- To understand how feedback about performance is encoded in the brain, we combine chronic neural recordings from singing birds with manipulations of auditory feedback to characterize how signals in this circuit change in response to persistent vocal errors. While initial experiments focus on the contributions of the cortica output nucleus of this circuit, we will also investigate how auditory feedback-related signals are transformed at different stages in the circuit.
- To directly test how signals in this circuit drive adaptive changes in song, we use electrical, chemical, and optogenetic methods to precisely alter neural activity during normal vocal behavior and in response to disruption of auditory feedback. Such experiments will help to elucidate which patterns of activity are necessary and/or sufficient to drive acute and/or long-lasting changes to song.
- In many species of birds, sensory learning of song occurs during an early critical period, and the influence of auditory feedback on song production declines with age. To investigate whether the mechanisms that mediate feedback-driven changes in adult song are the same as those that enable juvenile motor learning, we record singing-related activity in the basal ganglia-thalamo-cortical circuit in juvenile birds engaged in sensorimotor learning. Comparison of neural activity patterns at different stages of learning will shed light on the neural processes that enable or limit auditory feedback-driven song plasticity. For example, does burst firing or variability in spike timing decrease as vocal output approaches the target? Just as in adult birds, we use electrical, pharmacological, and optogenetic techniques to directly alter patterns of neural activity in this circuit and assess their causal role in learning.
- Developing an animal model of rhythm perception
In collaboration with Dr. Annirudh Patel in the Psychology Department, we are investigating the role of auditory-motor interactions in “beat perception”, or the ability to flexibly and predictively perceive a steady pulse. First, we are testing whether songbirds can recognize beat-based rhythms in a flexible manner, and if so, we will test the hypothesis that activity in vocal premotor brain regions are necessary for beat-based timing and tempo flexibility. Such studies will allow us to understand how auditory-motor interactions can influence beat perception and motor function in both normal and pathological conditions.