Sensorimotor Maps of Vowel Perception and Production

Overview

Speech develops through a co-structuring of auditory and motor representations, especially in the first years of life during language acquisition. In the present study, we will test by means of functional magnetic resonance imaging whether vowel perception and production might depend on a coordination of auditory and motor, articulatory, cortical maps. The outcome of this study will lead to a better understanding of whether both vowel perception and production are processed in the human brain and will provide important insight into brain-language relationships. Besides new theoretical perspectives on speech perception and production, this project might raise important questions concerning patients with speech disorders by identifying which aspects of speech perception and production are functionally linked.

The goal of this study is to explore the functional neuroanatomy of vowel processing. To this aim, we will investigate the neural basis of both attentive auditory perception and production of natural French vowels using functional magnetic resonance imaging. More specifically, we will compare vowels that varied along a given phonetic feature dimension while keeping other feature characteristics constant. The phonetic features to be tested are roundedness (rounded/unrounded vowels), place of articulation (front/back vowels) and height (close, close-mid, open-mid vowels). Our study posed three specific questions. First, where exactly in the human brain is the perceptual and motor segregation of different vowel categories accomplished? Second, are these stimulus dimensions implemented topographically in an orthogonal manner, as they vary orthogonally in natural speech? Most specifically, one would expect a topographic segregation between two vowel categories (e.g., front vs back vowels) in both auditory and motor cortices that are characterized by widely distinct acoustic and articulatory values. Third, does these possible sound-related topographic activations in auditory and motor cortices overlap during vowel perception and production? This latter result would support a functional coupling between speech perception and production systems.

Conditions