 However, not all forms of synesthesia are easily explained by adjacency.Alternatively, synesthesia may arise through "disinhibited feedback" or a reduction in the amount of inhibition along feedback pathways .It is well established that information not only travels from the primary sensory areas to association areas such as the parietal lobe or the limbic system, but also travels back in the opposite direction, from "higher order" cortical regions to early sensory areas.