Figure 3
Perceived sensation intensities and adaptation. (A) The bar plots represent the number of significantly different pressure levels perceived by the subjects for all AS (related to N = 5 repetitions x 4 AS = 20 for each stimulation condition). Two-tailed Kruskal-Wallis test was performed (p < 0.05). (B) The adaptation time is shown at different frequencies and amplitudes of the stimulation trains tested with both subjects. A1, A2, and A3 or F1, F2, and F3 are the amplitudes or frequencies, respectively, at which the subjects reported perceptual threshold (A1, F1), medium intensity (A2, F2) and high intensity (A3, F3) of the sensation perceived during the mapping procedure. F1 = 10–50 Hz, F2 = 200–350 Hz, F3 = 700–800 Hz, A1 = 100–200 µA, A2 = 250–350 µA, A3 = 400–500 µA, depending on the AS, for Subject 1; F1 = 10–50 Hz, F2 = 150–250 Hz, F3 = 400–500 Hz, A1 = 200–300 µA, A2 = 350–450 µA, A3 = 500–600 µA, depending on the AS, for Subject 2. The data in the figure are represented as the mean ± std. No error bar on LFM for subject 1 in panel A is shown, since in all the repetitions the number of different sensation levels were always 3. *Indicates p < 0.01. The two-tailed Kruskal-Wallis test with Tukey-Kramer correction for multiple groups of data was performed. N = 3 frequencies or amplitudes x 20 repetitions = 60 for both subjects for each condition (LAM and LFM).
