of phase-locking of a MON unit.
Synchronization coefficients R are plotted as function of sphere
displacement in still (filled circles) and running (open circles) water.
Linear regressions (broken lines) were fitted to the data shown in B and C and
compared by analysis of covariance (ANCOVA) to determine whether responses
were masked in running water. To determine the degree of masking, the areas
under the functions shown in B and C were calculated. Areas under the curves
obtained from measurements in running water (dark shaded areas) were expressed
as a percentage of the area under the curves obtained from measurements in
still water (light shaded areas).
