title: Processing of hand-related verbs specifically affects the planning and execution of arm reaching movements.
abstract: Even though a growing body of research has shown that the processing of action language affects the planning and execution of motor acts, several aspects of this interaction are still hotly debated. The directionality (i.e. does understanding action-related language induce a facilitation or an interference with the corresponding action?), the time course, and the nature of the interaction (i.e. under what conditions does the phenomenon occur?) are largely unclear. To further explore this topic we exploited a go/no-go paradigm in which healthy participants were required to perform arm reaching movements toward a target when verbs expressing either hand or foot actions were shown, and to refrain from moving when abstract verbs were presented. We found that reaction times (RT) and percentages of errors increased when the verb involved the same effector used to give the response. This interference occurred very early, when the interval between verb presentation and the delivery of the go signal was 50 ms, and could be elicited until this delay was about 600 ms. In addition, RTs were faster when subjects used the right arm than when they used the left arm, suggesting that action-verb understanding is left-lateralized. Furthermore, when the color of the printed verb and not its meaning was the cue for movement execution the differences between RTs and error percentages between verb categories disappeared, unequivocally indicating that the phenomenon occurs only when the semantic content of a verb has to be retrieved. These results are compatible with the theory of embodied language, which hypothesizes that comprehending verbal descriptions of actions relies on an internal simulation of the sensory-motor experience of the action, and provide a new and detailed view of the interplay between action language and motor acts.
authors.affiliation: Department of Neuroscience, Istituto Neurologico Mediterraneo Neuromed, Pozzilli (IS), Italy. giovanni.mirabella@uniroma1.it
authors.forename: Giovanni
authors.initials: G
authors.lastname: Mirabella
authors.forename: Sara
authors.initials: S
authors.lastname: Iaconelli
authors.forename: Silvia
authors.initials: S
authors.lastname: Spadacenta
authors.forename: Paolo
authors.initials: P
authors.lastname: Federico
authors.forename: Vittorio
authors.initials: V
authors.lastname: Gallese
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D001132:Arm / Q000502:physiology; D007839:Functional Laterality; D006801:Humans; D033182:Intention; D007802:Language; D009068:Movement; D011597:Psychomotor Performance; D011930:Reaction Time; D014705:Verbal Behavior; D055815:Young Adult