Temporal discontinuities in neocortical dynamics

Our aim is to define and measure parameters of intracranial EEG that characterize stable states of neocortex and its capacity for rapid state transitions. Our experimental data consist of recordings of "spontaneous" EEG from intracranial arrays in animals and a human subject. We pre-process the data to extract large-scale "global" patterns in contrast to "localizing" neural signals. We define a set of novel parameters and measure them over numerous trials. We use the values and ranges of variation of these new parameters in the EEG to define quantitatively the differences in EEGs in four states: awake, asleep, and before and during partial complex seizure.