Figure 5.

Sources of the significant effects of contrast (A), orientation (B) and of their interaction (C). Sources were reconstructed on the MNI template using a L2 minimum norm approach. Source activity was averaged on a 50 ms time window centered on the response peak of each subject before averaging across subjects. Only clusters of activity exceeding 51% of the maximal amplitude and extending on more than five vertices are displayed. As shown above, the contralateral sources of the contrast × orientation interaction are located within the occipital pole, presumably V1. No sources were found in the ipsilateral occipital cortex (not shown).