Thursday, May 15, 2008

Another Theory of the Evolution of Language: Peter F. MacNeilage on the Origin of Speech

There is a new book in the Oxford „Studies in the Evolution of Language“ Series by Peter F. MacNeilage, a professor of psychology at the University of Texas at Austin, called quite simply, “The Origin of Speech.”

MacNeilage advances something he calls the Frame/Content Theory of vocal communication: It poses that

segmental ‘‘content’’ elements are placed into syllable-structure ‘‘frames.’’“ (MacNeilage 2008: 57).

Taking evidence form speech errors, MacNeilage assumes that frame, “the continual rhythmic alternation between an open and closed mouth” (MacNeilage 1998), and content (the actual vowels and consonants) are two fundamentally different mechanisms included in speech.

He proposes

“that in both evolution and in development, frames come first and content later.” (MacNeilage 2008: 58)

So here’s his account of how the evolution of language took place:

"As I reconstruct the process, motor frames for speech evolved from mandibular cyclicities [i.e. the movements made when ingesting food, such as chewing] via an intermediate stage of visuofacial communicative smacks [i.e. the kind of communicative lipsmacks found in non-human primates], which eventually became paired with phonation to form protosyllables. These protosyllables initially filled a vocal-grooming role. They proved effective because they made for the omnidirectional transmission of a standard communicative signal, readily extended across time, and with sharp acoustic alternations between closed and open states of suffcient complexity to sustain a listener’s interest. At some point, one of the limited sets of protosyllabic forms – a nasalized variant –became paired with a female parental concept, resulting in the form [mama]. This was a social invention—and a momentous one. It paved the way for a series of similar single events linking, one by one, additional items at two hitherto unrelated levels of function – concepts and sound patterns. Once this invention got from the infant – parent matrix into broader society, subsequent concept – sound pairings for new words got established by cultural agreement, and the history of these agreements got passed along to successive generations of language users. This led to the one-word stage of true language, which is as far as the F/C theory goes (MacNeilage 2008: 293)"


To me this sounds like another of these „just so“ stories, which I though we’d been over by now. However, the framework surely doesn’t rise or fall with the fairytale part, and I don’t know enough about the book and about phonology in general to judge its validity. The parts that I’ve read, for example his discussion of the genetic underpinnings of language, including the FOXP2 gene, are really interesting. People interested in the motoric, neural and phonological/phonetics aspects of language should check out the book, there’s a lot of cool stuff in there.

For instance, I didn’t know that there is a “phonological loop” in short-time memory”/ “working memory” – which is "some kind of temporary storage of information [...] necessary for performing a wide range of cognitive skills including comprehension, learning and reasoning" (Baddeley 1995: 755) which organizes linguistic input and output and controls articulation. MacNeilage follows the proposal of Alan Baddely, a leading researcher in the area of short-time memor, who proposes that the “phonological loop”:

"has evolved, probably from more basic auditory and verbal production mechanisms, as a device for language acquisition’’ (Baddeley, 1995: 762)
Both see it as a central system in language evolution, because it allows

  1. for the comparison of the production attempt and target representation, which for example, may be important in world learning.
  2. to put together and hold in memory incoming information during comprehension.
  3. for “the holding of output information in various stages of completion during the assembly of a spoken sentence“ (MacNeilage 2008: 191).

MacNeilage also places his approach into the “emerging intellectual context” of Embodiment, because he shares its desire to explain higher mental functions in terms of the integral interaction of mind and body. He is also opposed to nativism and nativistic brands of evolutionary psychology. Instead, he sets his hopes on Dynamical systems theory and self-organization,

"the emergence of new states from the interaction of variables in a complex system, in the absence of an external controller.“

Thus his approach blends in well with the stance taken by people like Simon Kirby and others, which I briefly described here.

Almost needless to say, he also discusses mirror neurons, which are in the news about any other day and are often seen as the explanation for about everything ranging from empathy (see for example this blog post over at Complex Adaptive Systems), to understanding the beliefs of others, to the evolution of language. For an interesting discussion, see this interdiciplinary discussion forum on the question: What do mirror neurons mean?

MacNeilage also holds that

"these neurons […] presumably played a crucial role in our evolving the capacity to relate observation and action as required in mimesis,” (MacNeilage 2008: 171)
which in turn, is crucial for learning speech and language, as well as for about every kind of social interaction in general. MacNeilage relates this to Merlin Donald’s (1991) notion of a general-purpose mimetic capacity being the underpinning and necessary precursors to language as well as to all cultural behaviors.

Furthermore, there are also mirror neurons implicated both in call production and call comprehension of monkeys, which might be seen as the neural basis of our capacity for vocal learning and speech. MacNeilage’s theory that speech evolved from ingestive rythms via smacks is also supported by the fact that there are neurons in the monkey mirror neuron system that are implicated both in chewing and communicative behaviors such as lipsmacks (Ferrari et al 2003, MacNeilage 2008: 175ff.).

In general, the research on mirror neurons thus seem to confirm MacNeilage’s proposals.

In sum: for me the book is a bit too technical, but MacNeilage’s approach seems to be pretty interesting., especially for people with a footing or interest in the neurobiological aspects of language.

On a related note, Edmund Blair Bolles of Babel’s Dawn has published a short piece on the evolang conference in the journal BioScience, titled "Case for Biological Origins of Language Grows Stronger", in which he reports on the new evidence for the evolution of language presented at the conference.

Also have a look at this post over at the Language Evolution blog, where Chris discusses the evolang talks of famous archaeologist Franceso d'Errico, who speculated on the possibility of Neanderthals having language, and the talk of infamous linguist Derek Bickerton, who proposed the major factor in language evolution was the emergence of a mental lexicon and not the evolution of syntax.

References:

Baddeley, Alan D. (1995). ‘Working memory.’ In M. S. Gazzaniga (ed.), The Cognitive Neurosciences. Cambridge, MA: MIT Press, 755–764.

Donald, M. (1991). Origins of the Modern Mind. Cambridge, MA: Harvard University Press.

Ferrari, P. F., Gallese, P., Rizzolatti, G., and Fogassi, L. (2003). ‘Mirror neurons responding to the observation of ingestive and communicative mouth movements in the monkey ventral premotor cortex.’ European Journal of Neuroscience, 17, 1703–1714.

MacNeilage, Peter F. (2008): The Origin of Speech: Oxford: Oxford University Press (Studies in the Evolution of Language 10).

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