Fig. 10. Flow velocities (red and blue curves) calculated from interrogation windows (see small squares on fish drawings). Interrogation windows with the red vectors were at the position of the neuromast. The interrogation windows with the blue vectors were slightly more rostral (A) or caudal (B), respectively. The black traces in A and B show the discharge rates (spikes/40 ms) obtained in a single trial of the E-afferent (A) and I-afferent (B) whose data are shown in Fig. 9. Negative velocities represent flow in the tail-to-head direction; positive velocities represent flow in the head-to-tail direction. Gray bars indicate the times when the first and third reproducible response components occurred. Zero indicates the time of valve opening.