Figure 2.

Behavioral data. Metacognitive efficiency (as quantified by meta-d′/d′) on the memory task was positively correlated with metacognitive efficiency on the visual task (r = 0.471, p = 0.005). One may worry that this effect was driven by potential outliers, because estimates of meta-d′/d′ here seem to produce extreme and implausible values in some individuals. To ensure that this effect is genuine and robust, we used a robust regression, as well as a nonparametric Spearman's rank correlation test, both of which downplay the effects of outliers. Significant results were obtained using both methods.