Figure 10.
A, Additional examples of synchronous activity between secondary auditory sites that are separated by large distances. For each bird, raster plots are sorted from top to bottom on the latency of the strongest peak in the AMUA signal of the site in the top row. The events in the raster plots of the sites in the bottom row are aligned to those of the raster plot in the top row. Note that the pattern of peak activity in the top row often matches to activity at the site in the bottom row, and that nonresponses in the top row correspond to nonresponses in the bottom row. Also note that deviant events, the density of which is indicated by the color bar on the right side of raster plots, tend to have lower peak latencies (i.e., occur more frequently toward the top of the raster plot). B, Image plots of mean IS indices for all sites in this study. Each colored pixel represents the mean of the IS of that site (for anatomical location of sites, see Fig. 3) with a selection of other sites. Each row of image plots corresponds to a different kind of selection. In the top row (ISB), the mean is calculated over the four highest IS values; in the middle row (ISD), it is calculated over the 16 highest IS values; in the bottom row (ISL), it is calculated over the 4 highest IS values between the focal site and sites that are at least separated by 600 μm from the focal site. Gray pixels are sites that either were generally unresponsive or did not have sufficient concurrent responses with other sites (<5% of epochs). C, Distribution of time lags of maximum normalized cross-covariance between secondary auditory site pairs. Site pairs have been categorized depending on whether or not the distance between them is >600 μm. For most site pairs, cross-covariance is maximal at 0.0 ms.