My lab studies neural mechanisms of pattern learning and recognition in the auditory system. We work in two species of songbirds, the European starling (Sturnus vulgaris) and the zebra finch (Taeniopygia guttata). Starlings and finches live in large groups with dynamic social structures and use song to communicate individual identity, sexual fitness, and other social signals. Songbirds can learn to recognize hundreds of songs from different individuals under challenging and variable acoustic conditions. Understanding how their brains separate signal from noise and form coherent perceptual categories will give insight into similar processes underlying speech perception and other forms of perceptual learning.
Current research areas include:
Auditory categorical recognition: Using behavioral methods, we examine how starlings learn categories of acoustic signals from sensory experience, how categories reflect variation in the features of the signals, and how learning affects subsequent perceptual processing. We also study how auditory categories form in natural social settings and depend on group structure and dynamics.
Population encoding of acoustic categories: Perceptual categories likely arise from coordinated activity in dynamic assemblies of neurons, which can integrate across time and frequency, filter out noise, infer missing features, and discriminate between patterns that differ in only a few critical features. We use chronic, multi-electrode methods to record from large populations of neurons in behaving animals and advanced statistical techniques to study population responses to songs and how distributions of activity change with learning and behavioral context.
Circuit mechanisms for perceptual learning: Little is known about the cell types and microcircuits of the avian auditory forebrain. Using slice and in vivo intracellular recordings, we are characterizing physiological responses, connectivity, and gene expression profiles. The goals are to develop models of systems-level processing in this area and to better understand evolutionary and functional similarities to homologous regions of the mammalian auditory cortex.