Effects of Transcranial Alternating Current Stimulation on Repetitive Finger Movements in Healthy Humans

Table 1

Effect of (four levels: beta, gamma, sham, and baseline), (two levels: first ten movements and whole sequence), and their interaction on movement kinematics. Significant effects are shown in bold. Post hoc tests confirmed that the main effect of and the interaction for amplitude slope was due to a frequency-dependent modulation of the amplitude slope estimated over the first 10 movements, but not over the whole trial. In contrast, the main effect of sequence on the slope and intercept of tapping velocity reflected a drop in velocity across the whole trial as opposed to a drop in velocity within the first 10 movements, over which there was a slight increase in velocity (Figure 2). Importantly, however, the longer-term physiological fatigue-related effects on velocity were independent of stimulation condition.

N Movements	0.57	3.51	0.63	—	—	—	—	—	—
CV	0.66	3.51	0.57	2.64	1.17	0.12	0.17	3.51	0.91
Amplitude intercept	0.85	3.51	0.47	3.26	1.17	0.09	4.52	3.51	0.07
Velocity intercept	1.28	3.51	0.29	62.13	1.17	<0.001	1.43	3.51	0.24
Amplitude slope	3.00	3.51	0.03	0.13	1.17	0.72	3.42	3.51	0.02
Velocity slope	1.97	3.51	0.12	44.30	1.17	<0.001	0.89	3.51	0.45

shown are only the results of CONDITION, since the number of movements considered in the early part of the motor task is always 10.