Mean difference in number of PSTH peak responses between neuronal recordings within primary auditory cortex columns.

<p><b>A–B</b>. Difference in number of PSTH peak responses during pure tone exposure. 25-ms (A), and 50-ms (B). <b>C–G</b>. Difference in number of PSTH peak responses during white noise burst exposure. 25-ms (C), 50-ms (D) 100-ms (E), 250-ms (F), and 500-ms (G). <b>H–L</b>. Difference in number of PSTH peak responses during upward FM sweep exposure. 25-ms (H), 50-ms (I) 100-ms (J), 250-ms (K), and 500-ms (L). <b>M–N</b>. Difference in number of PSTH peak responses during con-specific vocalization. Forward (M), time-reversed (N). Note the progressive increase in dissimilarity between responses as a function of acoustic signal duration during FM sweep exposure. Peak variability indices varied between 0 and 5, with an index value of 0 corresponding to no variations in the number of peak responses (diagonal) and a value of 5 representing the largest mean difference in peak response numbers measured. Numbers in color table axes correspond to recording site numbers, see <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0114550#pone-0114550-g001" target="_blank">Fig. 1</a> for electrode site description. NP: number of peaks.