SummaryI. This review indicates that:a. There is no cognitive deficit which is characteristic of all epileptics, i.e., of seizures.b. There is no clear–cut evidence of an impairment which differentiates deterioration in epilepsy from deterioration in other disorders.c. The correlation of focal cerebral dysfunction with specific seizure phenomena is becoming the basis of clinical diagnosis in the epilepsies. Investigations of psychological deficit in relation to these variables suggest that different kinds of deficit may be associated with specific foci of cerebral dysfunction in epileptics.d. Further investigation is needed to establish whether these deficits are related to deterioration in epilepsy.2. It is recommended that:a. Epileptics be subdivided on the basis of cerebral dysfunction and seizure phenomena.b. Since all clinicians do not use the same criteria in differentiating between idiopathic and symptomatic epilepsy, the investigator of cognitive functioning, instead of accepting these labels at face value, should investigate what the criteria are and specify them in describing his groups.c. A test, or battery of tests, covering a range of intellectual processes, including memory, should be used in order to evaluate patterns of cognitive deficit.d. Control groups should be more extensively used in order to establish diagnostic value for an observed deficit.e. Epileptic groups, defined as in a and b, when followed over a period of time, may contribute to our knowledge of deterioration in epilepsy.f. Only by investigating cognitive deficits along with other areas of functioning– personality, and general social efficiency – can we arrive at an overall concept of the consequences of the epile