title: Primary motor cortex functionally contributes to language comprehension: An online rTMS study.
abstract: Among various questions pertinent to grounding human cognitive functions in a neurobiological substrate, the association between language and motor brain structures is a particularly debated one in neuroscience and psychology. While many studies support a broadly distributed model of language and semantics grounded, among other things, in the general modality-specific systems, theories disagree as to whether motor and sensory cortex activity observed during language processing is functional or epiphenomenal. Here, we assessed the role of motor areas in linguistic processing by investigating the responses of 28 healthy volunteers to different word types in semantic and lexical decision tasks, following repetitive transcranial magnetic stimulation (rTMS) of primary motor cortex. We found that early rTMS (delivered within 200ms of word onset) produces a left-lateralised and meaning-specific change in reaction speed, slowing down behavioural responses to action-related words, and facilitating abstract words - an effect present only during semantic, but not lexical, decision. We interpret these data in light of action-perception theory of language, bolstering the claim that motor cortical areas play a functional role in language comprehension.
authors.affiliation: Center of Functionally Integrative Neuroscience, Institute for Clinical Medicine, Aarhus University, Denmark; Center for Cognition and Decision Making, Higher School of Economics, Moscow, Russian Federation. Electronic address: vukovicnikola@cfin.au.dk.
authors.forename: Nikola
authors.initials: N
authors.lastname: Vukovic
authors.affiliation: Center for Cognition and Decision Making, Higher School of Economics, Moscow, Russian Federation.
authors.forename: Matteo
authors.initials: M
authors.lastname: Feurra
authors.affiliation: Center for Cognition and Decision Making, Higher School of Economics, Moscow, Russian Federation.
authors.forename: Anna
authors.initials: A
authors.lastname: Shpektor
authors.affiliation: Center for Cognition and Decision Making, Higher School of Economics, Moscow, Russian Federation; Department of Psychology, Northumbria University, Newcastle upon Tyne, United Kingdom.
authors.forename: Andriy
authors.initials: A
authors.lastname: Myachykov
authors.affiliation: Center of Functionally Integrative Neuroscience, Institute for Clinical Medicine, Aarhus University, Denmark; Center for Cognition and Decision Making, Higher School of Economics, Moscow, Russian Federation; Medical Research Council Cognition and Brain Sciences Unit, Cambridge, United Kingdom.
authors.forename: Yury
authors.initials: Y
authors.lastname: Shtyrov
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D032882:Comprehension / Q000502:physiology*; D003657:Decision Making; D004569:Electroencephalography; D005260:Female; D006801:Humans; D007600:Judgment; D007802:Language; D008297:Male; D009044:Motor Cortex / Q000502:physiology*; D010775:Photic Stimulation; D011930:Reaction Time / Q000502:physiology; D012660:Semantics; D050781:Transcranial Magnetic Stimulation; D014825:Vocabulary; D055815:Young Adult
keywords: Language; Motor cortex; Semantics; TMS