SFI Presents Linguistics Seminar

Andy Wedel. Courtesy photo

SFI News:

Andy Wedel of the University of Arizona will present a Santa Fe Institute Seminar titled “The Lexicon as a Dynamical System: The Drive to Keep Words Distinct and the Evolution of Pheneme Inventories” at 12: 15 p.m. Wednesday, Dec. 11 in the Collins Conference Room at the Santa Fe Institute (1390 Hyde Park Road, Santa Fe). This seminar is free and open to the public. Those attending are invited to bring their own lunch.

Seminar Abstract: All human languages make use of small systems of signal categories, such as the sounds [p] and [b], in combination to compose meaningful lexical categories, such as the words “pat” and “bat.” These perceptually contrastive, yet individually meaningless signal categories are often called phonemes. Over generations, the properties and number of categories within phoneme systems changes, but little is understood about what drives and constrains this process.

However, recent evolutionary models of language change that treat language as a complex dynamical system provide an exciting new set of testable hypotheses, based on the proposal that long-term language change is ultimately driven by biases operating at the level of individual utterances. While there are potentially many such biases, we focus on a bias against lexical confusability as a model system.

A bias against lexical confusability provides a particularly rich model because the lexicon of each language is distinct, with the result that predictions for individual languages are also distinct.

Because of the large range of relevant time-scales, we use multiple approaches to test scale-specific hypotheses. In this talk, I will present (i) an overview of computational simulations that illustrate and support the general hypothesis, (ii) a cross-linguistic study showing that the probability of historical loss of a phoneme is inversely correlated with its role in disambiguating words, (iii) and a game-based laboratory model showing that phonemes become more or less hyperarticulated over the course of two days in correlation with their role in lexical disambiguation in the task.

 All these findings are predicted by the hypothesis that utterance-level micro-changes compound to produce macro-changes in language over generations.