Motoric Mechanisms for the Emergence of Non-local Phonological Patterns

Abstract

Non-local phonological patterns can be difficult to analyze in the context of speech production models. Some patterns – e.g., vowel harmonies, nasal harmonies – can be readily analyzed to arise from temporal extension of articulatory gestures (i.e., spreading); such patterns can be viewed as articulatorily local. However, there are other patterns – e.g., nasal consonant harmony, laryngeal feature harmony – which cannot be analyzed as spreading; instead these patterns appear to enforce agreement between features of similar segments without affecting intervening segments. Indeed, there are numerous typological differences between spreading harmonies and agreement harmonies, and this suggests that there is a mechanistic difference in the ways that spreading and agreement harmonies arise. This paper argues that in order to properly understand spreading and agreement patterns, the gestural framework of Articulatory Phonology must be enriched with respect to how targets of the vocal tract are controlled in planning and production. Specifically, it is proposed that production models should distinguish between excitatory and inhibitory articulatory gestures, and that gestures which are below a selection threshold can influence the state of the vocal tract, despite not being active. These ideas are motivated by several empirical phenomena, which include anticipatory posturing before production of a word form, and dissimilatory interactions in distractor-target response paradigms. Based on these ideas, a model is developed which provides two distinct mechanisms for the emergence of non-local phonological patterns.

Predicting One’s Turn With Both Body and Mind: Anticipatory Speech Postures During Dyadic Conversation

“…One possibility is that the emergence of postures is not strategic but is instead a passive, incidental consequence of how the planning and motor systems are coupled. We base this possibility on Tilsen’s (2019) explanation of the anticipatory postures observed in laboratory tasks. In this account, the postures arise when partly activated but unselected speech gestures cascade their influences into current articulatory targets, across a partly permeable threshold.…”

On the timing and coordination of articulatory movements: Historical perspectives and current theoretical challenges

“…This could mean speakers withheld the whole utterance behind a “leaky” control gate. Tilsen (2019) has developed this account in detail using Selection‐Coordination Theory. Kawamoto et al (2008) observed cases in which speakers did fully realize constrictions, to the point of building up air pressure for plosive consonants.…”

The Morphogenesis of Speech Gestures: From Local Computations to Global Patterns

“…This paper contributes to the literature on motor control as a dynamical phenomenon, initiated by Bernstein (1967) and Feldman (1966), and extended to speech by Fowler et al (1980), by showing how the low degree of freedom tasks of a motor control system are obtained via a dynamical computational process that starts out with a very large number of degrees of freedom (see also, Roon and Gafos, 2016; Tilsen, 2019). The contribution is to isolate the high degree system, the low degree system, and the extremely specific BVAM dynamical process as a candidate dynamical system that starts with the high degree of freedom system and ends with the low degree of freedom system.…”

“…We do not take this work to be a rejection of Task Dynamics or subsequent models inspired by it (e.g. Sorenson and Gafos, 2016; Tilsen, 2019), but a deepening of its predictive logic that is better able to predict major aspects of actual speech dynamics.…”

“…The mystery of particulation, therefore, is not likely to be solved by positing separate organs of speech in the vocal tract, since the organ that probably contributes the most contrasts to the differentiation among speech sounds, the tongue, is not particulated anatomically. A formal cause of particulation has been proposed within the Task-Dynamic Model and Articulatory Phonology (Browman and Goldstein, 1989; Saltzman and Munhall, 1989; Sorenson and Gafos, 2016; Tilsen, 2019), which assume articulatory tasks to be expressed in terms of Constriction Locations and Degrees defined as finite spatial constrictions which control the vocal tract from specific initial to final points in time. So, particulation is built-in, and there is no problem to solve.…”