Fig. 4. (A) Measured amplitude of extracellular receptor potentials (ERPs; circles) from a neuromast in the supraorbital lateral line of the ruffe. The sphere was moved along an axis parallel to the lateral line (x-axis) at a distance d=10 mm. This is referred to as an excitation pattern (see text). ERPs were fitted with the model given by Eqn 4 (solid line), describing the measured excitation patterns (b=–0.9±0.2 mm; d'=8.5±0.3 mm; =–9±3°). (B) Phase of ERPs.