Significant out-degree CCEPs and the correlation with the distance between stimulus site and the closest RNS contact. Each data represents the ratio of significant out-degree CCEPs on MTG/STG, namely the number of stimulus pairs producing significant CCEPs divided by the number of all stimulus pairs. The stimulus sites with distances of 0–5 mm to the closest RNS contacts (G1: 0–5 mm) showed more significant out-degree early latency period than those with distances more than 10 mm to the closest RNS contacts (G3-4: >10 mm) (A) (P = 0.035). There was no difference in the significant out-degree CCEPs between G1 and G3-4 for middle (B) or late latency period (C) (P > 0.05, for both). A Wilcoxon Signed-rank test was used for all statistical tests. The numbers for each group for early, middle and late latency periods are 16.