Quantifying song bout production during zebra finch sensory-motor learning suggests a sensitive period for vocal practice

Abstract

Using an event-triggered recording system, the quantity of daily song bout production was measured weekly in male zebra finches (Taeniopygia guttata) during sensory-motor learning and at one year of age. Our aim was to ask whether the development of a stereotyped vocal pattern involves a practice-driven component. If so, we hypothesized that juvenile males learning song should sing more often than adults reciting a vocal pattern they had already learned, and that greater levels of juvenile singing should be associated with improvement in the quality of the adult song. Across the period measured (36-365 days of age), subjects showed an inverted U-shaped pattern of daily song bout production. Song bout production was lowest during subsong, with increased production associated with plastic song and song crystallization, although individual differences were large. Daily song bout production decreased in adulthood. Higher levels of song bout production during plastic song correlated with fewer sequencing errors in adult song patterns (r 2 =0.77). In contrast, quantity of singing during song crystallization showed no relationship to vocal stereotypy (r 2 =0.002). Our data suggest a sensitive period for vocal practice during zebra finch sensory-motor learning with consequences for the note-sequence fidelity of the adult vocal pattern.

Diurnal oscillation of vocal development associated with clustered singing by juvenile songbirds

“…As previously reported (Johnson et al, 2002), total amounts of diurnal singing were similarly maintained between the juvenile and adult stages (Fig. 1B, Fig.…”

“…1B, gray to red). The total number of diurnal singing bouts in the juvenile stage was almost the same as or slightly higher than that in the adult stage, as previously reported (Johnson et al, 2002). In contrast, the diurnal distribution and frequency of singing showed differences between the two stages (Fig.…”

“…This singing is not produced as a response to or aimed toward a specific individual but it is generated by undirected practice. The total number of song bouts produced during the critical period of vocal learning correlates with the number of learned song syllables and the stability of the syllable sequence (Johnson et al, 2002). This correlation suggests the importance of an appropriate amount of singing at the critical period for the acquisition of a qualified song.…”

Singing-driven gene expression in the developing songbird brain

“…Indeed, Clayton [43] has suggested that the ZENK response may be preparatory for learning or storage of memory, rather than participating directly in these processes. Given the integrative synaptic connectivity of RA, such a role is consistent with the emergence of robust ZENK protein labeling during plastic song, when levels of vocal practice peak [44] and characteristics of the mature vocal pattern first appear.…”

“…However, because our working hypothesis stipulates that gene expression related to neural development and song learning is in part under behavioral regulation, it became important to know the quantity of singing produced by juvenile birds as they learned their vocal pattern. Therefore, using a computerized sound-event triggered recording system, we measured 24 h song bout totals at weekly intervals in a group of developing male zebra finches housed on a 14:10 light:dark cycle [44].…”