Figure 4.

Additional results. a, Significant MEP facilitation was seen when switching toward the contralateral hand at 6 and 12 ms interpulse intervals, but no significant effect was seen when switching to the ipsilateral hand. b, A negative correlation was present between the relative facilitation of the contralateral, compared with the ipsilateral, hand and the RT on switch trials. c, Example location of significant correlation between MEP effect size and white matter intensity and scatter plot of individual data within this cluster.