Figure 6.

Trial-to-trial relationship between BOLD response amplitude and envelope reconstruction accuracy. No brain region showed a significant positive or negative relationship between single-trial BOLD amplitudes and the speech envelope reconstruction accuracy r_z(att). Lowering the statistical threshold however revealed a network of speech-related brain areas showing a positive relationship between both measures. Regions encompass the superior temporal sulcus (STS), Broca's area (BA), the middle (MFG) and inferior frontal gyri (IFG), the precentral gyrus (PreCG), the inferior parietal lobe (IPL), and the medial frontal cortex (MFC). Negative relationships between BOLD amplitude and r_z(att) tended to occur in the white matter, ventricles, visual cortex (VC), and cerebellum (CE). The latter finding suggests that low single-trial envelope reconstruction accuracies may to some extent result from subject motion during data acquisition. The figure depicts positive and negative relationships between single-trial fMRI response amplitudes and speech envelope reconstruction accuracy for the to-be-attended stream at different statistical thresholds. All voxel-level thresholds are uncorrected; minimum cluster size was set to 50 voxels.