fMRIs were acquired in the volunteers by applying the same stimulation pattern used in the DOT experiment. The experiment was performed in a 3T Signa Excite HD scanner (General Electric). T1-weighted volume was acquired to precise anatomical localization (, , flip , , in plane resolution, spacing between , , ). The anatomical slices covered the whole brain and were acquired parallel to the anterior–posterior commissure. A sequence of 415 T2*-weighted spiral volumes was acquired, 15 axial slices each, field of view is 256 mm, slice thickness is 4 mm, interslice gap is 1 mm, matrix of voxels, flip angle is 77 deg, TR is 2000 ms, and TE is 24 ms.