Fig. 4.

Reduction rate of McGill pain sum score under tactile feedback condition and no tactile feedback condition. a For all participants, reduction rates ranged from 2.2 to 67.8 % (average 41.8 ± standard deviation 19.8 %) under tactile FB condition and from −20.0 to 71.4 % (28.2 ± 29.5 %) under no tactile FB condition. b Average reduction rates under the two conditions were different with a significance probability p < 0.05 (p = 0.047). Negative values mean increase of pain. Error bars indicate standard deviations of reduction rates evaluated several times. No error bar means that a reduction rate was evaluated only once