Ownership and self-attribution in illusory movements: the role of parietal structures

Objectives: The sense of body-ownership grounds on the ability to feel our bodies as part of an experience. Conscious recognition of ourselves as intentional agents, instead, allows us to develop a sense of agency. The development of both body-ownership and agency self-attribution is based on integrated processing of sensorymotor information in a neural network including prefrontal, pre-/motor and parietal regions. The present study aimed at investigating their involvement in consciously perceiving movement illusions, and the link between electrophysiological and phenomenological correlates of self-attributed illusory movements. Participants and methods: Hand illusory movements were induced in fifteen participants by applying vibratory stimulations to flexor tendons of the forearm. We recorded both self-report and electrophysiological (EEG) responses to the stimulation. EEG data have been further explored by source localization analyses. Results: Data analysis highlighted that psychophysical features of the conscious experience of illusory movements are internally consistent. Further, while such experience is mediated by a broad frontal-parietal network, prefrontal medial structures seemed to play a primary role for its awareness and superior parietal structures seemed instead to play a crucial role in modulating its actual occurrence. Conclusions: Vibratory stimulations are able to induce vivid movement illusions and to elicit the activation of a network involved also in real action execution. Together with the consistency of reported psychophysical correlates of conscious experience, that suggests that illusory movements have been coded, at least in part, as real actions and plausibly lead to ownership and self-attribution evaluation processes that may be mirrored by parietal informationintegration mechanisms.