The aim of our study is to show by fMRI the involvement of the motor system in the perception of speech, and more particularly how this implication is modulated by the degree of prototypicity of the stimuli.

Each participant will undergo two visits:

Phase 1: The Gipsa-Lab Laboratory's Department of Speech and Cognition. This first visit will make it possible to make recordings of their vowel productions and to verify that the participants correspond to the criteria necessary for the study (passing the Edinburgh manual laterality test and auditory thresholds checked using a " An audiogram). It will also be an opportunity to provide them with the consent documents and the fact sheet, which will give them time to read it before the MRI exam. The duration of this first visit will be approximately 1 hour.

Phase 2: fMRI review in the 3Tesla MRI Unit at the Grenoble University Hospital Center. Participants will first undergo a medical examination in order to verify their absence of contraindication to the MRI examination. At the end of this medical examination, the consent of participation will be signed. The participants will then be able to carry out the MRI examination for a duration of about 1h15, then the behavioral judgment test of perceptual distance. The total duration of this second visit will be approximately 1h45.

Inclusion Criteria:

• Medicall exam before MRI
• Pregnant Women
• Patients aged 18-45 years, Right-handed
• without neurologic and/or psychiatric troubles
• normal audition
• Audition normale
• French mother tongue
• Social security affiliation

Exclusion Criteria:

• protected person
• MRI contraindication
• claustrophobia
• respirtaory and cardiovascular pathology
• toxic substances taking