Fig. 7.

Generalization penalty (difference between within-transformation performance and across-transformation performance) is higher for A1 ensembles than for SRAF ensembles. Each dot corresponds to average classifier performance for a specific vocalization/transformation combination. Conditions in which SRAF units show smaller penalty than A1 units are connected with cyan lines, conditions, in which SRAF units show more penalty are connected by yellow lines. Mean penalty values for each brain area are marked with black arrows. A and B: generalization penalty when discriminating each vocalization from one other vocalization (pairwise classification). D and E: generalization penalty when discriminating each vocalization from all others (8-way classification). A and D: generalization penalty when generalization is performed only across the original vocalizations and one vocalization at a time (per-transformation generalization). B and E: generalization penalty when generalization is performed across all eight transformations and the originals at once (all-transformation generalization). C and F: generalization penalty as function of the number of cells in ensemble. C: pairwise classification across all eight transformations, as in B. E: 8-way classification across eight transformations, as in D. *P < 0.05; ***P < 0.001.