Extended Data Fig. 6: Mechanical-task performance and single-electrode performance.

a, Mechanical JNDs for participant C1 with either the injured (contralateral) or uninjured (ipsilateral) hand are similar. Each point represents a different fingertip. b, Normalized intensity ratings from participant C1 on 3 different digits (denoted by different colors). Ratings are consistent across digits. Note that the normalization was performed based on the grand mean rating, which included ratings of single-electrode ICMS stimuli and tended to be weaker than the mechanical ones. c, JNDs for a subset of electrodes from participant C1 when the reference stimulus was 50 or 70 µA. Dashed lines connect to the same electrode. d, The discriminability of an electrode (JND) is inversely correlated with its detection threshold. e, JNDs for biomimetic and linear stimuli across participants and electrodes (n = 20). Biomimetic stimuli yield significantly lower JNDs than linear stimuli, expressed in terms of charge per phase. f, Normalized intensity ratings for one electrode. Linear ICMS (gray) does not give rise to significantly more intense sensations than does biomimetic ICMS (blue) when comparing stimuli with the same maximum amplitude. The mean relative intensity of the biomimetic stimuli was 92 ± 3% of the intensity of the linear ones (n = 5 electrode). Lines and shaded areas in B and F represent mean and standard deviation. Box and whisker in A represent 5th, 25th, 50th, 75th, and 95th percentiles.