Figure 1.
Timeline of the three trial types in a block and the rest trial.
The ‘Warning’ and ‘Go’ represent the auditory ‘warning’ and ‘go’ cue, respectively. The small arrows pointing down indicate when SAI was tested. Before the experiment, the researcher defined whether the low and high tone meant move 2nd or 5th digit, respectively. The movement trial indicates trials that were used for analysis, while the dummy trial indicates trials that were not used for analysis. In this figure, 2nd digit movement was being analyzed and the high tone indicates the movement condition, while the low tone would inform the participant to perform the 5th digit movement and would serve as the dummy trial. ‘100 ms’ on the left side of the timeline represents the time between the ‘warning’ cue and when SAI was tested in the post-warning 1 phase (PW1). ‘1 s’ represents the time between the ‘warning’ cue and when SAI was tested in the post-warning 2 phase (PW2). ‘100 ms’ on the right side of the timeline represents the time between ‘go’ cue and when SAI was tested in the post-go phase (PG). ‘2–3 s’ is the varied interval between the ‘warning’ and ‘go’ cue, while the ‘4–5 s’ indicate the varied length of the trial. In the “no stimulation” condition, neither TMS nor nerve stimulation was delivered, but the participant still completed the trial with the ‘warning’ and ‘go’ cue present. The rest trial, SAI was tested, but no auditory cues were given and the participant did not complete the movement.
Table 1.
Percentage of MSO to obtain ∼1 mV MEP in each condition.
Table 2.
Unconditioned MEP size for FDI and ADM during all conditions.
Figure 2.
Differences in SAI across the three pre-movement phases.
Group-averaged SAI ratio data (with standard error of the mean) for each pre-movement time point (i.e., PW1, PW2, PG) and muscle (FDI, ADM). Values greater than 1 indicate a reduction in SAI, while values less than 1 indicate an increase in SAI. An asterisk over a bar connecting two different conditions indicates significant differences. Significant differences were tested at p≤0.05.
Figure 3.
Raw traces of conditioned and unconditioned MEPs for FDI and ADM.
Each trace is an individual trial that is representative of the group-averaged data. A: Raw EMG traces of SAI in FDI during preparation for 2nd digit movement. B: Raw EMG traces of SAI in FDI during preparation for 5th digit movement. C: Raw EMG traces of SAI in ADM during preparation for 2nd digit movement. D: Raw EMG traces of SAI in FDI during preparation for 5th digit movement.
Table 3.
SAI data and SAI ratio for FDI and ADM during all conditions.
Figure 4.
Differences in spinal excitability across the three pre-movement phases.
Group-averaged spinal excitability data (with standard error of the mean) for each pre-movement time point (i.e., PW1, PW2, PG) and muscle (FDI, ADM). Values greater than 1 indicate an increase in spinal excitability, while values less than 1 indicate decreases in spinal excitability. An asterisk over a bar connecting two different conditions indicates significant differences. Significant differences were tested at p≤0.05.
Figure 5.
Raw traces of H-reflexes for FDI and ADM.
Each trace is an individual trial that is representative of the group-averaged data of the H-reflex. A: Raw EMG traces of the H-reflex in FDI during preparation for 2nd digit movement. B: Raw EMG traces of the H-reflex in FDI during preparation for 5th digit movement. C: Raw EMG traces of the H-reflex in ADM during preparation for 2nd digit movement. D: Raw EMG traces of the H-reflex in FDI during preparation for 5th digit movement.
Table 4.
Spinal excitability data and spinal excitability ratio data for FDI and ADM during all conditions.