Task related modulation of the motor system during language processing.
Recent neurophysiological and brain imaging studies have shown that the motor system is involved in language processing. However, it is an open question whether this involvement is a necessary requisite to understand language or rather a side effect of distinct cognitive processes underlying it. In order to clarify this issue we carried out three behavioral experiments, using a go-no go paradigm. Italian verbs expressing hand actions, foot actions or an abstract content served as stimuli. Participants used their right hands to respond. In Experiment 1, in which a semantics decision task with an early delivery of the go signal (during processing language material) was used, slower responses were found for hand action-related verbs than for foot action-related verbs. In Experiment 2, using the same task with either an early or a delayed delivery of the go signal (when language material had been already processed), no difference was found between responses to the two verb categories in the delayed delivery condition. In Experiment 3, in which a lexical decision task with an early delivery of the go signal was used, again no difference between the two verb categories was found. The present findings demonstrate that during language processing the modulation of the motor system crucially occurs while performing a semantics decision task, thus supporting the notion that this involvement is a necessary step to understand language rather than a side effect of upstream cognitive processes.
Sato
Marc
M
Dipartimento di Neuroscienze, Sezione di Fisiologia, Università di Parma, Via Volturno 39, Parma, Italy.
Mengarelli
Marisa
M
Riggio
Lucia
L
Gallese
Vittorio
V
Buccino
Giovanni
G
D000328:Adult; D001921:Brain / Q000502:physiology; D032882:Comprehension / Q000502:physiology; D005528:Foot / Q000502:physiology; D007839:Functional Laterality / Q000502:physiology; D006225:Hand / Q000502:physiology; D006801:Humans; D007802:Language; D007807:Language Tests / Q000706:statistics & numerical data; D009044:Motor Cortex / Q000502:physiology*; D011597:Psychomotor Performance / Q000502:physiology*; D011930:Reaction Time / Q000502:physiology; D012660:Semantics; D014705:Verbal Behavior / Q000502:physiology*; D014706:Verbal Learning / Q000502:physiology; D014825:Vocabulary; D055815:Young Adult