Are speech universals hard-wired…in the body?

Why do we use the particular movements we use in speaking (or walking, swallowing, etc.)? Why are speech movements so similar across languages? Recent language evolution models question the role of strong innateness in cognition (e.g., Thompson et al. 2016) while stressing the importance of possible physical constraints (e.g., de Boer 2016). Humans can produce many of our most complex motor behaviors (swallowing, vocalizing, suckling, smiling, etc.) at birth without experience – or indeed without a brain above the brainstem; this indicates a degree to which the biomechanical and neural (central and peripheral) structures needed for complex action appear to be “built in”. A model is described, based on neurophysiological and computational motor research, in which action is governed by such neuromuscular structures (“modules”), and in which these structures emerge and/or change ontogenetically through use. Simulations of oral movements using biomechanically realistic models in the ArtiSynth platform (www.artisynth.org; e.g., Fels et al. 2003, Stavness et al., 2012, Gick et al. 2014) support this view, showing that the vocal tract offers only a small inventory of reliable, biomechanically robust actions. These results are consistent with a theory of embodied phonetics built on an inventory of functionally defined primitives, each of which serves a specific phonetic function in speech (see Gick & Stavness 2013). Importantly, these primitives, being functionally defined, make no reference to traditional, anatomically defined body parts such as “lip” or “tongue tip”.