Fig. 1.

Component maps, hemodynamic responses, and functional modulation. a, d, g, and j show the activation maps of the four ICs rendered onto the MNI template at representative transverse (Left), coronal (Center), and sagittal (Right) slices, coordinates in millimeters are given at the top-right corners. The maps are shown in neurological convention (left hemisphere is on the left). IC areas were considered significant when exceeding a cluster extent of at least 27 contiguous voxels, and at 1% false-positive discovery rate, thresholds are given below each IC map. Activations are plotted in red, deactivations in blue. b, c, e, f, h, i, k, and l display the HRFs within the respective ICs as estimated via deconvolution from 1 to 20 sec after stimulus onset, in arbitrary units. The group average from the 13 participants is plotted as a solid line; error bars indicate ± 1 SEM, and dots represent all individual estimates. The empirical HRFs were used to estimate single-trial amplitudes in the fMRI data to assess systematic preerror activity, here group averaged (±1 SEM) trial sequences from −6 to +2 around response errors are shown (c, f, i, and l). These plots represent the residual data after removal of variability accounted for by response conflict, feedback, stimulus sequence, and response times.