Figure 5. Graphs displaying the presence (bar) or absence (square) of the behavioral reactions to different pseudo-target sounds.

Slightly different stimulus sets (x-axes) were prepared for 2 separate groups of animals (A, 1st test, n = 13; and B, 2nd test, n = 13) (y-axes). The pseudo-target sounds used in the recognition tests are shown on the x-axes. “Maj” and “Min”; modified step sounds with 7 major and 7 minor segments of the step sound doubled. “Int”; modified step sound with the intersegment intervals expanded. “Ord”; modified step sound with the segment-order shuffled. “LC”, “MC” and “HC”; modified step sounds with the low-, mid-, and high-frequency range removed from the step sound, respectively. “R” and “sR”; modified step sounds with the entire sound reversed in time and with individual segments locally time-reversed, respectively. *, p<0.05 and **, p<0.01 and n.s., not significant on a non-parametric statistical test (see text for statistical details).