Figure 4
Experimental set up. (A) Tactile stimuli for near-threshold tactile stimuli perception (NtSP)and somatosensory temporal discrimination threshold (STDT) were delivered on the index finger of the dominant hand during tACS. tACS was delivered over CP3/4 at four different frequencies (alpha, beta, gamma and sham) in a randomized order. Each block lasted about 25 min and the inter-block interval was twice as long as the previous block duration (except after sham). (B) During alpha, beta, and gamma tACS, tactile stimuli were delivered at four different phases of tACS stimulation (0°, 90°, 180°, and 270°) to investigate the effect of tACS phase on NtSP.
