Properties of EFP.

(A, B) EFPs (200–600 Hz) are more precise in timing stimulus onset than MUA. Data are based on a 90% detection reliability. The detection reliability refers to the probability at which MUA/EFP peaks were detected across all trials for the same sound stimulus. The MUA data in B were a subgroup of the original data in which values larger than the maximum of the data in the EFP group were excluded. (C, D) Topographical organization of the response latencies of the EFP (200–600 Hz). The recording depth is displayed as the median and quartiles for each detection reliability between 5% and 95% at a step of 5%. As indicated by the asterisks, the median recording depth was significantly correlated with the response latency and its variability. (E–G) The number of firing neurons affects the properties of the EFPs. The number of firing neurons refers to the average number of negative peaks whose amplitudes exceeded the detection threshold of the wideband signal (20–3,000 Hz; see Fig 1A and 1B) within a time window of ±3 ms relative to the averaged latency of the EFP over 80 repetitions. Data for this figure are included in S1 Data. EFP, extracellular field potential; MUA, multiunit activity.