The collective mental state that these symptoms create is called an "aura", which I always associated with religious meaning...I guess it's applicable because many leading religious figures are now said to have had some form of epilepsy, etc. Anyway, an aura results from "simple partial seizures" that are preceded by these mental symptoms, followed by convulsions. They produce a dream-like state in the sufferer, and are able to be remembered afterward. This can lead the patient to believe they experienced a religious or spiritual vision.
Furthermore, these symptoms are often mistaken for schiophrenia. The personality change is interesting. It was observed in the film as well, when the epileptic man's father spoke of his son, it was as if he was a completely different person sometimes.
Another article I read established another link between epilepsy and schizophrenia. It determined that those suffering from epilepsy are at an increased risk of schizophrenia, which makes sense, although it isn't determined whether this link is environmental or genetic.