Fig. 2.

Structural equation model for spatial working memory. The model comprises only variables that significantly mediated the effects of age on discrimination (d′) decline in the spatial working memory domain across the adult life span. Path coefficients are standardized estimates. Positive predictors of spatial working memory performance are presented in blue (dark gray) squares and negative predictors in red (light gray) squares. Note that two factors that have positive effects on spatial working memory (Capacity of the Metamemory in Adulthood Scale [MIA] and cultural activities) had opposite effects when mediating the effects of age on working memory. These factors decreased with age to the extent that their effects were negative. MMSE Mini-Mental State Scale, BMI body mass index, MAP mean arterial pressure, fr frequency. ^aTotal intake or time = frequency × duration. ^bLog-transformed variable. *P < 0.05, **P < 0.01, ***P < 0.001 (color figure online)