Tactile detection thresholds The tactile detection threshold (TDT) of mechanoreceptors was evaluated using psychophysical testing methods. A touch sensation was elicited using von Frey filaments (OptiHair, MARSTOCK nerv test, Schriesheim, Germany) 16. This test kit consists of 11 monofilaments of varying stiffness, which are calibrated to apply defined forces of 0.25 - 512 mN (±10%). The filaments were pushed vertically for about 1 second to the different test sites on each side (ipsi- and contra-lesional in stroke-patients and right- and left side in controls). The tests started with a supra-threshold stimulus, which was consecutively lowered until the patient did not feel the filament anymore. Following the filament with the lowest perceived pressure, the applied force was re-increased until the patient recognized the touch again. This procedure was repeated twice in the same session to find the threshold with the stair-case-method. The final threshold was calculated from the mean of the three infra- and three supra-thresholds. If the patient felt even the lowest stimulus available (0.25mN), the infra-threshold was set to 0.125mN.