Is Phonology Embodied? Evidence from Mechanical Stimulation

Abstract

Across languages, certain syllables are systematically preferred to others (e.g., plaf > ptaf ). Here, we examine whether these preferences arise from motor simulation. In the simulation account, ill-formed syllables (e.g., ptaf ) are disliked because their motor plans are harder to simulate. Four experiments compared sensitivity to the syllable structure of labial- vs. corona-initial speech stimuli (e.g., plaf > pnaf > ptaf vs. traf > tmaf > tpaf ); meanwhile, participants (English vs. Russian speakers) lightly bit on their lips or tongues. Results suggested that the perception of these stimuli was selectively modulated by motor stimulation (e.g., stimulating the tongue differentially affected sensitivity to labial vs. coronal stimuli). Remarkably, stimulation did not affect sensitivity to syllable structure. This dissociation suggests that some (e.g., phonetic) aspects of speech perception are reliant on motor simulation, hence, embodied ; others (e.g., phonology), however, are possibly abstract. These conclusions speak to the role of embodiment in the language system, and the separation between phonology and phonetics, specifically. Supplementary Information The online version contains supplementary material available at 10.1007/s10936-022-09871-x.

Phonetic categorization relies on motor simulation, but combinatorial phonological computations are abstract

“…The correlation between articulatory and linguistic preferences does not settle this question, as it does not prove that the motor system has a causal role in the combinatorial function of speech sounds. In fact, existing evidence suggests that, unlike the categorization of speech sounds, perceiving their combination (i.e., phonology) is mostly impervious to disruption of the articulatory motor system 22 , 23 , and instead recruits the pars triangularis of the frontal operculum (part of Broca’s area) 24 . Moreover, people can extract the sound structure of speech well before they can talk; even newborns do so 25 .…”

“…But whether the motor system does, in fact, mediate the formation of combinatorial structure is uncertain.The correlation between articulatory and linguistic preferences does not settle this question, as it does not prove that the motor system has a causal role in the combinatorial function of speech sounds. In fact, existing evidence suggests that, unlike the categorization of speech sounds, perceiving their combination (i.e., phonology) is mostly impervious to disruption of the articulatory motor system 22,23 , and instead recruits the pars triangularis…”

Phonological similarity between words is represented in declarative memory as spatial distance

“…There is growing evidence that phonology is created, stored, and shared through the embodied learning of sound production, shaped by the inputs in the environment but also by the experience of creating sounds and recognizing them (Fogassi & Ferrari, 2008 ; Nathan, 2017 ). Berent & Platt, ( 2022 ) showed phonetics and lexical phonological associations are grounded in our sensorimotor system, whereas the phonological structure is abstract. These perceptual aspects of phonology were found to hamper memory performance.…”