ABSTRACT
Sensory experience during sensitive periods in development may direct the organization of neural substrates, thereby permanently influencing subsequent adult behavior. We report a sensitive period during the imitative motor learning phase of sensorimotor integration in birdsong development. By temporarily and reversibly blocking efference to the vocal muscles, we disrupted vocal motor practice during selected stages of song development. Motor disruption during prolonged periods early in development, which allows recovery of vocal control prior to the onset of adult song, has no effect on adult song production. However, song disruption late in development, during the emergence of adult song, results in permanent motor defects in adult song production. These results reveal a decreased ability to compensate for interference with motor function when disturbances occur during the terminal stage of vocal motor development. Temporary disruption of syringeal motor control in adults does not produce permanent changes in song production. Permanent vocal aberrations in juveniles are evident exclusively in learned song elements rather than nonlearned calls, suggesting that the sensitive period is associated with motor learning.
Subject(s)
Imprinting, Psychological/physiology , Psychomotor Performance/physiology , Songbirds/physiology , Vocal Cord Paralysis/physiopathology , Vocalization, Animal/physiology , Acoustic Stimulation , Aging/physiology , Animals , Botulinum Toxins, Type A , Feedback/physiology , Imprinting, Psychological/drug effects , Male , Phonation/drug effects , Phonation/physiology , Psychomotor Performance/drug effects , Sound Spectrography , Time Factors , Vocal Cord Paralysis/chemically induced , Vocal Cords/drug effects , Vocal Cords/physiology , Vocalization, Animal/drug effectsABSTRACT
We investigated the role of developmental vocal experience in adult song perception by muting juvenile male zebra finches prior to song development and testing their behavioral responses to song playback as adults. Birds were raised in a normal social and acoustic environment. Non-treated sibling control birds demonstrated statistically significant phonotactic preferences for particular conspecific familiar or novel songs. Muted birds responded to playbacks at chance levels, showing no preferences for individual conspecific songs. These results suggest that the acquisition of a bird's own song may contribute to the perceptual processing, recognition, or discrimination of different conspecific songs.