Figure 5. Mediation analysis of age on reaction time validity through the mediator (neural validity). There was a significant full mediation of age on reaction time validity through the mediator (i.e., alpha validity effect in the left parietal cortex), such that the increase in reaction time validity scores (i.e., cost of attention reallocation) with increased age was driven by stronger alpha desynchronizations to valid relative to invalidly-cued trials in the left parietal cortex. Each arrow is labeled with the standardized Beta coefficient values for the respective regression model. * p < .01, ** p <.005.