Common Coding of Speech Imitation

Abstract Most current speech scientists regard both speech perception and production to be tightly linked. Hearing or seeing speech results in the engagement of a covert imitative response, also referred to as automatic imitation. Current theories of speech and language processing firmly incorporate close connections between speech perception and speech production. For instance, the integrated theory of language production and comprehension assumes that listeners rely on an analysis-by-synthesis process during speech comprehension. This process is predicted to engage covert imitation, especially for familiar speech utterances. Behaviorally, covert imitation can be evaluated using a paradigm originally developed in cognitive psychology, the stimulus-response compatibility (SRC) paradigm. While most SRC experiments employ manual stimuli, a small but growing set of studies have been using speech stimuli to clarify how observing speech results in a covert imitative response. However, it is unclear if the integrated theory can explain the effects reported from speech SRC studies. Here, we evaluate to which extent the theory of event coding (TEC) can explain results from automatic imitation experiments with speech stimuli. TEC is a framework for action planning and action perception based on the ideomotor principle and common coding principles of action and perception. TEC offers a flexible framework for evaluating the link between action perception and action production but has to date not been applied to speech processing. In this chapter, we evaluated how well the integrated theory and TEC can explain current findings. We conclude that TEC can account for more published results than the integrated theory, but that neither theory can explain all findings. Recommendations are made for improvements to both theories.