Correlation among fMRI Contrast of ANT
The unsatisfactory reliability estimates might be due to the collinearity of conditions for calculating attention network contrast. We calculated the correlation among the eight contrasts using the region-based activations to verify the prediction. As demonstrated by Figure 6 , there was severe collinearity between the congruent and incongruent condition (r = 0.86), alerting contrast and center cue condition (r = 0.66), and orienting contrast and spatial cue condition (r = 0.50). The executive contrast shared few variances with the congruent (r = -0.12) and incongruent conditions (r = 0.40), which might question the usage of executive contrast to measure the executive process as the interested part had been canceled out because of subtraction.