Fig. 8.
Results from experiment 6. SICICSPA3 and SICICSAP3 in both FDI (A) or ADM (B) were equally effective when measured at rest or during tonic contraction. However, there was significantly less SICI during tonic movement than at rest in both muscles. Panels C and D show how SICI changed during the SRTT (C, D). Compared to MEPs evoked at the time of the imperative stimulus (auditory tone), SICI became less effective when probed during the reaction period, although the time course differed between CSPA and CSAP. SICI obtained with CSAP decreased earlier (RT35%) than SICI tested with CSPA, which only declined at RT70% regardless of whether FDI (C) or ADM (D) were involved in the task. This result suggests that at least two inhibitory networks are involved in controlling action responses, each showing specific temporal dynamics. Asterisks indicate significant main effects of “Brain state” (panels A and B) and significant “Orientation x time” interactions (panels C and D) (p < 0.05). The green box in panels C and D indicate significant differences in post hoc pairwise comparisons (p < 0.05).