Neurobiologists studying the finch now say the improvisation arises from a component of a crucial learning circuit in a section of the forebrain that seems to generate the trial and error necessary to master sophisticated motor skills, such as singing in birds or speech and sports in humans.
"It means this part of the brain is important for instructing or allowing changes in the song," said Mimi Kao, first author of a paper in the February 10, 2005, issue of the journal Nature that demonstrates how the region modulates bird song in real time. Kao, a Howard Hughes Medical Institute (HHMI) predoctoral fellow, is in the final months of her doctoral training in the laboratory of co-author Allison Doupe at the University of California, San Francisco's Keck Center for Integrative Neuroscience.
A similar brain pathway in humans may explain how children learn to talk by listening to themselves and others, and how adults learn and hone new motor skills, such as tennis. The process relies on feedback about what works and what doesn't, also called experience-dependent or performance-based learning.
"That all requires paying attention to how we're doing, experimenting with different things, and gradually getting better," said senior author Michael Brainard, assistant professor of physiology at UCSF, whose lab is funded in part by a grant from HHMI. "It makes sense that one part of the brain has as part of its job introducing that kind of variability."
Kao began with an experiment to stimulate the region of the forebrain called LMAN (lateral magnocellular nucleus of the anterior nidopallium). In the avian brain, LMAN receives input about complex movements from the b
Contact: Jennifer Donovan
Howard Hughes Medical Institute