Why language processing takes advantage of perceptual and motor structures of the brain
Dr. Tatjana Nazir, CNRS Lyon
Abstract: Over the past 15 years a number of studies provided evidence that under certain conditions brain structures that are involved in perception and action are recruited for purposes of language processing. Hence, while hearing a sentence such as “Paul writes a letter” motor brain structures involved in the planning and execution of hand actions start to be activated a few hundreds of milliseconds after the onset of the word writes. Yet, no such increase in motor brain activity is seen for the same word embedded in a sentence such as “Paul wants to write a letter”.
When the phenomenon was first discovered it was assumed that language-induced activity in modality specific brain structures served the elaboration of word meaning: Understanding the word to write involves the mental simulation of the action of writing, which is performed in the motor cortex. However, the variation of language-induced motor activity with linguistic and extra-linguistic factors rapidly casted doubt on this interpretation.
In my presentation I will first describe a series of linguistic conditions that trigger language-induced motor activity and those that do not. I will then focus on the primary function of the motor structures that are exapted by language and propose an alternative hypothesis for their role in language processes. Finally, I will discuss potential consequences of recruiting perceptual and motor structures during language processing for mind and behavior.
Bio: Tatjana A. Nazir is a cognitive psychologist, research director, and head of the Institut des Sciences Cognitives - Marc Jeannerod (UMR5304 - CNRS-University Lyon 1) in Bron, France. Her research focuses on the role environment plays in the development of cognitive processes (Embodied Cognition). In particular, how brain structures dedicated to perception, emotion and action influence human language, and how shared neural circuits between action, perception and language can be used for purposes of training and rehabilitation of language deficits.