Grand-averaged early and late phase of the sustained field (SF) measured from the left and right hemisphere. As shown in the insets, the early SF (300-1000 ms) had a higher mean amplitude than the late SF (1000-3000 ms). Further, the early SF was larger in the active conditions than in the passive ones, and more prominent in the left hemisphere. The AEFs are from the sensor exhibiting maximum response, and the amplitude results have been calculated from the vector sum from the sensor pair with the maximum response. Error bars indicate the standard error of the mean (SEM).