Fig. 2.
Tests of robustness. (A) Schematic RA cell loss. After a subset of RA is removed, the song is performed, and the new error is computed. (B) Error in song as a function of number of HVC perturbations per 105 iterations for the full RA network and for subpopulations of RA. Arrows indicate error from full RA network to error from RA network after cell loss. Error is averaged over randomly drawn subsets of RA and over trials. HVC perturbations increase the ability of a subpopulation of the RA network to represent song. (C) Target song shift. After 105 iterations, the target song is altered, and relearning proceeds for 3,000 iterations. (D) Relearning trajectory after target song changes. (E) Number of iterations to half-decay of learning trajectory. HVC perturbations speed up the adaptation process with minor penalty in final error. Error bars represent standard error.