MEMBER

Species behavioural differences that do not result from exposure to different environments are well documented, yet little is known about the developmental and evolutionary changes in brains that are responsible for them. Such differences are thought to be due to species differences in “neural default settings” that cause species brains to organize their own development and incoming experiential information in divergent ways. These “predispositions” are important for understanding cognitive development because they provide the scaffolding upon which learning builds complex perceptions, emotions, evaluations and reactions. Our laboratory uses transplants of embryonic brain tissue between two bird species at early stages of development to learn more about the brain mechanisms underlying species behavioural differences. The resulting animals, called chimeras, provide an opportunity to survey the brain for particular regions that, when transplanted between species, will transform the performance of a particular target behavior by the host individuals to the form shown by donor individuals.

We concentrate on auditory communication behaviours, because they are cognitively and socially complex and biologically important. Using transplants in combination with neuroanatomical and electrophysiological techniques, and molecular and metabolic-based methods for imaging brain activity, we identify interacting cell groups in the developing nervous system that make decisive contributions to species differences in the architecture of neural circuits underlying communicative behaviours, and specify the role these regions play in neural and behavioral development. These studies also shed light on the particular developmental mechanisms evolution uses to change brains and behaviours.

A second line of research focuses on neural correlates of human auditory perception. We develop methods for studying changes in ongoing brain activity during the perception of naturalistic time-varying sound sequences such as speech or music, with a particular interest in applying these methods to study the neural mechanisms of pitch perception (prosodic perception in speech), auditory category formation (phonetic categories in speech), and how these mechanisms emerge ontogenetically.