Spike count and latency plots for paired tone stimulation (data from Fig. 7). A, Mean ± SE spikes per BD tone or pedestal (left y-axis, filled circles) and mean ± SD first spike latency with regard to stimulus onset (right y-axis, open squares) as a function of the time between the offset of the BD tone and the onset of the NE tone. The number of action potentials evoked by the BD tone began to decline before its offset was contiguous with the onset of the NE tone. B, Spikes per stimulus (as in A; error bars are omitted for clarity), and last spike latency with regard to stimulus onset (right y-axis, open triangles) as a function of the time between the offset of the BD tone and the onset of the NE tone. The last spike latency of the cell began to decrease as the gap between the leading BD tone and the lagging NE tone decreased because of the progressive deletion of spikes from the end of the response burst (see Fig. 7). The duration of the NE tone is illustrated with a black bar; the BD tone is not shown. Circles with awhite fill are spike counts at the two time intervals when the BD tone was contiguous with but did not overlap the NE tone. The gray box indicates the range of times over which the BD tone was contiguous with or overlapped the BD tone to form a single composite stimulus with an amplitude increment (i.e., a pedestal). In this and similar figures, pedestal data that were not within 3 dB of maximum stimulus amplitude were omitted (see Testing with tone pairs); 15 trials per stimulus.