derived as the mean of the second distribution u2212 0 5 coefficient of variation of the second distribution if the peaks of the negative log likelihood of the bimodal fit is less than zero across all time points of the seizure the distribution of phase locked high gamma plhg can be assumed to follow a unimodal gaussian distribution the threshold for recruitment into the seizure core can be calculated at the time point demonstrating the first peak in the negative log likelihood of the unimodal fit that is greater than zero and the threshold can be defined as the mean of the distribution 3 coefficient of variation in the subset of recordings in which the peak of the negative log likelihood is not greater than zero the threshold can be manually determined fig7 shows for the purpose of illustration and not limitation the results of measurements and calculations taken from an epileptogenic brain which received a failed resection surgery fig7 b shows the plhfo time series during a seizure for all the intracranial recording electrodes the electrodes with a corresponding plhfo time series that exceeds the threshold defined using the algorithm described above at 22 8 seconds are colored grey.