Figure 1

The electrode arrays used for FP recordings. (A) shows a flexible surface electrode array (TMS International BV, Enschede, The Netherlands) that contains 64 recording electrodes arranged in an 8 × 8 square matrix. The inter-electrode-distance (IED) between two consecutive recording electrodes in both (x and y) directions is 4 mm and each recording electrode has a circular recording surface of 1.2 mm in diameter. (B) shows our custom made 20-channel bar electrode array. The distance between two consecutive recording bars is 5 mm and each bar width is 1 mm in a linear arrangement.