Fig. 3.

Effect of coil orientation on direct responses. (A) Direct response size as a function of stimulus intensity relative to ODRT, averaged across seven subjects. Solid line indicates measurements with brain current downwards; dashed line indicates brain current upwards. Solid circles indicate responses significantly different from zero (P < 0.05). Error bars show standard errors. (B and C) Example response from one subject (1DI muscle) with an intensity of 74%, brain current downwards (B) and upwards (C). (D) Same subject, intensity 84%, brain current upwards.