Correlati psicofisici ed elettrofisiologici (EEG) delle illusioni motorie indotte da vibrazione

[Autom. eng. transl.] The vibratory stimulation of the tendons at the skeletal joints can induce the perception of illusory movements. This phenomenon was used to study the relationship between proprioception and motor functions with implications also in the rehabilitation field, but the underlying processes are still the object of study. The present research aims to investigate the psychophysical (frequency, intensity and duration) and electrophysiological (EEG) correlates of these illusory perceptions. 17 right-handed volunteers took part in the research. After EEG assembly, the participants wore a splint at the right wrist joint and a superficial stimulator was placed at the corresponding tendons. Participants were therefore asked - for each reiteration (15 trials) - to report and qualify any perception of movement related to the right hand. The EEG signal was used for the extraction of the frequency data and for the localization of the sources (sLORETA). Correlation analyzes between psychophysical data have shown that participants who report illusions most often tend to have more intense illusions and that those who perceive them more intensely estimate longer duration. The analysis of EEG frequency components showed a significant decrease of upper-alpha in correspondence with trials with illusory perceptions of insular and prefrontal regions. Finally, the correlation analyzes between behavioral and localization data showed an association between the activation of parietal areas and the frequency of illusory perception. The reported evidences show a close consonance between psychophysical and electrophysiological data related to illusory phenomena of motor nature , and suggest that pre- and post-central structures play specific roles in their definition.