Figure 1.

Laterality indices (1 = completely left‐lateralized activation; 0 = bilateral activation; −1 = completely right lateralized activation) for the four controls and two patients (preoperative data only), calculated based on the activation extent (i.e. number of significantly activated voxels). Only positive responses are considered here. a: Motor ROI; b: Visual ROI. The controls had approximately bilateral activation in both ROIs for both the separate and combined tasks, consistent with bilaterally distributed CVR. In patient 1, the motor ROI CVR was left‐lateralized. In addition, activation was left‐lateralized in both tasks, but to a greater extent in the combined task. This pattern was also observed to a lesser extent in the visual ROI in this patient. In patient 2, the motor ROI had left‐lateralized CVR, bilateral activation in the separate motor task and left‐lateralized activation in the combined visual–motor task. CVR in the visual ROI was normal in this patient, consistent with approximately bilateral activation in both the separate visual and combined visual–motor task).