The structure of variance computed for the differences in force and mode vectors from phase 1 to phase 3 for each perturbation and finger pressing condition. A: mode space (VUCM,Δm and VORT,Δm). B: force space (VUCM,ΔF and VORT,ΔF). These data have been log transformed for normality. DoF, degrees-of-freedom. *Pressing/perturbed combinations that are significantly different from one another. **VORT that is significantly different from its associated VUCM.