|Dr. Frank Johnson is an associate professor of psychology and neuroscience at the Florida State University, where his principal research activities involve the neural and behavioral mechanisms underlying vocal learning. In particular, his lab studies the zebra finch, a songbird that learns a vocal pattern much in the same way that humans acquire language. Songbirds are the preeminent animal model for human vocal learning, and they represent the only model system that allows investigation of vocal learning at cellular and molecular levels. Dr. Johnson earned his Ph.D. at the University of California, Riverside.
Male zebra finches learn a vocal pattern during juvenile life in a manner that bears a striking behavioral resemblance to human vocal learning. Following an early tutoring phase where the song of an adult male is heard, juvenile male zebra finches begin a sensory-motor learning phase where auditory feedback is used to shape initially variable vocal sounds into the sequence of distinct note types heard earlier in life. The neural circuit that controls this learning is composed of two neural pathways that converge on a common vocal/motor output. Here, I will present the view that the interaction between these two pathways is one of ontogenetic variation and selection. Interestingly, the neural pathway responsible for generating vocal variation includes the basal ganglia, a brain region highly conserved in architecture and neurochemistry across birds and mammals. Thus, our findings in songbirds suggest a broader model, where basal ganglia function contributes to the pre-existing behavioral variation necessary for operant learning to occur.