Motor imagery, movement observation and movement execution: cerebral hemodynamic patterns in fNIRS

Previous studies have shown congruent cerebral activation during motor imagery, movement observation and movement execution. Moreover, recent neuroimaging studies have reveled similarities in hemodynamic patterns between motor imagery and movement execution as well as motor imagery and movement observation. The aim of this study was to investigate differences in hemodynamic responses among these three conditions, pointing out the contribution of motor areas. We used a fNIRS event related paradigm in co-registration with EEG. Healthy right-handed participants were asked either to imagine, observe or execute right hand movements. During the tasks, changes in oxygenated and deoxygenated hemoglobin were recorded in the left fronto-central, central and parietal areas with fNIRS (24 channel - 8 detectors and 8 injectors). Cerebral activity was simultaneously recorded by EEG. Data analyses showed variations in hemodynamic responses across the conditions, with significant similarities between motor imagery and movement observation. Therefore, the present results showed that differences in hemodynamic profiles are congruent with the type of motor task. Specifically changes in hemodynamic responses within motor areas mirror the specific role of cortical areas underpinning the tasks. Moreover, there are preliminary evidences of a congruent modulation of EEG data in relation with hemodynamic data.