Figure Legends
Figure 1. WM-related activation and deactivation and their age-related changes.
A: lateral and medial maps of task-evoked activity in the “2back -0back” condition, red/yellow indicates positive activity, blue/cyan indicates negative activity; B: age-related changes of task-evoked activity in the “2back -0back” condition, red/yellow indicates changes in positive regions, blue/cyan indicates changes in negative regions; C: scatter plots of brain activities of regions showing significant age-related alterations. The results were corrected for multiple comparisons at p < 0.05. Brain maps were generated using the BrainNet viewer toolbox (Xia et al., 2013).
Figure 2. Regions showing age-related enhanced background connectivity with dysfunctional task-evoked seed regions.
Upper: seed region in the inferior parietal lobule (IPL) and brain regions where significant age impacts on background connectivity derived from the IPL were found; Lower: seed region in the anterior cingulate cortex (ACC) and brain regions where significant age impacts on background connectivity derived from the ACC were found. The results were thresholded at corrected p < 0.05.
Figure 3. Mediation models on age, regional activity, background connectivity and WM performance.
A: Activation and background connectivity in the inferior parietal lobule (IPL) mediated age-related effects on the accuracy rate (AR) of the 2-back; B: Deactivation and background connectivity in the anterior cingulate cortex (ACC) mediated age-related effects on the reaction time (RT) of the 0-back. All coefficients are standardized and presented as Estimate (Standard Error). Covariates included gender and years of education and were not shown in the models. *** < 0.001, ** < 0.01, * < 0.05. CI, confidence interval.
Figure S1. Maps of background connectivity derived from seed regions.
A: Group-level connectivity map derived from the anterior cingulate cortex (ACC); B: group-level connectivity map derived from the inferior parietal lobule (IPL). Images were thresholded at uncorrected p < 0.001.