Fig 1.
(A) Schematic representation of the stimulus orientations. The APB hotspot is indicated as a blue dot. The AM orientation of the E-field is approximately perpendicular to the central sulcus (gray curve). The PM is oriented 90° clockwise from the AM. (B) Schematic representation of paired-pulse stimulation. Thirty-two paired-pulse configurations were utilized based on the following features: Two orientations of the CS: AM and PM; two orientations of the TS: AM and PM; four CS intensities: 50, 70, 90, and 110% RMT; two ISIs: 1.5 and 2.7 ms. The ellipsis indicates an intentional omission of the subdivision for all configurations, except for the first one.
Table 1.
TMS pulse durations of the conditioning (CS) and test stimuli (TS) at each CS intensity as a percentage of the resting motor threshold (RMT).
Fig 2.
MEP amplitude from the linear mixed-effects model as a function of the CS and TS orientation and the CS intensity at 1.5- and 2.7-ms ISIs.
The median single-pulse MEP amplitude is marked by the dashed horizontal line. The left and right panels represent the data for the TS in the AM and PM orientations, respectively. MEPs induced by paired-pulse stimulation are grouped by the CS intensities (50, 70, 90, and 110% RMT), and subdivided into two ISIs (1.5 ms–green, and 2.7 –orange), and CS orientations (AM orientation, dots; PM orientation, crosses). The error bars represent the 95% confidence interval of the estimated marginal means.
Table 2.
Type-III analysis of variance table for the linear mixed-effects model analysis of the MEP amplitude.
Fig 3.
MEP amplitude as a function of the absolute CS intensities in V/m.
TS in (A) AM and (B) PM orientations. The absolute CS intensities were computed as the RMT multiplied by the CS rising-phase duration (see Table 1). The absolute E-field intensities are subject-specific, thus, the data for each subject are presented in separate charts. The dashed, gray horizontal lines indicate the median amplitude of 20 single TS pulses.