title: The origin of word-related motor activity.
abstract: Conceptual processing of verbs consistently recruits the left posterior middle temporal gyrus (lpMTG). The left precentral motor cortex also responds to verbs, with higher activity for action than nonaction verbs. The early timing of this effect has suggested that motor features of words' meaning are accessed directly, bypassing access to conceptual representations in lpMTG. An alternative hypothesis is that the retrieval of conceptual representations in lpMTG is necessary to drive more specific, motor-related representations in the precentral gyrus. To test these hypotheses, we first showed that repetitive transcranial magnetic stimulation (rTMS) applied to the verb-preferring lpMTG site selectively impoverished the semantic processing of verbs. In a second experiment, rTMS perturbation of lpMTG, relative to no stimulation (no-rTMS), eliminated the action-nonaction verb distinction in motor activity, as indexed by motor-evoked potentials induced in peripheral muscles with single-pulse TMS over the left primary motor cortex. rTMS pertubation of an occipital control site, relative to no-rTMS, did not affect the action-nonaction verb distinction in motor activity, but the verb contrast did not differ reliably from the lpMTG effect. The results show that lpMTG carries core semantic information necessary to drive the activation of specific (motor) features in the precentral gyrus.
authors.affiliation: Department of Psychology, Harvard University, Cambridge, MA 02138, USA Center for Mind/Brain Sciences - CIMeC, University of Trento, 38122 Trento, Italy.
authors.forename: Liuba
authors.initials: L
authors.lastname: Papeo
authors.affiliation: Center for Mind/Brain Sciences - CIMeC, University of Trento, 38122 Trento, Italy.
authors.forename: Angelika
authors.initials: A
authors.lastname: Lingnau
authors.affiliation: Center for Neuroscience and Cognitive Systems@UniTn, Istituto Italiano di Tecnologia, 38068 Rovereto, Italy.
authors.forename: Sara
authors.initials: S
authors.lastname: Agosta
authors.affiliation: Berenson-Allen Center for Noninvasive Brain Stimulation and Department of Neurology, Beth Israel Deaconess Medical Center, Boston, MA 02215, USA Institut Guttmann, Badalona 08916, Spain.
authors.forename: Alvaro
authors.initials: A
authors.lastname: Pascual-Leone
authors.affiliation: Center for Neuroscience and Cognitive Systems@UniTn, Istituto Italiano di Tecnologia, 38068 Rovereto, Italy.
authors.forename: Lorella
authors.initials: L
authors.lastname: Battelli
authors.affiliation: Department of Psychology, Harvard University, Cambridge, MA 02138, USA Center for Mind/Brain Sciences - CIMeC, University of Trento, 38122 Trento, Italy.
authors.forename: Alfonso
authors.initials: A
authors.lastname: Caramazza
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D019054:Evoked Potentials, Motor / Q000502:physiology*; D005260:Female; D007839:Functional Laterality; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D009044:Motor Cortex / Q000098:blood supply / Q000502:physiology*; D010100:Oxygen / Q000097:blood; D010775:Photic Stimulation; D011930:Reaction Time; D012660:Semantics; D050781:Transcranial Magnetic Stimulation; D014825:Vocabulary; D055815:Young Adult
chemical_list: D010100:Oxygen
keywords: brain stimulation; concepts; embodied cognition; functional connectivity; nouns and verbs