Fig. 1.

Schematic of the paradigm of combined whisker stimulation. A, The principal and adjacent whiskers (PW and AW, respectively) in the same row were briefly deflected either in the rostral or caudal direction at intervals of 0, 1, 2, 3, 4, 6, 8, 10, 12, and 30 msec. The timing of whisker stimulation is indicated by arrows. The paired whiskers were deflected in the same direction under all stimulus conditions. B, Protocols to test the selectivity for specific combinations of whiskers. Response to combined stimulation of a PW and a rostral AW was compared with that of the PW and a caudal AW.C, Protocols to test the selectivity for direction of whisker deflection. A pair of whiskers was stimulated in two opposite directions (rostral or caudal) from the resting position.