Rhythm appears to be a fundamental capacity of humans. Rhythm plays a role in the prenatal environment and the early socialization of infants (Bertoncini, et al., 1995; Fassbender, 1996; Hargreaves, 1986; Papoušek, 1996). It has been implicated in the coordination of motor activity and locomotion (Iverson & Thelen, 1999). Rhythmic processing is a late deteriorating function in neurodegenerative diseases, such as Alzheimer’s (Beatty, et al., 1999). Rhythm appears to be a basic element in the construction of more complex human behaviors and interactions, such as music and language (Iverson & Thelen, 1999; Patel, et al., 1998), and has been implicated in aspects of memory (Brower, 1993; Payne & Holzman, 1986; Patel, et al., 1998).
A greater understanding of rhythm processing will therefore benefit from joint explorations across these domains of human behavior, in particular in music and language because of their universal presence across cultures and throughout the lifespan. Both music and speech share the same acoustic medium. Both are processed by the same perceptual apparatus. I find it reasonable to assume that the cognitive heuristics used for making sense of music and speech are at least similar, because we lack sufficient evidence to suggest that humans have evolved two entirely different mental modules for music and for language. To the contrary, there is great evidence to suggest that the distinction between music and speech is only achieved at higher levels of processing (Patel, et al., 1998).
There are many aspects of temporal processing that are relevant for this examination, and which necessarily impact an understanding of the subject. Unfortunately, well-formed and agreed upon definitions are in short supply. Paul Fraisse (1982), for instance, has written: “The task of those who study rhythm is a difficult one, because a precise, generally accepted definition of rhythm does not exist.” (149) What’s more, the definitions that occasionally arise lack consistency in what they describe. In an attempt to clarify and tease apart the various aspects of temporal organization, I provide my own definitions of certain aspects, which I trust are no less nor more arbitrary than most. I make no attempt however to be exhaustive in these definitions, in part because there appear to be many equally valid ways to divide up the temporal domain. I merely seek a first approximation of terms to address those aspects which will most facilitate questions dealing jointly with music and speech. Read the rest of this entry »