In a study involving 63 patients, they were even able to show that certain learning and memory tasks remain completely unaffected. The patients under study had all suffered from epileptic fits since early childhood, and had been epileptics for an average of more than 20 years. When areas of the brain important to memory are affected by the epilepsy, patients are often no longer able to access new information. However, the so-called crystalline intelligence, based on knowledge and behavioral strategies, remains intact. Only the tasks associated with so-called fluid intelligence are restricted in scope.
Fluid intelligence refers to the flexible and rapid processing of information in the brain.
Thus, while the epilepsy patients had difficulties memorizing a list of words, they had no vocabulary problems. Apparently, their memory functions do not deteriorate any faster than the age-related deterioration observed in the population at large. The researchers think that any observed damages must have occurred very early on, and are not the result of continuing epilepsy.