Interaction between auditory and motor systems in speech perception

Abstract

Based on the Motor Theory of speech perception, the interaction between the auditory and motor systems plays an essential role in speech perception. Since the Motor Theory was proposed, it has received remarkable attention in the fi eld. However, each of the three hypotheses of the theory still needs further verifi cation. In this review, we focus on how the auditory-motor anatomical and functional associations play a role in speech perception and discuss why previous studies could not reach an agreement and particularly whether the motor system involvement in speech perception is task-load dependent. Finally, we suggest that the function of the auditory-motor link is particularly useful for speech perception under adverse listening conditions and the further revised Motor Theory is a potential solution to the "cocktail-party" problem.

The Motor System's [Modest] Contribution to Speech Perception

“…More recently, another even weaker version of the motor theory has been proposed, based on converging experimental evidence from studies involving speech perception in difficult listening situations (Wu et al, 2014). This version claims the motor system influences speech perception, but it is not sufficient or essential for perception, suggesting instead that the motor system plays an ancillary role in in which it is primarily engaged during noisy or degraded listening scenarios (Wilson, 2009;Wu et al, 2014).…”

“…More recently, another even weaker version of the motor theory has been proposed, based on converging experimental evidence from studies involving speech perception in difficult listening situations (Wu et al, 2014). This version claims the motor system influences speech perception, but it is not sufficient or essential for perception, suggesting instead that the motor system plays an ancillary role in in which it is primarily engaged during noisy or degraded listening scenarios (Wilson, 2009;Wu et al, 2014). Additional support comes from a computational model of speech recognition in which auditory and motor theories were found to be indistinguishable during ideal listening conditions but not during degraded conditions MOTOR CONTRIBUTION TO SPEECH PERCEPTION 5 (Barnaud, Bessière, Diard, & Schwartz, 2018;Laurent, Barnaud, Schwartz, Bessière, & Diard, 2017).…”

“…On the other hand, speech production, or the precise coordination of articulatory movements, has been classically linked to brain regions in the left inferior frontal lobe (Price, 2000). These systems may not act independently of one another; some scientists propose that the auditory system supports speech production (Guenther, Hampson, & Johnson, 1998;Hickok, Houde, & Rong, 2011;Houde & Jordan, 1998), while others assert that the motor system is required for optimal speech perception (Liberman, Cooper, Shankweiler, & Studdert-Kennedy, 1967;Liberman & Mattingly, 1985;Meister, Wilson, Deblieck, Wu, & Iacoboni, 2007;Wilson, 2009;Wu, Chen, Wu, & Li, 2014).…”

“…The first claim will not be addressed in this paper. The second claim, derived from the motor theory of speech perception, is driven by evidence demonstrating motor system involvement during speech recognition tasks (Fadiga, Craighero, Buccino, & Rizzolatti, 2002;Meister et al, 2007;Watkins, Strafella, & Paus, 2003;Wu et al, 2014).…”

Rapid cortical plasticity induced by active associative learning of novel words in human adults

“…These routes are thought to participate in acoustic/phonological transcoding (Catani et al, 2005). The recurrent motor-perceptual interaction is known to facilitate speech perception of unfamiliar speech stimuli, e.g., distorted speech and novel or low-frequency words (Wu et al, 2014;Stokes et al, 2019). Therefore, greater involvement of the entire perisylvian network into the APW compared to the NPW response in our experiment may indicate that newly learned semantic association boosted perceptual processing of incoming novel linguistic stimuli.…”