Figure 5.

Increased insular activity during stimulation is associated with downregulation of sensorimotor phantom hand activity after stimulation. (A) To assess what neural processes during intervention stimulation predicted the subsequent downregulation of sensorimotor cortex activity, we carried out a whole‐brain regression analysis. To create our regressor, we first extracted the phantom hand movement activity levels post‐stimulation within the cluster shown in Figure 3A and created an interparticipant regressor. This was then used as a whole‐brain regressor of phantom hand movement activity during intervention. (B) Voxels showing a negative correlation are shown (no positive correlation was found). Increased activity in the ipsilateral (ie, to the missing hand) mid, posterior, and rostrodorsal posterior insula, S2, and S1, as well as the bilateral posterior cingulate gyrus, cingulate gyrus, and supplementary motor cortex during task‐concurrent intervention stimulation was predictive of a subsequent downregulation of activity in the primary sensorimotor missing hand cortex after stimulation (see Figs 4 and 6 for related results). A = anterior; CS = central sulcus; P = posterior; tDCS = transcranial direct current stimulation. [Color figure can be viewed at www.annalsofneurology.org]