title: Interaction Between Words and Symbolic Gestures as Revealed By N400.
abstract: What happens if you see a person pronouncing the word "go" after having gestured "stop"? Differently from iconic gestures, that must necessarily be accompanied by verbal language in order to be unambiguously understood, symbolic gestures are so conventionalized that they can be effortlessly understood in the absence of speech. Previous studies proposed that gesture and speech belong to a unique communication system. From an electrophysiological perspective the N400 modulation was considered the main variable indexing the interplay between two stimuli. However, while many studies tested this effect between iconic gestures and speech, little is known about the capability of an emblem to modulate the neural response to subsequently presented words. Using high-density EEG, the present study aimed at evaluating the presence of an N400 effect and its spatiotemporal dynamics, in terms of cortical activations, when emblems primed the observation of words. Participants were presented with symbolic gestures followed by a semantically congruent or incongruent verb. A N400 modulation was detected, showing larger negativity when gesture and words were incongruent. The source localization during N400 time window evidenced the activation of different portions of temporal cortex according to the gesture and word congruence. Our data provide further evidence of how the observation of an emblem influences verbal language perception, and of how this interplay is mainly instanced by different portions of the temporal cortex.
authors.affiliation: Brain Center for Social and Motor Cognition, Istituto Italiano di Tecnologia, Via Volturno 39/E, 43100, Parma, Italy, maddalena.fabbridestro@iit.it.
authors.forename: Maddalena
authors.initials: M
authors.lastname: Fabbri-Destro
authors.forename: Pietro
authors.initials: P
authors.lastname: Avanzini
authors.forename: Elisa
authors.initials: E
authors.lastname: De Stefani
authors.forename: Alessandro
authors.initials: A
authors.lastname: Innocenti
authors.forename: Cristina
authors.initials: C
authors.lastname: Campi
authors.forename: Maurizio
authors.initials: M
authors.lastname: Gentilucci
mesh_terms: D000328:Adult; D002540:Cerebral Cortex / Q000502:physiology*; D032882:Comprehension / Q000502:physiology*; D004569:Electroencephalography; D005071:Evoked Potentials; D005260:Female; D005868:Gestures; D006801:Humans; D008297:Male; D012660:Semantics; D013702:Temporal Lobe / Q000502:physiology; D014796:Visual Perception / Q000502:physiology; D055815:Young Adult