within subject covariance structure of the data. A backward stepwise method was used to remove insignificant effects. Further exploration of main and interaction effects was performed using Wald's tests (Kenward and Roger, 1997) for pairwise comparisons and the significance levels were adjusted with Bonferroni correction for multiple comparisons. The demographic, cognitive, and behavioral data (i.e., age, MMSE score, BIS-11 scores, reaction time, and error responses) were analyzed using t-tests.
