Cognitive Changes Following Temporal Lobectomy for Relief of Temporal Lobe Epilepsy

Problem In a preliminary study by Meyer and Yates,1it was reported that after temporal lobectomy some intellectual changes take place and that evaluation of the effects of the operation requires a breakdown into dominant and nondominant groups. The present investigation is an attempt to confirm the tentative findings of the preliminary study on larger samples of dominant and nondominant patients, to define more closely the nature of deficits, and to assess long-term effects. Tests and Testing Procedures The three intelligence tests described in the preliminary study, i. e., the Wechsler-Bellevue Intelligence Scale, the Mill Hill Vocabulary Test, and Raven's Progressive Matrices, have been retained. Six new learning tests were designed in order to answer the problems concerning learning ability. The New Word Learning and Retention Test (NWLT) has also been retained, as it is the original test on which the deficit was detected. This test involves learning of