A typographical error was made in reporting the formula for the baseline calculation in the above-titled article.All classification results and analyses in the article are correct and were calculated using the correct formulas.The correct formula for calculation of the baseline value, which was reported incorrectly on page 260 of the article, is: 57.482 -1.629 x educational level + 0.078 x age.The correct formula for calculation of the critical level value, which was reported incorrectly on page 261 of the article, is: