Research Paper Volume 12, Issue 5 pp 4617—4640

Alterations of hand sensorimotor function and cortical motor representations over the adult lifespan

Figure 5. Visualization of the cortical motor representation parameters: area, volume, and maximal motor evoked potential (MAXMEP). Area was measured in cm² by calculating the area of a polygon expanding over all active points. Volume was measured in μV*cm² and defined as the sum of the mean motor evoked potential (MEP) peak-to-peak amplitudes of all active points, serving as an approximation of the three-dimensional integration of the map. The maximal mean MEP value of all active points was obtained as MAXMEP and measured in μV.