Temporal patterning in speech and birdsong

Speech and birdsong are complex motor behaviors in which patterning over time is itself informational. This is obvious in the case of speech, but in birdsong, too, the sequencing (and possibly timing) of syllables determines in part the well-formedness of the song. Despite gross differences in function, in the physical substrate (method of sound production), in brain structure, and in the scale of the animals, recent work has revealed a surprising degree of similarity in their solutions to the problem of controlling temporal patterning.  There are differences, too, of course, and when we find them, it deepens our understanding about the (unique) structure of speech. Because Steve has had a lasting interest in birds and birdsong (Anderson 2006), this seemed to be an appropriate context to review these similarities. Two of them will be the focus of discussion here: decomposition of the behavior into a sequence of discrete motor units and the role of an internal clock system, partly independent of the units themselves.