Neural correlates of the perception of prosodic focus in French: An fMRI study
Résumé
The studies of the neural correlates of the perception of prosody have led to different conclusions (for a review: Baum & Pell, 1999). The present functional magnetic brain imaging (fMRI) study deals with the perception of prosodic contrastive focus in French (example: Mary ate the apple? No, JOHN ate the apple; see Wildgruber et al., 2004; Tong et al., 2005 for related studies). Twenty-two right-handed French speakers participated in the experiment. The two conditions consisted in the auditory judgement of two kinds of utterances: with contrastive prosodic focus (Focus condition, Task) and without (Neutral condition, Control). The stimuli were delivered via headphones. The task was to judge whether the utterances contained focus or not. The subjects answered using two response keys. An event-related paradigm was designed (48 events per condition; 30 null-events). The behavioural responses were correct in more than 90% of the trials. The Focus vs. Neutral contrast revealed bilateral frontal activation (left BA 6 and BA 47 and right BA 44 and BA47), temporal activation (left BA 22 and right BA 21) and parietal activation (bilateral BA 40 and left BA 7). The Neutral vs. Focus contrast showed activation in the post-central gyrus (BA 1, 43) and left insula. A ROI analysis showed significant left hemisphere predominance for left inferior frontal (BA 47) and supramarginal (BA 40) gyri, as well as for left anterior insula (BA 13) during the Focus condition. Overall, these results suggest that the auditory perception of contrastive prosodic focus involves a left-dominant temporo-parieto-frontal network.