t-HFS/t-LFS schedule and procedure. Session 1–4 (s4 = pre-condition) served to create a stable baseline performance. After session 4 (pre-condition), either t-HFS (group 1, n = 14) or t-LFS (group 2, n = 13) was applied to the right index-finger (d2) for a duration of 20 minutes. After termination of t-HFS/t-LFS post measurements of tactile discrimination thresholds were performed for the right d2. Additionally, 24 hours (rec-24 h as well as one week (rec-1 week) after t-HFS/t-LFS the measurement of 2-point discrimination thresholds was repeated. For group 3 (t-HFS; n = 17) and group 4 (t-LFS; n = 16), which both address the question of the spatial selectiviy of the induced effects, tactile discrimination thresholds for all fingers of the right hand (d1–d5) were assessed before (pre) and after (post) t-HFS/t-LFS.