Changes in oscillatory cortical activity related to a visuomotor task in young and elderly healthy subjects

Objective: In order to better understand the spatio-temporal interaction of the activated cortical areas when the movement is visuo-guided and to assess the age effect on the spatio-temporal pattern of cortical activity, we have compared a proximo-distal movement with visual–motor control and hand–eye coordination (targeting movement) with a distal and a proximal movement. Methods: Brainʹs electrical activity was studied using the analysis of event-related (de)synchronizations (ERD/S) of cortical μ and β rhythms in 17 subjects, 8 young and 9 elderly subjects. Results: In both populations, we found an earlier and broader μ and β ERD during the preparation of the targeting movement compared to distal and proximal movements, principally involving the contralateral parietal region. During the execution, a spreading over the parietocentral region during proximal movement and over the parietal region during targeting movement was observed. After the execution of proximal and targeting movements, a wider and higher beta ERS was observed only in the young subjects. In the elderly subjects, our results showed a significant decrease of beta ERS during the targeting task. Conclusions: These results suggest there was a larger recruitment of cortical areas, involving notably the parietal cortex when the movement is visuo-guided. Moreover, cerebral aging-related changes in the spatio-temporal beta ERS pattern suggests an impaired sensory integration.