"Human Electrocorticographic (ECoG)" Signals Example results from one patient. Panel A shows a lateral x-ray. Yellow circles mark the electrodes implicated in receptive language, as subsequently identified by electrocortical stimulation mapping. Panel B is a photograph taken during implantation. Panel C shows the SIGFRIED mapping results in a schematic two-dimensional layout: the size and redness of each disc represents the significance of the involvement of each electrode in the task, relative to baseline. In panel D, the same statistic is mapped to color on a three-dimensional brain model rendered from the patient's MRI.