Comparison of the CSD amplitudes in the parietal cortex among three different latencies (0, 22, 47 ms). Cont SI area, contralateral SI area; Cont SPL, contralateral superior parietal lobule; Ipsi SI area, ipsilateral SI area; Ipsi SPL, ipsilateral superior parietal lobule. **, *, #, Significant difference by P < 0.01, P < 0.05, P < 0.01, respectively