  We consider the electrical signals recorded from a subdural array of
electrodes placed on the pial surface of the brain for chronic evaluation of
epileptic patients before surgical resection. A simple and computationally fast
method to analyze the interictal phase synchrony between such electrodes is
introduced and developed with the aim of detecting and localizing the foci of
the epileptic seizures. We evaluate the method by comparing the results of
surgery to the localization predicted here. We find an indication of good
correspondence between the success or failure in the surgery and the agreement
between our identification and the regions actually operated on.
