title: Phonological processing in speech perception: What do sonority differences tell us?
abstract: Previous research has associated the inferior frontal and posterior temporal brain regions with a number of phonological processes. In order to identify how these specific brain regions contribute to phonological processing, we manipulated subsyllabic phonological complexity and stimulus modality during speech perception using fMRI. Subjects passively attended to visual or auditory pseudowords. Similar to previous studies, a bilateral network of cortical regions was recruited during the presentation of visual and auditory stimuli. Moreover, pseudowords recruited a similar network of regions as words and letters. Few regions in the whole-brain results revealed neural processing differences associated with phonological complexity independent of modality of presentation. In an ROI analysis, the only region sensitive to phonological complexity was the posterior part of the inferior frontal gyrus (IFGpo), with the complexity effect only present for print. In sum, the sensitivity of phonological brain areas depends on the modality of stimulus presentation and task demands.
authors.affiliation: Centre for Research on Brain, Language and Music, Rabinovitch House, McGill University, 3640 rue de la Montagne, Montreal, Quebec H3G 2A8, Canada; Rehabilitation Department, Laval University, Quebec, QC, Canada; Centre de Recherche de l'Institut Universitaire en santé mentale de Québec, Quebec, QC, Canada. Electronic address: isabelle.deschamps.1@ulaval.ca.
authors.forename: Isabelle
authors.initials: I
authors.lastname: Deschamps
authors.affiliation: McGill University, Faculty of Medicine, School of Communication Sciences and Disorders, 1266 Avenue des Pins, Montreal, Quebec H3G 1A8, Canada; Centre for Research on Brain, Language and Music, Rabinovitch House, McGill University, 3640 rue de la Montagne, Montreal, Quebec H3G 2A8, Canada.
authors.forename: Shari R
authors.initials: SR
authors.lastname: Baum
authors.affiliation: McGill University, Faculty of Medicine, School of Communication Sciences and Disorders, 1266 Avenue des Pins, Montreal, Quebec H3G 1A8, Canada; Centre for Research on Brain, Language and Music, Rabinovitch House, McGill University, 3640 rue de la Montagne, Montreal, Quebec H3G 2A8, Canada; Haskins Laboratories, 300 George St., Suite 900, New Haven, CT 06511, USA.
authors.forename: Vincent L
authors.initials: VL
authors.lastname: Gracco
mesh_terms: D000161:Acoustic Stimulation; D000293:Adolescent; D000328:Adult; D001921:Brain / Q000502:physiology*; D001931:Brain Mapping; D006801:Humans; D008279:Magnetic Resonance Imaging; D010700:Phonetics; D010775:Photic Stimulation; D017397:Prefrontal Cortex / Q000502:physiology; D013067:Speech Perception / Q000502:physiology*; D055815:Young Adult
keywords: Functional magnetic resonance imaging; Phonological processing; Sonority differences; Speech perception