Data were collected from four subjects with intractable epilepsy who were implanted with chronic subdural grid electrodes as part of a pre-operative procedure to localize the epileptogenic focus. The surgeons determined electrode placement and treatment based solely on the clinical needs of each patient. Data were recorded at three hospitals: the University of California, San Francisco (UCSF) Hospital (subjects UC1 and UC2), the Johns Hopkins School of Medicine (subject JH1), and the Stanford School of Medicine (subject ST1). All subjects gave written informed consent to participate in the study in accordance with the University of California, Berkeley Institutional Review Board as well as the review board of the relevant hospital (i.e., the UCSF, Johns Hopkins Medicine, or Stanford Institutional Review Board).
ECoG data were acquired using a custom built Tucker Davis Technologies recording system (256 channel amplifier and Z-series digital signal processor board) at UCSF and Stanford, or via a clinical 128-channel Harmonie system (Stellate) recording system at Johns Hopkins. Data were sampled at 3052 Hz (UCSF and Stanford) or at 1000 Hz (Johns Hopkins). Signals were digitized for further analysis and, for subjects UC1, UC2, and S1, were resampled offline to 1000 Hz. ECoG data were individually referenced to the average potential of all electrodes.
ECoG data were acquired using a custom built Tucker Davis Technologies recording system (256 channel amplifier and Z-series digital signal processor board) at UCSF and Stanford, or via a clinical 128-channel Harmonie system (Stellate) recording system at Johns Hopkins. Data were sampled at 3052 Hz (UCSF and Stanford) or at 1000 Hz (Johns Hopkins). Signals were digitized for further analysis and, for subjects UC1, UC2, and S1, were resampled offline to 1000 Hz. ECoG data were individually referenced to the average potential of all electrodes.