Fig. 4.

Top: Magnetic responses from the left and right middle channels of subject 2 during calculation. Middle: Magnetic field patterns of the responses peaks during calculation. The sensor array is viewed from the right and left. The arrows indicate the dipoles. The isocontours are separated by 15 fT. The areas with red lines indicate magnetic flux emerging from the head, and the areas with blue lines indicate the flux into the head. Bottom: The locations in the inferior parietal area of each hemisphere of one subject during calculation, superimposed on the subject’s own 3D MRI. Left and right figures show the brain surface viewed from the left and right sides, respectively.