Abstract
Songbirds’ vocal mastery is impressive, but to what extent is it a result of practice? Can they, similar to humans, plan targeted changes to their songs in a practice-free manner without intermittently singing? In adult zebra finches, we drive the pitch of a song syllable away from its stable (baseline) variant acquired from a tutor, then we withdraw reinforcement and subsequently deprive them of song experience by muting or deafening. In this deprived state, birds do not recover their baseline song. However, they revert their songs towards the target by about one standard deviation of their recent practice, provided the latter signaled a pitch mismatch with the target. Thus, targeted vocal plasticity does not require immediate sensory experience, showing that zebra finches are capable of goal-directed vocal planning.
Significance statement Zebra finches are capable of making target-directed changes to their songs without requiring sensory feedback.
Competing Interest Statement
The authors have declared no competing interest.
Footnotes
We removed WNC birds from the analysis of fine-grained vocal changes (Figure 4). In the previous version of the manuscript, we reported that WNd birds initially (in early windows) recover pitch not more slowly than do WNC birds. However, this does not add to the main argument of the paper. Whether target mismatch experience is necessary for revertive pitch changes depends on whether pitch changes differ between WNd and dLO birds and not between deafened and WNC birds. To control for deafening induced changes (independent of learning or target mismatch experience), we still assess pitch changes in WNd and dLO birds relative to pitch changes in deaf control birds (dC) as we did before. Furthermore, WNC birds also experienced target mismatch during the measurement window (recovery) itself and their recovery dynamics could not be time-aligned to that of WNd birds because of incompatible experimental protocols. Based on these considerations, we concluded that the comparison between WNC and WNd is uninformative for testing the hypothesis and removed it from the manuscript. Minor changes: We removed supplementary figure 2 showing that pitch recovery of birds after NCM lesion because it is not trivially comparable to the muted birds and it did not add an important point to the paper. The violin plot in Figure 2D showed the mean of the data as a line. In Figure 2D, the violin is so narrow at that point that the line for the mean turned into a point that could be mistaken with a data point. To avoid this confusion, we extended the width of the line indicating the mean of the data. We simplified Figure 5 by removing the different illustrations for WNd and WNC from the figure and combined it into one illustration focusing on the current vocal output and its sensory experience.
