Extended Data Fig. 10: Foot-strike sensory substitution task.

Evaluation of the foot-strike sensory substitution system. a, Experimental setup depicting reference axes. As part of the task, four separate surfaces were presented at orientations (ψ, φ) ∈ {(0°, 0°), (15°, 60°), (15°, −60°), (30°, 0°)}. b, Stimulation patterns superimposed on smartphone display during rotation around the forward axis. The virtual mesh highlights the LiDAR-reconstructed surface. c–e, Unit normal vectors of foot and variable surface centred on a common origin during task with feedback. The significance of the results for each individual was evaluated using the Wilcoxon signed-rank test over repeat trials (across all three phases), given the null hypothesis that the median of the data is identical to the control. Effect size was characterized according to rank-biserial correlation. c, Subject 1, male, age 37 years (n = 57, P < 0.0001, r = −0.59). d, Subject 2, female, age 35 years (n = 55, P < 0.0001, r = −0.75). e, Subject 3, male, age 21 years (n = 60, P = 0.00027, r = −0.47). f–h, Unit normal vectors of foot and variable surface centred on a common origin during task without feedback (control). f, Subject 1, male, age 37 years. g, Subject 2, female, age 35 years. h, Subject 3, male, age 21 years.