Exploratory whole-brain correlations of GMV with metacognitive accuracy across the entire study sample. At a reduced threshold of p<0.001 uncorrected (T=3.38) (though not at a corrected family-wise error threshold), there was a positive whole-brain correlation in the rostral anterior cingulate cortex (rACC), supporting the ROI analyses. Other regions observed at this reduced threshold included the precuneus; temporal and occipital cortices; and parahippocampal, fusiform, and precentral gyri. There were no whole-brain negative correlations with metacognitive accuracy, at either the corrected or uncorrected thresholds.