Experimental test of the birdsong error-correction model

摘要

Adult zebra finches require auditory feedback to maintain their songs. It has been proposed that the lateral magnocellular nucleus of the anterior nidopallium (LMAN) mediates song plasticity based on auditory feedback. In this model, neurons in LMAN, tuned to the spectral and temporal properties of the bird's own song (BOS), are thought to compute the difference between the auditory feedback from the bird's vocalizations and an internal song template. This error-correction signal is then used to initiate changes in the motor system that make future vocalizations a better match to the song template. This model was tested by recording from single LMAN neurons while manipulating the auditory feedback heard by singing birds. In contrast to the model predictions, LMAN spike patterns are insensitive to manipulations of auditory feedback. These results suggest that BOS tuning in LMAN is not used for error detection and constrain the nature of any error signal from LMAN to the motor system. Finally, LMAN neurons produce spikes locked precisely to the bird's song, independent of the auditory feedback heard by the bird. This finding suggests that a large portion of the input to this nucleus is from the motor control signals that generate the song rather than from auditory feedback.