A) MEG sensor layout (2D) view (Courtesy: NIMH MEG Core) The first two letters for each sensor label represents the location of the sensor: The first letter codes for hemispheres, left (L) and right (R); the second letter codes for the anatomical regions/lobes, temporal(T), frontal (F), parietal (P), occipetal (O) and central (C). B) Event related fields (ERFs) during S1 (1.8 sec) time locked to onset of the stimulus. Some key sensors where significant activity differences between VV and VA tasks are observed are magnified in size.