1. A method of identifying a contra-ictal status of a subject, the method comprising: obtaining, by one or more physiological sensors, an electroencephalogram (EEG) signal dataset from the subject; using a processor to complete steps of: generating an N-dimensional feature vector for each of different time points of the EEG signal dataset; identifying a grouping of contra-ictal feature vectors that is substantially free of pro-ictal feature vectors, wherein the contra-ictal feature vectors are associated with a low susceptibility of having a seizure and the pro-ictal feature vectors are associated with high susceptibility of having a seizure; identifying a grouping of pro-ictal feature vectors that is substantially free of contra-ictal feature vectors; using the grouping of contra-ictal feature vectors to provide an output associated with a contra-ictal status and using the grouping of pro-ictal feature vectors to provide an output associated with a pro-ictal status; comparing the contra-ictal output to at least one threshold to determine a contra-ictal state; comparing the pro-ictal output to at least one threshold to determine a pro-ictal state; selecting an indicator from among at least three indicators based on the contra-ictal state and the pro-ictal state, each of the at least three indicators corresponding to a different susceptibility of having a seizure, wherein the selected indicator indicates whether the subject has the contra-ictal status; and displaying, by a seizure advisory system, the selected indicator.