UC San Diego

The brain's representation of the auditory world is not static, but changes based on an animal's history and current goals. We explored experience-dependent changes in both behavioral and neural representations of behaviorally relevant auditory stimuli in the caudal a secondary auditory fore brainregion, in European starlings. To accomplish this, we first designed and built a system that facilitated simultaneous neural and behavioral recording, allowing--for the first time--neural responses to be recorded while birds performed auditory-mediated operant tasks. We found that when birds were engaged in an auditory task, neurons had more information in their stimulus-driven firing rates about the task-relevant stimulus classes than when birds were not engaged in the task. We also trained birds to quickly learn novel stimulus classifications and showed that neural responses change over the course of learning. For most neurons, stimulus-driven neural responses decreased with learning, and they did so most strongly for the newly learned stimuli. We suggest that these effects may be due in part to stimulus-specific adaptation, and its modulation by behavioral state. We also observed the formation of task- dependent firing rate modulation with learning. These results highlight the plasticity of the avian auditory system, and further our understanding of the way that nervous systems adapt to the changing environment and behavioral goals of an organism