Urteaga, M. & Laka, I.
UPV/EHU
Event Related Desynchronisation (ERD) of the mu wave is associated to motor system activation. We report mu ERD modulations in three increasingly complex sentence types: intransitives, transitives and ditransitives. Materials consisted of 54 Basque sentences per condition, containing a verb and an auxiliary ?ezkutatu naiz\" (I hide), ?ezkutatu dut? (I hide it), ?ezkutatu diot\" (I hide it to her). Participants were 26 Basque native speakers (13 female; mean age =20±2.3; all right handed). A 64 channel BrainVison cap was used to record the EEG data. All conditions showed a clear ERD of mu waves from ca. 400ms post-stimulus. Intransitive sentences showed greater ERD (p<0.05) at 1000ms in the motor area (C3, C1, C5, Cz), premotor area (FC3, FC1, FC5) and inferior frontal gyrus (F5, F7) than transitive and ditransitive sentences. Our results show that greater ERD does not correlate with thematic complexity conceived as number of arguments, but it is rather associated with the presence versus absence of an agent in the sentence. Our findings suggest that agentive/nonagentive verbs involve different cortical processing, and provide strong evidence for the coinvolvement of natural language syntax and the motor system.