Abstract
In order to characterize the neural signature of a motor imagery (MI) task, the present study investigates for the first time the oscillation characteristics including both of the time-frequency measurements, event related spectral perturbation and intertrial coherence (ITC) underlying the variations in the temporal measurements (event related potentials, ERP) directly related to a MI task. We hypothesize that significant variations in both of the time-frequency measurements underlie the specific changes in the ERP directly related to MI. For the MI task, we chose a simple everyday task (throwing a tennis ball), that does not require any particular motor expertise, set within the controlled virtual reality scenario of a tennis court. When compared to the rest condition a consistent, long-lasting negative fronto-central ERP wave was accompanied by significant changes in both time frequency measurements suggesting long-lasting cortical activity reorganization. The ERP wave was characterized by two peaks at about 300 ms (N300) and 1000 ms (N1000). The N300 component was centrally localized on the scalp and was accompanied by significant phase consistency in the delta brain rhythms in the contralateral central scalp areas. The N1000 component spread wider centrally and was accompanied by a significant power decrease (or event related desynchronization) in low beta brain rhythms localized in fronto-precentral and parieto-occipital scalp areas and also by a significant power increase (or event related synchronization) in theta brain rhythms spreading fronto-centrally. During the transition from N300 to N1000, a contralateral alpha (mu) as well as post-central and parieto-theta rhythms occurred. The visual representation of movement formed in the minds of participants might underlie a top-down process from the fronto-central areas which is reflected by the amplitude changes observed in the fronto-central ERPs and by the significant phase synchrony in contralateral fronto-central delta and contralateral central mu to parietal theta presented here.
Highlights
Motor imagery (MI) is the mental simulation of a given action (Jeannerod, 1994; Jeannerod and Decety, 1995)
In order to characterize the neural signature of a MI task, the present study investigates its oscillation characteristics, including both of the time-frequency measurements [event related spectral perturbation (ERSP) and intertrial coherence (ITC; Delorme and Makeig, 2004)], which underlie the specific variations in temporal measurements (ERP) of a MI task
The present study combined both the time (ERP) and timefrequency domain measurements for the characterization of the mental simulation of this simple everyday goal-directed movement of throwing a tennis ball with the dominant upper limb
Summary
Motor imagery (MI) is the mental simulation of a given action (Jeannerod, 1994; Jeannerod and Decety, 1995). MI is free from interference by real movement, which makes it interesting when investigating the neural organization of motor control. To this end, MI coupled with the event related potentials (ERP) technique has been widely used in both healthy (Cheron and Borenstein, 1992; Abbruzzese et al, 1999; Rossini et al, 1999) and clinical populations (Filippi et al, 2001; Volz et al, 2015). The time-frequency characteristics of EEG oscillations, notably power spectrum and phase synchrony, may elucidate mechanisms of brain function such as MI, and complement anatomical information from fMRI or even from advanced inverse solution models (Cebolla et al, 2014)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
