Figure 2. Classification of AVCN units based on PSTH types.

A1–A4: Response patterns during tone burst stimulation (100 ms, 80 dB SPL at CF) of four units; dot raster to 50 stimulus presentations above, PSTH below (bin width 0.5 ms). A1: primary-like (PL), A2: primary-like with notch (PL_N), A3: transient chopper (C_T), A4: sustained chopper (C_S). The insets show the inter-spike interval (ISI) distribution during the first 20 ms of the stimulus of the respective units (bin width 0.1 ms); B1: Relation between mean ISI and S.D. of ISI for the different unit types (symbols as indicated in the figure) B2: Relation between the first spike latency (FSL) and the jitter of the FSL. Note that both types of chopper units have lower ISIs and a lower variation in ISI than PL and PL_N units. Shortest latencies are observed in PL_N units.