Focal (f)	Electrode contacts located within the seizure onset zone (on average for all patients 10.1% of all contacts, varying between 1.4 and 29.7%)
Neighbor (n)	Electrode contacts not more than two contacts distant to those from category “f” (on average 17.2%, varying between 6.9 and 42.9%)
Contralateral (c)	Electrode contacts homologous to those from “f” and “n” in the contralateral hemisphere (available for 12 patients with a bilateral electrode implantation; on average 7.8%, varying between 3.4 and 18.5%)
Extra-focal (e)	All remaining electrode contacts (on average 67.5%, varying between 32.8 and 89.6%)