Appendix figure 1. Placement of the sixteen electrodes on the right arm.

Four configurations were tested, either with five (1–5, see Materials and methods), ten (1–4, 6–8, 14–16, from Bitzer and van der Smagt, 2006), or fourteen channels (from Ejaz et al., 2015).

DOI: http://dx.doi.org/10.7554/eLife.13420.019