title: Perception drives production across sensory modalities: A network for sensorimotor integration of visual speech.
abstract: Sensory information is critical for movement control, both for defining the targets of actions and providing feedback during planning or ongoing movements. This holds for speech motor control as well, where both auditory and somatosensory information have been shown to play a key role. Recent clinical research demonstrates that individuals with severe speech production deficits can show a dramatic improvement in fluency during online mimicking of an audiovisual speech signal suggesting the existence of a visuomotor pathway for speech motor control. Here we used fMRI in healthy individuals to identify this new visuomotor circuit for speech production. Participants were asked to perceive and covertly rehearse nonsense syllable sequences presented auditorily, visually, or audiovisually. The motor act of rehearsal, which is prima facie the same whether or not it is cued with a visible talker, produced different patterns of sensorimotor activation when cued by visual or audiovisual speech (relative to auditory speech). In particular, a network of brain regions including the left posterior middle temporal gyrus and several frontoparietal sensorimotor areas activated more strongly during rehearsal cued by a visible talker versus rehearsal cued by auditory speech alone. Some of these brain regions responded exclusively to rehearsal cued by visual or audiovisual speech. This result has significant implications for models of speech motor control, for the treatment of speech output disorders, and for models of the role of speech gesture imitation in development.
authors.affiliation: Department of Cognitive Sciences, University of California, Irvine, Irvine, CA 92697, United States. Electronic address: jvenezia@uci.edu.
authors.forename: Jonathan H
authors.initials: JH
authors.lastname: Venezia
authors.affiliation: Department of Communication Sciences and Disorders, Baylor University, Waco, TX 76798, United States.
authors.forename: Paul
authors.initials: P
authors.lastname: Fillmore
authors.affiliation: Department of Linguistics, University of Maryland, College Park, MD 20742, United States.
authors.forename: William
authors.initials: W
authors.lastname: Matchin
authors.affiliation: Department of Cognitive Sciences, University of California, Irvine, Irvine, CA 92697, United States.
authors.forename: A Lisette
authors.initials: AL
authors.lastname: Isenberg
authors.affiliation: Department of Cognitive Sciences, University of California, Irvine, Irvine, CA 92697, United States.
authors.forename: Gregory
authors.initials: G
authors.lastname: Hickok
authors.affiliation: Department of Communication Sciences and Disorders, University of South Carolina, Columbia, SC 29208, United States.
authors.forename: Julius
authors.initials: J
authors.lastname: Fridriksson
mesh_terms: D000328:Adult; D001931:Brain Mapping / Q000379:methods*; D002540:Cerebral Cortex / Q000502:physiology*; D003463:Cues; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D009415:Nerve Net / Q000502:physiology*; D013060:Speech / Q000502:physiology*; D013067:Speech Perception / Q000502:physiology*; D014796:Visual Perception / Q000502:physiology*; D055815:Young Adult
keywords: Audiovisual speech; Multisensory integration; Sensorimotor integration; Speech production; fMRI