title: Dorsal and Ventral Pathways for Prosody.
abstract: Our vocal tone--the prosody--contributes a lot to the meaning of speech beyond the actual words. Indeed, the hesitant tone of a "yes" may be more telling than its affirmative lexical meaning. The human brain contains dorsal and ventral processing streams in the left hemisphere that underlie core linguistic abilities such as phonology, syntax, and semantics. Whether or not prosody--a reportedly right-hemispheric faculty--involves analogous processing streams is a matter of debate. Functional connectivity studies on prosody leave no doubt about the existence of such streams, but opinions diverge on whether information travels along dorsal or ventral pathways. Here we show, with a novel paradigm using audio morphing combined with multimodal neuroimaging and brain stimulation, that prosody perception takes dual routes along dorsal and ventral pathways in the right hemisphere. In experiment 1, categorization of speech stimuli that gradually varied in their prosodic pitch contour (between statement and question) involved (1) an auditory ventral pathway along the superior temporal lobe and (2) auditory-motor dorsal pathways connecting posterior temporal and inferior frontal/premotor areas. In experiment 2, inhibitory stimulation of right premotor cortex as a key node of the dorsal stream decreased participants' performance in prosody categorization, arguing for a motor involvement in prosody perception. These data draw a dual-stream picture of prosodic processing that parallels the established left-hemispheric multi-stream architecture of language, but with relative rightward asymmetry.
authors.affiliation: Otto Hahn Group Neural Bases of Intonation in Speech, Max Planck Institute for Human Cognitive and Brain Sciences, 04103 Leipzig, Germany; Institute of Neuroscience and Psychology, University of Glasgow, Glasgow G12 8QB, UK. Electronic address: sammler@cbs.mpg.de.
authors.forename: Daniela
authors.initials: D
authors.lastname: Sammler
authors.affiliation: Institute of Neuroscience and Psychology, University of Glasgow, Glasgow G12 8QB, UK; Laboratoire de Neurosciences Cognitives, FR 3C, Aix-Marseille Université, 13331 Marseille, France.
authors.forename: Marie-Hélène
authors.initials: MH
authors.lastname: Grosbras
authors.affiliation: Department of Neuropsychology, Max Planck Institute for Human Cognitive and Brain Sciences, 04103 Leipzig, Germany.
authors.forename: Alfred
authors.initials: A
authors.lastname: Anwander
authors.affiliation: School of Psychology, Bangor University, Gwynedd LL57 2AS, UK.
authors.forename: Patricia E G
authors.initials: PE
authors.lastname: Bestelmeyer
authors.affiliation: Institute of Neuroscience and Psychology, University of Glasgow, Glasgow G12 8QB, UK; Institut des Neurosciences de La Timone, UMR 7289, CNRS and Aix-Marseille Université, 13005 Marseille, France; International Laboratory for Brain, Music and Sound Research, University of Montréal and McGill University, Montréal H3C 3J7, Canada.
authors.forename: Pascal
authors.initials: P
authors.lastname: Belin
mesh_terms: D001306:Auditory Pathways; D007839:Functional Laterality; D006801:Humans; D008279:Magnetic Resonance Imaging; D009044:Motor Cortex / Q000502:physiology; D064847:Multimodal Imaging; D009415:Nerve Net; D059906:Neuroimaging; D013067:Speech Perception; D013702:Temporal Lobe / Q000502:physiology; D055815:Young Adult
keywords: DWI; TMS; dual pathway model; fMRI; fiber tracts; language; larynx; motor simulation; prosody; right-hemispheric lateralization