Observing, imitating and executing: an electrophysiological investigation of acting and inter-acting processes

Objective: Action and inter-action imply the relation with non-biological entities, like objects and tools, or biological ones, as human beings. Both of them detain a primal position in our life, they foster the creation of social relations and the development of mental representations. The aim of this study is to explore, by using ERP analysis, the processes involved in action and inter-action pianification and intentional attribution during observation, imitation and execution of acts towards objects (BIO-nonBIO condition) or with other human agents (BIO-BIO condition). Participants and Methods: EEG signal has been recorded to 13 subjects, filtered and then reducted by ERP procedure. The data have been analysed by repeated measures analysis of variance (ANOVA) with a 3x2x5x2 model (TASKxCONDITIONxSITExSIDE). Results: Firstly, morphological analysis showed a negative deflection, Readiness Potential, foregoing the movement onset. Secondly, the phenomenon arises about 500 ms before the action and it is mainly localized on parieto-temporal areas. Moreover it is ampler in the execution task and for BIO-BIO condition. Conclusions: These results have been read at the light of recent theories related to action planning and intention regulation. ERPs responses was related to motor task even if crosswise active and, interestingly, in case of inter-actions between human agents. The spatio-temporal distribution has been evaluated considering the neuroanatomical network involved.