Figure 7.  Results of a generalization test for birds that were trained to discriminate between four light-sound compounds. The proportion of R2 responses is plotted for each of the 64 test stimuli. The top panel is for birds trained with R1 correct only in the presence of the soft sound, dim light compound (R2 was correct in the presence of the other three compounds). The bottom panel is for birds trained with R2 correct only in the presence of the loud sound accompanied by the bright light (R1 was correct in the presence of the other three compounds).