Fig. 8.

Analysis of song data from two birds before and after bilateral medial HVC ablation is used to generate models that replicate the behavior of the birds. A: transition probability histogram for bird 411 before (filled bars) and after (unfilled bars) ablation. A start (S) transition is a transition from an introductory note, call, or long gap to the syllable A or, after ablation, to syllable E. The end transition includes any transition from a syllable to an introductory note, call, or long gap. There are a large number of atypical F-E transitions after medial ablation. B: transition probability histogram for bird 513. There are a large number of atypical B-A transitions after medial ablation. C: model simulation of the behavior of bird 411 before and after simulated medial HVC ablation. D: model simulation of bird 513 before and after simulated medial HVC ablation. Note the close correspondence between experimental data and the models.