"We now consider," wrote Hughlings Jackson1 in 1880, "certain psychical states during the onset of epileptic seizures which are much more elaborate than crude sensations."
"I speak first," he continued, "of certain highly elaborate mental states, sometimes called 'intellectual aurae.'... The state is often like that occasionally experienced by healthy people as a feeling of 'reminiscence.'... It is sometimes called 'dreamy feelings' or is described as 'dreams mixing up with present thoughts,' 'double consciousness,' 'feeling of being somewhere else,' 'as if I went back to all that occurred in my childhood.' These are all voluminous mental states and yet of different kinds; no doubt they ought to be classified."
In recent years we have studied these "psychical states" clinically, as Jackson did. They may appear in the onset of an epileptic seizure that originates in temporal regions of the brain, and they may, in fact, constitute the only clinical
MULLAN S, PENFIELD W. Illusions of Comparative Interpretation and EmotionProduction by Epileptic Discharge and by Electrical Stimulation in the Temporal Cortex. AMA Arch NeurPsych. 1959;81(3):269-284. doi:10.1001/archneurpsyc.1959.02340150001001