Table 7.

Mediation Analyses of Scaled RT on Distractor-Present Trials

	PE	SE	Lower CI	Upper CI
Event-related Activation as mediator
Model 1: Age → Left MFG → Scaled RT	−0.009	0.009	−0.031	0.005
Model 2: Age → Right MFG → Scaled RT	−0.010	0.008	−0.033	0.001
Model 3: Age → Left FEF → Scaled RT	−0.008	0.008	−0.032	0.002
Age as mediator
Model 4: Left MFG → Age → Scaled RT	0.031	0.011	0.014	0.054*
Model 5: Right MFG → Age → Scaled RT	0.028	0.008	0.016	0.047*
Model 6: Left FEF → Age → Scaled RT	0.041	0.015	0.015	0.073*

Note. n = 21 younger adults and 20 older adults, following removal of one outlier (see Results). For each regression model, the outcome variable was scaled reaction time for distractor-present trials. Potential mediator variable listed in bold font. PE = point estimate of regression coefficient for the mediator variable, defined as the mean of the estimated regression coefficients for the indirect (mediating) effect, across 20,000 bootstrap samples; SE = bootstrap derived estimate of the standard error of the indirect effect point estimate. Lower CI / Upper CI = lower / upper bounds of 95% bias-corrected and accelerated bootstrap confidence interval for indirect effect. MFG = middle frontal gyrus; FEF = frontal eye field.

^*p < .05 for regression coefficient of mediator variable, as defined by 95% confidence interval that does not include 0.