Fig. 4. Hyper-activation during within and inter-hemispheric transfer in schizophrenia.

Patterns of hyper-activation are rendered on four consecutive sagittal mid-line slices of the binarized white matter mask used to localize activations within longitudinal and transverse white matter tracts (see Methods). Two effects are evident: First, for both the a intra-hemispheric and b inter-hemispheric conditions (depicted by schematic figures on the right), schizophrenia patients are characterized by hyper-activation in mid-line callosal structures, including the genu, body, and splenium. Secondly, the extent of hyper-activation is amplified in the inter-hemispheric condition, suggesting that the network demands of this condition may be more sensitive in modulating hyper-engagement in schizophrenia of callosal pathways, including the splenium, frontal, motor, and visual areas across the hemispheres.