Figure 5.

Population raster plots of the observed and expected responses obtained in response to the long distress sequence in the left (a) and right (b) hemispheres of the auditory cortex. Population responses are shown as colormaps, in which the colors indicate the normalized spike-counts of the units studied. In each unit, spike-count was normalized to the maximum number of spikes obtained in time-bins of the unit’s observed and expected PSTHs (see also Fig. 4). Units were ordered according to their “Maximum R” obtained by cross-correlating the observed post-stimulus time histogram of a particular unit with the energy envelope of the natural sequence that evoked the response. In other words, units whose response is represented at the bottom of the colormaps were classified as “better followers” of the sequence envelope than units that appear at the top. The “Maximum R” values obtained in each unit in response to the long sequences are shown in (c).