Psychosurgery and the Porteus Maze Tests: review and reanalysis of data.

Abstract

Because of current interest in assessing psychosurgery outcome, a reanalysis of Porteus maze test findings was done. The maze tests are generally considered to measure foresight and judgment. Review of the literature relating to the effects of practice on the test shows average gains of 1.25 years on the second application of the test and an additional gain of 0.70 years on the third application. Much of the early psychosurgery research did not take practice effects into account. Reanalysis of data shows that the magnitude of changes in maze performance depends on the site of surgery and length of time between surgery and testing. The more posterior the frontal lobe surgery, the shorter the postoperative interval, the greater the loss in maze test ability. Losses following relatively posterior frontal lobe surgery are probably permanent.