'Core and Shell' Structure of Parrot Brain (image) Duke University Share Print E-Mail Caption The parrot's brain has a nested 'core and shell' structure for vocal learning. Neurons in the shell surrounding the established vocal centers of the parrot brain play a part in vocal learning and other complex motor behaviors, resolving controversies over the size of brain areas involved in song and speech imitation. Credit Courtesy of Jonathan E. Lee, Duke University Usage Restrictions None Share Print E-Mail Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.