Figure 3. Normalized volume (VOLnorm = volume (VOL)/maximal motor evoked potential (MAXMEP)) for dominant first dorsal interosseus (FDI) (left panel) and abductor digiti minimi (ADM) (right panel) by age. Below each plot the best fitting model is stated in a rectangle. Ribbons depict the 95% confidence interval of the fit. Both regressions were non-significant.