Before revision:  In addition,  local inter-channel relations between (FP1, AF3), (F6, F8) and (FP2, AF4) may  provide useful information as well .
After revision:  In addition, experimental results suggest that global inter-channel relations between the left and right hemispheres are important for emotion recognition and local inter-channel relations between (FP1, AF3), (F6, F8) and (FP2, AF4) may provide useful information as well .