Coupling relations underlying complex coordinative patterns in speech production

Abstract

In studying linguistic behavior, we are often faced to complex dynamical patterns arising from the highly coordinated activity of many partially autonomous processes. In this work, we apply a new approach aimed at studying abstract coupling relations coordinating the behavior of dynamical systems governed by goal oriented behavior. The approach, based on an original version of recurrence analysis, allows to deal with the principal difficulties of this task, which are mainly related to the heterogeneity, the lack of separability and the lack of stationarity of the processes under study. The method is validated trough simulations of theoretical systems and it is adopted to capture (1) invariant abstract coupling structure underlying systematically varying trajectories of the speech articulators involved in the production of labial and coronal plosive and fricative consonants (produced at slow and fast speech rate by five German speakers and recorded via electromagnetic articulography); (2) systematic differences in the coordination between energy modulations observed at different frequency bands in the acoustic signal and showing the interplay between syllable and stress related processes and its relation to rhythmic differences between typologically different languages (pear story narrations were recorded from five speakers per language in German, Italian, French, English, and Polish).